File indexing completed on 2024-05-12 04:51:31

 /*
     SPDX-FileCopyrightText: 1998-2008 Sebastian Trueg <trueg@k3b.org>
     SPDX-License-Identifier: GPL-2.0-or-later
 */
 #include "k3bffmpegwrapper.h"
 #include "k3bplugin_i18n.h"
 
 #include <config-k3b.h>
 
 extern "C" {
 /*
  Recent versions of FFmpeg uses C99 constant macros which are not present in C++ standard.
  The macro __STDC_CONSTANT_MACROS allow C++ to use these macros. Although it's not defined by C++ standard
  it's supported by many implementations.
  See bug 236036 and discussion: https://lists.ffmpeg.org/pipermail/ffmpeg-devel/2010-May/095488.html
  */
 #define __STDC_CONSTANT_MACROS
 #ifdef NEWFFMPEGAVCODECPATH
 #include <libavcodec/avcodec.h>
 #include <libavformat/avformat.h>
 #else
 #include <ffmpeg/avcodec.h>
 #include <ffmpeg/avformat.h>
 #endif
 }
 
 #include <cstring>
 #include <cmath>
 
 
 #ifndef HAVE_FFMPEG_CODEC_MP3
 #  define CODEC_ID_MP3 CODEC_ID_MP3LAME
 #endif
 
 K3bFFMpegWrapper* K3bFFMpegWrapper::s_instance = nullptr;
 
 
 class K3bFFMpegFile::Private
 {
 public:
     ::AVFormatContext* formatContext;
     const ::AVCodec* codec;
     ::AVCodecContext* codecContext;
     ::AVStream *audio_stream;
 
     K3b::Msf length;
 
     // for decoding. ffmpeg requires 16-byte alignment.
     ::AVFrame* frame = nullptr;
     ::AVPacket* packet = nullptr;
     char* outputBufferPos = nullptr;
     int outputBufferSize = 0;
     ::AVSampleFormat sampleFormat;
     bool isSpacious;
 };
 
 
 K3bFFMpegFile::K3bFFMpegFile( const QString& filename )
     : m_filename(filename)
 {
     d = new Private;
     d->formatContext = nullptr;
     d->codec = nullptr;
     d->audio_stream = nullptr;
     d->frame = av_frame_alloc();
 }
 
 
 K3bFFMpegFile::~K3bFFMpegFile()
 {
     close();
     av_frame_free(&d->frame);
     delete d;
 }
 
 
 bool K3bFFMpegFile::open()
 {
     close();
 
     // open the file
     int err = ::avformat_open_input( &d->formatContext, m_filename.toLocal8Bit(), 0, 0 );
     if( err < 0 ) {
         qDebug() << "(K3bFFMpegFile) unable to open " << m_filename << " with error " << err;
         return false;
     }
 
     // analyze the streams
     ::avformat_find_stream_info( d->formatContext, 0 );
 
     // we only handle files containing one audio stream
     if( d->formatContext->nb_streams == 1 ) {
         d->audio_stream = d->formatContext->streams[0];
     } else  {
         for (uint i = 0; i < d->formatContext->nb_streams; ++i) {
             if (d->formatContext->streams[i]->codecpar->codec_type == AVMEDIA_TYPE_AUDIO) {
                 if (!d->audio_stream) {
                     d->audio_stream = d->formatContext->streams[i];
                 } else {
                     d->audio_stream = nullptr;
                     qDebug() << "(K3bFFMpegFile) more than one audio stream in " << m_filename;
                     return false;
                 }
             }
         }
     }
 
     // get the codec
     d->codec = ::avcodec_find_decoder(
         d->audio_stream->codecpar->codec_id
     );
     if( !d->codec ) {
         qDebug() << "(K3bFFMpegFile) no codec found for " << m_filename;
         return false;
     }
 
     // get the codec context
     d->codecContext = ::avcodec_alloc_context3(d->codec);
     ::avcodec_parameters_to_context(d->codecContext, d->audio_stream->codecpar);
     if(d->codecContext->codec_type != AVMEDIA_TYPE_AUDIO) {
         qDebug() << "(K3bFFMpegFile) not a simple audio stream: " << m_filename;
         return false;
     }
 
     // open the codec on our context
     qDebug() << "(K3bFFMpegFile) found codec for " << m_filename;
     if( ::avcodec_open2( d->codecContext, d->codec, 0 ) < 0 ) {
         qDebug() << "(K3bFFMpegDecoderFactory) could not open codec.";
         return false;
     }
 
     // determine the length of the stream
     d->length = K3b::Msf::fromSeconds(
         static_cast<double>(d->formatContext->duration) / static_cast<double>(AV_TIME_BASE));
 
     if( d->length == 0 ) {
         qDebug() << "(K3bFFMpegDecoderFactory) invalid length.";
         return false;
     }
 
     d->sampleFormat = d->codecContext->sample_fmt;
     d->isSpacious = ::av_sample_fmt_is_planar(d->sampleFormat) &&
         d->codecContext->channels > 1;
     d->packet = ::av_packet_alloc();
 
     // dump some debugging info
     ::av_dump_format( d->formatContext, 0, m_filename.toLocal8Bit(), 0 );
 
     return true;
 }
 
 
 void K3bFFMpegFile::close()
 {
     d->outputBufferSize = 0;
     ::av_packet_free(&d->packet);
 
     if( d->codec ) {
         ::avcodec_close(d->codecContext);
         d->codec = nullptr;
         ::avcodec_free_context(&d->codecContext);
         d->codecContext = nullptr;
     }
 
     if( d->formatContext ) {
         ::avformat_close_input( &d->formatContext );
         d->formatContext = nullptr;
     }
 
     d->audio_stream = nullptr;
 }
 
 
 K3b::Msf K3bFFMpegFile::length() const
 {
     return d->length;
 }
 
 
 int K3bFFMpegFile::sampleRate() const
 {
     return d->codecContext->sample_rate;
 }
 
 
 int K3bFFMpegFile::channels() const
 {
     return d->codecContext->channels;
 }
 
 
 int K3bFFMpegFile::type() const
 {
     return d->codecContext->codec_id;
 }
 
 
 QString K3bFFMpegFile::typeComment() const
 {
     switch( type() ) {
     case AV_CODEC_ID_WAVPACK:
         return i18n("WavPack");
     case AV_CODEC_ID_APE:
         return i18n("Monkey's Audio (APE)");
     case AV_CODEC_ID_AAC:
         return i18n("Advanced Audio Coding (AAC)");
     default:
         return QString::fromLocal8Bit( d->codec->name );
     }
 }
 
 
 QString K3bFFMpegFile::title() const
 {
     // FIXME: is this UTF8 or something??
     AVDictionaryEntry *ade = av_dict_get( d->formatContext->metadata, "TITLE", nullptr, 0 );
     return ade && ade->value && ade->value[0] != '\0' ? QString::fromLocal8Bit( ade->value ) : QString();
 }
 
 
 QString K3bFFMpegFile::author() const
 {
     // FIXME: is this UTF8 or something??
     AVDictionaryEntry *ade = av_dict_get( d->formatContext->metadata, "ARTIST", nullptr, 0 );
     return ade && ade->value && ade->value[0] != '\0' ? QString::fromLocal8Bit( ade->value ) : QString();
 }
 
 
 QString K3bFFMpegFile::comment() const
 {
     // FIXME: is this UTF8 or something??
     AVDictionaryEntry *ade = av_dict_get( d->formatContext->metadata, "COMMENT", nullptr, 0 );
     return ade && ade->value && ade->value[0] != '\0' ? QString::fromLocal8Bit( ade->value ) : QString();
 }
 
 
 int K3bFFMpegFile::read(char* buf, int bufLen)
 {
     if (!buf ) {
         return -1;
     }
 
     if(d->outputBufferSize <= 0)
         d->outputBufferPos = new char[bufLen];
 
     int ret = fillOutputBuffer();
     if (ret <= 0) {
         return ret;
     }
 
     int len = qMin(bufLen, ret);
     ::memcpy(buf, d->outputBufferPos, len);
 
     // TODO: only swap if needed
     for(int i = 0; i < len-1; i += 2)
         std::swap(buf[i], buf[i+1]); // BE -> LE
 
     d->outputBufferSize -= len;
     if(d->outputBufferSize > 0)
         d->outputBufferPos += len;
     else
         delete[] d->outputBufferPos;
 
     return len;
 }
 
 
 int K3bFFMpegFile::readPacket()
 {
     if( ::av_read_frame( d->formatContext, d->packet ) < 0 ) {
         return 0;
     }
 
     return d->packet->size;
 }
 
 
 int K3bFFMpegFile::fillOutputBuffer()
 {
     static int ret = -1;
 
     // decode if the output buffer is empty
     while( d->outputBufferSize <= 0 ) {
         d->outputBufferSize = 0;
 
         if ( ret >= 0 ) {
             ret = ::avcodec_receive_frame( d->codecContext, d->frame );
 
             if ( ret == AVERROR(EAGAIN) || ret == AVERROR_EOF ) {
                 ret = -1;
                 continue;
             }
             else if ( ret < 0 ) {
                 qDebug() << "(K3bFFMpegFile) decoding failed for " << m_filename;
                 return -1;
             }
 
             int nb_s = d->frame->nb_samples;
             const int nb_ch = 2;  // copy only 2 channels even if there're more
             d->outputBufferSize = nb_s * nb_ch * 2;  // 2 means 2 bytes (16bit)
 
             if( d->isSpacious ) {
                 if( d->sampleFormat == AV_SAMPLE_FMT_FLTP ) {
                     constexpr int width = sizeof(float);  // sample width of float audio
                     for( int sample = 0; sample < nb_s; sample++ ) {
                         for( int ch = 0; ch < nb_ch; ch++ ) {
                             float val = *(reinterpret_cast<float*>(
                                 d->frame->extended_data[ch] + sample * width));
                             val = ::abs(val) > 1 ? ::copysign(1.0, val) : val;
                             int16_t result = static_cast<int16_t>(
                                 val * 32767.0 + 32768.5) - 32768;
                             ::memcpy(
                                 d->outputBufferPos + (sample * nb_ch + ch) * 2,
                                 &result,
                                 2  // 2 is sample width of 16 bit audio
                             );
                         }
                     }
                 } else if ( d->sampleFormat == AV_SAMPLE_FMT_S16P ) {
                     for(int sample = 0; sample < nb_s; sample++) {
                         for(int ch = 0; ch < nb_ch; ch++) {
                             ::memcpy(
                                 d->outputBufferPos + (sample * nb_ch + ch) * 2,
                                 d->frame->extended_data[ch] + sample * 2,
                                 2 // 16 bit here as well
                             );
                         }
                     }
                 } else {
                     qDebug() << "(K3bFFMpegFile) some planar formats are not supported yet";
                     return -1;
                 }
             } else {
                 qDebug() << "(K3bFFMpegFile) non planar and monophonic audio support is not implemented";
                 return -1;
             }
         } else {
             // make sure we have data to decode
             if( readPacket() == 0 ) {
                 return 0;
             }
             ret = ::avcodec_send_packet( d->codecContext, d->packet );
             if( ret < 0 ) {
                 qDebug() << "(K3bFFMpegFile) error submitting packet to the decoder";
                 return -1;
             }
             continue;
         }
     }
 
     return d->outputBufferSize;
 }
 
 
 bool K3bFFMpegFile::seek( const K3b::Msf& msf )
 {
     d->outputBufferSize = 0;
 
     double seconds = (double)msf.totalFrames()/75.0;
     quint64 timestamp = (quint64)(seconds * (double)AV_TIME_BASE);
 
     // FIXME: do we really need the start_time and why?
     return ( ::av_seek_frame( d->formatContext, -1, timestamp + d->formatContext->start_time, 0 ) >= 0 );
 }
 
 
 
 
 
 
 K3bFFMpegWrapper::K3bFFMpegWrapper()
 {
     //::av_register_all();
 }
 
 
 K3bFFMpegWrapper::~K3bFFMpegWrapper()
 {
     s_instance = nullptr;
 }
 
 
 K3bFFMpegWrapper* K3bFFMpegWrapper::instance()
 {
     if( !s_instance ) {
         s_instance = new K3bFFMpegWrapper();
     }
 
     return s_instance;
 }
 
 
 K3bFFMpegFile* K3bFFMpegWrapper::open( const QString& filename ) const
 {
     K3bFFMpegFile* file = new K3bFFMpegFile( filename );
     if( file->open() ) {
 #ifndef K3B_FFMPEG_ALL_CODECS
         //
         // only allow tested formats. ffmpeg seems not to be too reliable with every format.
         // mp3 being one of them sadly. Most importantly: allow the libsndfile decoder to do
         // its thing.
         //
         if( file->type() == AV_CODEC_ID_AAC ||
             file->type() == AV_CODEC_ID_APE ||
             file->type() == AV_CODEC_ID_WAVPACK )
 #endif
             return file;
     }
 
     delete file;
     return nullptr;
 }