[FFmpeg-devel] [PATCH] mpeg4videodec: silence "Invalid and inefficient vfw-avi packed B frames detected" warning

[Don Moir]

----- Original Message ----- 
From: "Reimar Döffinger" <Reimar.Doeffinger at gmx.de>
To: "FFmpeg development discussions and patches" <ffmpeg-devel at ffmpeg.org>
Sent: Friday, August 30, 2013 2:58 PM
Subject: Re: [FFmpeg-devel] [PATCH] mpeg4videodec: silence "Invalid and inefficient vfw-avi packed B frames detected" warning


On Thu, Aug 29, 2013 at 10:07:29PM +0200, wm4 wrote:
> On Thu, 29 Aug 2013 21:55:17 +0200
> Reimar Döffinger <Reimar.Doeffinger at gmx.de> wrote:
>
> > On Thu, Aug 29, 2013 at 07:48:32PM +0000, Paul B Mahol wrote:
> > > On 8/29/13, wm4 <nfxjfg at googlemail.com> wrote:
> > > > On Thu, 29 Aug 2013 21:31:54 +0200
> > > > Nicolas George <nicolas.george at normalesup.org> wrote:
> > > >
> > > >> Le duodi 12 fructidor, an CCXXI, wm4 a ecrit :
> > > >> > Seeking (resetting the decoder) causes the warning to be printed again.
> > > >> > Disabling warnings is not an option, because warnings are supposed to
> > > >> > signal that something might be wrong.
> > > >>
> > > >> So it is printed once after each seek. How is that a problem?
> > > >>
> > > >> It informs about a problem that can have practical consequences (try
> > > >> playing
> > > >> this kind of files with a limited CPU) and can be fixed (although not with
> > > >> ffmpeg for now). That is exactly what a warning is made for. Simply
> > > >> removing
> > > >> it would be idiotic.
> > > >
> > > > The warning is completely meaningless and confusing.
> > >
> > > Perhaps warning can be printed only if error recognition is set to
> > > some reasonable value?
> >
> > One of the reasons for the warning is to make people stop using the
> > tools that create these broken files.
> > Ideally also to fix them.
>
>> This doesn't work, you'll just annoy your users because you want to make
>> a point. Most people who want to play (or transcode) a video couldn't
>> care less how the original video was created.

>It's not like the message jumps out of your monitor and tries to devour
>you alive. This is useful information about a video that can have
>potential issues. And as was pointed out, the way this file
>was created is very relevant.
>In part due to performance, in part because for example this
>format isn't working with the new VDPAU API (I am told).
>Also, if users are easily annoyed by programs trying to give
>them useful information, they can set the log level to fatal.

For me and in rare cases, the warnings are only useful during development. The end users I deal with have no interest or would not 
even know what the warnings mean.

On top of that, since I have multiple videos running at the same time, you might not even have a clue what video triggered the 
warning.

So I set av_set_log_callback but only thing that is useful to me is the fatal errors which I can filter. log level is bypassed if 
you set the callback which is the way it should be.

Outside of fatal errors, I would just compile the rest out for release if I could.


I