[Libav-user] detecting format compatibility

[Carl Eugen Hoyos]

2017-12-06 14:01 GMT+01:00 Anton Shekhovtsov <shekh.anton at gmail.com>:

> I am looking for a generic method to detect if specific codec-container
> combination would "work".

This is generally not possible with FFmpeg:
You are expected to know what you try to put into a container.
This is further complicated by several facts (issues) about FFmpeg:
General purpose containers (like avi) accept everything.
Other containers like mpeg-ts and mpeg-ps accept everything
although a very small number of codecs is actually supported.
Other containers do support certain codecs but FFmpeg does
not support writing them.

> I tested this approach:
> Prepare writing to memory buffer and execute just avformat_write_header and
> av_write_trailer (no actual packets).
> If neither function returns an error, assume the formats are compatible.
>
> This seems to solve great part of the problem, but there are exceptions:

> pcm in mp4 is successful (no errors reported)

This surprises me, the error that is shown here in my tests
is often reported by users.

Carl Eugen