[MPlayer-users] Bug report: ffmpeg creates a better file than mencoder

Igor Katson descentspb at gmail.com
Fri Dec 26 10:18:20 CET 2008


Reimar Döffinger wrote:
> On Fri, Dec 26, 2008 at 11:37:04AM +0300, Igor Katson wrote:
>   
>> I want to extract a png image from lots a videofiles, provided a seek 
>> point. In 80% of the cases, -vo png does this successfully.
>> The cmd in this case is e.g
>>
>> mplayer video.avi -frames 1 -ss 1 -vo png
>>
>> But there are files with broken index or smth (here I can't figure out the 
>> reason), like the one attached, and -vo png does not produce any output. 
>> Options -idx and -forceidx do not help. The output in this case is e.g. the 
>> following (if -v turned on):
>>     
>
> That video does not contain enough keyframes so seeking forward will seek to to
> the end of the video.
> You can use e.g.
> -vf framestep=30
> and take the file 00000002.png.
> Or -vf framestep=I
> can be interesting as well since when a good encoder was used this will
> result in most pngs being right after a scene change (and possibly also at
> better-than-average quality).
>
>   
> -lavcopts vqscale=2:keyint=1
>   
Thanks. So, is it correct, that -ovc lavc and ffmpeg default options 
just have a different keyint value, and that's why ffmpeg has done the job?



More information about the MPlayer-users mailing list