[FFmpeg-devel] [PATCH] libavformat: fix inputs initialization in mpegts muxer with filters

Andreas Håkon andreas.hakon at protonmail.com
Tue Apr 23 10:16:07 EEST 2019

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Tuesday, 23 de April de 2019 1:07, Michael Niedermayer <michael at niedermayer.cc> wrote:

> On Mon, Apr 22, 2019 at 11:42:57AM +0000, Andreas Håkon wrote:
> > Please, revise the code! I hope you understand it when you look at my
> > descriptions.
> I would prefer to have some testcase that shows a problem
> what you write basically sounds like
> there are 2 similar pieces of code but they differ, so you change
> one assuming the other is correct. Maybe the change is correct but
> the explanation is insufficient

Hi Michael,

I agree that a testcase is preferable. However, I can use the Mathematical Demonstration
by reduction to the absurd:

- The only difference between block A and B (the two "if () ... else if () ...") is that the
first one is executed when a filter graph is running.
- In the second block (block B) the "ost->inputs_done = 1;" is executed prior to return.
- In the first block (bloc A) is not executed.

Why is then executed in the Block B?

If the only difference is the filter graph, and nothing related to inputs, then only one
of these two can be true:

1) Or the Block B doesn't needs the code "ost->inputs_done = 1;"
2) Or the Block A needs it too.

And I don't think the option 1 is true.

So by reduction to the absurd is demonstrated.


More information about the ffmpeg-devel mailing list