[Libav-user] Extract AVFrameSideData

Devin Heitmueller dheitmueller at kernellabs.com
Fri Jun 7 19:16:45 EEST 2019

Hi Lyncher,

On Fri, Jun 7, 2019 at 11:48 AM <lyncher at sapo.pt> wrote:
> I'm not getting how can I define the codec ID to an AVPacket.....
> Should I set something at AVCodecContext?

So those fields are not describing the AVPacket.  They're describing
the codec.  That said, the codec itself has three different references
to the AVMediaType (the codec description, codec context, and codec
parameters).  While I know it uses at least one of those to know what
type of AVFrames can be dispatched to it (e.g. to prevent you from
sending audio AVFrames to a video encoder), I'm not sure which the .id
field ties directly to, or what happens if all three of those values
aren't the same.  At least the codec parameters needs to reflect the
subtitle type in order for subtitle decoders such as ccaption_dec to
be able to accept packets from it.

Interesting.  I would have to do some experimentation to see what the
right path is here.


Devin J. Heitmueller - Kernel Labs

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