Files
itgmania212121/stepmania/src/arch/Sound/RageSoundDriver_Generic_Software.h
T
2004-05-15 20:28:17 +00:00

166 lines
6.0 KiB
C++

#ifndef RAGE_SOUND_GENERIC_SOFTWARE
#define RAGE_SOUND_GENERIC_SOFTWARE
#include "RageSoundDriver.h"
#include "RageThreads.h"
#include "RageTimer.h"
#include "RageUtil_CircularBuffer.h"
static const int samples_per_block = 512;
class RageSound_Generic_Software: public RageSoundDriver
{
/*
* Thread safety and state transitions:
*
* STOPPED: The sound is idle, and can be used to play a new sound. The decoding and
* mixing threads will not touch a sound in this state.
*
* PLAYING: The sound is being decoded by the decoding thread, and played by the mixing
* thread. If the decoding thread hits EOF, the decoding thread will changed the state
* to STOPPING.
*
* STOPPING: The sound is being played by the mixing thread. No new data will be decoded.
* Once the data buffer is empty (all sound has been played), Update() will call StopMixing,
* and the sound will be changed to STOPPED.
*
* HALTING: The main thread has called StopMixing. The mixing thread will flush the buffered
* data without playing it, and then move the sound to STOPPED.
*
* The mixing thread operates without any locks. This can lead to a little overlap. For
* example, if StopMixing() is called, moving the sound from PLAYING to HALTING, the mixing
* thread might be in the middle of mixing data. Although HALTING means "discard buffered
* data", some data will still be mixed. This is OK; the data is valid, and the flush will
* happen on the next iteration.
*
* The only state change made by the decoding thread is on EOF: the state is changed
* from PLAYING to STOPPING. This is done while m_Mutex is held, to prevent
* races with other threads.
*
* The only state change made by the mixing thread is from HALTING to STOPPED.
* This is done with no locks; no other thread can take a sound out of the HALTING state.
*/
struct sound_block
{
int16_t buf[samples_per_block];
int16_t *p; // beginning of the unread data
int frames_in_buffer; // total number of frames (not samples) at p
int position; // position value of p
sound_block() { frames_in_buffer = position = 0; p = buf; }
};
struct sound
{
RageSoundBase *snd;
int sound_id;
RageTimer start_time;
float volume;
CircBuf<sound_block> buffer;
int64_t frames_read, frames_written;
int64_t frames_buffered() const { return frames_written - frames_read; }
/* If true, this sound is in STOPPED and available for use. */
bool available;
enum
{
STOPPED, /* idle */
/* This state is set by the decoder thread, indicating that the sound has just
* reached EOF. Once the mixing thread finishes flushing buffer, it'll change
* to the STOPPING_FINISH state. */
STOPPING,
HALTING, /* stop immediately */
PLAYING
} state;
sound();
void Init();
};
/* List of currently playing sounds: XXX no vector */
sound sounds[32];
bool shutdown_decode_thread;
static int DecodeThread_start(void *p);
void DecodeThread();
RageThread m_DecodeThread;
bool GetDataForSound( sound &s );
protected:
/* Start the decoding. This should be called once the hardware is set up and
* GetSampleRate will return the correct value. */
void StartDecodeThread();
/* Call this before calling StartDecodeThread to set the desired decoding buffer
* size. This is the number of frames that Mix() will try to be able to return
* at once. This should generally be slightly larger than the sound writeahead,
* to allow filling the buffer after an underrun. The default is 4096 frames. */
void SetDecodeBufferSize( int frames );
/* Override this to set the priority of the decoding thread, which should be above
* normal priority but not realtime. */
virtual void SetupDecodingThread() { }
/*
* Read mixed data.
*
* frames: buffer to read into
* nframes: number of frames (not samples) to read
* frameno: frame number at which this sound will be heard
* current_frameno: frame number that is currently being heard
*
* current_frameno is used for handling start timing.
*
* This function only mixes data; it will not lock any mutexes or do any file access, and
* is safe to call from a realtime thread.
*/
void Mix( int16_t *frames, int nframes, int64_t frameno, int64_t current_frameno );
/* This mutex is used for serializing with the decoder thread. Locking this mutex
* can take a while. */
RageMutex m_Mutex;
/* This mutex locks all sounds[] which are "available". (Other sound may safely
* be accessed, and sounds may be set to available, without locking this.) */
RageMutex m_SoundListMutex;
public:
virtual void Update(float delta);
void StartMixing( RageSoundBase *snd ); /* used by RageSound */
void StopMixing( RageSoundBase *snd ); /* used by RageSound */
RageSound_Generic_Software();
virtual ~RageSound_Generic_Software();
};
#endif
/*
* (c) 2002-2004 Glenn Maynard
* All rights reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* copy of this software and associated documentation files (the
* "Software"), to deal in the Software without restriction, including
* without limitation the rights to use, copy, modify, merge, publish,
* distribute, and/or sell copies of the Software, and to permit persons to
* whom the Software is furnished to do so, provided that the above
* copyright notice(s) and this permission notice appear in all copies of
* the Software and that both the above copyright notice(s) and this
* permission notice appear in supporting documentation.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
* OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT OF
* THIRD PARTY RIGHTS. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR HOLDERS
* INCLUDED IN THIS NOTICE BE LIABLE FOR ANY CLAIM, OR ANY SPECIAL INDIRECT
* OR CONSEQUENTIAL DAMAGES, OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS
* OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
* OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
* PERFORMANCE OF THIS SOFTWARE.
*/