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/***************************************************************************
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* Copyright (C) 2005 - 2007 by *
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* Christian Muehlhaeuser, Last.fm Ltd <chris@last.fm> *
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* Erik Jaelevik, Last.fm Ltd <erik@last.fm> *
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* This program is free software; you can redistribute it and/or modify *
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* it under the terms of the GNU General Public License as published by *
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* the Free Software Foundation; either version 2 of the License, or *
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* (at your option) any later version. *
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* This program is distributed in the hope that it will be useful, *
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* but WITHOUT ANY WARRANTY; without even the implied warranty of *
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the *
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* GNU General Public License for more details. *
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* You should have received a copy of the GNU General Public License *
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* along with this program; if not, write to the *
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* Free Software Foundation, Inc., *
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* 51 Franklin Steet, Fifth Floor, Boston, MA 02111-1307, USA. *
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***************************************************************************/
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#include "mp3transcode.h"
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#include "containerutils.h"
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#define MP3_MIN_BUFFER_SIZE 4096
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struct mpstr_tag mpeg;
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MP3Transcode::MP3Transcode() :
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m_decodedBufferCapacity( 32 * 1024 ),
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m_mpegInitialised( false )
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LOGL( 3, "Initialising MP3 Transcoding" );
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if ( !InitMP3( &mpeg ) )
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LOGL( 1, "Something went wrong when initiliasing mpglib. "
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" God knows what. Chris can read the \"best documentation "
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" there is\" to find out. :P" );
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// Maybe give these a good start value? They'll grow as needed anyway.
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m_decBufSize = 1; // On my machine this grows to about 120K
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m_encBufSize = 1; // And this grows to about 6K or so.
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m_encBufReadIndex = m_encBufWriteIndex = 0;
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m_decBufReadIndex = m_decBufWriteIndex = 0;
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m_decodedBuffer = (char*)malloc( m_decBufSize );
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m_encodedBuffer = (char*)malloc( m_encBufSize );
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MP3Transcode::~MP3Transcode()
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if ( m_decodedBuffer )
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free( m_decodedBuffer);
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m_decodedBuffer = NULL;
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if ( m_encodedBuffer )
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free( m_encodedBuffer);
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m_encodedBuffer = NULL;
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MP3Transcode::supportedMimeTypes() const
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return QStringList( "application/x-mp3" );
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MP3Transcode::supportedFileExtensions() const
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return QStringList( "mp3" );
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MP3Transcode::expandRingBuffer( char** buffer, int& bufSize, int& readIndex, int& writeIndex, int growSize )
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//qDebug() << "resizing buffer from" << bufSize
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// << "to" << bufSize + growSize;
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tmp = (char*)realloc( *buffer, sizeof(char) * ( bufSize + growSize ) );
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Q_ASSERT( !"Could not reallocate buffer!" );
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// Don't screw up the read order or ugly noises will ensue
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if ( readIndex > writeIndex )
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memmove( *buffer + readIndex + growSize,
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bufSize - readIndex );
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readIndex += growSize;
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MP3Transcode::processData( const QByteArray &buffer )
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int length = buffer.size();
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const char* src = buffer.data();
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int neededSize = getEncodedBufferFilled() + buffer.size();
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if ( neededSize >= m_encBufSize )
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expandRingBuffer( &m_encodedBuffer, m_encBufSize,
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m_encBufReadIndex, m_encBufWriteIndex,
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neededSize - m_encBufSize + 1 );
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cnt = qMin( length, m_encBufSize - m_encBufWriteIndex );
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memcpy( m_encodedBuffer + m_encBufWriteIndex, src, cnt );
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wr = (m_encBufWriteIndex + cnt) % m_encBufSize;
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m_encBufWriteIndex = wr;
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// wait till we got a minimal buffer of data, which we need for mpglib
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// being able to properly read the audio metadata (samplerate, channels...)
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if ( getEncodedBufferFilled() <= MP3_MIN_BUFFER_SIZE )
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char tempBuffer[16384];
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unsigned char inTemp[MP3_MIN_BUFFER_SIZE];
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length = MP3_MIN_BUFFER_SIZE;
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cnt = qMin(length, m_encBufSize - m_encBufReadIndex);
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memcpy( inTemp + outLen, m_encodedBuffer + m_encBufReadIndex, cnt);
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rd = (m_encBufReadIndex + cnt) % m_encBufSize;
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m_encBufReadIndex = rd;
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int result = decodeMP3(
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MP3_MIN_BUFFER_SIZE, // size of in-data
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tempBuffer, // out-data
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sizeof( tempBuffer ), // size of out-data
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&size ); // done size
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if ( result == MP3_ERR )
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LOG( 1, "decodeMP3 failed. result: " << result );
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if ( !m_mpegInitialised )
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long sampleRate = freqs[mpeg.fr.sampling_frequency];
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int channels = mpeg.fr.stereo > 0 ? mpeg.fr.stereo : 2;
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LOGL( 4, "mpegTranscode (Samplerate:" << sampleRate <<
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"Channels:" << channels << ")" );
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// For certain corrupt previews, we get a result of OK, but the sample
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// rate comes out all wrong. If we let these proceed, things will crash
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if ( sampleRate != 44100 || channels != 2 )
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LOGL( 1, "Stream is not 44.1k stereo, aborting" );
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m_mpegInitialised = true;
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emit streamInitialized( sampleRate, channels );
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while ( result == MP3_OK )
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const char* src = tempBuffer;
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int neededSize = getDecodedBufferFilled() + size;
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if ( neededSize >= m_decBufSize )
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expandRingBuffer( &m_decodedBuffer, m_decBufSize,
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m_decBufReadIndex, m_decBufWriteIndex,
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( neededSize - m_decBufSize + 1 ) );
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cnt = qMin(length, m_decBufSize - m_decBufWriteIndex);
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memcpy( m_decodedBuffer + m_decBufWriteIndex, src, cnt);
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wr = (m_decBufWriteIndex + cnt) % m_decBufSize;
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m_decBufWriteIndex = wr;
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result = decodeMP3( &mpeg, NULL, 0, tempBuffer, sizeof( tempBuffer ), &size );
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if ( result == MP3_ERR )
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LOGL( 1, "decodeMP3 failed. result: " << result );
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MP3Transcode::clearBuffers()
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m_decBufReadIndex = m_decBufWriteIndex = 0;
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m_encBufReadIndex = m_encBufWriteIndex = 0;
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m_mpegInitialised = false;
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if ( !InitMP3( &mpeg ) )
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LOGL( 1, "Something went wrong when initiliasing mpglib. "
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" God knows what. Chris can read the \"best documentation "
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" there is\" to find out. :P" );
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MP3Transcode::getEncodedBufferFilled()
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if ( m_encBufWriteIndex >= m_encBufReadIndex )
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return m_encBufWriteIndex - m_encBufReadIndex;
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return ( m_encBufSize - ( m_encBufReadIndex - m_encBufWriteIndex ) );
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MP3Transcode::getDecodedBufferFilled()
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if ( m_decBufWriteIndex >= m_decBufReadIndex )
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return m_decBufWriteIndex - m_decBufReadIndex;
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return ( m_decBufSize - ( m_decBufReadIndex - m_decBufWriteIndex ) );
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MP3Transcode::needsData()
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return getDecodedBufferFilled() < m_decodedBufferCapacity;
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MP3Transcode::hasData()
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return ( getDecodedBufferFilled() > 0 );
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MP3Transcode::data( QByteArray& fillMe, int numBytes )
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length = qMin( numBytes, ssize_t( getDecodedBufferFilled() ) );
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cnt = qMin (length, m_decBufSize - m_decBufReadIndex );
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fillMe.append( QByteArray::fromRawData( m_decodedBuffer + m_decBufReadIndex, cnt ) );
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rd = ( m_decBufReadIndex + cnt ) % m_decBufSize;
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m_decBufReadIndex = rd;
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Q_EXPORT_PLUGIN2( transcode, MP3Transcode )
added
removed
src/mp3transcode/mp3transcode.cpp
