[Libav-user] Extract AVFrameSideData

[lyncher at sapo.pt]

Hi, I'm trying to extract a A53CC captions from AVFrameSideData.
There are some filter that are aware of this kind of side data 
(sidedata) but I cannot find a way to have access to it (unless using 
lavfi+movie).

I would like to be able to retrieve the CC bytes from a previously 
decoded AVFrame and using ccaption_dec to format it in SRT (or any other 
supported format).
I was thinking to create a Filter that receives an AVFrame and returns 
an AVPacket.... but this combination seems no to be possible.
How can I extract AVSideData from a AVFrame and output it in a filter as 
AV_CODEC_ID_EIA_608?

Thanks
lyncher