[FFmpeg-devel] [PATCH] avformat: add apic to AVStream

[James Almer]

On 3/29/2021 10:20 AM, Nicolas George wrote:
> James Almer (12021-03-29):
>> Can this be done? id3v2 attached pics for many formats are handled by the
>> generic demux code in avformat_open_input() and not by the actual demuxer.
>> And in demuxers like asf, it seems to be done in read_header().
>> Would seeking be able to fetch these pictures again? The comment in the
>> AV_DISPOSITION_ATTACHED_PIC doxy makes me think it's not possible.
>>
>> Personally, even if possible i think triggering a seek just to fetch an
>> attachment is inefficient and disruptive to the user's demuxing/decoding
>> process, and a step backwards considering it used to always be available,
>> for both seekable and non-seekable input, the latter which will no longer be
>> able to access the picture past the original packet.
> 
> As I said, at worse it accesses a field just like now. So of course it
> can be done.
> 
> The point is that having a function to get the packet rather than just a
> pointer gives us more freedom to extend the API later.

Not against it in that case, even if it will probably never stop just 
being an abstraction layer to fetch an always available packet, but know 
that this will kill Andreas' idea of defining how the (until now) public 
packet can be used to simplify attached pics in muxing scenarios, or 
make it considerably more complex to the point it's no longer worth it.

> 
> Regards,
> 
> 
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