[LAD] using libsndfile to write signed short

[Joël Krähemann]

On Thu, 2014-09-25 at 21:02 +0100, Harry van Haaren wrote:
> On Thu, Sep 25, 2014 at 8:50 PM, Joël Krähemann <weedlight at gmail.com> wrote:
> > Does someone know about writing WAV using libsndfile?
> > My file becomes 174M big as using sf_writef_short() within 8s
> 
> Are you sure you're only writing each sample once? Sounds like there's
> an error in writing "nframe" samples for each sample or something.
> 
> Its pretty easy: and there's a brilliant to-the-point blog post on
> using C++ interface (sndfile.hh) here:
> http://parumi.wordpress.com/2007/12/16/how-to-write-wav-files-in-c-using-libsndfile/
> 
> If there's still issues, please pastebin some code, or ask a more
> specific question :)
> 
> HTH, -Harry

There probably only those three functions involved:

void
ags_export_output_launch(AgsTask *task)
{
  AgsExportOutput *export_output;
  AgsExportThread *export_thread;
  AgsDevout *devout;
  AgsAudioFile *audio_file;
  gchar *filename;

  export_output = AGS_EXPORT_OUTPUT(task);
  devout = export_output->devout;
  export_thread = export_output->export_thread;
  filename = export_output->filename;

  /* open read/write audio file */
  audio_file = ags_audio_file_new(filename,
                                  devout,
                                  0, devout->dsp_channels);

  audio_file->samplerate = (int) devout->frequency;
  audio_file->channels = devout->dsp_channels;
  //  audio_file->format = devout->bits;                                                                                                                                                                                                     
  audio_file->frames = export_output->frames;

  ags_audio_file_rw_open(audio_file,
                         TRUE);


  g_message("export output");

  /* start export thread */
  g_object_set(G_OBJECT(export_thread),
               "audio-file\0", audio_file,
               NULL);
  ags_thread_start(export_thread);
}


void
ags_export_thread_run(AgsThread *thread)
{
  AgsExportThread *export_thread;
  AgsDevout *devout;

  export_thread = AGS_EXPORT_THREAD(thread);

  devout =  thread->devout;

  if((AGS_DEVOUT_BUFFER1 & (devout->flags)) != 0){
    ags_audio_file_write(export_thread->audio_file,
                         devout->buffer[0], devout->buffer_size);
  }else if((AGS_DEVOUT_BUFFER2 & (devout->flags)) != 0){
    ags_audio_file_write(export_thread->audio_file,
                         devout->buffer[1], devout->buffer_size);
  }else if((AGS_DEVOUT_BUFFER3 & (devout->flags)) != 0){
    ags_audio_file_write(export_thread->audio_file,
                         devout->buffer[2], devout->buffer_size);
  }else if((AGS_DEVOUT_BUFFER0 & (devout->flags)) != 0){
    ags_audio_file_write(export_thread->audio_file,
                         devout->buffer[3], devout->buffer_size1);
  }
}

void
ags_sndfile_write(AgsPlayable *playable, signed short *buffer, guint
buffer_length)
{
  AgsSndfile *sndfile;
  sf_count_t multi_frames, retval;

  sndfile = AGS_SNDFILE(playable);

  multi_frames = buffer_length;
  retval = sf_write_short(sndfile->file, buffer, multi_frames);

  if(retval > multi_frames){
    //    sf_seek(sndfile->file, (multi_frames - retval),
SEEK_CUR);                                                                                                                                                                         
  }
}