[FFmpeg-user] Developer "cehoyos" closed my bug without any explanation, and without solving it

[Thomas Worth]

On Tue, Oct 11, 2016 at 2:19 AM, Sven C. Dack <sven.c.dack at sky.com> wrote:

> On 11/10/16 08:31, Alexey Eromenko wrote:
>
>> I have a strong belief, that produced MP4 files should be played on
>> all popular players, and any potential issues must be documented.
>>
>> Additionally ffmpeg should provide a BIG WARNING that a resulting file
>> will not be playable on Apple decoders, and offer to fix it
>> automatically.
>>
>> -Alexey
>>
> No. This isn't about what you belief. Before you can expect ffmpeg or all
> popular players to play your files do you have to provide the correct input
> files and options to ffmpeg. That's a fact and it's how ffmpeg works. Once
> you get this right will ffmpeg be your best friend and will produce the
> files you need, but not before then.
>

Has anyone actually looked at the MP4 file, BrokenVideo-8min.mp4? It was
written with a video track timescale of 0, a track duration of 0 and due to
that, outrageous packet durations. Regardless of the quality of input
(which I'm sure was bad), the muxer should still be able to detect that
something is obviously wrong. In this case, the muxer should probably just
fail with an error. No reasonable person should expect MP4s written this
way to work correctly. Based on the fact that ffmpeg is writing timescale 0
and duration 0, I'd say this should probably be considered a bug. But
that's just my opinion.