[Libav-user] How to read in planar data?

[Mark McKay]

Just reposting with properly formatted code:

void AudioReader::loadAudioFrame(AVPacket& packet)
{
     int err = avcodec_send_packet(aCodecCtx, &packet);
     if (err < 0)
     {
         qDebug("Error sending packet to decoder");
         return;
     }

     int numChannels = aCodecCtx->channels;
     while (err >= 0)
     {
         err = avcodec_receive_frame(aCodecCtx, aFrame);
         if (err == AVERROR(EAGAIN) || err == AVERROR_EOF)
         return;

         if (err < 0)
         {
             qDebug() << "Error decoding packet: " << err;
             return;
         }

         int bytesPerSample = 
av_get_bytes_per_sample(aCodecCtx->sample_fmt);
         if (bytesPerSample < 0) {
         /* This should not occur, checking just for paranoia */
         fprintf(stderr, "Failed to calculate data size\n");
         exit(1);
         }


         int bufferSize = av_samples_get_buffer_size(NULL,
         aCodecCtx->channels,
         aFrame->nb_samples,
         aCodecCtx->sample_fmt,
         1);

         switch(aCodecCtx->sample_fmt)
         {
         ...
         case AV_SAMPLE_FMT_FLTP:
         {
             //Serial format - change to interleaved order
             for (int i = 0; i < aFrame->nb_samples; i++)
             {
                 for (int ch = 0; ch < numChannels; ch++)
                 {
                     _audioBytes.append((const char *)aFrame->data[ch] + 
i * sizeof(float), sizeof(float));
                 }
             }
             break;
         }
         }
}



On 2019-12-06 15:55, Mark McKay wrote:

> I'm having trouble trying to figure out how to read in planar data.  I 
> have a file that has data in the AV_SAMPLE_FMT_FLTP format with two 
> channels.  Below is my attempt to read in the data.  This will crash 
> with a memory problem if I try to read in the second channel (but it 
> will complete if I bypass the second and just read from channel 0).  Am 
> I doing this right?