[FFmpeg-devel] [PATCH v2] fftools/ffmpeg_mux: fix reporting muxer EOF as error

[Marton Balint]

On Sun, 23 Apr 2023, Anton Khirnov wrote:

> Quoting Marton Balint (2023-04-23 11:42:48)
>> On Sun, 23 Apr 2023, Anton Khirnov wrote:
>>> Quoting Marton Balint (2023-04-23 11:12:38)
>>>> This seems like yet another clash of AVERROR_EOF error codes coming from
>>>> different places with different semantics. For
>>>> av_interleaved_write_frame(), AVERROR_EOF is an error condition, so
>>>> file encoding should fail,
>>>
>>> Why should it fail? I'd think a muxer returning EOF is the way to signal
>>> non-error muxer-side termination.
>>
>> That would be an API change. AVERROR_EOF is not special in any way from
>> other error codes for av_interleaved_write_frame. A muxer cannot signal
>> non-error muxer side termination with existing API.
>
> All error codes (should) have a specific meaning. I cannot think of a
> good reason for a muxer to return AVERROR_EOF to signal an error.
> Can you?

Previously, we expeced users to treat any negative error code as error for 
av_interleaved_write_frame(). This is what is documented. ffmpeg.c 
followed this approach. Don't you see the slightest problem if we 
suddenly change this?

Here is a real case of av_interlaved_write_frame() returning EOF:

https://ffmpeg.org/pipermail/ffmpeg-devel/2023-February/306247.html

Regards,
Marton