view src/cdrom/macosx/AudioFilePlayer.h @ 3880:74e828c64315 SDL-1.2

Fixed bug #292 I might be on crack here. It looks like SDL_ConvertMono() in src/audio/SDL_audiocvt.c adds the left and right channels of a stereo stream together, and clamps the new mono channel if it would overflow. Shouldn't it be dividing by 2 to average the two sample points instead of clamping? Otherwise the mono sample point's volume doubles in the conversion. This would also make the conversion faster, as it replaces two branches per sample frame with a bitwise shift. --ryan.
author Sam Lantinga <slouken@libsdl.org>
date Sun, 24 Sep 2006 15:45:37 +0000
parents dc6b59e925a2
children 782fd950bd46 c121d94672cb 9df8136abec0
line wrap: on
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/*
    SDL - Simple DirectMedia Layer
    Copyright (C) 1997-2004 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>

#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;
    
    AudioUnitInputCallback          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, UInt32 *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, AudioBuffer *ioData);
    OSStatus            (*GetFileData)(struct S_AudioFileManager *afm, void** inOutData, UInt32 *inOutDataSize);
    void                (*AfterRender)(struct S_AudioFileManager *afm);

/*public:*/
    /*static*/
    OSStatus            (*FileInputProc)(void                             *inRefCon,
                                         AudioUnitRenderActionFlags      inActionFlags,
                                         const AudioTimeStamp            *inTimeStamp,
                                         UInt32                          inBusNumber,
                                         AudioBuffer                     *ioData);
} AudioFileManager;


AudioFileManager *new_AudioFileManager (AudioFilePlayer *inParent,
                      SInt16          inForkRefNum, 
                      SInt64          inFileLength,
                      UInt32          inChunkSize);
    
void delete_AudioFileManager(AudioFileManager *afm);

#endif