Cecil Westerhof via ffmpeg-user <ffmpeg-user@ffmpeg.org> writes:
After some experiments I solved it by putting -ss and -to behind -i
and not forgetting to alter the between values.
But this takes about a third more time.
Is there be a better solution?
I am now using:
ffmpeg -y \
-i input.mp4 \
-ss 00:26:05 \
-to 00:44:04 \
-vf "
drawbox=enable='between(t, 1565, 1566.6)':
color = black :
w = in_w :
h = in_h :
thickness = fill
" \
-acodec copy \
-vcodec libx264 \
-crf 23 \
-preset veryfast \
output.mkv
> I have the recording of a zoom meeting where I need to cut out a
> portion from and the first little bit has to be blacked out.
>
> I use the following command:
> ffmpeg -y \
> -ss 00:26:05 \
> -to 00:44:04 \
> -i input.mp4 \
> -vf "
> drawbox=enable='between(t, 0, 1.6)' :
> color = black :
> w = in_w :
> h = in_h :
> thickness = fill
> " \
> -acodec copy \
> -vcodec libx264 \
> -crf 23 \
> -preset veryfast \
> output.mkv
>
> This creates a seemingly correct file, with one little problem: the
> time starts at 00:00:27 and ends at 00:18:26. (As displayed by the
> player mpv.)
>
> When I play it with vlc I find out that the 27 seconds of audio are
> before the video. Mpv starts with the video, but vlc starts with the
> audio.
> What could be the problem?
>
>
> I am using ffmpeg version 4.3.3-0+deb11u.
>
>
> The metadata of the input file:
> Input #0, mov,mp4,m4a,3gp,3g2,mj2, from
> 'GMT20211216-184321_Recording_640x360.mp4':
> Metadata:
> major_brand : mp42
> minor_version : 0
> compatible_brands: isommp42
> creation_time : 2021-12-16T18:43:21.000000Z
> Duration: 01:21:57.47, start: 0.000000, bitrate: 646 kb/s
> Chapter #0:0: start 0.000000, end 4917.440000
> Metadata:
> title : Recording Started
> Stream #0:0(und): Audio: aac (LC) (mp4a / 0x6134706D), 32000 Hz, mono,
> fltp, 126 kb/s (default)
> Metadata:
> creation_time : 2021-12-16T18:43:21.000000Z
> handler_name : AAC audio
> Stream #0:1(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p,
> 640x360, 518 kb/s, 25 fps, 25 tbr, 30k tbn, 60k tbc (default)
> Metadata:
> creation_time : 2021-12-16T18:43:21.000000Z
> handler_name : H.264/AVC video
> encoder : AVC Coding
> Stream #0:2(und): Data: bin_data (text / 0x74786574)
> Metadata:
> creation_time : 2021-12-16T18:43:21.000000Z
> handler_name : Text
>
> The metadata of the output file:
> Input #0, matroska,webm, from 'howToReachYourNewYearsResolutionsIn2022.mkv':
> Metadata:
> COMPATIBLE_BRANDS: isommp42
> MAJOR_BRAND : mp42
> MINOR_VERSION : 0
> ENCODER : Lavf58.45.100
> Duration: 00:18:26.34, start: 0.000000, bitrate: 346 kb/s
> Chapter #0:0: start 0.000000, end 3352.440000
> Metadata:
> title : Recording Started
> Stream #0:0: Video: h264, none, 640x360, 25 fps, 25 tbr, 1k tbn, 2k tbc
> (default)
> Metadata:
> HANDLER_NAME : H.264/AVC video
> ENCODER : Lavc58.91.100 libx264
> DURATION : 00:18:26.336000000
> Stream #0:1: Audio: aac (LC), 32000 Hz, mono, fltp (default)
> Metadata:
> HANDLER_NAME : AAC audio
> DURATION : 00:18:26.336000000
>
>
> By the way when I create a mp4 file (which is not really an option,
> because I need to create chapters), the video seems to be correct,
> with one strange thing: both mpv and vlc think it is 00:55:52 long.
> Which it is not: it stops where it should 00:17:59.
--
Cecil Westerhof
Senior Software Engineer
LinkedIn: http://www.linkedin.com/in/cecilwesterhof
_______________________________________________
ffmpeg-user mailing list
ffmpeg-user@ffmpeg.org
https://ffmpeg.org/mailman/listinfo/ffmpeg-user
To unsubscribe, visit link above, or email
ffmpeg-user-requ...@ffmpeg.org with subject "unsubscribe".
