MP2ExportProcessor Class Reference

Inheritance diagram for MP2ExportProcessor:

Collaboration diagram for MP2ExportProcessor:

Public Member Functions
	~MP2ExportProcessor () override
bool	Initialize (AudacityProject &project, const Parameters &parameters, const wxFileNameWrapper &filename, double t0, double t1, bool selectedOnly, double sampleRate, unsigned channels, MixerOptions::Downmix *mixerSpec, const Tags *tags) override
	Called before start processing. More...
ExportResult	Process (ExportProcessorDelegate &delegate) override
Public Member Functions inherited from ExportProcessor
	ExportProcessor (const ExportProcessor &)=delete
ExportProcessor &	operator= (const ExportProcessor &)=delete
	ExportProcessor ()=default
virtual	~ExportProcessor ()
virtual bool	Initialize (AudacityProject &project, const Parameters &parameters, const wxFileNameWrapper &filename, double t0, double t1, bool selectedOnly, double rate, unsigned channels, MixerOptions::Downmix *mixerSpec=nullptr, const Tags *tags=nullptr)=0
	Called before start processing. More...
virtual ExportResult	Process (ExportProcessorDelegate &delegate)=0

Static Private Member Functions
static int	AddTags (ArrayOf< char > &buffer, bool *endOfFile, const Tags *tags)

Private Attributes
struct {
TranslatableString   status
double   t0
double   t1
wxFileNameWrapper   fName
std::unique_ptr< Mixer >   mixer
ArrayOf< char >   id3buffer
int   id3len
twolame_options *   encodeOptions {}
std::unique_ptr< FileIO >   outFile
}	context

Static Private Attributes
static constexpr size_t	pcmBufferSize = 9216 / 2
static constexpr size_t	mp2BufferSize = 16384u

Additional Inherited Members
Public Types inherited from ExportProcessor
using	Parameters = std::vector< std::tuple< ExportOptionID, ExportValue > >

Detailed Description

Definition at line 243 of file ExportMP2.cpp.

Constructor & Destructor Documentation

~MP2ExportProcessor()

MP2ExportProcessor::~MP2ExportProcessor ( )

override

Definition at line 326 of file ExportMP2.cpp.

{
   if(context.encodeOptions)
      twolame_close(&context.encodeOptions);
}

References context.

Member Function Documentation

AddTags()

int MP2ExportProcessor::AddTags ( ArrayOf< char > &  buffer, bool *  endOfFile, const Tags *  tags  )

staticprivate

Definition at line 483 of file ExportMP2.cpp.

{
#ifdef USE_LIBID3TAG
   id3_tag_holder tp { id3_tag_new() };
 
   for (const auto &pair : tags->GetRange()) {
      const auto &n = pair.first;
      const auto &v = pair.second;
      const char *name = "TXXX";
 
      if (n.CmpNoCase(TAG_TITLE) == 0) {
         name = ID3_FRAME_TITLE;
      }
      else if (n.CmpNoCase(TAG_ARTIST) == 0) {
         name = ID3_FRAME_ARTIST;
      }
      else if (n.CmpNoCase(TAG_ALBUM) == 0) {
         name = ID3_FRAME_ALBUM;
      }
      else if (n.CmpNoCase(TAG_YEAR) == 0) {
         // LLL:  Some apps do not like the newer frame ID (ID3_FRAME_YEAR),
         //       so we add old one as well.
         AddFrame(tp.get(), n, v, "TYER");
         name = ID3_FRAME_YEAR;
      }
      else if (n.CmpNoCase(TAG_GENRE) == 0) {
         name = ID3_FRAME_GENRE;
      }
      else if (n.CmpNoCase(TAG_COMMENTS) == 0) {
         name = ID3_FRAME_COMMENT;
      }
      else if (n.CmpNoCase(TAG_TRACK) == 0) {
         name = ID3_FRAME_TRACK;
      }
 
      AddFrame(tp.get(), n, v, name);
   }
 
   tp->options &= (~ID3_TAG_OPTION_COMPRESSION); // No compression
 
   // If this version of libid3tag supports it, use v2.3 ID3
   // tags instead of the newer, but less well supported, v2.4
   // that libid3tag uses by default.
   #ifdef ID3_TAG_HAS_TAG_OPTION_ID3V2_3
   tp->options |= ID3_TAG_OPTION_ID3V2_3;
   #endif
 
   *endOfFile = false;
 
   id3_length_t len;
 
   len = id3_tag_render(tp.get(), 0);
   buffer.reinit(len);
   len = id3_tag_render(tp.get(), (id3_byte_t *)buffer.get());
 
 
   return len;
#else //ifdef USE_LIBID3TAG
   return 0;
#endif
}

References Tags::GetRange(), name, ArrayOf< X >::reinit(), TAG_ALBUM, TAG_ARTIST, TAG_COMMENTS, TAG_GENRE, TAG_TITLE, TAG_TRACK, and TAG_YEAR.

Referenced by Initialize().

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Initialize()

bool MP2ExportProcessor::Initialize ( AudacityProject &  project, const Parameters &  parameters, const wxFileNameWrapper &  filename, double  t0, double  t1, bool  selectedOnly, double  rate, unsigned  channels, MixerOptions::Downmix *  mixerSpec, const Tags *  tags  )

overridevirtual

Called before start processing.

Parameters

project	Processor may access project data, take care to exclude any data race
parameters	A format-dependent set of parameters used in exporting
selectedOnly	Set to true if all tracks should be mixed, to false if only the selected tracks should be mixed and exported.
tags	A Tags object that will over-ride the one in *project and be used to tag the file that is exported. @retern Implementations may simply return false without any error reporting. This is to temporarily preserve old behavior, which is to be removed in the nearest future.

Implements ExportProcessor.

Definition at line 333 of file ExportMP2.cpp.

{
   context.t0 = t0;
   context.t1 = t1;
   context.fName = fName;
 
   bool stereo = (channels == 2);
   const auto version = static_cast<TWOLAME_MPEG_version>(
      ExportPluginHelpers::GetParameterValue(parameters,
         MP2OptionIDVersion, 1));
 
   const auto bitrate = version == TWOLAME_MPEG1 
      ? ExportPluginHelpers::GetParameterValue(
         parameters,
         MP2OptionIDBitRateMPEG1, 192)
      : ExportPluginHelpers::GetParameterValue(
         parameters,
         MP2OptionIDBitRateMPEG2, 96);
   const auto &tracks = TrackList::Get( project );
 
   wxLogNull logNo;             /* temporarily disable wxWidgets error messages */
 
   twolame_options *&encodeOptions = context.encodeOptions;
   encodeOptions = twolame_init();
 
   twolame_set_version(encodeOptions, version);
   twolame_set_in_samplerate(encodeOptions, static_cast<int>(sampleRate));
   twolame_set_out_samplerate(encodeOptions, static_cast<int>(sampleRate));
   twolame_set_bitrate(encodeOptions, bitrate);
   twolame_set_num_channels(encodeOptions, stereo ? 2 : 1);
 
   if (twolame_init_params(encodeOptions) != 0)
   {
      throw ExportException(_("Cannot export MP2 with this sample rate and bit rate"));
   }
 
   // Put ID3 tags at beginning of file
   if (metadata == NULL)
      metadata = &Tags::Get( project );
 
   context.outFile = std::make_unique<FileIO>(fName, FileIO::Output);
   if (!context.outFile->IsOpened()) {
      throw ExportException(_("Unable to open target file for writing"));
   }
   
   bool endOfFile;
   context.id3len = AddTags(context.id3buffer, &endOfFile, metadata);
   if (context.id3len && !endOfFile) {
      if ( context.outFile->Write(context.id3buffer.get(), context.id3len).GetLastError() ) {
         // TODO: more precise message
         throw ExportErrorException("MP2:292");
      }
      context.id3len = 0;
      context.id3buffer.reset();
   }
 
   context.status = selectionOnly
      ? XO("Exporting selected audio at %ld kbps")
           .Format( bitrate )
      : XO("Exporting the audio at %ld kbps")
           .Format( bitrate );
 
   context.mixer = ExportPluginHelpers::CreateMixer(tracks, selectionOnly,
         t0, t1,
         stereo ? 2 : 1, pcmBufferSize, true,
         sampleRate, int16Sample, mixerSpec);
 
   return true;
}

References _, AddTags(), context, ExportPluginHelpers::CreateMixer(), encodeOptions, fName, Tags::Get(), TrackList::Get(), ExportPluginHelpers::GetParameterValue(), int16Sample, anonymous_namespace{ExportMP2.cpp}::MP2OptionIDBitRateMPEG1, anonymous_namespace{ExportMP2.cpp}::MP2OptionIDBitRateMPEG2, anonymous_namespace{ExportMP2.cpp}::MP2OptionIDVersion, FileIO::Output, pcmBufferSize, project, anonymous_namespace{ClipSegmentTest.cpp}::sampleRate, t0, t1, tracks, and XO().

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Process()

ExportResult MP2ExportProcessor::Process ( ExportProcessorDelegate &  delegate )

overridevirtual

Implements ExportProcessor.

Definition at line 409 of file ExportMP2.cpp.

{
   delegate.SetStatusString(context.status);
   // We allocate a buffer which is twice as big as the
   // input buffer, which should always be enough.
   // We have to multiply by 4 because one sample is 2 bytes wide!
   ArrayOf<unsigned char> mp2Buffer{ mp2BufferSize };
 
   auto exportResult = ExportResult::Success;
 
   {
      while (exportResult == ExportResult::Success) {
         auto pcmNumSamples = context.mixer->Process();
         if (pcmNumSamples == 0)
            break;
 
         short *pcmBuffer = (short *)context.mixer->GetBuffer();
 
         int mp2BufferNumBytes = twolame_encode_buffer_interleaved(
            context.encodeOptions,
            pcmBuffer,
            pcmNumSamples,
            mp2Buffer.get(),
            mp2BufferSize);
 
         if (mp2BufferNumBytes < 0) {
            // TODO: more precise message
            throw ExportErrorException("MP2:339");
         }
 
         if ( context.outFile->Write(mp2Buffer.get(), mp2BufferNumBytes).GetLastError() ) {
            // TODO: more precise message
            throw ExportDiskFullError(context.fName);
         }
         exportResult = ExportPluginHelpers::UpdateProgress(
            delegate, *context.mixer, context.t0, context.t1);
      }
   }
 
   int mp2BufferNumBytes = twolame_encode_flush(
      context.encodeOptions,
      mp2Buffer.get(),
      mp2BufferSize);
 
   if (mp2BufferNumBytes > 0)
      if ( context.outFile->Write(mp2Buffer.get(), mp2BufferNumBytes).GetLastError() ) {
         // TODO: more precise message
         throw ExportErrorException("MP2:362");
      }
 
   /* Write ID3 tag if it was supposed to be at the end of the file */
 
   if (context.id3len)
      if ( context.outFile->Write(context.id3buffer.get(), context.id3len).GetLastError() ) {
         // TODO: more precise message
         throw ExportErrorException("MP2:371");
      }
 
   if ( !context.outFile->Close() ) {
      // TODO: more precise message
      throw ExportErrorException("MP2:377");
   }
   return exportResult;
}

References context, mp2BufferSize, ExportProcessorDelegate::SetStatusString(), Success, and ExportPluginHelpers::UpdateProgress().

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Member Data Documentation

struct { ... } MP2ExportProcessor::context

Referenced by Initialize(), Process(), and ~MP2ExportProcessor().

encodeOptions

twolame_options* MP2ExportProcessor::encodeOptions {}

Definition at line 258 of file ExportMP2.cpp.

Referenced by Initialize().

fName

wxFileNameWrapper MP2ExportProcessor::fName

Definition at line 254 of file ExportMP2.cpp.

Referenced by Initialize().

id3buffer

ArrayOf<char> MP2ExportProcessor::id3buffer

Definition at line 256 of file ExportMP2.cpp.

id3len

int MP2ExportProcessor::id3len

Definition at line 257 of file ExportMP2.cpp.

mixer

std::unique_ptr<Mixer> MP2ExportProcessor::mixer

Definition at line 255 of file ExportMP2.cpp.

mp2BufferSize

constexpr size_t MP2ExportProcessor::mp2BufferSize = 16384u

staticconstexprprivate

Definition at line 247 of file ExportMP2.cpp.

Referenced by Process().

outFile

std::unique_ptr<FileIO> MP2ExportProcessor::outFile

Definition at line 259 of file ExportMP2.cpp.

pcmBufferSize

constexpr size_t MP2ExportProcessor::pcmBufferSize = 9216 / 2

staticconstexprprivate

Definition at line 246 of file ExportMP2.cpp.

Referenced by Initialize().

status

TranslatableString MP2ExportProcessor::status

Definition at line 251 of file ExportMP2.cpp.

t0

double MP2ExportProcessor::t0

Definition at line 252 of file ExportMP2.cpp.

Referenced by Initialize().

t1

double MP2ExportProcessor::t1

Definition at line 253 of file ExportMP2.cpp.

Referenced by Initialize().

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The documentation for this class was generated from the following file:

• ExportMP2.cpp