[FFmpeg-devel] [PATCH] remove warning when an mpeg stream starts with a non-I-frame

Robert Krüger krueger at lesspain.de
Fri Aug 30 10:12:54 CEST 2013

On Fri, Aug 30, 2013 at 2:07 AM, Michael Niedermayer <michaelni at gmx.at> wrote:
> On Thu, Aug 29, 2013 at 10:27:09PM +0200, Robert Krüger wrote:
>> On Thu, Aug 29, 2013 at 6:01 PM, Paul B Mahol <onemda at gmail.com> wrote:
>> > On 8/29/13, Robert Krueger <krueger at lesspain.de> wrote:
>> >> The warning as it is now produces a lot of noise for perfectly valid
>> >> cases, i.e. for streams that start with b-frames (in decoding order)
>> >> that only reference the first I-frame, which is the case, for example,
>> >> for typical XDCAM streams.
>> >
>> > Isn't it better to check if frame is not I-frame or b-frame instead of
>> > removing warning?
>> Updated patch attached. This is based on my understanding of the spec
>> and assumption what the warning is for. I hope this is now the correct
>> condition to specifically exclude the mentioned case. A file that has
>> these properties is attached to trac ticket #479.
>>  mpegvideo.c |    4 ++--
>>  1 file changed, 2 insertions(+), 2 deletions(-)
>> ef0c3873a21e2f977d22f54639c69ea5d20a547a  improve_first_frame_mpeg_warning.patch
>> From 3606cc587b63c28d04da1b7f2cf52cbacd323e48 Mon Sep 17 00:00:00 2001
>> From: =?UTF-8?q?Robert=20Kr=C3=BCger?= <krueger at lesspain.de>
>> Date: Thu, 29 Aug 2013 21:59:14 +0200
>> Subject: [PATCH] avcodec/mpegvideo: exclude closed-gop leading b-frame case
>>  from warning
> fixed differently
> Thanks for analyzing the problem
> [...]

Thank you. Is there any possibility to change the log level of the new
message from info to debug? My motivation for this patch was that in
our libavcodec-based application, which deals with this kind of
material a lot, we had the logs full of warnings for these cases which
is now replaced by an info log. I am not sure what the current
guidelines are for using log levels but the message seems rather
targeted at developers than at end-users. OTOH, if you disagree, I
will just set the log level of the application to warning, which may
be a good idea anyway.

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