[FFmpeg-user] Poor quality of screencast 1920x1200 on Linux
boguslaw.lotko at chello.at
Wed Apr 30 13:11:54 CEST 2014
On 04/30/2014 09:57 AM, Carl Eugen Hoyos wrote:
> Bogdan Lotko <boguslaw.lotko <at> chello.at> writes:
>> ffmpeg -f x11grab -s 1920x1200
>> -framerate 30 -vb 2000k -i :0.0 output.avi
> "q=31.0" in your output indicates that the bitrate is
> not sufficient / cannot be reached for some reason.
> For maximum quality, remove "-vb 2000k" and use
> "-qscale 2 -mbd 2" instead.
>> ffmpeg version 2.2.1 Copyright (c) 2000-2014 the FFmpeg developers
> Mostly unrelated:
> Please use current FFmpeg git head when asking for
> support on this mailing list.
> (2.2.1 is new atm but this will change.)
>> As I wrote I'd like to use it for presentation so
>> the video will be played on Windows.
> Do you mean "on Windows with (vanilla) WMP" or "on
> Windows with vlc"?
> For WMP either use -vcodec msmpeg4 (larger files) or
> "-vtag" - unfortunately I forgot the value, it should
> be either "MP4S" or "MP4V" (XVID should also work).
>> My goal is just to produce a video with acceptable quality
> Reading your console output, -qscale 2 should increase the
> quality but please understand that all "normal" video
> codecs only support yuv420p and are by definition not
> well suitable for screen capture.
> There are alternatives (everything with "rle" and Flash
> screen video) that support RGB but I suspect none of them
> will play on vanilla WMP.
> -vcodec libx264rgb is high-quality, high-performance but
> is only supported if the playback software is FFmpeg-based
> Please do not top-post here, it is considered rude.
> Carl Eugen
> ffmpeg-user mailing list
> ffmpeg-user at ffmpeg.org
Thank you very much I'll test these possibilities.
Meanwhile I've got the acceptable results using the following settings:
ffmpeg -f x11grab -framerate 30 -video_size 1920x1080 -i :0.0 -vcodec
libx264 -preset ultrafast -maxrate 2048k -bufsize 3072k -vf
"format=yuv420p" -g 60 output.avi
(-video_size 1920x1200) does not work)
Unfortunately I have no time to for learning more about this great software.
Thank you for your help,
with best regards,
b.lotko at chello.at
Phone: +43 1 2852458
Mobile: +43 676 6615012
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