sm64pc/tools/audiofile-0.3.6/libaudiofile/modules/PCM.cpp
2020-05-07 20:21:22 +02:00

203 lines
5.5 KiB
C++

/*
Audio File Library
Copyright (C) 2000, Silicon Graphics, Inc.
Copyright (C) 2010, Michael Pruett <michael@68k.org>
This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 2.1 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
Lesser General Public License for more details.
You should have received a copy of the GNU Lesser General Public
License along with this library; if not, write to the
Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301 USA
*/
/*
PCM.cpp - read and file write module for uncompressed data
*/
#include "config.h"
#include "PCM.h"
#include <assert.h>
#include <math.h>
#include "Compiler.h"
#include "FileModule.h"
#include "Track.h"
#include "afinternal.h"
#include "audiofile.h"
#include "compression.h"
#include "util.h"
bool _af_pcm_format_ok (AudioFormat *f)
{
assert(!isnan(f->pcm.slope));
assert(!isnan(f->pcm.intercept));
assert(!isnan(f->pcm.minClip));
assert(!isnan(f->pcm.maxClip));
return true;
}
class PCM : public FileModule
{
public:
static PCM *createCompress(Track *track, File *fh, bool canSeek,
bool headerless, AFframecount *chunkFrames);
static PCM *createDecompress(Track *track, File *fh, bool canSeek,
bool headerless, AFframecount *chunkFrames);
virtual const char *name() const OVERRIDE { return "pcm"; }
virtual void runPull() OVERRIDE;
virtual void reset2() OVERRIDE;
virtual void runPush() OVERRIDE;
virtual void sync1() OVERRIDE;
virtual void sync2() OVERRIDE;
private:
int m_bytesPerFrame;
/* saved_fpos_next_frame and saved_nextfframe apply only to writing. */
int m_saved_fpos_next_frame;
int m_saved_nextfframe;
PCM(Mode, Track *, File *, bool canSeek);
};
PCM::PCM(Mode mode, Track *track, File *fh, bool canSeek) :
FileModule(mode, track, fh, canSeek),
m_bytesPerFrame(track->f.bytesPerFrame(false)),
m_saved_fpos_next_frame(-1),
m_saved_nextfframe(-1)
{
if (mode == Decompress)
track->f.compressionParams = AU_NULL_PVLIST;
}
PCM *PCM::createCompress(Track *track, File *fh, bool canSeek,
bool headerless, AFframecount *chunkframes)
{
return new PCM(Compress, track, fh, canSeek);
}
void PCM::runPush()
{
AFframecount frames2write = m_inChunk->frameCount;
AFframecount n;
/*
WARNING: due to the optimization explained at the end
of arrangemodules(), the pcm file module cannot depend
on the presence of the intermediate working buffer
which _AFsetupmodules usually allocates for file
modules in their input or output chunk (for reading or
writing, respectively).
Fortunately, the pcm module has no need for such a buffer.
*/
ssize_t bytesWritten = write(m_inChunk->buffer, m_bytesPerFrame * frames2write);
n = bytesWritten >= 0 ? bytesWritten / m_bytesPerFrame : 0;
if (n != frames2write)
reportWriteError(n, frames2write);
m_track->nextfframe += n;
m_track->totalfframes = m_track->nextfframe;
assert(!canSeek() || (tell() == m_track->fpos_next_frame));
}
void PCM::sync1()
{
m_saved_fpos_next_frame = m_track->fpos_next_frame;
m_saved_nextfframe = m_track->nextfframe;
}
void PCM::sync2()
{
assert(!canSeek() || (tell() == m_track->fpos_next_frame));
/* We can afford to seek because sync2 is rare. */
m_track->fpos_after_data = tell();
m_track->fpos_next_frame = m_saved_fpos_next_frame;
m_track->nextfframe = m_saved_nextfframe;
}
PCM *PCM::createDecompress(Track *track, File *fh, bool canSeek,
bool headerless, AFframecount *chunkframes)
{
return new PCM(Decompress, track, fh, canSeek);
}
void PCM::runPull()
{
AFframecount framesToRead = m_outChunk->frameCount;
/*
WARNING: Due to the optimization explained at the end of
arrangemodules(), the pcm file module cannot depend on
the presence of the intermediate working buffer which
_AFsetupmodules usually allocates for file modules in
their input or output chunk (for reading or writing,
respectively).
Fortunately, the pcm module has no need for such a buffer.
*/
/*
Limit the number of frames to be read to the number of
frames left in the track.
*/
if (m_track->totalfframes != -1 &&
m_track->nextfframe + framesToRead > m_track->totalfframes)
{
framesToRead = m_track->totalfframes - m_track->nextfframe;
}
ssize_t bytesRead = read(m_outChunk->buffer, m_bytesPerFrame * framesToRead);
AFframecount framesRead = bytesRead >= 0 ? bytesRead / m_bytesPerFrame : 0;
m_track->nextfframe += framesRead;
assert(!canSeek() || (tell() == m_track->fpos_next_frame));
/*
If we got EOF from read, then we return the actual amount read.
Complain only if there should have been more frames in the file.
*/
if (framesRead != framesToRead && m_track->totalfframes != -1)
reportReadError(framesRead, framesToRead);
m_outChunk->frameCount = framesRead;
}
void PCM::reset2()
{
m_track->fpos_next_frame = m_track->fpos_first_frame +
m_bytesPerFrame * m_track->nextfframe;
m_track->frames2ignore = 0;
}
FileModule *_AFpcminitcompress (Track *track, File *fh, bool canSeek,
bool headerless, AFframecount *chunkFrames)
{
return PCM::createCompress(track, fh, canSeek, headerless, chunkFrames);
}
FileModule *_AFpcminitdecompress (Track *track, File *fh, bool canSeek,
bool headerless, AFframecount *chunkFrames)
{
return PCM::createDecompress(track, fh, canSeek, headerless, chunkFrames);
}