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
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/*
    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