Mercurial > sdl-ios-xcode
view src/cdrom/macosx/AudioFilePlayer.h @ 4216:5b99971a27b4 SDL-1.2
Fixed bug #698
Hans de Goede 2009-02-13 01:10:52 PST
Since the new "glitch free" version of pulseaudio (used in Fedora 10 amongst
others), the sound of SDL using apps (like a simple playmus call) has been
crackling.
While looking in to fixing this I noticed that the current pulseaudio code in
SDL uses pa_simple. However pa_simple uses a thread to pump pulseaudio events
and ipc, given that SDL already has its own thread for audio handling this is
clearly suboptimal, leading to unnecessary context switching IPC, etc. Also
pa_simple does not allow one to implement the WaitAudio() callback for SDL
audiodrivers properly.
Given that my work is mostly a rewrite (although some original pieces remain)
I'm attaching the new .c and .h file, as that is easier to review then the huge
diff.
Let me know if you also want the diff.
This new version has the following features:
-no longer use an additional thread next to the SDL sound thread
-do not crackle with glitch free audio
-when used with a newer pulse, which does glitch free audio, the total latency
is
the same as with the alsa driver
-proper WaitAudio() implementation, saving another mixlen worth of latency
-adds a WaitDone() implementation
This patch has been written in consultancy with Lennart Poetering (the
pulseaudio author) and has been reviewed by him for correct use of the pa API.
author | Sam Lantinga <slouken@libsdl.org> |
---|---|
date | Mon, 21 Sep 2009 09:27:08 +0000 |
parents | 386181851388 |
children | 4c088d2b29eb |
line wrap: on
line source
/* SDL - Simple DirectMedia Layer Copyright (C) 1997-2009 Sam Lantinga This library is free software; you can redistribute it and/or modify it under the terms of the GNU Library General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. This library is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public License for more details. You should have received a copy of the GNU Library General Public License along with this library; if not, write to the Free Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA Sam Lantinga slouken@libsdl.org This file based on Apple sample code. We haven't changed the file name, so if you want to see the original search for it on apple.com/developer */ #include "SDL_config.h" /*~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ AudioFilePlayer.h */ #ifndef __AudioFilePlayer_H__ #define __AudioFilePlayer_H__ #include <CoreServices/CoreServices.h> #include <AudioUnit/AudioUnit.h> #if MAC_OS_X_VERSION_MAX_ALLOWED <= 1050 #include <AudioUnit/AUNTComponent.h> #endif #include "SDL_error.h" const char* AudioFilePlayerErrorStr (OSStatus error); /* void ThrowResult (OSStatus result, const char *str); #define THROW_RESULT(str) \ if (result) { \ ThrowResult (result, str); \ } */ typedef void (*AudioFilePlayNotifier)(void *inRefCon, OSStatus inStatus); enum { kAudioFilePlayErr_FilePlayUnderrun = -10000, kAudioFilePlay_FileIsFinished = -10001, kAudioFilePlay_PlayerIsUninitialized = -10002 }; struct S_AudioFileManager; #pragma mark __________ AudioFilePlayer typedef struct S_AudioFilePlayer { /*public:*/ int (*SetDestination)(struct S_AudioFilePlayer *afp, AudioUnit *inDestUnit); void (*SetNotifier)(struct S_AudioFilePlayer *afp, AudioFilePlayNotifier inNotifier, void *inRefCon); void (*SetStartFrame)(struct S_AudioFilePlayer *afp, int frame); /* seek in the file */ int (*GetCurrentFrame)(struct S_AudioFilePlayer *afp); /* get the current frame position */ void (*SetStopFrame)(struct S_AudioFilePlayer *afp, int frame); /* set limit in the file */ int (*Connect)(struct S_AudioFilePlayer *afp); void (*Disconnect)(struct S_AudioFilePlayer *afp); void (*DoNotification)(struct S_AudioFilePlayer *afp, OSStatus inError); int (*IsConnected)(struct S_AudioFilePlayer *afp); AudioUnit (*GetDestUnit)(struct S_AudioFilePlayer *afp); void (*Print)(struct S_AudioFilePlayer *afp); /*private:*/ AudioUnit mPlayUnit; SInt16 mForkRefNum; AURenderCallbackStruct mInputCallback; AudioStreamBasicDescription mFileDescription; int mConnected; struct S_AudioFileManager* mAudioFileManager; AudioFilePlayNotifier mNotifier; void* mRefCon; int mStartFrame; #pragma mark __________ Private_Methods int (*OpenFile)(struct S_AudioFilePlayer *afp, const FSRef *inRef, SInt64 *outFileSize); } AudioFilePlayer; AudioFilePlayer *new_AudioFilePlayer(const FSRef *inFileRef); void delete_AudioFilePlayer(AudioFilePlayer *afp); #pragma mark __________ AudioFileManager typedef struct S_AudioFileManager { /*public:*/ /* this method should NOT be called by an object of this class as it is called by the parent's Disconnect() method */ void (*Disconnect)(struct S_AudioFileManager *afm); int (*DoConnect)(struct S_AudioFileManager *afm); OSStatus (*Read)(struct S_AudioFileManager *afm, char *buffer, ByteCount *len); const char* (*GetFileBuffer)(struct S_AudioFileManager *afm); const AudioFilePlayer *(*GetParent)(struct S_AudioFileManager *afm); void (*SetPosition)(struct S_AudioFileManager *afm, SInt64 pos); /* seek/rewind in the file */ int (*GetByteCounter)(struct S_AudioFileManager *afm); /* return actual bytes streamed to audio hardware */ void (*SetEndOfFile)(struct S_AudioFileManager *afm, SInt64 pos); /* set the "EOF" (will behave just like it reached eof) */ /*protected:*/ AudioFilePlayer* mParent; SInt16 mForkRefNum; SInt64 mAudioDataOffset; char* mFileBuffer; int mByteCounter; int mReadFromFirstBuffer; int mLockUnsuccessful; int mIsEngaged; int mNumTimesAskedSinceFinished; void* mTmpBuffer; UInt32 mBufferSize; UInt32 mBufferOffset; /*public:*/ UInt32 mChunkSize; SInt64 mFileLength; SInt64 mReadFilePosition; int mWriteToFirstBuffer; int mFinishedReadingData; /*protected:*/ OSStatus (*Render)(struct S_AudioFileManager *afm, AudioBufferList *ioData); OSStatus (*GetFileData)(struct S_AudioFileManager *afm, void** inOutData, UInt32 *inOutDataSize); void (*AfterRender)(struct S_AudioFileManager *afm); /*public:*/ /*static*/ OSStatus (*FileInputProc)(void *inRefCon, AudioUnitRenderActionFlags *ioActionFlags, const AudioTimeStamp *inTimeStamp, UInt32 inBusNumber, UInt32 inNumberFrames, AudioBufferList *ioData); } AudioFileManager; AudioFileManager *new_AudioFileManager (AudioFilePlayer *inParent, SInt16 inForkRefNum, SInt64 inFileLength, UInt32 inChunkSize); void delete_AudioFileManager(AudioFileManager *afm); #endif