chore(vad): try to hook vad to received data from the API (WIP)

Signed-off-by: Ettore Di Giacinto <mudler@localai.io>

core/http/endpoints/openai/realtime.go

@@ -8,10 +8,13 @@ import (
 	"strings"
 	"sync"
 
+	"github.com/go-audio/audio"
 	"github.com/gofiber/websocket/v2"
 	"github.com/mudler/LocalAI/core/config"
 	"github.com/mudler/LocalAI/pkg/grpc/proto"
 	model "github.com/mudler/LocalAI/pkg/model"
+	"github.com/mudler/LocalAI/pkg/sound"
+
 	"google.golang.org/grpc"
 
 	"github.com/rs/zerolog/log"
@@ -456,9 +459,17 @@ func handleVAD(session *Session, conversation *Conversation, c *websocket.Conn,
 			// Check if there's audio data to process
 			session.AudioBufferLock.Lock()
 			if len(session.InputAudioBuffer) > 0 {
-				// TODO: what to put in the VADRequest request?
-				// Data is received as buffer, but we want PCM as float32 here...
-				resp, err := session.ModelInterface.VAD(context.Background(), &proto.VADRequest{})
+
+				adata := sound.BytesToInt16sLE(session.InputAudioBuffer)
+
+				soundIntBuffer := &audio.IntBuffer{
+					Format: &audio.Format{SampleRate: 16000, NumChannels: 1},
+				}
+				soundIntBuffer.Data = sound.ConvertInt16ToInt(adata)
+
+				resp, err := session.ModelInterface.VAD(context.Background(), &proto.VADRequest{
+					Audio: soundIntBuffer.AsFloat32Buffer().Data,
+				})
 				if err != nil {
 					log.Error().Msgf("failed to process audio: %s", err.Error())
 					sendError(c, "processing_error", "Failed to process audio", "", "")

pkg/sound/float32.go

@@ -0,0 +1,20 @@
+package sound
+
+import (
+	"encoding/binary"
+	"math"
+)
+
+func BytesToFloat32Array(aBytes []byte) []float32 {
+	aArr := make([]float32, 3)
+	for i := 0; i < 3; i++ {
+		aArr[i] = BytesFloat32(aBytes[i*4:])
+	}
+	return aArr
+}
+
+func BytesFloat32(bytes []byte) float32 {
+	bits := binary.LittleEndian.Uint32(bytes)
+	float := math.Float32frombits(bits)
+	return float
+}

pkg/sound/int16.go

@@ -0,0 +1,65 @@
+package sound
+
+/*
+
+MIT License
+
+Copyright (c) 2024 Xbozon
+
+*/
+
+func ResampleInt16(input []int16, inputRate, outputRate int) []int16 {
+	// Calculate the resampling ratio
+	ratio := float64(inputRate) / float64(outputRate)
+
+	// Calculate the length of the resampled output
+	outputLength := int(float64(len(input)) / ratio)
+
+	// Allocate a slice for the resampled output
+	output := make([]int16, outputLength)
+
+	// Perform linear interpolation for resampling
+	for i := 0; i < outputLength-1; i++ {
+		// Calculate the corresponding position in the input
+		pos := float64(i) * ratio
+
+		// Calculate the indices of the surrounding input samples
+		indexBefore := int(pos)
+		indexAfter := indexBefore + 1
+		if indexAfter >= len(input) {
+			indexAfter = len(input) - 1
+		}
+
+		// Calculate the fractional part of the position
+		frac := pos - float64(indexBefore)
+
+		// Linearly interpolate between the two surrounding input samples
+		output[i] = int16((1-frac)*float64(input[indexBefore]) + frac*float64(input[indexAfter]))
+	}
+
+	// Handle the last sample explicitly to avoid index out of range
+	output[outputLength-1] = input[len(input)-1]
+
+	return output
+}
+
+func ConvertInt16ToInt(input []int16) []int {
+	output := make([]int, len(input)) // Allocate a slice for the output
+	for i, value := range input {
+		output[i] = int(value) // Convert each int16 to int and assign it to the output slice
+	}
+	return output // Return the converted slice
+}
+
+func BytesToInt16sLE(bytes []byte) []int16 {
+	// Ensure the byte slice length is even
+	if len(bytes)%2 != 0 {
+		panic("bytesToInt16sLE: input bytes slice has odd length, must be even")
+	}
+
+	int16s := make([]int16, len(bytes)/2)
+	for i := 0; i < len(int16s); i++ {
+		int16s[i] = int16(bytes[2*i]) | int16(bytes[2*i+1])<<8
+	}
+	return int16s
+}