[Libav-user] Mp3 play using ffmpeg

[Robert Schmidt]

On Thu, Oct 31, 2013 at 9:46 AM, Yamusani Vinay <yamusanivinay at gmail.com> wrote:
>
> the error is while decoding the length obtained  is negative.
>

One possibility is that you might be trying to decode a non-audio
packet.  On line 110, after you've read a packet from the file, you
check if your decoding context is for audio, which will always be
true.  What I think you want to do is instead check that the packet
you retrieved is associated with your audio stream and not some other
stream in the file.

Something like

    if (packet.stream_index == audioStream)

It's possible this code worked for a .wav file if the file only had a
single stream containing audio data.

Hope this helps.

Rob