Mercurial > sdl-ios-xcode
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 |
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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