mirror of
https://github.com/genodelabs/genode.git
synced 2024-12-23 15:32:25 +00:00
99 lines
2.9 KiB
C++
99 lines
2.9 KiB
C++
/*
|
|
* \brief Audio-out session interface
|
|
* \author Norman Feske
|
|
* \author Sebastian Sumpf
|
|
* \author Christian Helmuth
|
|
* \author Stefan Kalkowski
|
|
* \date 2009-12-02
|
|
*
|
|
* A audio-out session corresponds to one output channel, which can be used to
|
|
* transmit audio frames. Payload is communicated over the packet-stream
|
|
* interface set up between 'Session_client' and 'Session_server'. The term
|
|
* _channel_ means literally one audio channel, e.g. front left or rear center.
|
|
* Therefore, a standard two-channel stereo track needs two audio-out sessions
|
|
* - one for "front left" and one for "front right". The channel format is
|
|
* FLOAT_LE currently.
|
|
*
|
|
* Audio channel identifiers (loosly related to WAV channels) are:
|
|
*
|
|
* * Front left, right, center
|
|
* * LFE (low frequency effets, subwoofer)
|
|
* * Rear left, right, center
|
|
*
|
|
* For example, consumer-oriented 6-channel (5.1) audio uses front
|
|
* left/right/center, rear left/right and LFE.
|
|
*/
|
|
|
|
/*
|
|
* Copyright (C) 2009-2013 Genode Labs GmbH
|
|
*
|
|
* This file is part of the Genode OS framework, which is distributed
|
|
* under the terms of the GNU General Public License version 2.
|
|
*/
|
|
|
|
#ifndef _INCLUDE__AUDIO_OUT_SESSION__AUDIO_OUT_SESSION_H_
|
|
#define _INCLUDE__AUDIO_OUT_SESSION__AUDIO_OUT_SESSION_H_
|
|
|
|
#include <base/signal.h>
|
|
#include <base/rpc.h>
|
|
#include <dataspace/capability.h>
|
|
#include <audio_out_session/capability.h>
|
|
#include <packet_stream_tx/packet_stream_tx.h>
|
|
#include <session/session.h>
|
|
|
|
namespace Audio_out {
|
|
|
|
enum {
|
|
QUEUE_SIZE = 16, /* buffer queue size */
|
|
FRAME_SIZE = 4, /* frame size in bytes */
|
|
PERIOD = 1024 /* frames per period */
|
|
};
|
|
|
|
struct Session : Genode::Session
|
|
{
|
|
typedef Packet_stream_policy<Packet_descriptor,
|
|
QUEUE_SIZE, QUEUE_SIZE,
|
|
float> Policy;
|
|
|
|
typedef Packet_stream_tx::Channel<Policy> Channel;
|
|
|
|
static const char *service_name() { return "Audio_out"; }
|
|
|
|
virtual ~Session() { }
|
|
|
|
/**
|
|
* Request client-side packet-stream interface of channel
|
|
*/
|
|
virtual Channel::Source *stream() { return 0; }
|
|
|
|
/**
|
|
* Flush the audio buffer
|
|
*/
|
|
virtual void flush(void) = 0;
|
|
|
|
/**
|
|
* Set synchronization session
|
|
*
|
|
* \param audio_out_session synchronization session
|
|
*
|
|
* Session can be kept in sync (or bundled) using this function, for
|
|
* example, the left and right stero channels. A session has exactly
|
|
* one synchronization session.
|
|
*/
|
|
virtual void sync_session(Session_capability audio_out_session) = 0;
|
|
|
|
|
|
/*******************
|
|
** RPC interface **
|
|
*******************/
|
|
|
|
GENODE_RPC(Rpc_flush, void, flush);
|
|
GENODE_RPC(Rpc_sync_session, void, sync_session, Session_capability);
|
|
GENODE_RPC(Rpc_channel_cap, Genode::Capability<Channel>, channel_cap);
|
|
|
|
GENODE_RPC_INTERFACE(Rpc_flush, Rpc_sync_session, Rpc_channel_cap);
|
|
};
|
|
}
|
|
|
|
#endif /* _INCLUDE__AUDIO_OUT_SESSION__AUDIO_OUT_SESSION_H_ */
|