[Libav-user] How to access the struct AVCodecTag?

Carl Eugen Hoyos ceffmpeg at gmail.com
Tue Mar 17 23:03:58 EET 2020

Am Di., 17. März 2020 um 21:50 Uhr schrieb Giuseppe Torelli
<giutorcom at gmail.com>:

> many thanks for replying. I'm really surprised there is no way to get all the encoders
> linked to a particular container.

You can get a default encoder for a given container but as explained
FFmpeg expects its
users to know what to put in a specific container (libavformat may
fail but if it does not
fail, this is still not an indication that the output file will be
readable at all or by specific

> I was able to use avcodec_find_encoder(28) where 28 is the ID for MPEG-4 Part 14 and I
> correctly get "libx264 H.264 / AVC / MPEG-4 AVC / MPEG-4 part 10" but of course there
> is also libx265 that encodes a video in the MP4 format.

I may misunderstand but avcodec_find_encoder() takes a codec_id, it
has no connection
at all to containers.
(H264 is 27 here, are you testing an ancient FFmpeg version?)

Please find out what top-posting means and avoid it here, Carl Eugen

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