ci : fix CUDA builds

whisper : auto-grow working areas for mel_calc_cuda (#2227 )
* whisper : auto-grow working areas for mel_calc_cuda, fixes #2226 * whisper : only calculate mel spectrogram on GPU if audio is <= 5 min
2025-06-24 17:15:19 +00:00 · 2024-06-11 11:40:19 +03:00 · 2024-06-10 21:51:32 +03:00 · 2024-06-10 11:00:15 +03:00 · 2024-06-06 18:51:36 +03:00 · 2024-06-06 16:20:46 +03:00
28 changed files with 709 additions and 348 deletions
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@ -459,7 +459,7 @@ jobs:
          path: build/bin/${{ matrix.build }}

  windows-cublas:
-    runs-on: windows-latest
+    runs-on: windows-2019

    strategy:
      matrix:
@ -498,7 +498,7 @@ jobs:
        run: >
          cmake -S . -B ./build -A ${{ matrix.arch }}
          -DCMAKE_BUILD_TYPE=${{ matrix.build }}
-          -DWHISPER_CUBLAS=${{ matrix.cublas }}
+          -DWHISPER_CUDA=${{ matrix.cublas }}
          -DWHISPER_SDL2=${{ matrix.sdl2 }}

      - name: Build ${{ matrix.cuda-toolkit }}
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@ -364,12 +364,12 @@ if (WHISPER_CUDA)
        if (WHISPER_STATIC)
            if (WIN32)
                # As of 12.3.1 CUDA Tookit for Windows does not offer a static cublas library
-                set(WHISPER_EXTRA_LIBS ${WHISPER_EXTRA_LIBS} CUDA::cudart_static CUDA::cublas CUDA::cublasLt)
+                set(WHISPER_EXTRA_LIBS ${WHISPER_EXTRA_LIBS} CUDA::cudart_static CUDA::cublas CUDA::cublasLt CUDA::cufft)
            else ()
-                set(WHISPER_EXTRA_LIBS ${WHISPER_EXTRA_LIBS} CUDA::cudart_static CUDA::cublas_static CUDA::cublasLt_static)
+                set(WHISPER_EXTRA_LIBS ${WHISPER_EXTRA_LIBS} CUDA::cudart_static CUDA::cublas_static CUDA::cublasLt_static CUDA::cufft_static)
            endif()
        else()
-            set(WHISPER_EXTRA_LIBS ${WHISPER_EXTRA_LIBS} CUDA::cudart CUDA::cublas CUDA::cublasLt)
+            set(WHISPER_EXTRA_LIBS ${WHISPER_EXTRA_LIBS} CUDA::cudart CUDA::cublas CUDA::cublasLt CUDA::cufft)
        endif()

        set(WHISPER_EXTRA_LIBS ${WHISPER_EXTRA_LIBS} CUDA::cuda_driver)
@ -679,6 +679,10 @@ add_library(${TARGET}
    whisper.cpp
    )

+if (WHISPER_CUDA)
+    target_sources(${TARGET} PRIVATE whisper-mel-cuda.cu)
+endif()
+
 include_directories (
    .
 )
--- a/9
+++ b/9
@ -286,8 +286,8 @@ ifdef WHISPER_CUDA

 	CFLAGS      += -DGGML_USE_CUDA -I/usr/local/cuda/include -I/opt/cuda/include -I$(CUDA_PATH)/targets/$(UNAME_M)-linux/include
 	CXXFLAGS    += -DGGML_USE_CUDA -I/usr/local/cuda/include -I/opt/cuda/include -I$(CUDA_PATH)/targets/$(UNAME_M)-linux/include
-	LDFLAGS     += -lcuda -lcublas -lculibos -lcudart -lcublasLt -lpthread -ldl -lrt -L/usr/local/cuda/lib64 -L/opt/cuda/lib64 -L$(CUDA_PATH)/targets/$(UNAME_M)-linux/lib -L/usr/lib/wsl/lib
-	WHISPER_OBJ += ggml-cuda.o
+	LDFLAGS     += -lcuda -lcublas -lculibos -lcudart -lcublasLt -lcufft -lpthread -ldl -lrt -L/usr/local/cuda/lib64 -L/opt/cuda/lib64 -L$(CUDA_PATH)/targets/$(UNAME_M)-linux/lib -L/usr/lib/wsl/lib
+	WHISPER_OBJ += ggml-cuda.o whisper-mel-cuda.o
 	WHISPER_OBJ += $(patsubst %.cu,%.o,$(wildcard ggml-cuda/*.cu))
 	NVCC        = nvcc
 	NVCCFLAGS   = --forward-unknown-to-host-compiler -arch=$(CUDA_ARCH_FLAG)
@ -299,6 +299,9 @@ ggml-cuda.o: ggml-cuda.cu ggml-cuda.h ggml.h ggml-backend.h ggml-backend-impl.h
 	$(NVCC) $(NVCCFLAGS) $(CXXFLAGS) -Wno-pedantic -c $< -o $@
 endif

+whisper-mel-cuda.o: whisper-mel-cuda.cu whisper.h ggml.h ggml-backend.h whisper-mel.hpp whisper-mel-cuda.hpp
+	$(NVCC) $(NVCCFLAGS) $(CXXFLAGS) -Wno-pedantic -c $< -o $@
+
 ifdef WHISPER_HIPBLAS
 	ROCM_PATH   ?= /opt/rocm
 	HIPCC       ?= $(ROCM_PATH)/bin/hipcc
@ -404,7 +407,7 @@ ggml-quants.o: ggml-quants.c ggml.h ggml-quants.h

 WHISPER_OBJ += ggml.o ggml-alloc.o ggml-backend.o ggml-quants.o

-whisper.o: whisper.cpp whisper.h ggml.h ggml-cuda.h
+whisper.o: whisper.cpp whisper.h whisper-mel.hpp ggml.h ggml-cuda.h
 	$(CXX) $(CXXFLAGS) -c $< -o $@

 ifndef WHISPER_COREML
--- a/README.md
+++ b/README.md
@ -4,6 +4,7 @@

 [![Actions Status](https://github.com/ggerganov/whisper.cpp/workflows/CI/badge.svg)](https://github.com/ggerganov/whisper.cpp/actions)
 [![License: MIT](https://img.shields.io/badge/license-MIT-blue.svg)](https://opensource.org/licenses/MIT)
+[![Conan Center](https://shields.io/conan/v/whisper-cpp)](https://conan.io/center/whisper-cpp)
 [![npm](https://img.shields.io/npm/v/whisper.cpp.svg)](https://www.npmjs.com/package/whisper.cpp/)

 Stable: [v1.6.2](https://github.com/ggerganov/whisper.cpp/releases/tag/v1.6.0) / [Roadmap | F.A.Q.](https://github.com/ggerganov/whisper.cpp/discussions/126)
@ -502,6 +503,16 @@ docker run -it --rm \
  whisper.cpp:main "./main -m /models/ggml-base.bin -f ./samples/jfk.wav"
 ```

+## Installing with Conan
+
+You can install pre-built binaries for whisper.cpp or build it from source using [Conan](https://conan.io/). Use the following command:
+
+```
+conan install --requires="whisper-cpp/[*]" --build=missing
+```
+
+For detailed instructions on how to use Conan, please refer to the [Conan documentation](https://docs.conan.io/2/).
+
 ## Limitations

 - Inference only
@ -710,7 +721,7 @@ The [main](examples/main) example provides support for output of karaoke-style m
 currently pronounced word is highlighted. Use the `-wts` argument and run the generated bash script.
 This requires to have `ffmpeg` installed.

-Here are a few *"typical"* examples:
+Here are a few _"typical"_ examples:

 ```bash
 ./main -m ./models/ggml-base.en.bin -f ./samples/jfk.wav -owts
--- a/bindings/go/examples/go-whisper/flags.go
+++ b/bindings/go/examples/go-whisper/flags.go
@ -68,10 +68,6 @@ func (flags *Flags) GetOut() string {
 	return strings.ToLower(flags.Lookup("out").Value.String())
 }

-func (flags *Flags) IsSpeedup() bool {
-	return flags.Lookup("speedup").Value.String() == "true"
-}
-
 func (flags *Flags) IsTokens() bool {
 	return flags.Lookup("tokens").Value.String() == "true"
 }
@ -111,10 +107,6 @@ func (flags *Flags) SetParams(context whisper.Context) error {
 		fmt.Fprintf(flags.Output(), "Setting duration to %v\n", duration)
 		context.SetDuration(duration)
 	}
-	if flags.IsSpeedup() {
-		fmt.Fprintf(flags.Output(), "Setting speedup to true\n")
-		context.SetSpeedup(true)
-	}
 	if threads := flags.GetThreads(); threads != 0 {
 		fmt.Fprintf(flags.Output(), "Setting threads to %d\n", threads)
 		context.SetThreads(threads)
@ -146,7 +138,6 @@ func registerFlags(flag *Flags) {
 	flag.Duration("offset", 0, "Time offset")
 	flag.Duration("duration", 0, "Duration of audio to process")
 	flag.Uint("threads", 0, "Number of threads to use")
-	flag.Bool("speedup", false, "Enable speedup")
 	flag.Uint("max-len", 0, "Maximum segment length in characters")
 	flag.Uint("max-tokens", 0, "Maximum tokens per segment")
 	flag.Float64("word-thold", 0, "Maximum segment score")
--- a/bindings/go/params.go
+++ b/bindings/go/params.go
@ -47,10 +47,6 @@ func (p *Params) SetPrintTimestamps(v bool) {
 	p.print_timestamps = toBool(v)
 }

-func (p *Params) SetSpeedup(v bool) {
-	p.speed_up = toBool(v)
-}
-
 // Set language id
 func (p *Params) SetLanguage(lang int) error {
 	if lang == -1 {
@ -177,9 +173,6 @@ func (p *Params) String() string {
 	if p.token_timestamps {
 		str += " token_timestamps"
 	}
-	if p.speed_up {
-		str += " speed_up"
-	}

 	return str + ">"
 }
--- a/bindings/go/pkg/whisper/context.go
+++ b/bindings/go/pkg/whisper/context.go
@ -76,11 +76,6 @@ func (context *context) SetTranslate(v bool) {
 	context.params.SetTranslate(v)
 }

-// Set speedup flag
-func (context *context) SetSpeedup(v bool) {
-	context.params.SetSpeedup(v)
-}
-
 func (context *context) SetSplitOnWord(v bool) {
 	context.params.SetSplitOnWord(v)
 }
--- a/bindings/go/pkg/whisper/interface.go
+++ b/bindings/go/pkg/whisper/interface.go
@ -41,7 +41,6 @@ type Context interface {
 	SetOffset(time.Duration)        // Set offset
 	SetDuration(time.Duration)      // Set duration
 	SetThreads(uint)                // Set number of threads to use
-	SetSpeedup(bool)                // Set speedup flag
 	SetSplitOnWord(bool)            // Set split on word flag
 	SetTokenThreshold(float32)      // Set timestamp token probability threshold
 	SetTokenSumThreshold(float32)   // Set timestamp token sum probability threshold
--- a/bindings/java/src/main/java/io/github/ggerganov/whispercpp/WhisperCppJnaLibrary.java
+++ b/bindings/java/src/main/java/io/github/ggerganov/whispercpp/WhisperCppJnaLibrary.java
@ -20,7 +20,7 @@ public interface WhisperCppJnaLibrary extends Library {
     * @return Whisper context on success, null on failure
     */
    Pointer whisper_init_from_file(String path_model);
-    
+
    /**
     * Provides default params which can be used with `whisper_init_from_file_with_params()` etc.
     * Because this function allocates memory for the params, the caller must call either:
@ -304,14 +304,6 @@ public interface WhisperCppJnaLibrary extends Library {
    /** Language id associated with the provided state */
    int whisper_full_lang_id_from_state(Pointer state);

-    /**
-     * Convert RAW PCM audio to log mel spectrogram but applies a Phase Vocoder to speed up the audio x2.
-     * The resulting spectrogram is stored inside the default state of the provided whisper context.
-     * @return 0 on success
-     */
-    int whisper_pcm_to_mel_phase_vocoder(Pointer ctx, final float[] samples, int n_samples, int n_threads);
-
-    int whisper_pcm_to_mel_phase_vocoder_with_state(Pointer ctx, Pointer state, final float[] samples, int n_samples, int n_threads);

    /** Get the start time of the specified segment. */
    long whisper_full_get_segment_t0(Pointer ctx, int i_segment);
--- a/bindings/java/src/main/java/io/github/ggerganov/whispercpp/params/WhisperFullParams.java
+++ b/bindings/java/src/main/java/io/github/ggerganov/whispercpp/params/WhisperFullParams.java
@ -129,14 +129,6 @@ public class WhisperFullParams extends Structure {
    /** Maximum tokens per segment (0, default = no limit) */
    public int max_tokens;

-    /** Flag to speed up the audio by 2x using Phase Vocoder. (default = false) */
-    public CBool speed_up;
-
-    /** Flag to speed up the audio by 2x using Phase Vocoder. (default = false) */
-    public void speedUp(boolean enable) {
-        speed_up = enable ? CBool.TRUE : CBool.FALSE;
-    }
-
    /** Overwrite the audio context size (0 = use default). */
    public int audio_ctx;

@ -321,7 +313,7 @@ public class WhisperFullParams extends Structure {
        return Arrays.asList("strategy", "n_threads", "n_max_text_ctx", "offset_ms", "duration_ms", "translate",
                "no_context", "single_segment", "no_timestamps",
                "print_special", "print_progress", "print_realtime", "print_timestamps",  "token_timestamps",
-                "thold_pt", "thold_ptsum", "max_len", "split_on_word", "max_tokens", "speed_up", "audio_ctx",
+                "thold_pt", "thold_ptsum", "max_len", "split_on_word", "max_tokens", "audio_ctx",
                "tdrz_enable", "suppress_regex", "initial_prompt", "prompt_tokens", "prompt_n_tokens", "language", "detect_language",
                "suppress_blank", "suppress_non_speech_tokens", "temperature", "max_initial_ts", "length_penalty",
                "temperature_inc", "entropy_thold", "logprob_thold", "no_speech_thold", "greedy", "beam_search",
--- a/bindings/ruby/ext/extconf.rb
+++ b/bindings/ruby/ext/extconf.rb
@ -1,6 +1,7 @@
 require 'mkmf'
 system("cp #{File.join(File.dirname(__FILE__),'..','..','..','whisper.cpp')} .")
 system("cp #{File.join(File.dirname(__FILE__),'..','..','..','whisper.h')} .")
+system("cp #{File.join(File.dirname(__FILE__),'..','..','..','whisper-mel.hpp')} .")
 system("cp #{File.join(File.dirname(__FILE__),'..','..','..','ggml.h')} .")
 system("cp #{File.join(File.dirname(__FILE__),'..','..','..','ggml.c')} .")
 system("cp #{File.join(File.dirname(__FILE__),'..','..','..','ggml-impl.h')} .")
--- a/bindings/ruby/ext/ruby_whisper.cpp
+++ b/bindings/ruby/ext/ruby_whisper.cpp
@ -311,12 +311,6 @@ static VALUE ruby_whisper_params_get_split_on_word(VALUE self) {
 static VALUE ruby_whisper_params_set_split_on_word(VALUE self, VALUE value) {
  BOOL_PARAMS_SETTER(self, split_on_word, value)
 }
-static VALUE ruby_whisper_params_get_speed_up(VALUE self) {
-  BOOL_PARAMS_GETTER(self, speed_up)
-}
-static VALUE ruby_whisper_params_set_speed_up(VALUE self, VALUE value) {
-  BOOL_PARAMS_SETTER(self, speed_up, value)
-}
 static VALUE ruby_whisper_params_get_diarize(VALUE self) {
  ruby_whisper_params *rwp;
  Data_Get_Struct(self, ruby_whisper_params, rwp);
@ -408,8 +402,6 @@ void Init_whisper() {
  rb_define_method(cParams, "token_timestamps=", ruby_whisper_params_set_token_timestamps, 1);
  rb_define_method(cParams, "split_on_word", ruby_whisper_params_get_split_on_word, 0);
  rb_define_method(cParams, "split_on_word=", ruby_whisper_params_set_split_on_word, 1);
-  rb_define_method(cParams, "speed_up", ruby_whisper_params_get_speed_up, 0);
-  rb_define_method(cParams, "speed_up=", ruby_whisper_params_set_speed_up, 1);
  rb_define_method(cParams, "diarize", ruby_whisper_params_get_diarize, 0);
  rb_define_method(cParams, "diarize=", ruby_whisper_params_set_diarize, 1);

--- a/bindings/ruby/tests/test_whisper.rb
+++ b/bindings/ruby/tests/test_whisper.rb
@ -117,13 +117,6 @@ class TestWhisper < Test::Unit::TestCase
    assert !@params.split_on_word
  end

-  def test_speed_up
-    @params.speed_up = true
-    assert @params.speed_up
-    @params.speed_up = false
-    assert !@params.speed_up
-  end
-
  def test_whisper
    @whisper = Whisper::Context.new(File.join(TOPDIR, '..', '..', 'models', 'ggml-base.en.bin'))
    params  = Whisper::Params.new
--- a/examples/addon.node/addon.cpp
+++ b/examples/addon.node/addon.cpp
@ -25,7 +25,6 @@ struct whisper_params {
    float entropy_thold = 2.4f;
    float logprob_thold = -1.0f;

-    bool speed_up       = false;
    bool translate      = false;
    bool diarize        = false;
    bool output_txt     = false;
@ -232,8 +231,6 @@ int run(whisper_params &params, std::vector<std::vector<std::string>> &result) {
            wparams.max_len          = params.output_wts && params.max_len == 0 ? 60 : params.max_len;
            wparams.audio_ctx        = params.audio_ctx;

-            wparams.speed_up         = params.speed_up;
-
            wparams.greedy.best_of        = params.best_of;
            wparams.beam_search.beam_size = params.beam_size;

--- a/examples/command/command.cpp
+++ b/examples/command/command.cpp
@ -38,7 +38,6 @@ struct whisper_params {

    grammar_parser::parse_state grammar_parsed;

-    bool speed_up      = false;
    bool translate     = false;
    bool print_special = false;
    bool print_energy  = false;
@ -76,7 +75,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
        else if (arg == "-ac"  || arg == "--audio-ctx")     { params.audio_ctx     = std::stoi(argv[++i]); }
        else if (arg == "-vth" || arg == "--vad-thold")     { params.vad_thold     = std::stof(argv[++i]); }
        else if (arg == "-fth" || arg == "--freq-thold")    { params.freq_thold    = std::stof(argv[++i]); }
-        else if (arg == "-su"  || arg == "--speed-up")      { params.speed_up      = true; }
        else if (arg == "-tr"  || arg == "--translate")     { params.translate     = true; }
        else if (arg == "-ps"  || arg == "--print-special") { params.print_special = true; }
        else if (arg == "-pe"  || arg == "--print-energy")  { params.print_energy  = true; }
@ -115,7 +113,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -ac N,      --audio-ctx N    [%-7d] audio context size (0 - all)\n",                params.audio_ctx);
    fprintf(stderr, "  -vth N,     --vad-thold N    [%-7.2f] voice activity detection threshold\n",        params.vad_thold);
    fprintf(stderr, "  -fth N,     --freq-thold N   [%-7.2f] high-pass frequency cutoff\n",                params.freq_thold);
-    fprintf(stderr, "  -su,        --speed-up       [%-7s] speed up audio by x2 (reduced accuracy)\n",     params.speed_up ? "true" : "false");
    fprintf(stderr, "  -tr,        --translate      [%-7s] translate from source language to english\n",   params.translate ? "true" : "false");
    fprintf(stderr, "  -ps,        --print-special  [%-7s] print special tokens\n",                        params.print_special ? "true" : "false");
    fprintf(stderr, "  -pe,        --print-energy   [%-7s] print sound energy (for debugging)\n",          params.print_energy ? "true" : "false");
@ -165,7 +162,6 @@ std::string transcribe(
    wparams.n_threads        = params.n_threads;

    wparams.audio_ctx = params.audio_ctx;
-    wparams.speed_up  = params.speed_up;

    wparams.temperature     = 0.4f;
    wparams.temperature_inc = 1.0f;
@ -371,7 +367,6 @@ int process_command_list(struct whisper_context * ctx, audio_async &audio, const
            wparams.n_threads        = params.n_threads;

            wparams.audio_ctx        = params.audio_ctx;
-            wparams.speed_up         = params.speed_up;

            wparams.prompt_tokens    = k_tokens.data();
            wparams.prompt_n_tokens  = k_tokens.size();
--- a/examples/common.h
+++ b/examples/common.h
@ -185,7 +185,7 @@ private:
    // It is assumed that PCM data is normalized to a range from -1 to 1
    bool write_audio(const float * data, size_t length) {
        for (size_t i = 0; i < length; ++i) {
-            const int16_t intSample = data[i] * 32767;
+            const int16_t intSample = int16_t(data[i] * 32767);
            file.write(reinterpret_cast<const char *>(&intSample), sizeof(int16_t));
            dataSize += sizeof(int16_t);
        }
--- a/examples/lsp/lsp.cpp
+++ b/examples/lsp/lsp.cpp
@ -26,7 +26,6 @@ struct whisper_params {
    float vad_thold    = 0.6f;
    float freq_thold   = 100.0f;

-    bool speed_up      = false;
    bool translate     = false;
    bool print_special = false;
    bool print_energy  = false;
@ -70,7 +69,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
        else if (arg == "-ac"  || arg == "--audio-ctx")     { params.audio_ctx     = std::stoi(argv[++i]); }
        else if (arg == "-vth" || arg == "--vad-thold")     { params.vad_thold     = std::stof(argv[++i]); }
        else if (arg == "-fth" || arg == "--freq-thold")    { params.freq_thold    = std::stof(argv[++i]); }
-        else if (arg == "-su"  || arg == "--speed-up")      { params.speed_up      = true; }
        else if (arg == "-tr"  || arg == "--translate")     { params.translate     = true; }
        else if (arg == "-ps"  || arg == "--print-special") { params.print_special = true; }
        else if (arg == "-pe"  || arg == "--print-energy")  { params.print_energy  = true; }
@ -102,7 +100,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -ac N,      --audio-ctx N    [%-7d] audio context size (0 - all)\n",                params.audio_ctx);
    fprintf(stderr, "  -vth N,     --vad-thold N    [%-7.2f] voice activity detection threshold\n",        params.vad_thold);
    fprintf(stderr, "  -fth N,     --freq-thold N   [%-7.2f] high-pass frequency cutoff\n",                params.freq_thold);
-    fprintf(stderr, "  -su,        --speed-up       [%-7s] speed up audio by x2 (reduced accuracy)\n",     params.speed_up ? "true" : "false");
    fprintf(stderr, "  -tr,        --translate      [%-7s] translate from source language to english\n",   params.translate ? "true" : "false");
    fprintf(stderr, "  -ps,        --print-special  [%-7s] print special tokens\n",                        params.print_special ? "true" : "false");
    fprintf(stderr, "  -pe,        --print-energy   [%-7s] print sound energy (for debugging)\n",          params.print_energy ? "true" : "false");
@ -184,7 +181,6 @@ json unguided_transcription(struct whisper_context * ctx, audio_async &audio, js
    wparams.n_threads        = params.n_threads;

    wparams.audio_ctx        = params.audio_ctx;
-    wparams.speed_up         = params.speed_up;
    wparams.suppress_non_speech_tokens = true;
    // run the transformer and a single decoding pass
    if (whisper_full(ctx, wparams, pcmf32.data(), pcmf32.size()) != 0) {
@ -223,7 +219,6 @@ json guided_transcription(struct whisper_context * ctx, audio_async &audio, cons
    wparams.n_threads        = params.n_threads;

    wparams.audio_ctx        = params.audio_ctx;
-    wparams.speed_up         = params.speed_up;

    // TODO: Do some time testing. Does an overly long prompt slow down processing?
    // Set up command sets/precompute prompts
--- a/examples/main/main.cpp
+++ b/examples/main/main.cpp
@ -47,7 +47,6 @@ struct whisper_params {
    float temperature     = 0.0f;
    float temperature_inc = 0.2f;

-    bool speed_up        = false;
    bool debug_mode      = false;
    bool translate       = false;
    bool detect_language = false;
@ -138,7 +137,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
        else if (arg == "-lpt"  || arg == "--logprob-thold")   { params.logprob_thold   = std::stof(argv[++i]); }
        else if (arg == "-tp"   || arg == "--temperature")     { params.temperature     = std::stof(argv[++i]); }
        else if (arg == "-tpi"  || arg == "--temperature-inc") { params.temperature_inc = std::stof(argv[++i]); }
-        // else if (arg == "-su"   || arg == "--speed-up")        { params.speed_up        = true; }
        else if (arg == "-debug"|| arg == "--debug-mode")      { params.debug_mode      = true; }
        else if (arg == "-tr"   || arg == "--translate")       { params.translate       = true; }
        else if (arg == "-di"   || arg == "--diarize")         { params.diarize         = true; }
@ -206,7 +204,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -lpt N,    --logprob-thold N   [%-7.2f] log probability threshold for decoder fail\n",   params.logprob_thold);
    fprintf(stderr, "  -tp,       --temperature N     [%-7.2f] The sampling temperature, between 0 and 1\n",    params.temperature);
    fprintf(stderr, "  -tpi,      --temperature-inc N [%-7.2f] The increment of temperature, between 0 and 1\n",params.temperature_inc);
-    // fprintf(stderr, "  -su,       --speed-up          [%-7s] speed up audio by x2 (reduced accuracy)\n",        params.speed_up ? "true" : "false");
    fprintf(stderr, "  -debug,    --debug-mode        [%-7s] enable debug mode (eg. dump log_mel)\n",           params.debug_mode ? "true" : "false");
    fprintf(stderr, "  -tr,       --translate         [%-7s] translate from source language to english\n",      params.translate ? "true" : "false");
    fprintf(stderr, "  -di,       --diarize           [%-7s] stereo audio diarization\n",                       params.diarize ? "true" : "false");
@ -1106,7 +1103,6 @@ int main(int argc, char ** argv) {
            wparams.split_on_word    = params.split_on_word;
            wparams.audio_ctx        = params.audio_ctx;

-            wparams.speed_up         = params.speed_up;
            wparams.debug_mode       = params.debug_mode;

            wparams.tdrz_enable      = params.tinydiarize; // [TDRZ]
--- a/examples/server/server.cpp
+++ b/examples/server/server.cpp
@ -61,7 +61,6 @@ struct whisper_params {
    float temperature     =  0.00f;
    float temperature_inc =  0.20f;

-    bool speed_up        = false;
    bool debug_mode      = false;
    bool translate       = false;
    bool detect_language = false;
@ -112,7 +111,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -wt N,     --word-thold N      [%-7.2f] word timestamp probability threshold\n",         params.word_thold);
    fprintf(stderr, "  -et N,     --entropy-thold N   [%-7.2f] entropy threshold for decoder fail\n",           params.entropy_thold);
    fprintf(stderr, "  -lpt N,    --logprob-thold N   [%-7.2f] log probability threshold for decoder fail\n",   params.logprob_thold);
-    // fprintf(stderr, "  -su,       --speed-up          [%-7s] speed up audio by x2 (reduced accuracy)\n",        params.speed_up ? "true" : "false");
    fprintf(stderr, "  -debug,    --debug-mode        [%-7s] enable debug mode (eg. dump log_mel)\n",           params.debug_mode ? "true" : "false");
    fprintf(stderr, "  -tr,       --translate         [%-7s] translate from source language to english\n",      params.translate ? "true" : "false");
    fprintf(stderr, "  -di,       --diarize           [%-7s] stereo audio diarization\n",                       params.diarize ? "true" : "false");
@ -159,7 +157,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params, serve
        else if (arg == "-wt"   || arg == "--word-thold")      { params.word_thold      = std::stof(argv[++i]); }
        else if (arg == "-et"   || arg == "--entropy-thold")   { params.entropy_thold   = std::stof(argv[++i]); }
        else if (arg == "-lpt"  || arg == "--logprob-thold")   { params.logprob_thold   = std::stof(argv[++i]); }
-        // else if (arg == "-su"   || arg == "--speed-up")        { params.speed_up        = true; }
        else if (arg == "-debug"|| arg == "--debug-mode")      { params.debug_mode      = true; }
        else if (arg == "-tr"   || arg == "--translate")       { params.translate       = true; }
        else if (arg == "-di"   || arg == "--diarize")         { params.diarize         = true; }
@ -768,7 +765,6 @@ int main(int argc, char ** argv) {
            wparams.split_on_word    = params.split_on_word;
            wparams.audio_ctx        = params.audio_ctx;

-            wparams.speed_up         = params.speed_up;
            wparams.debug_mode       = params.debug_mode;

            wparams.tdrz_enable      = params.tinydiarize; // [TDRZ]
--- a/examples/stream/stream.cpp
+++ b/examples/stream/stream.cpp
@ -27,7 +27,6 @@ struct whisper_params {
    float vad_thold    = 0.6f;
    float freq_thold   = 100.0f;

-    bool speed_up      = false;
    bool translate     = false;
    bool no_fallback   = false;
    bool print_special = false;
@ -62,7 +61,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
        else if (arg == "-ac"   || arg == "--audio-ctx")     { params.audio_ctx     = std::stoi(argv[++i]); }
        else if (arg == "-vth"  || arg == "--vad-thold")     { params.vad_thold     = std::stof(argv[++i]); }
        else if (arg == "-fth"  || arg == "--freq-thold")    { params.freq_thold    = std::stof(argv[++i]); }
-        else if (arg == "-su"   || arg == "--speed-up")      { params.speed_up      = true; }
        else if (arg == "-tr"   || arg == "--translate")     { params.translate     = true; }
        else if (arg == "-nf"   || arg == "--no-fallback")   { params.no_fallback   = true; }
        else if (arg == "-ps"   || arg == "--print-special") { params.print_special = true; }
@ -100,7 +98,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -ac N,    --audio-ctx N   [%-7d] audio context size (0 - all)\n",                   params.audio_ctx);
    fprintf(stderr, "  -vth N,   --vad-thold N   [%-7.2f] voice activity detection threshold\n",           params.vad_thold);
    fprintf(stderr, "  -fth N,   --freq-thold N  [%-7.2f] high-pass frequency cutoff\n",                   params.freq_thold);
-    fprintf(stderr, "  -su,      --speed-up      [%-7s] speed up audio by x2 (reduced accuracy)\n",        params.speed_up ? "true" : "false");
    fprintf(stderr, "  -tr,      --translate     [%-7s] translate from source language to english\n",      params.translate ? "true" : "false");
    fprintf(stderr, "  -nf,      --no-fallback   [%-7s] do not use temperature fallback while decoding\n", params.no_fallback ? "true" : "false");
    fprintf(stderr, "  -ps,      --print-special [%-7s] print special tokens\n",                           params.print_special ? "true" : "false");
@ -314,7 +311,6 @@ int main(int argc, char ** argv) {
            wparams.n_threads        = params.n_threads;

            wparams.audio_ctx        = params.audio_ctx;
-            wparams.speed_up         = params.speed_up;

            wparams.tdrz_enable      = params.tinydiarize; // [TDRZ]

--- a/examples/talk-llama/talk-llama.cpp
+++ b/examples/talk-llama/talk-llama.cpp
@ -59,7 +59,6 @@ struct whisper_params {
    float vad_thold  = 0.6f;
    float freq_thold = 100.0f;

-    bool speed_up       = false;
    bool translate      = false;
    bool print_special  = false;
    bool print_energy   = false;
@ -100,7 +99,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
        else if (arg == "-ngl" || arg == "--n-gpu-layers")   { params.n_gpu_layers   = std::stoi(argv[++i]); }
        else if (arg == "-vth" || arg == "--vad-thold")      { params.vad_thold      = std::stof(argv[++i]); }
        else if (arg == "-fth" || arg == "--freq-thold")     { params.freq_thold     = std::stof(argv[++i]); }
-        else if (arg == "-su"  || arg == "--speed-up")       { params.speed_up       = true; }
        else if (arg == "-tr"  || arg == "--translate")      { params.translate      = true; }
        else if (arg == "-ps"  || arg == "--print-special")  { params.print_special  = true; }
        else if (arg == "-pe"  || arg == "--print-energy")   { params.print_energy   = true; }
@ -149,7 +147,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -ngl N,   --n-gpu-layers N [%-7d] number of layers to store in VRAM\n",           params.n_gpu_layers);
    fprintf(stderr, "  -vth N,   --vad-thold N    [%-7.2f] voice activity detection threshold\n",        params.vad_thold);
    fprintf(stderr, "  -fth N,   --freq-thold N   [%-7.2f] high-pass frequency cutoff\n",                params.freq_thold);
-    fprintf(stderr, "  -su,      --speed-up       [%-7s] speed up audio by x2 (reduced accuracy)\n",     params.speed_up ? "true" : "false");
    fprintf(stderr, "  -tr,      --translate      [%-7s] translate from source language to english\n",   params.translate ? "true" : "false");
    fprintf(stderr, "  -ps,      --print-special  [%-7s] print special tokens\n",                        params.print_special ? "true" : "false");
    fprintf(stderr, "  -pe,      --print-energy   [%-7s] print sound energy (for debugging)\n",          params.print_energy ? "true" : "false");
@ -205,7 +202,6 @@ std::string transcribe(
    wparams.prompt_n_tokens  = prompt_tokens.empty() ? 0       : prompt_tokens.size();

    wparams.audio_ctx        = params.audio_ctx;
-    wparams.speed_up         = params.speed_up;

    if (whisper_full(ctx, wparams, pcmf32.data(), pcmf32.size()) != 0) {
        return "";
--- a/examples/talk/talk.cpp
+++ b/examples/talk/talk.cpp
@ -26,7 +26,6 @@ struct whisper_params {
    float vad_thold    = 0.6f;
    float freq_thold   = 100.0f;

-    bool speed_up      = false;
    bool translate     = false;
    bool print_special = false;
    bool print_energy  = false;
@ -60,7 +59,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
        else if (arg == "-ac"  || arg == "--audio-ctx")     { params.audio_ctx     = std::stoi(argv[++i]); }
        else if (arg == "-vth" || arg == "--vad-thold")     { params.vad_thold     = std::stof(argv[++i]); }
        else if (arg == "-fth" || arg == "--freq-thold")    { params.freq_thold    = std::stof(argv[++i]); }
-        else if (arg == "-su"  || arg == "--speed-up")      { params.speed_up      = true; }
        else if (arg == "-tr"  || arg == "--translate")     { params.translate     = true; }
        else if (arg == "-ps"  || arg == "--print-special") { params.print_special = true; }
        else if (arg == "-pe"  || arg == "--print-energy")  { params.print_energy  = true; }
@ -96,7 +94,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -ac N,    --audio-ctx N   [%-7d] audio context size (0 - all)\n",                params.audio_ctx);
    fprintf(stderr, "  -vth N,   --vad-thold N   [%-7.2f] voice activity detection threshold\n",        params.vad_thold);
    fprintf(stderr, "  -fth N,   --freq-thold N  [%-7.2f] high-pass frequency cutoff\n",                params.freq_thold);
-    fprintf(stderr, "  -su,      --speed-up      [%-7s] speed up audio by x2 (reduced accuracy)\n",     params.speed_up ? "true" : "false");
    fprintf(stderr, "  -tr,      --translate     [%-7s] translate from source language to english\n",   params.translate ? "true" : "false");
    fprintf(stderr, "  -ps,      --print-special [%-7s] print special tokens\n",                        params.print_special ? "true" : "false");
    fprintf(stderr, "  -pe,      --print-energy  [%-7s] print sound energy (for debugging)\n",          params.print_energy ? "true" : "false");
@ -132,7 +129,6 @@ std::string transcribe(whisper_context * ctx, const whisper_params & params, con
    wparams.n_threads        = params.n_threads;

    wparams.audio_ctx        = params.audio_ctx;
-    wparams.speed_up         = params.speed_up;

    if (whisper_full(ctx, wparams, pcmf32.data(), pcmf32.size()) != 0) {
        return "";
--- a/examples/wchess/wchess.cmd/wchess.cmd.cpp
+++ b/examples/wchess/wchess.cmd/wchess.cmd.cpp
@ -26,7 +26,6 @@ struct whisper_params {

    float grammar_penalty = 100.0f;

-    bool speed_up      = false;
    bool translate     = false;
    bool print_special = false;
    bool print_energy  = false;
@ -57,7 +56,6 @@ void whisper_print_usage(int /*argc*/, char ** argv, const whisper_params & para
    fprintf(stderr, "  -ac N,      --audio-ctx N    [%-7d] audio context size (0 - all)\n",                params.audio_ctx);
    fprintf(stderr, "  -vth N,     --vad-thold N    [%-7.2f] voice activity detection threshold\n",        params.vad_thold);
    fprintf(stderr, "  -fth N,     --freq-thold N   [%-7.2f] high-pass frequency cutoff\n",                params.freq_thold);
-    fprintf(stderr, "  -su,        --speed-up       [%-7s] speed up audio by x2 (reduced accuracy)\n",     params.speed_up ? "true" : "false");
    fprintf(stderr, "  -tr,        --translate      [%-7s] translate from source language to english\n",   params.translate ? "true" : "false");
    fprintf(stderr, "  -ps,        --print-special  [%-7s] print special tokens\n",                        params.print_special ? "true" : "false");
    fprintf(stderr, "  -pe,        --print-energy   [%-7s] print sound energy (for debugging)\n",          params.print_energy ? "true" : "false");
@ -89,7 +87,6 @@ bool whisper_params_parse(int argc, char ** argv, whisper_params & params) {
        else if (arg == "-ac"  || arg == "--audio-ctx")     { params.audio_ctx     = std::stoi(argv[++i]); }
        else if (arg == "-vth" || arg == "--vad-thold")     { params.vad_thold     = std::stof(argv[++i]); }
        else if (arg == "-fth" || arg == "--freq-thold")    { params.freq_thold    = std::stof(argv[++i]); }
-        else if (arg == "-su"  || arg == "--speed-up")      { params.speed_up      = true; }
        else if (arg == "-tr"  || arg == "--translate")     { params.translate     = true; }
        else if (arg == "-ps"  || arg == "--print-special") { params.print_special = true; }
        else if (arg == "-pe"  || arg == "--print-energy")  { params.print_energy  = true; }
--- a/whisper-mel-cuda.cu
+++ b/whisper-mel-cuda.cu
@ -0,0 +1,363 @@
+#define CUB_IGNORE_DEPRECATED_CPP_DIALECT
+#include "whisper-mel-cuda.hpp"
+#include "whisper.h"
+
+#include <cuda.h>
+#include <cuda_runtime.h>
+#include <cufft.h>
+#include <cublas_v2.h>
+#include <cuComplex.h>
+#include <cub/device/device_reduce.cuh>
+#include <device_launch_parameters.h>
+
+#include <algorithm>
+
+#if defined(_MSC_VER)
+#pragma warning(disable: 4324) // added padding
+#endif
+
+#ifndef NDEBUG
+#   define DO_CHECKS 1
+#else
+#   define DO_CHECKS 0
+#endif
+
+namespace {
+
+#if DO_CHECKS
+const char* cufftGetErrorString(cufftResult_t res) {
+    switch (res) {
+    case CUFFT_SUCCESS: return "The cuFFT operation was successful";
+    case CUFFT_INVALID_PLAN: return "cuFFT was passed an invalid plan handle";
+    case CUFFT_ALLOC_FAILED: return "cuFFT failed to allocate GPU or CPU memory";
+    case CUFFT_INVALID_TYPE: return "No longer used";
+    case CUFFT_INVALID_VALUE: return "User specified an invalid pointer or parameter";
+    case CUFFT_INTERNAL_ERROR: return "Driver or internal cuFFT library error";
+    case CUFFT_EXEC_FAILED: return "Failed to execute an FFT on the GPU";
+    case CUFFT_SETUP_FAILED: return "The cuFFT library failed to initialize";
+    case CUFFT_INVALID_SIZE: return "User specified an invalid transform size";
+    case CUFFT_UNALIGNED_DATA: return "No longer used";
+    case CUFFT_INCOMPLETE_PARAMETER_LIST: return "Missing parameters in call";
+    case CUFFT_INVALID_DEVICE: return "Execution of a plan was on different GPU than plan creation";
+    case CUFFT_PARSE_ERROR: return "Internal plan database error";
+    case CUFFT_NO_WORKSPACE: return "No workspace has been provided prior to plan execution";
+    case CUFFT_NOT_IMPLEMENTED: return "Function does not implement functionality for parameters given.";
+    case CUFFT_LICENSE_ERROR: return "Used in previous versions.";
+    case CUFFT_NOT_SUPPORTED: return "Operation is not supported for parameters given.";
+    default: return "Unknown error";
+    }
+}
+
+#   define CUDA_CHECK_GEN(err, success, error_fn)                                            \
+         do {                                                                                \
+            auto err_ = (err);                                                               \
+            if (err_ != (success)) {                                                         \
+                fprintf(stderr, "%s %s:%d - %s\n", #err, __FILE__, __LINE__, error_fn(err_)); \
+            }                                                                                \
+        } while (0)
+#else
+#   define CUDA_CHECK_GEN(err, success, error_fn) err
+#endif
+
+#define CUDA_CHECK(err) CUDA_CHECK_GEN(err, cudaSuccess, cudaGetErrorString)
+#define CUBLAS_CHECK(err) CUDA_CHECK_GEN(err, CUBLAS_STATUS_SUCCESS, cublasGetStatusString)
+#define CUFFT_CHECK(err) CUDA_CHECK_GEN(err, CUFFT_SUCCESS, cufftGetErrorString)
+
+__global__ void k_fill_stft_input(
+    const float * padded_samples,
+    const int n_frames,
+    const float * hann_window,
+    float * stft_in
+) {
+    auto y = blockIdx.y * blockDim.y + threadIdx.y;
+    // if (y >= n_frames) return;
+    auto x = blockIdx.x * blockDim.x + threadIdx.x;
+    // if (x >= WHISPER_N_FFT) return;
+
+    auto line = padded_samples + y * WHISPER_HOP_LENGTH;
+    auto outLine = stft_in + y * WHISPER_N_FFT;
+
+    outLine[x] = line[x] * hann_window[x];
+}
+
+__global__ void k_calc_magnitudes(
+    const cuComplex* stft_out,
+    const int n_frames,
+    float * magnitudes
+) {
+    auto y = blockIdx.y * blockDim.y + threadIdx.y;
+    // if (y >= n_frames) return;
+    auto x = blockIdx.x * blockDim.x + threadIdx.x;
+    // if (x >= WHISPER_N_FFT_HALF) return;
+
+    auto idx = y * WHISPER_N_FFT_HALF + x;
+
+    auto r = stft_out[idx].x;
+    auto i = stft_out[idx].y;
+    magnitudes[idx] = r * r + i * i;
+}
+
+__global__ void k_calc_log_mel(
+    const float * mel_data,
+    const int n_mel,
+    const float * max_val,
+    float * log_mel
+) {
+    auto x = blockIdx.x * blockDim.x + threadIdx.x;
+    if (x >= n_mel) return;
+
+    float val = mel_data[x];
+
+    constexpr float e = 1e-10f;
+    if (val < e) val = e;
+
+    val = log10(val);
+
+    const float max = log10(*max_val) - 8.f;
+    if (val < max) val = max;
+
+    log_mel[x] = (val + 4) / 4;
+}
+
+void fill_stft_input(
+    const float * padded_samples,
+    int n_frames,
+    const float * hann_window,
+    float * stft_in,
+    cudaStream_t stream
+) {
+    dim3 block(WHISPER_N_FFT, 1);
+    dim3 grid(1, n_frames);
+
+    k_fill_stft_input<<<grid, block, 0, stream>>>(padded_samples, n_frames, hann_window, stft_in);
+}
+
+void calc_magnitudes(
+    const cuComplex* stft_out,
+    int n_frames,
+    float * magnitudes,
+    cudaStream_t stream
+) {
+    dim3 block(WHISPER_N_FFT_HALF, 1);
+    dim3 grid(1, n_frames);
+    k_calc_magnitudes<<<grid, block, 0, stream>>>(stft_out, n_frames, magnitudes);
+}
+
+constexpr auto LOG_MEL_PREFIX_SIZE = 256;
+
+void calc_log_mel(
+    const float * mel_data,
+    int n_mel,
+    void * tempStorage,
+    int tempStorageSize,
+    float * log_mel,
+    cudaStream_t stream
+) {
+    float * max_val = reinterpret_cast<float *>(tempStorage);
+    void * maxTemp = reinterpret_cast<char*>(tempStorage) + LOG_MEL_PREFIX_SIZE;
+
+    size_t nbytes = size_t(tempStorageSize - LOG_MEL_PREFIX_SIZE);
+    cub::DeviceReduce::Max(maxTemp, nbytes, mel_data, max_val, n_mel, stream);
+
+    int block = 256;
+    int grid = (n_mel + block - 1) / block;
+
+    k_calc_log_mel<<<grid, block, 0, stream>>>(mel_data, n_mel, max_val, log_mel);
+}
+
+class mel_calc_cuda : public whisper_mel_calc {
+    const int m_n_mel;
+
+    ggml_backend_t m_backend = nullptr;
+
+    cudaStream_t m_stream = nullptr;
+    cublasHandle_t m_cublas_handle = nullptr;
+
+    float * m_hann_window = nullptr;
+
+    float * m_filters = nullptr;
+
+    // max samples for which we have allocated memory for the temp working areas below (cufft, log_mel)
+    int m_n_max_samples = 0;
+
+    size_t m_cufft_workspace_size = 0;
+    void * m_cufft_workspace = nullptr;
+
+    size_t m_log_mel_temp_storage_size = 0;
+    void * m_log_mel_temp_storage = nullptr;
+public:
+    mel_calc_cuda(ggml_backend_t backend, const whisper_filters & filters)
+        : m_n_mel(filters.n_mel)
+        , m_backend(backend)
+    {
+        if (filters.n_fft != WHISPER_N_FFT_HALF) {
+            throw std::invalid_argument("MelFilters n_frames must be WHISPER_N_FFT_HALF");
+        }
+        assert(filters.data.size() == filters.n_mel * WHISPER_N_FFT_HALF);
+
+        CUDA_CHECK(cudaStreamCreate(&m_stream));
+        CUBLAS_CHECK(cublasCreate(&m_cublas_handle));
+        CUBLAS_CHECK(cublasSetMathMode(m_cublas_handle, CUBLAS_TF32_TENSOR_OP_MATH));
+        CUBLAS_CHECK(cublasSetStream(m_cublas_handle, m_stream));
+
+        // create Hann window
+        {
+            auto hw = whisper_mel_calc::hann_window();
+            CUDA_CHECK(cudaMallocAsync(&m_hann_window, hw.len * sizeof(float), m_stream));
+            CUDA_CHECK(cudaMemcpyAsync(m_hann_window, hw.data, hw.len * sizeof(float), cudaMemcpyHostToDevice, m_stream));
+        }
+
+        // fill filters
+        {
+            auto& f = filters.data;
+            CUDA_CHECK(cudaMallocAsync(&m_filters, f.size() * sizeof(float), m_stream));
+            CUDA_CHECK(cudaMemcpyAsync(m_filters, f.data(), f.size() * sizeof(float), cudaMemcpyHostToDevice, m_stream));
+        }
+
+        // preallocate working areas enough for the most common cases (<= 30s)
+        ensure_working_areas(WHISPER_N_SAMPLES);
+    }
+
+    ~mel_calc_cuda() {
+        CUDA_CHECK(cudaStreamSynchronize(m_stream));
+        CUDA_CHECK(cudaStreamDestroy(m_stream));
+        CUDA_CHECK(cudaFree(m_hann_window));
+        CUDA_CHECK(cudaFree(m_cufft_workspace));
+        CUDA_CHECK(cudaFree(m_filters));
+        CUDA_CHECK(cudaFree(m_log_mel_temp_storage));
+    }
+
+    void ensure_working_areas(int n_samples) {
+        if (n_samples <= m_n_max_samples) {
+            return;
+        }
+
+        const auto max_padded_samples = n_samples + WHISPER_N_SAMPLES + WHISPER_N_FFT;
+        const auto max_frames = 1 + (max_padded_samples - WHISPER_N_FFT) / WHISPER_HOP_LENGTH;
+
+        // cufft workspace
+        {
+            if (m_cufft_workspace) {
+                CUDA_CHECK(cudaFree(m_cufft_workspace));
+                m_cufft_workspace_size = 0;
+                m_cufft_workspace = nullptr;
+            }
+            CUFFT_CHECK(cufftEstimate1d(WHISPER_N_FFT, CUFFT_R2C, max_frames, &m_cufft_workspace_size));
+            CUDA_CHECK(cudaMallocAsync(&m_cufft_workspace, m_cufft_workspace_size, m_stream));
+        }
+
+        // device reduce working area
+        {
+            if (m_log_mel_temp_storage) {
+                CUDA_CHECK(cudaFree(m_log_mel_temp_storage));
+                m_log_mel_temp_storage_size = 0;
+                m_log_mel_temp_storage = nullptr;
+            }
+
+            const auto max_mels = 160;
+
+            size_t nbytes = 0;
+            float* temp = nullptr;
+            cub::DeviceReduce::Max(nullptr, nbytes, temp, temp, max_frames * max_mels);
+            m_log_mel_temp_storage_size = nbytes + LOG_MEL_PREFIX_SIZE;
+
+            CUDA_CHECK(cudaMallocAsync(&m_log_mel_temp_storage, m_log_mel_temp_storage_size, m_stream));
+        }
+
+        m_n_max_samples = n_samples;
+    }
+
+    virtual whisper_mel calculate(whisper_span<const float> samples, int /*n_threads*/) override {
+        ensure_working_areas(samples.len);
+
+        const size_t mirror_pad = WHISPER_N_FFT / 2;
+        const size_t padded_size = samples.len + WHISPER_N_SAMPLES + WHISPER_N_FFT;
+
+        // pad
+        std::vector<float> padded_samples(padded_size);
+        std::reverse_copy(samples.data + 1, samples.data + 1 + mirror_pad, padded_samples.begin()); // reflect
+        std::copy(samples.data, samples.data + samples.len, padded_samples.begin() + mirror_pad); // copy
+
+        // fill the rest of the data
+        // it should canonically be mirrored at the end as well,
+        // but we just assume the last MEL_FRAME_SIZE/2 samples are zeros
+        std::fill(padded_samples.begin() + mirror_pad + samples.len, padded_samples.end(), 0.f);
+
+        const auto n_frames = 1 + (padded_samples.size() - WHISPER_N_FFT) / WHISPER_HOP_LENGTH;
+
+        float * cu_padded_samples = nullptr;
+        CUDA_CHECK(cudaMallocAsync(&cu_padded_samples, padded_samples.size() * sizeof(float), m_stream));
+        CUDA_CHECK(cudaMemcpyAsync(cu_padded_samples, padded_samples.data(), padded_samples.size() * sizeof(float), cudaMemcpyHostToDevice, m_stream));
+
+        float * stft_in = nullptr; // contiguous buffer for stft input
+        CUDA_CHECK(cudaMallocAsync(&stft_in, n_frames * WHISPER_N_FFT * sizeof(float), m_stream));
+
+        fill_stft_input(cu_padded_samples, int(n_frames), m_hann_window, stft_in, m_stream);
+
+        cufftComplex* stft_out;
+        CUDA_CHECK(cudaMallocAsync(&stft_out, n_frames * WHISPER_N_FFT_HALF * sizeof(cufftComplex), m_stream));
+
+        cufftHandle plan;
+        CUFFT_CHECK(cufftCreate(&plan));
+        CUFFT_CHECK(cufftSetAutoAllocation(plan, 0));
+        {
+            size_t waSize;
+            CUFFT_CHECK(cufftMakePlan1d(plan, WHISPER_N_FFT, CUFFT_R2C, int(n_frames), &waSize));
+            assert(waSize <= m_cufft_workspace_size);
+            CUFFT_CHECK(cufftSetWorkArea(plan, m_cufft_workspace));
+            CUFFT_CHECK(cufftSetStream(plan, m_stream));
+        }
+        CUFFT_CHECK(cufftExecR2C(plan, stft_in, stft_out));
+
+        const auto n_mag_frames = n_frames - 1; // drop last frame
+        float * magnitudes;
+        CUDA_CHECK(cudaMallocAsync(&magnitudes, n_mag_frames * WHISPER_N_FFT_HALF * sizeof(float), m_stream));
+        calc_magnitudes(stft_out, int(n_mag_frames), magnitudes, m_stream);
+
+        float * mel_data = nullptr;
+        CUDA_CHECK(cudaMallocAsync(&mel_data, m_n_mel * n_mag_frames * sizeof(float), m_stream));
+
+        const float fone = 1.0f, fzero = 0.0f;
+        CUBLAS_CHECK(cublasSgemm(m_cublas_handle, CUBLAS_OP_T, CUBLAS_OP_N,
+            int(n_mag_frames), m_n_mel, WHISPER_N_FFT_HALF,
+            &fone,
+            magnitudes, WHISPER_N_FFT_HALF,
+            m_filters, WHISPER_N_FFT_HALF,
+            &fzero,
+            mel_data, int(n_mag_frames)));
+
+        whisper_mel ret;
+        // Calculate semi-padded sample length to ensure compatibility
+        int n_len_org = 1 + int(samples.len + mirror_pad - WHISPER_N_FFT) / WHISPER_HOP_LENGTH;
+        whisper_mel_init(ret, m_backend, int(n_mag_frames), n_len_org, m_n_mel);
+        assert(ggml_nbytes(ret.tensor) == m_n_mel * n_mag_frames * sizeof(float));
+
+        float* log_mels = reinterpret_cast<float*>(ret.tensor->data);
+
+        calc_log_mel(
+            mel_data, int(m_n_mel * n_mag_frames),
+            m_log_mel_temp_storage , int(m_log_mel_temp_storage_size),
+            log_mels, m_stream);
+
+        CUDA_CHECK(cudaStreamSynchronize(m_stream));
+
+        // cleanup
+        CUFFT_CHECK(cufftDestroy(plan));
+        CUDA_CHECK(cudaFreeAsync(mel_data, m_stream));
+        CUDA_CHECK(cudaFreeAsync(magnitudes, m_stream));
+        CUDA_CHECK(cudaFreeAsync(stft_out, m_stream));
+        CUDA_CHECK(cudaFreeAsync(stft_in, m_stream));
+        CUDA_CHECK(cudaFreeAsync(cu_padded_samples, m_stream));
+
+        return ret;
+    }
+};
+
+}
+
+whisper_mel_calc * whisper_mel_calc_create_cuda(ggml_backend_t backend, const whisper_filters & filters) {
+    if (filters.n_fft != WHISPER_N_FFT_HALF) {
+        return nullptr;
+    }
+    return new mel_calc_cuda(backend, filters);
+}
--- a/whisper-mel-cuda.hpp
+++ b/whisper-mel-cuda.hpp
@ -0,0 +1,3 @@
+#include "whisper-mel.hpp"
+
+whisper_mel_calc * whisper_mel_calc_create_cuda(ggml_backend_t backend, const whisper_filters & filters);
--- a/whisper-mel.hpp
+++ b/whisper-mel.hpp
@ -0,0 +1,34 @@
+#pragma once
+#include "ggml-backend.h"
+#include <vector>
+
+struct whisper_mel {
+    int n_len_org = 0;
+
+    ggml_context * ctx = nullptr;
+    ggml_tensor * tensor = nullptr;
+    ggml_backend_buffer_t buffer = nullptr;
+};
+
+void whisper_mel_init(whisper_mel & mel, ggml_backend_t backend, int n_len, int n_len_org, int n_mel);
+
+void whisper_mel_free(whisper_mel & mel);
+
+struct whisper_filters {
+    int32_t n_mel;
+    int32_t n_fft;
+
+    std::vector<float> data;
+};
+
+template <typename T>
+struct whisper_span {
+    T * data;
+    int len;
+};
+
+struct whisper_mel_calc {
+    virtual ~whisper_mel_calc();
+    virtual whisper_mel calculate(whisper_span<const float> samples, int n_threads) = 0;
+    static whisper_span<const float> hann_window();
+};
--- a/whisper.cpp
+++ b/whisper.cpp
@ -10,6 +10,7 @@

 #ifdef GGML_USE_CUDA
 #include "ggml-cuda.h"
+#include "whisper-mel-cuda.hpp"
 #endif

 #ifdef GGML_USE_SYCL
@ -24,6 +25,8 @@
 #include "ggml-alloc.h"
 #include "ggml-backend.h"

+#include "whisper-mel.hpp"
+
 #include <atomic>
 #include <algorithm>
 #include <cassert>
@ -380,21 +383,6 @@ static const std::map<whisper_alignment_heads_preset, whisper_aheads> g_aheads {

 static std::vector<uint32_t> get_alignment_heads_by_layer(const whisper_context_params & cparams, int il, int32_t n_text_layer, int32_t n_head);

-struct whisper_mel {
-    int n_len;
-    int n_len_org;
-    int n_mel;
-
-    std::vector<float> data;
-};
-
-struct whisper_filters {
-    int32_t n_mel;
-    int32_t n_fft;
-
-    std::vector<float> data;
-};
-
 struct whisper_vocab {
    using id    = int32_t;
    using token = std::string;
@ -813,6 +801,8 @@ struct whisper_state {
    whisper_kv_cache kv_pad;

    whisper_mel mel;
+    whisper_mel_calc * mel_calc = nullptr;
+    whisper_mel_calc * mel_calc_fallback = nullptr;

    whisper_batch batch;

@ -833,7 +823,6 @@ struct whisper_state {
    struct ggml_tensor * embd_enc  = nullptr;

    // helpers for GPU offloading
-    std::vector<float> inp_mel;
    std::vector<float> inp_mask;

    // decode output (2-dimensional array: [n_tokens][n_vocab])
@ -904,7 +893,7 @@ static void read_safe(whisper_model_loader * loader, T & dest) {
    BYTESWAP_VALUE(dest);
 }

-static bool kv_cache_init(
+static bool whisper_kv_cache_init(
             struct whisper_kv_cache & cache,
                      ggml_backend_t   backend,
                           ggml_type   wtype,
@ -947,7 +936,7 @@ static bool kv_cache_init(
    return true;
 }

-static void kv_cache_free(struct whisper_kv_cache & cache) {
+static void whisper_kv_cache_free(struct whisper_kv_cache & cache) {
    ggml_free(cache.ctx);
    ggml_backend_buffer_free(cache.buffer);
    cache.ctx = nullptr;
@ -1261,9 +1250,12 @@ static ggml_backend_t whisper_backend_init(const whisper_context_params & params
    }
 #endif

+    GGML_UNUSED(params);
+
    if (backend_gpu) {
        return backend_gpu;
    }
+
    return ggml_backend_cpu_init();
 }

@ -1825,7 +1817,8 @@ static bool whisper_encode_external(const whisper_state & wstate) {

 static struct ggml_cgraph * whisper_build_graph_conv(
        whisper_context & wctx,
-          whisper_state & wstate) {
+          whisper_state & wstate,
+              const int   mel_offset) {
    const auto & model   = wctx.model;
    const auto & hparams = model.hparams;

@ -1844,9 +1837,32 @@ static struct ggml_cgraph * whisper_build_graph_conv(

    ggml_cgraph * gf = ggml_new_graph(ctx0);

-    struct ggml_tensor * mel = ggml_new_tensor_2d(ctx0, GGML_TYPE_F32, 2*n_ctx, n_mels);
-    ggml_set_name(mel, "mel");
-    ggml_set_input(mel);
+    ggml_tensor * mel_inp = wstate.mel.tensor;
+    ggml_tensor * mel;
+    if (mel_inp) {
+        const int n_len = int(mel_inp->ne[0]);
+        const int out_s = 2 * n_ctx;
+        const int i0 = std::min(mel_offset, n_len);
+        const int i1 = std::min(mel_offset + out_s, n_len);
+        const int mel_s = i1 - i0;
+
+        assert(mel_inp->type == GGML_TYPE_F32);
+        assert(mel_inp->ne[1] == n_mels);
+
+        ggml_tensor * cur = ggml_view_2d(ctx0, mel_inp, out_s, n_mels, mel_inp->nb[1], ggml_row_size(mel_inp->type, i0));
+
+        if (mel_s < out_s) {
+            mel = ggml_pad(ctx0, cur, out_s - mel_s, 0, 0, 0);
+        }
+        else {
+            mel = ggml_cont(ctx0, cur);
+        }
+    }
+    else {
+        // just create some tensor so that the graph/buffer size estimation is correct
+        mel = ggml_new_tensor_2d(ctx0, GGML_TYPE_F32, 2 * n_ctx, n_mels);
+    }
+    ggml_set_name(mel, "mel"); // used with external encoding

    struct ggml_tensor * cur = nullptr;

@ -2228,45 +2244,21 @@ static bool whisper_encode_internal(
    {
        auto & alloc = wstate.alloc_conv.alloc;

-        ggml_cgraph * gf = whisper_build_graph_conv(wctx, wstate);
+        ggml_cgraph * gf = whisper_build_graph_conv(wctx, wstate, mel_offset);

        if (!ggml_gallocr_alloc_graph(alloc, gf)) {
            // should never happen as we pre-allocate the memory
            return false;
        }

-        struct ggml_tensor * mel = ggml_graph_get_tensor(gf, "mel");
-
-        // set the input
-        {
-            const auto & mel_inp = wstate.mel;
-            const int n_ctx      = wstate.exp_n_audio_ctx > 0 ? wstate.exp_n_audio_ctx : wctx.model.hparams.n_audio_ctx;
-
-            assert(mel->type == GGML_TYPE_F32);
-            assert(mel_inp.n_mel == wctx.model.hparams.n_mels);
-
-            wstate.inp_mel.resize(ggml_nelements(mel));
-
-            float * dst = wstate.inp_mel.data();
-            memset(dst, 0, ggml_nbytes(mel));
-
-            const int i0 = std::min(mel_offset,           mel_inp.n_len);
-            const int i1 = std::min(mel_offset + 2*n_ctx, mel_inp.n_len);
-
-            for (int j = 0; j < mel_inp.n_mel; ++j) {
-                for (int i = i0; i < i1; ++i) {
-                    dst[j*2*n_ctx + (i - i0)] = mel_inp.data[j*mel_inp.n_len + i];
-                }
-            }
-
-            ggml_backend_tensor_set(mel, wstate.inp_mel.data(), 0, ggml_nelements(mel)*sizeof(float));
+        if (!ggml_graph_compute_helper(wstate.backend, gf, n_threads)) {
+            return false;
        }

-        if (!whisper_encode_external(wstate)) {
-            if (!ggml_graph_compute_helper(wstate.backend, gf, n_threads)) {
-                return false;
-            }
-        } else {
+        if (whisper_encode_external(wstate)) {
+            ggml_tensor * mel = ggml_graph_get_tensor(gf, "mel");
+            assert(mel->ne[1] == wctx.model.hparams.n_mels);
+            GGML_UNUSED(mel);
 #if defined(WHISPER_USE_COREML)
            whisper_coreml_encode(wstate.ctx_coreml, mel->ne[0], mel->ne[1], (float *) mel->data, (float *) wstate.embd_enc->data);
 #elif defined(WHISPER_USE_OPENVINO)
@ -2857,20 +2849,70 @@ static std::string to_timestamp(int64_t t, bool comma = false) {
 }

 #define SIN_COS_N_COUNT WHISPER_N_FFT
-static float sin_vals[SIN_COS_N_COUNT];
-static float cos_vals[SIN_COS_N_COUNT];
+namespace {
+struct whisper_global_cache {
+    // In FFT, we frequently use sine and cosine operations with the same values.
+    // We can use precalculated values to speed up the process.
+    float sin_vals[SIN_COS_N_COUNT];
+    float cos_vals[SIN_COS_N_COUNT];

-// In FFT, we frequently use sine and cosine operations with the same values.
-// We can use precalculated values to speed up the process.
-static void fill_sin_cos_table() {
-    static bool is_filled = false;
-    if (is_filled) return;
-    for (int i = 0; i < SIN_COS_N_COUNT; i++) {
-        double theta = (2*M_PI*i)/SIN_COS_N_COUNT;
-        sin_vals[i] = sinf(theta);
-        cos_vals[i] = cosf(theta);
+    // Hann window (Use cosf to eliminate difference)
+    // ref: https://pytorch.org/docs/stable/generated/torch.hann_window.html
+    // ref: https://github.com/openai/whisper/blob/main/whisper/audio.py#L147
+    float hann_window[WHISPER_N_FFT];
+
+    whisper_global_cache() {
+        fill_sin_cos_table();
+        fill_hann_window(sizeof(hann_window)/sizeof(hann_window[0]), true, hann_window);
    }
-    is_filled = true;
+
+    void fill_sin_cos_table() {
+        for (int i = 0; i < SIN_COS_N_COUNT; i++) {
+            double theta = (2 * M_PI * i) / SIN_COS_N_COUNT;
+            sin_vals[i] = sinf(theta);
+            cos_vals[i] = cosf(theta);
+        }
+    }
+
+    void fill_hann_window(int length, bool periodic, float * output) {
+        int offset = -1;
+        if (periodic) {
+            offset = 0;
+        }
+        for (int i = 0; i < length; i++) {
+            output[i] = 0.5 * (1.0 - cosf((2.0 * M_PI * i) / (length + offset)));
+        }
+    }
+} global_cache;
+}
+
+// Mel spectrogram
+
+void whisper_mel_init(whisper_mel & mel, ggml_backend_t backend, int n_len, int n_len_org, int n_mel) {
+    WHISPER_LOG_INFO("%s: n_len = %d, n_len_org = %d, n_mel = %d\n", __func__, n_len, n_len_org, n_mel);
+    mel.n_len_org = n_len_org;
+    assert(!mel.ctx);
+    mel.ctx = ggml_init({ggml_tensor_overhead(), nullptr, true});
+    mel.tensor = ggml_new_tensor_2d(mel.ctx, GGML_TYPE_F32, n_len, n_mel);
+    mel.buffer = ggml_backend_alloc_buffer(backend, ggml_nbytes(mel.tensor) + ggml_backend_get_alignment(backend));
+    auto alloc = ggml_tallocr_new(mel.buffer);
+    ggml_tallocr_alloc(&alloc, mel.tensor);
+}
+
+void whisper_mel_free(whisper_mel & mel) {
+    ggml_free(mel.ctx);
+    ggml_backend_buffer_free(mel.buffer);
+
+    mel.n_len_org = 0;
+    mel.ctx = nullptr;
+    mel.tensor = nullptr;
+    mel.buffer = nullptr;
+}
+
+whisper_mel_calc::~whisper_mel_calc() = default; // export vtable
+
+whisper_span<const float> whisper_mel_calc::hann_window() {
+    return {global_cache.hann_window, WHISPER_N_FFT};
 }

 // naive Discrete Fourier Transform
@ -2888,8 +2930,8 @@ static void dft(const std::vector<float> & in, std::vector<float> & out) {

        for (int n = 0; n < N; n++) {
            int idx = (k * n * sin_cos_step) % (SIN_COS_N_COUNT); // t = 2*M_PI*k*n/N
-            re += in[n]*cos_vals[idx]; // cos(t)
-            im -= in[n]*sin_vals[idx]; // sin(t)
+            re += in[n]*global_cache.cos_vals[idx]; // cos(t)
+            im -= in[n]*global_cache.sin_vals[idx]; // sin(t)
        }

        out[k*2 + 0] = re;
@ -2940,8 +2982,8 @@ static void fft(const std::vector<float> & in, std::vector<float> & out) {
    const int sin_cos_step = SIN_COS_N_COUNT / N;
    for (int k = 0; k < N/2; k++) {
        int idx = k * sin_cos_step; // t = 2*M_PI*k/N
-        float re = cos_vals[idx]; // cos(t)
-        float im = -sin_vals[idx]; // sin(t)
+        float re = global_cache.cos_vals[idx]; // cos(t)
+        float im = -global_cache.sin_vals[idx]; // sin(t)

        float re_odd = odd_fft[2*k + 0];
        float im_odd = odd_fft[2*k + 1];
@ -2954,24 +2996,20 @@ static void fft(const std::vector<float> & in, std::vector<float> & out) {
    }
 }

-static bool hann_window(int length, bool periodic, std::vector<float> & output) {
-    if (output.size() < static_cast<size_t>(length)) {
-        output.resize(length);
-    }
-    int offset = -1;
-    if (periodic) {
-        offset = 0;
-    }
-    for (int i = 0; i < length; i++) {
-        output[i] = 0.5*(1.0 - cosf((2.0*M_PI*i)/(length + offset)));
-    }
+namespace {

-    return true;
-}
+struct whisper_mel_data {
+    int n_len;
+    int n_len_org;
+    int n_mel;
+    float * data;
+};

-static void log_mel_spectrogram_worker_thread(int ith, const std::vector<float> & hann, const std::vector<float> & samples,
-                                              int n_samples, int frame_size, int frame_step, int n_threads,
-                                              const whisper_filters & filters, whisper_mel & mel) {
+void log_mel_spectrogram_worker_thread(int ith, const float * hann, const std::vector<float> & samples,
+                                              int n_samples, int n_threads,
+                                              const whisper_filters & filters, whisper_mel_data & mel) {
+    const auto frame_size = WHISPER_N_FFT;
+    const auto frame_step = WHISPER_HOP_LENGTH;
    std::vector<float> fft_in(frame_size, 0.0);
    std::vector<float> fft_out(2 * frame_size);
    int n_fft = filters.n_fft;
@ -2984,7 +3022,7 @@ static void log_mel_spectrogram_worker_thread(int ith, const std::vector<float>
    for (; i < std::min(n_samples / frame_step + 1, mel.n_len); i += n_threads) {
        const int offset = i * frame_step;

-        // apply Hanning window (~10% faster)
+        // apply Hann window (~10% faster)
        for (int j = 0; j < std::min(frame_size, n_samples - offset); j++) {
            fft_in[j] = hann[j] * samples[offset + j];
        }
@ -3036,101 +3074,109 @@ static void log_mel_spectrogram_worker_thread(int ith, const std::vector<float>
    }
 }

-// ref: https://github.com/openai/whisper/blob/main/whisper/audio.py#L110-L157
-static bool log_mel_spectrogram(
-              whisper_state & wstate,
-              const float * samples,
-              const int   n_samples,
-              const int   /*sample_rate*/,
-              const int   frame_size,
-              const int   frame_step,
-              const int   n_mel,
-              const int   n_threads,
-              const whisper_filters & filters,
-              const bool   debug,
-              whisper_mel & mel) {
-    const int64_t t_start_us = ggml_time_us();
+struct mel_calc_cpu : public whisper_mel_calc {
+    ggml_backend_t m_backend;
+    const whisper_filters & m_filters;
+    mel_calc_cpu(ggml_backend_t backend, const whisper_filters & filters) : m_backend(backend), m_filters(filters) {}

-    // Hanning window (Use cosf to eliminate difference)
-    // ref: https://pytorch.org/docs/stable/generated/torch.hann_window.html
-    // ref: https://github.com/openai/whisper/blob/main/whisper/audio.py#L147
-    std::vector<float> hann;
-    hann_window(frame_size, true, hann);
+    // ref: https://github.com/openai/whisper/blob/main/whisper/audio.py#L110-L157
+    whisper_mel calculate(whisper_span<const float> ssamples, int n_threads) override {
+        // Hann window
+        const float * hann = global_cache.hann_window;

+        // Calculate the length of padding
+        int64_t stage_1_pad = WHISPER_SAMPLE_RATE * 30;
+        int64_t stage_2_pad = WHISPER_N_FFT / 2;

-    // Calculate the length of padding
-    int64_t stage_1_pad = WHISPER_SAMPLE_RATE * 30;
-    int64_t stage_2_pad = frame_size / 2;
+        const int n_samples = int(ssamples.len);
+        const float * samples = ssamples.data;

-    // Initialize a vector and copy data from C array to it.
-    std::vector<float> samples_padded;
-    samples_padded.resize(n_samples + stage_1_pad + stage_2_pad * 2);
-    std::copy(samples, samples + n_samples, samples_padded.begin() + stage_2_pad);
+        // Initialize a vector and copy data from C array to it.
+        std::vector<float> samples_padded;
+        samples_padded.resize(n_samples + stage_1_pad + stage_2_pad * 2);
+        std::copy(samples, samples + n_samples, samples_padded.begin() + stage_2_pad);

-    // pad 30 seconds of zeros at the end of audio (480,000 samples) + reflective pad 200 samples at the end of audio
-    std::fill(samples_padded.begin() + n_samples + stage_2_pad, samples_padded.begin() + n_samples + stage_1_pad + 2 * stage_2_pad, 0);
+        // pad 30 seconds of zeros at the end of audio (480,000 samples) + reflective pad 200 samples at the end of audio
+        std::fill(samples_padded.begin() + n_samples + stage_2_pad, samples_padded.begin() + n_samples + stage_1_pad + 2 * stage_2_pad, 0);

-    // reflective pad 200 samples at the beginning of audio
-    std::reverse_copy(samples + 1, samples + 1 + stage_2_pad, samples_padded.begin());
+        // reflective pad 200 samples at the beginning of audio
+        std::reverse_copy(samples + 1, samples + 1 + stage_2_pad, samples_padded.begin());

-    mel.n_mel     = n_mel;
-    // https://github.com/pytorch/pytorch/blob/main/aten/src/ATen/native/SpectralOps.cpp#L936
-    // Calculate number of frames + remove the last frame
-    mel.n_len     = (samples_padded.size() - frame_size) / frame_step;
-    // Calculate semi-padded sample length to ensure compatibility
-    mel.n_len_org = 1 + (n_samples + stage_2_pad - frame_size) / frame_step;
-    mel.data.resize(mel.n_mel * mel.n_len);
+        whisper_mel_data mel;
+        mel.n_mel     = m_filters.n_mel;
+        // https://github.com/pytorch/pytorch/blob/main/aten/src/ATen/native/SpectralOps.cpp#L936
+        // Calculate number of frames + remove the last frame
+        mel.n_len     = (samples_padded.size() - WHISPER_N_FFT) / WHISPER_HOP_LENGTH;
+        // Calculate semi-padded sample length to ensure compatibility
+        mel.n_len_org = 1 + (n_samples + stage_2_pad - WHISPER_N_FFT) / WHISPER_HOP_LENGTH;

+        std::vector<float> host_mel_data;

-    {
-        std::vector<std::thread> workers(n_threads - 1);
-        for (int iw = 0; iw < n_threads - 1; ++iw) {
-            workers[iw] = std::thread(
-                    log_mel_spectrogram_worker_thread, iw + 1, std::cref(hann), samples_padded,
-                    n_samples + stage_2_pad, frame_size, frame_step, n_threads,
-                    std::cref(filters), std::ref(mel));
+        whisper_mel ret;
+        whisper_mel_init(ret, m_backend, mel.n_len, mel.n_len_org, mel.n_mel);
+        if (ggml_backend_buffer_is_host(ret.buffer)) {
+            mel.data = reinterpret_cast<float*>(ret.tensor->data);
+        } else {
+            host_mel_data.resize(mel.n_len * mel.n_mel);
+            mel.data = host_mel_data.data();
        }

-        // main thread
-        log_mel_spectrogram_worker_thread(0, hann, samples_padded, n_samples + stage_2_pad, frame_size, frame_step, n_threads, filters, mel);
+        {
+            std::vector<std::thread> workers(n_threads - 1);
+            for (int iw = 0; iw < n_threads - 1; ++iw) {
+                workers[iw] = std::thread(
+                        log_mel_spectrogram_worker_thread, iw + 1, hann, samples_padded,
+                        n_samples + stage_2_pad, n_threads,
+                        std::cref(m_filters), std::ref(mel));
+            }

-        for (int iw = 0; iw < n_threads - 1; ++iw) {
-            workers[iw].join();
+            // main thread
+            log_mel_spectrogram_worker_thread(0, hann, samples_padded, n_samples + stage_2_pad, n_threads, m_filters, mel);
+
+            for (int iw = 0; iw < n_threads - 1; ++iw) {
+                workers[iw].join();
+            }
        }
+
+        // clamping and normalization
+        double mmax = -1e20;
+        for (int i = 0; i < mel.n_mel*mel.n_len; i++) {
+            if (mel.data[i] > mmax) {
+                mmax = mel.data[i];
+            }
+        }
+
+        mmax -= 8.0;
+
+        for (int i = 0; i < mel.n_mel*mel.n_len; i++) {
+            if (mel.data[i] < mmax) {
+                mel.data[i] = mmax;
+            }
+
+            mel.data[i] = (mel.data[i] + 4.0)/4.0;
+        }
+
+        if (!host_mel_data.empty()) {
+            // the ret buffer is not host-accessible so we used this temporary buffer and now we need to upload it
+            ggml_backend_tensor_set(ret.tensor, host_mel_data.data(), 0, ggml_nbytes(ret.tensor));
+        }
+
+        return ret;
    }
+};
+}

-    // clamping and normalization
-    double mmax = -1e20;
-    for (int i = 0; i < mel.n_mel*mel.n_len; i++) {
-        if (mel.data[i] > mmax) {
-            mmax = mel.data[i];
-        }
-    }
-
-    mmax -= 8.0;
-
-    for (int i = 0; i < mel.n_mel*mel.n_len; i++) {
-        if (mel.data[i] < mmax) {
-            mel.data[i] = mmax;
-        }
-
-        mel.data[i] = (mel.data[i] + 4.0)/4.0;
-    }
-
-    wstate.t_mel_us += ggml_time_us() - t_start_us;
-
-    // Dump log_mel_spectrogram
-    if (debug) {
-        std::ofstream outFile("log_mel_spectrogram.json");
-        outFile << "[";
-        for (uint64_t i = 0; i < mel.data.size() - 1; i++) {
-            outFile << mel.data[i] << ", ";
-        }
-        outFile << mel.data[mel.data.size() - 1] << "]";
-        outFile.close();
-    }
-
-    return true;
+whisper_mel_calc * whisper_mel_calc_create(ggml_backend_t backend, const whisper_filters & filters) {
+#if GGML_USE_CUDA
+    if (ggml_backend_is_cuda(backend)) {
+        auto ret = whisper_mel_calc_create_cuda(backend, filters);
+        // run a warmup to avoid the first kernel launch overhead (thus we get the best perf even on the first run)
+        const float warmup[256] = {0};
+        ret->calculate({warmup, 256}, 1);
+        return ret;
+    } else
+#endif
+        return new mel_calc_cpu(backend, filters);
 }

 // split text into tokens
@ -3246,8 +3292,6 @@ static std::string whisper_openvino_get_path_cache(std::string path_bin) {
 #endif

 struct whisper_state * whisper_init_state(whisper_context * ctx) {
-    fill_sin_cos_table();
-
    whisper_state * state = new whisper_state;

    state->backend = whisper_backend_init(ctx->params);
@ -3257,15 +3301,17 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {
        return nullptr;
    }

+    state->mel_calc = whisper_mel_calc_create(state->backend, ctx->model.filters);
+
    // at this point, we don't know yet how many decoders will be used, so we overallocate 3x ctx
    // in theory, there can be a case where this is not enough, but in practice it should always be enough
    const int factor = 3;

-    if (!kv_cache_init(state->kv_self, ctx->backend, ctx->itype,
+    if (!whisper_kv_cache_init(state->kv_self, state->backend, ctx->itype,
                ctx->model.hparams.n_text_state,
                ctx->model.hparams.n_text_layer,
                GGML_PAD(ctx->model.hparams.n_text_ctx, 256)*factor)) {
-        WHISPER_LOG_ERROR("%s: kv_cache_init() failed for self-attention cache\n", __func__);
+        WHISPER_LOG_ERROR("%s: whisper_kv_cache_init() failed for self-attention cache\n", __func__);
        whisper_free_state(state);
        return nullptr;
    }
@ -3275,11 +3321,11 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {
        WHISPER_LOG_INFO("%s: kv self size  = %7.2f MB\n", __func__, memory_size / 1e6);
    }

-    if (!kv_cache_init(state->kv_cross, ctx->backend, ctx->itype,
+    if (!whisper_kv_cache_init(state->kv_cross, state->backend, ctx->itype,
                ctx->model.hparams.n_text_state,
                ctx->model.hparams.n_text_layer,
                GGML_PAD(ctx->model.hparams.n_audio_ctx, 256))) {
-        WHISPER_LOG_ERROR("%s: kv_cache_init() failed for cross-attention cache\n", __func__);
+        WHISPER_LOG_ERROR("%s: whisper_kv_cache_init() failed for cross-attention cache\n", __func__);
        whisper_free_state(state);
        return nullptr;
    }
@ -3289,11 +3335,11 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {
        WHISPER_LOG_INFO("%s: kv cross size = %7.2f MB\n", __func__, memory_size / 1e6);
    }

-    if (!kv_cache_init(state->kv_pad, ctx->backend, ctx->itype,
+    if (!whisper_kv_cache_init(state->kv_pad, state->backend, ctx->itype,
                ctx->model.hparams.n_audio_state,
                1,
                GGML_PAD(ctx->model.hparams.n_audio_ctx, 256))) {
-        WHISPER_LOG_ERROR("%s: kv_cache_init() failed for self-attention cache\n", __func__);
+        WHISPER_LOG_ERROR("%s: whisper_kv_cache_init() failed for self-attention cache\n", __func__);
        whisper_free_state(state);
        return nullptr;
    }
@ -3305,7 +3351,7 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {

    // [EXPERIMENTAL] Token-level timestamps with DTW
    if (ctx->params.dtw_token_timestamps) {
-        if (!aheads_masks_init(ctx->params, ctx->model.hparams, state->aheads_masks, ctx->backend)) {
+        if (!aheads_masks_init(ctx->params, ctx->model.hparams, state->aheads_masks, state->backend)) {
            WHISPER_LOG_ERROR("%s: aheads_masks_init() failed for alignment heads masks\n", __func__);
            whisper_free_state(state);
            return nullptr;
@ -3348,9 +3394,9 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {

    // conv allocator
    {
-        bool ok = whisper_allocr_graph_init(state->alloc_conv, ctx->backend,
+        bool ok = whisper_allocr_graph_init(state->alloc_conv, state->backend,
                [&]() {
-                    return whisper_build_graph_conv(*ctx, *state);
+                    return whisper_build_graph_conv(*ctx, *state, 0);
                });

        if (!ok) {
@ -3364,7 +3410,7 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {

    // encoder allocator
    if (!whisper_encode_external(*state)) {
-        bool ok = whisper_allocr_graph_init(state->alloc_encode, ctx->backend,
+        bool ok = whisper_allocr_graph_init(state->alloc_encode, state->backend,
                [&]() {
                    return whisper_build_graph_encoder(*ctx, *state);
                });
@ -3380,7 +3426,7 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {

    // cross allocator
    {
-        bool ok = whisper_allocr_graph_init(state->alloc_cross, ctx->backend,
+        bool ok = whisper_allocr_graph_init(state->alloc_cross, state->backend,
                [&]() {
                    return whisper_build_graph_cross(*ctx, *state);
                });
@ -3396,7 +3442,7 @@ struct whisper_state * whisper_init_state(whisper_context * ctx) {

    // decoder allocator
    {
-        bool ok = whisper_allocr_graph_init(state->alloc_decode, ctx->backend,
+        bool ok = whisper_allocr_graph_init(state->alloc_decode, state->backend,
                [&]() {
                    const auto & hparams = ctx->model.hparams;

@ -3668,9 +3714,16 @@ struct whisper_context * whisper_init_no_state(struct whisper_model_loader * loa

 void whisper_free_state(struct whisper_state * state) {
    if (state) {
-        kv_cache_free(state->kv_self);
-        kv_cache_free(state->kv_cross);
-        kv_cache_free(state->kv_pad);
+        whisper_kv_cache_free(state->kv_self);
+        whisper_kv_cache_free(state->kv_cross);
+        whisper_kv_cache_free(state->kv_pad);
+
+        whisper_mel_free(state->mel);
+
+        delete state->mel_calc;
+        state->mel_calc = nullptr;
+        delete state->mel_calc_fallback;
+        state->mel_calc_fallback = nullptr;

 #ifdef WHISPER_USE_COREML
        if (state->ctx_coreml != nullptr) {
@ -3729,11 +3782,37 @@ void whisper_free_params(struct whisper_full_params * params) {
 }

 int whisper_pcm_to_mel_with_state(struct whisper_context * ctx, struct whisper_state * state, const float * samples, int n_samples, int n_threads) {
-    if (!log_mel_spectrogram(*state, samples, n_samples, WHISPER_SAMPLE_RATE, WHISPER_N_FFT, WHISPER_HOP_LENGTH, ctx->model.filters.n_mel, n_threads, ctx->model.filters, false, state->mel)) {
-        WHISPER_LOG_ERROR("%s: failed to compute mel spectrogram\n", __func__);
-        return -1;
+    const int64_t t_start_us = ggml_time_us();
+
+    whisper_mel_free(state->mel);
+    if (n_samples <= 5 * 60 * WHISPER_SAMPLE_RATE) {
+        // calculate mel spectrogram for lengths up to 5 minutes on the most optimal mel calculator
+        state->mel = state->mel_calc->calculate({samples, n_samples}, n_threads);
+    } else {
+        // calcuate mel spectrogram for longer audios on the CPU
+        // 1. gpu calculations may use hundreds of megabytes of memory for longer audios so we're being conservative
+        //    with our gpu demands
+        // 2. the time to transcribe audios this long will be dominated by the decoding time, so the mel calculation
+        //    taking longer is not a major concern
+        if (!state->mel_calc_fallback) {
+            state->mel_calc_fallback = new mel_calc_cpu(state->backend, ctx->model.filters);
+        }
+        state->mel = state->mel_calc_fallback->calculate({samples, n_samples}, n_threads);
    }

+    state->t_mel_us += ggml_time_us() - t_start_us;
+
+    // Dump log_mel_spectrogram
+    //{
+    //    auto& mel = state->mel;
+    //    std::ofstream outFile("log_mel_spectrogram.json");
+    //    outFile << "[";
+    //    for (uint64_t i = 0; i < mel.data.size() - 1; i++) {
+    //        outFile << mel.data[i] << ", ";
+    //    }
+    //    outFile << mel.data[mel.data.size() - 1] << "]";
+    //    outFile.close();
+    //}
    return 0;
 }

@ -3741,30 +3820,6 @@ int whisper_pcm_to_mel(struct whisper_context * ctx, const float * samples, int
    return whisper_pcm_to_mel_with_state(ctx, ctx->state, samples, n_samples, n_threads);
 }

-// same as whisper_pcm_to_mel, but applies a Phase Vocoder to speed up the audio x2 (PV without phase lock is not good)
-int whisper_pcm_to_mel_phase_vocoder_with_state(struct whisper_context * ctx, struct whisper_state * state, const float * samples, int n_samples, int n_threads) {
-    if (!log_mel_spectrogram(*state, samples, n_samples, WHISPER_SAMPLE_RATE, 2 * WHISPER_N_FFT, 2 * WHISPER_HOP_LENGTH, ctx->model.filters.n_mel, n_threads, ctx->model.filters, false, state->mel)) {
-        WHISPER_LOG_ERROR("%s: failed to compute mel spectrogram\n", __func__);
-        return -1;
-    }
-
-    return 0;
-}
-
-// same as whisper_pcm_to_mel, but applies a Phase Vocoder to speed up the audio x2 (PV without phase lock is not good)
-int whisper_pcm_to_mel_phase_vocoder(struct whisper_context * ctx, const float * samples, int n_samples, int n_threads) {
-    return whisper_pcm_to_mel_phase_vocoder_with_state(ctx, ctx->state, samples, n_samples, n_threads);
-}
-
-// same as whisper_pcm_to_mel, but applies WSOLA to speed up the audio x2
-// TODO
-
-// same as whisper_pcm_to_mel, but applies HPTSM to speed up the audio x2
-// TODO
-
-// same as whisper_pcm_to_mel, but applies PV (with phase lock) to speed up the audio x2
-// TODO
-
 int whisper_set_mel_with_state(
        struct whisper_context * ctx,
          struct whisper_state * state,
@ -3776,12 +3831,10 @@ int whisper_set_mel_with_state(
        return -1;
    }

-    state->mel.n_len     = n_len;
-    state->mel.n_len_org = n_len;
-    state->mel.n_mel     = n_mel;
+    whisper_mel_free(state->mel);
+    whisper_mel_init(state->mel, ctx->backend, n_len, n_len, n_mel);

-    state->mel.data.resize(n_len*n_mel);
-    memcpy(state->mel.data.data(), data, n_len*n_mel*sizeof(float));
+    ggml_backend_tensor_set(state->mel.tensor, data, 0, ggml_nbytes(state->mel.tensor));

    return 0;
 }
@ -4665,7 +4718,6 @@ struct whisper_full_params whisper_full_default_params(enum whisper_sampling_str
        /*.split_on_word     =*/ false,
        /*.max_tokens        =*/ 0,

-        /*.speed_up          =*/ false,
        /*.debug_mode        =*/ false,
        /*.audio_ctx         =*/ 0,

@ -5339,15 +5391,9 @@ int whisper_full_with_state(

    if (n_samples > 0) {
        // compute log mel spectrogram
-        if (params.speed_up) {
-            // TODO: Replace PV with more advanced algorithm
+        if (whisper_pcm_to_mel_with_state(ctx, state, samples, n_samples, params.n_threads) != 0) {
            WHISPER_LOG_ERROR("%s: failed to compute log mel spectrogram\n", __func__);
-            return -1;
-        } else {
-            if (whisper_pcm_to_mel_with_state(ctx, state, samples, n_samples, params.n_threads) != 0) {
-                WHISPER_LOG_ERROR("%s: failed to compute log mel spectrogram\n", __func__);
-                return -2;
-            }
+            return -2;
        }
    }

@ -5384,7 +5430,7 @@ int whisper_full_with_state(
    // if length of spectrogram is less than 1.0s (100 frames), then return
    // basically don't process anything that is less than 1.0s
    // see issue #39: https://github.com/ggerganov/whisper.cpp/issues/39
-    if (seek_end < seek_start + (params.speed_up ? 50 : 100)) {
+    if (seek_end < seek_start + 100) {
        WHISPER_LOG_WARN("%s: input is too short - %d ms < 1000 ms. consider padding the input audio with silence\n", __func__, (seek_end - seek_start)*10);
        return 0;
    }
@ -6096,8 +6142,8 @@ int whisper_full_with_state(
                        const auto t1 = seek + 2*(tokens_cur[i].tid - whisper_token_beg(ctx));

                        if (!text.empty()) {
-                            const auto tt0 = params.speed_up ? 2*t0 : t0;
-                            const auto tt1 = params.speed_up ? 2*t1 : t1;
+                            const auto tt0 = t0;
+                            const auto tt1 = t1;

                            if (params.print_realtime) {
                                if (params.print_timestamps) {
@ -6143,8 +6189,8 @@ int whisper_full_with_state(
                if (!text.empty()) {
                    const auto t1 = seek + seek_delta;

-                    const auto tt0 = params.speed_up ? 2*t0 : t0;
-                    const auto tt1 = params.speed_up ? 2*t1 : t1;
+                    const auto tt0 = t0;
+                    const auto tt1 = t1;

                    if (params.print_realtime) {
                        if (params.print_timestamps) {
@ -7235,7 +7281,7 @@ static void whisper_exp_compute_token_level_timestamps_dtw(
    // operation (after median filter)
    // IN: Tensor with N_TOKENS*N_AUDIO_TOKENS*N_ALIGNMENT_HEADS dims
    // OUT: Tensor with N_ALIGNMENT_HEADS*N_TOKENS*N_AUDIO_TOKENS dims
-    w = ggml_norm(gctx, w, 1e-9);
+    w = ggml_norm(gctx, w, 1e-9f);
    w = ggml_permute(gctx, ggml_permute(gctx, w, 2, 1, 0 ,3), 0, 2, 1, 3);

    // Pass median filter - this is done over AUDIO_TOKENS dimension.
--- a/whisper.h
+++ b/whisper.h
@ -31,8 +31,10 @@

 #define WHISPER_SAMPLE_RATE 16000
 #define WHISPER_N_FFT       400
+#define WHISPER_N_FFT_HALF  (WHISPER_N_FFT / 2 + 1)
 #define WHISPER_HOP_LENGTH  160
 #define WHISPER_CHUNK_SIZE  30
+#define WHISPER_N_SAMPLES   (WHISPER_SAMPLE_RATE * WHISPER_CHUNK_SIZE)

 #ifdef __cplusplus
 extern "C" {
@ -266,22 +268,6 @@ extern "C" {
                               int   n_samples,
                               int   n_threads);

-    // Convert RAW PCM audio to log mel spectrogram but applies a Phase Vocoder to speed up the audio x2.
-    // The resulting spectrogram is stored inside the default state of the provided whisper context.
-    // Returns 0 on success
-    WHISPER_API int whisper_pcm_to_mel_phase_vocoder(
-        struct whisper_context * ctx,
-                   const float * samples,
-                           int   n_samples,
-                           int   n_threads);
-
-    WHISPER_API int whisper_pcm_to_mel_phase_vocoder_with_state(
-        struct whisper_context * ctx,
-          struct whisper_state * state,
-                   const float * samples,
-                           int   n_samples,
-                           int   n_threads);
-
    // This can be used to set a custom log mel spectrogram inside the default state of the provided whisper context.
    // Use this instead of whisper_pcm_to_mel() if you want to provide your own log mel spectrogram.
    // n_mel must be 80
@ -499,7 +485,6 @@ extern "C" {

        // [EXPERIMENTAL] speed-up techniques
        // note: these can significantly reduce the quality of the output
-        bool speed_up;          // speed-up the audio by 2x using Phase Vocoder
        bool debug_mode;        // enable debug_mode provides extra info (eg. Dump log_mel)
        int  audio_ctx;         // overwrite the audio context size (0 = use default)
Author	SHA1	Message	Date
Georgi Gerganov	059bcd3009	ci : fix CUDA builds	2024-06-11 11:40:19 +03:00
Borislav Stanimirov	20c542c713	whisper : auto-grow working areas for mel_calc_cuda (#2227 ) * whisper : auto-grow working areas for mel_calc_cuda, fixes #2226 * whisper : only calculate mel spectrogram on GPU if audio is <= 5 min	2024-06-10 21:51:32 +03:00
Georgi Gerganov	c2bdb960cd	whisper : free whisper_mel instances (#2220 )	2024-06-10 11:00:15 +03:00
Georgi Gerganov	87acd6d629	whisper : whisper_state/backend fixes (#2217 ) * whisper : fixes * ci : WHISPER_CUBLAS -> WHISPER_CUDA	2024-06-06 18:51:36 +03:00
Borislav Stanimirov	f842d31171	whisper : calculate mel spectrogram directly into a ggml_tensor (#2208 ) * whisper : calculate mel spectrogram directly into a ggml_tensor * whisper : remove unused temp buffer from state * whisper : fix not initializing wstate.embd_enc	2024-06-06 16:20:46 +03:00
Borislav Stanimirov	ffef323c4c	whisper : add CUDA-specific computation mel spectrograms (#2206 ) * whisper : use polymorphic class to calculate mel spectrogram * whisper : add cuda-specific mel spectrogram calculation * whisper : conditionally compile cufftGetErrorString to avoid warnings * build : add new files to makefile * ruby : add new files to conf script * build : fix typo in makefile * whisper : suppress cub warning for deprecated C++ std in whisper-mel-cuda	2024-06-04 09:32:23 +03:00
Borislav Stanimirov	af5833e298	whisper : remove `speed_up` and `phase_vocoder` functions (#2198 ) whisper : fix cast warning * whisper : remove phase_vocoder functions, ref #2195 * whisper : remove speed_up from whisper_full_params, closes #2195	2024-05-31 11:37:29 +03:00
Martin Delille	b87494bb8f	readme : add conan badge (#2196 ) * Add conan badge * Fix markdown formating	2024-05-30 15:43:28 +03:00
Carlos Zoido	ad130431aa	readme : add install instructions for Conan (#2189 )	2024-05-30 15:06:15 +03:00
Borislav Stanimirov	e130b66642	whisper: use global cache for sin/cos vals and Hann window (#2194 ) - also rename Hanning to Hann as it's named after Julius von Hann as per Wikipedia	2024-05-29 19:09:21 +03:00