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k3b/plugins/decoder/mp3/k3bmaddecoder.cpp

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/*
*
* $Id$
* Copyright (C) 2003 Sebastian Trueg <trueg@k3b.org>
*
* This file is part of the K3b project.
* Copyright (C) 1998-2007 Sebastian Trueg <trueg@k3b.org>
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
* See the file "COPYING" for the exact licensing terms.
*/
//
// Some notes on mp3:
// A mp3 Frame is always samples/samplerate seconds in length
//
//
//
// What we need are raw 16 bit stereo samples at 44100 Hz which results in 588 samples
// per block (2352 bytes: 32*588 bit). 1 second are 75 blocks.
//
#include <config.h>
#include "k3bmaddecoder.h"
#include "k3bmad.h"
#include <k3bpluginfactory.h>
#include <kurl.h>
#include <kdebug.h>
#include <klocale.h>
#include <tqstring.h>
#include <tqfile.h>
#include <tqvaluevector.h>
#include <stdlib.h>
#include <cmath>
#include <cstdlib>
#include <config.h>
#ifdef HAVE_TAGLIB
#include <taglib/tag.h>
#include <taglib/mpegfile.h>
#endif
K_EXPORT_COMPONENT_FACTORY( libk3bmaddecoder, K3bPluginFactory<K3bMadDecoderFactory>( "k3bmaddecoder" ) )
int K3bMadDecoder::MaxAllowedRecoverableErrors = 10;
class K3bMadDecoder::MadDecoderPrivate
{
public:
MadDecoderPrivate()
: outputBuffer(0),
outputPointer(0),
outputBufferEnd(0) {
mad_header_init( &firstHeader );
}
K3bMad* handle;
TQValueVector<unsigned long long> seekPositions;
bool bOutputFinished;
char* outputBuffer;
char* outputPointer;
char* outputBufferEnd;
// the first frame header for technical info
mad_header firstHeader;
bool vbr;
};
K3bMadDecoder::K3bMadDecoder( TQObject* parent, const char* name )
: K3bAudioDecoder( parent, name )
{
d = new MadDecoderPrivate();
d->handle = new K3bMad();
}
K3bMadDecoder::~K3bMadDecoder()
{
cleanup();
delete d->handle;
delete d;
}
TQString K3bMadDecoder::metaInfo( MetaDataField f )
{
#ifdef HAVE_TAGLIB
TagLib::MPEG::File file( TQFile::encodeName( filename() ).data() );
if ( file.tag() ) {
switch( f ) {
case META_TITLE:
return TStringToQString( file.tag()->title() );
case META_ARTIST:
return TStringToQString( file.tag()->artist() );
case META_COMMENT:
return TStringToQString( file.tag()->comment() );
default:
return TQString();
}
}
else {
return TQString();
}
#else
return K3bAudioDecoder::metaInfo( f );
#endif
}
bool K3bMadDecoder::analyseFileInternal( K3b::Msf& frames, int& samplerate, int& ch )
{
initDecoderInternal();
frames = countFrames();
if( frames > 0 ) {
// we convert mono to stereo all by ourselves. :)
ch = 2;
samplerate = d->firstHeader.samplerate;
return true;
}
else
return false;
}
bool K3bMadDecoder::initDecoderInternal()
{
cleanup();
d->bOutputFinished = false;
if( !d->handle->open( filename() ) )
return false;
if( !d->handle->skipTag() )
return false;
if( !d->handle->seekFirstHeader() )
return false;
return true;
}
unsigned long K3bMadDecoder::countFrames()
{
kdDebug() << "(K3bMadDecoder::countFrames)" << endl;
unsigned long frames = 0;
bool error = false;
d->vbr = false;
bool bFirstHeaderSaved = false;
d->seekPositions.clear();
while( !error && d->handle->findNextHeader() ) {
if( !bFirstHeaderSaved ) {
bFirstHeaderSaved = true;
d->firstHeader = d->handle->madFrame->header;
}
else if( d->handle->madFrame->header.bitrate != d->firstHeader.bitrate )
d->vbr = true;
//
// position in stream: postion in file minus the not yet used buffer
//
unsigned long long seekPos = d->handle->inputPos() -
(d->handle->madStream->bufend - d->handle->madStream->this_frame + 1);
// save the number of bytes to be read to decode i-1 frames at position i
// in other words: when seeking to seekPos the next decoded frame will be i
d->seekPositions.append( seekPos );
}
if( !d->handle->inputError() && !error ) {
// we need the length of the track to be multiple of frames (1/75 second)
float seconds = (float)d->handle->madTimer->seconds +
(float)d->handle->madTimer->fraction/(float)MAD_TIMER_RESOLUTION;
frames = (unsigned long)ceil(seconds * 75.0);
kdDebug() << "(K3bMadDecoder) length of track " << seconds << endl;
}
cleanup();
kdDebug() << "(K3bMadDecoder::countFrames) end" << endl;
return frames;
}
int K3bMadDecoder::decodeInternal( char* _data, int maxLen )
{
d->outputBuffer = _data;
d->outputBufferEnd = d->outputBuffer + maxLen;
d->outputPointer = d->outputBuffer;
bool bOutputBufferFull = false;
while( !bOutputBufferFull && d->handle->fillStreamBuffer() ) {
// a mad_synth contains of the data of one mad_frame
// one mad_frame represents a mp3-frame which is always 1152 samples
// for us that means we need 4*1152 bytes of output buffer for every frame
// since one sample has 16 bit
if( d->outputBufferEnd - d->outputPointer < 4*1152 ) {
bOutputBufferFull = true;
}
else if( d->handle->decodeNextFrame() ) {
//
// Once decoded the frame is synthesized to PCM samples. No errors
// are reported by mad_synth_frame();
//
mad_synth_frame( d->handle->madSynth, d->handle->madFrame );
// this fills the output buffer
if( !createPcmSamples( d->handle->madSynth ) ) {
return -1;
}
}
else if( d->handle->inputError() ) {
return -1;
}
}
// flush the output buffer
size_t buffersize = d->outputPointer - d->outputBuffer;
return buffersize;
}
unsigned short K3bMadDecoder::linearRound( mad_fixed_t fixed )
{
// round
fixed += (1L << ( MAD_F_FRACBITS - 16 ));
// clip
if( fixed >= MAD_F_ONE - 1 )
fixed = MAD_F_ONE - 1;
else if( fixed < -MAD_F_ONE )
fixed = -MAD_F_ONE;
// quatisize
return fixed >> (MAD_F_FRACBITS + 1 - 16 );
}
bool K3bMadDecoder::createPcmSamples( mad_synth* synth )
{
unsigned short nsamples = synth->pcm.length;
// this should not happen since we only decode if the
// output buffer has enough free space
if( d->outputBufferEnd - d->outputPointer < nsamples*4 ) {
kdDebug() << "(K3bMadDecoder) buffer overflow!" << endl;
return false;
}
// now create the output
for( int i = 0; i < nsamples; i++ ) {
/* Left channel */
unsigned short sample = linearRound( synth->pcm.samples[0][i] );
*(d->outputPointer++) = (sample >> 8) & 0xff;
*(d->outputPointer++) = sample & 0xff;
/* Right channel. If the decoded stream is monophonic then
* the right output channel is the same as the left one.
*/
if( synth->pcm.channels == 2 )
sample = linearRound( synth->pcm.samples[1][i] );
*(d->outputPointer++) = (sample >> 8) & 0xff;
*(d->outputPointer++) = sample & 0xff;
} // pcm conversion
return true;
}
void K3bMadDecoder::cleanup()
{
d->handle->cleanup();
}
bool K3bMadDecoder::seekInternal( const K3b::Msf& pos )
{
//
// we need to reset the complete mad stuff
//
if( !initDecoderInternal() )
return false;
//
// search a position
// This is all hacking, I don't really know what I am doing here... ;)
//
double mp3FrameSecs = static_cast<double>(d->firstHeader.duration.seconds)
+ static_cast<double>(d->firstHeader.duration.fraction) / static_cast<double>(MAD_TIMER_RESOLUTION);
double posSecs = static_cast<double>(pos.totalFrames()) / 75.0;
// seekPosition to seek after frame i
unsigned int frame = static_cast<unsigned int>( posSecs / mp3FrameSecs );
// Rob said: 29 frames is the theoretically max frame reservoir limit (whatever that means...)
// it seems that mad needs at most 29 frames to get ready
unsigned int frameReservoirProtect = ( frame > 29 ? 29 : frame );
frame -= frameReservoirProtect;
// seek in the input file behind the already decoded data
d->handle->inputSeek( d->seekPositions[frame] );
kdDebug() << "(K3bMadDecoder) Seeking to frame " << frame << " with "
<< frameReservoirProtect << " reservoir frames." << endl;
// decode some frames ignoring MAD_ERROR_BADDATAPTR errors
unsigned int i = 1;
while( i <= frameReservoirProtect ) {
d->handle->fillStreamBuffer();
if( mad_frame_decode( d->handle->madFrame, d->handle->madStream ) ) {
if( MAD_RECOVERABLE( d->handle->madStream->error ) ) {
if( d->handle->madStream->error == MAD_ERROR_BUFLEN )
continue;
else if( d->handle->madStream->error != MAD_ERROR_BADDATAPTR ) {
kdDebug() << "(K3bMadDecoder) Seeking: recoverable mad error ("
<< mad_stream_errorstr(d->handle->madStream) << ")" << endl;
continue;
}
else {
kdDebug() << "(K3bMadDecoder) Seeking: ignoring ("
<< mad_stream_errorstr(d->handle->madStream) << ")" << endl;
}
}
else
return false;
}
if( i == frameReservoirProtect ) // synth only the last frame (Rob said so ;)
mad_synth_frame( d->handle->madSynth, d->handle->madFrame );
++i;
}
return true;
}
TQString K3bMadDecoder::fileType() const
{
switch( d->firstHeader.layer ) {
case MAD_LAYER_I:
return "MPEG1 Layer I";
case MAD_LAYER_II:
return "MPEG1 Layer II";
case MAD_LAYER_III:
return "MPEG1 Layer III";
default:
return "Mp3";
}
}
TQStringList K3bMadDecoder::supportedTechnicalInfos() const
{
return TQStringList::split( ";",
i18n("Channels") + ";" +
i18n("Sampling Rate") + ";" +
i18n("Bitrate") + ";" +
i18n("Layer") + ";" +
i18n("Emphasis") + ";" +
i18n("Copyright") + ";" +
i18n("Original") + ";" +
i18n("CRC") );
}
TQString K3bMadDecoder::technicalInfo( const TQString& name ) const
{
if( name == i18n("Channels") ) {
switch( d->firstHeader.mode ) {
case MAD_MODE_SINGLE_CHANNEL:
return i18n("Mono");
case MAD_MODE_DUAL_CHANNEL:
return i18n("Dual");
case MAD_MODE_JOINT_STEREO:
return i18n("Joint Stereo");
case MAD_MODE_STEREO:
return i18n("Stereo");
default:
return "?";
}
}
else if( name == i18n("Sampling Rate") )
return i18n("%1 Hz").arg(d->firstHeader.samplerate);
else if( name == i18n("Bitrate") ) {
if( d->vbr )
return i18n("VBR");
else
return i18n("%1 bps").arg(d->firstHeader.bitrate);
}
else if( name == i18n("Layer") ){
switch( d->firstHeader.layer ) {
case MAD_LAYER_I:
return "I";
case MAD_LAYER_II:
return "II";
case MAD_LAYER_III:
return "III";
default:
return "?";
}
}
else if( name == i18n("Emphasis") ) {
switch( d->firstHeader.emphasis ) {
case MAD_EMPHASIS_NONE:
return i18n("None");
case MAD_EMPHASIS_50_15_US:
return i18n("50/15 ms");
case MAD_EMPHASIS_CCITT_J_17:
return i18n("CCITT J.17");
default:
return i18n("Unknown");
}
}
else if( name == i18n("Copyright") )
return ( d->firstHeader.flags & MAD_FLAG_COPYRIGHT ? i18n("Yes") : i18n("No") );
else if( name == i18n("Original") )
return ( d->firstHeader.flags & MAD_FLAG_ORIGINAL ? i18n("Yes") : i18n("No") );
else if( name == i18n("CRC") )
return ( d->firstHeader.flags & MAD_FLAG_PROTECTION ? i18n("Yes") : i18n("No") );
else
return TQString();
}
K3bMadDecoderFactory::K3bMadDecoderFactory( TQObject* parent, const char* name )
: K3bAudioDecoderFactory( parent, name )
{
}
K3bMadDecoderFactory::~K3bMadDecoderFactory()
{
}
K3bAudioDecoder* K3bMadDecoderFactory::createDecoder( TQObject* parent,
const char* name ) const
{
return new K3bMadDecoder( parent, name );
}
bool K3bMadDecoderFactory::canDecode( const KURL& url )
{
//
// HACK:
//
// I am simply no good at this and this detection code is no good as well
// It always takes waves for mp3 files so we introduce this hack to
// filter out wave files. :(
//
TQFile f( url.path() );
if( !f.open( IO_ReadOnly ) )
return false;
char buffer[12];
if( f.readBlock( buffer, 12 ) != 12 )
return false;
if( !tqstrncmp( buffer, "RIFF", 4 ) &&
!tqstrncmp( buffer + 8, "WAVE", 4 ) )
return false;
f.close();
K3bMad handle;
if( !handle.open( url.path() ) )
return false;
handle.skipTag();
if( !handle.seekFirstHeader() )
return false;
if( handle.findNextHeader() ) {
int c = MAD_NCHANNELS( &handle.madFrame->header );
int layer = handle.madFrame->header.layer;
unsigned int s = handle.madFrame->header.samplerate;
//
// find 4 more mp3 headers (random value since 2 was not enough)
// This way we get most of the mp3 files while sorting out
// for example wave files.
//
int cnt = 1;
while( handle.findNextHeader() ) {
// compare the found headers
if( MAD_NCHANNELS( &handle.madFrame->header ) == c &&
handle.madFrame->header.layer == layer &&
handle.madFrame->header.samplerate == s ) {
// only support layer III for now since otherwise some wave files
// are taken for layer I
if( ++cnt >= 5 ) {
kdDebug() << "(K3bMadDecoder) valid mpeg 1 layer " << layer
<< " file with " << c << " channels and a samplerate of "
<< s << endl;
return ( layer == MAD_LAYER_III );
}
}
else
break;
}
}
kdDebug() << "(K3bMadDecoder) unsupported format: " << url.path() << endl;
return false;
}
#include "k3bmaddecoder.moc"