1

I am confused a bit. scale video filter does not scales the video to specified dimensions but doing something different.

For example:

$ youtube-dl -f 134 https://youtu.be/aqz-KE-bpKQ -o 1.mp4 # download file 640x360    360p  723k , avc1.4d401e, 30fps, video only, 24.87MiB
$ ffmpeg -i 1.mp4 -vf scale=2000:100 2.mp4
$ ffplay 1.mp4 & ffplay 2.mp4 &

I am awaiting that the second video will be deformed as wide and narrow at height, but:

enter image description here

Here is output of ffprobe for both files:

$ ffprobe 1.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '1.mp4':
  Metadata:
    major_brand     : dash
    minor_version   : 0
    compatible_brands: iso6avc1mp41
    creation_time   : 2018-12-12T10:08:34.000000Z
  Duration: 00:10:34.57, start: 0.000000, bitrate: 328 kb/s
    Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, bt709, progressive), 640x360 [SAR 1:1 DAR 16:9], 0 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      creation_time   : 2018-12-12T10:08:34.000000Z
      handler_name    : ISO Media file produced by Google Inc. Created on: 12/12/2018.
$ ffprobe 2.mp4
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '2.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.83.100
  Duration: 00:10:34.57, start: 0.000000, bitrate: 443 kb/s
    Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 2000x100 [SAR 4:45 DAR 16:9], 440 kb/s, 30 fps, 30 tbr, 15360 tbn, 60 tbc (default)
    Metadata:
      handler_name    : VideoHandler

So, I missed something or video filter works in wrong way? How to fix this?

PS:

$ ffmpeg -version
ffmpeg version 3.4.6-0ubuntu0.18.04.1 Copyright (c) 2000-2019 the FFmpeg developers
built with gcc 7 (Ubuntu 7.3.0-16ubuntu3)
configuration: --prefix=/usr --extra-version=0ubuntu0.18.04.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --enable-gpl --disable-stripping --enable-avresample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librubberband --enable-librsvg --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-omx --enable-openal --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-chromaprint --enable-frei0r --enable-libopencv --enable-libx264 --enable-shared
libavutil      55. 78.100 / 55. 78.100
libavcodec     57.107.100 / 57.107.100
libavformat    57. 83.100 / 57. 83.100
libavdevice    57. 10.100 / 57. 10.100
libavfilter     6.107.100 /  6.107.100
libavresample   3.  7.  0 /  3.  7.  0
libswscale      4.  8.100 /  4.  8.100
libswresample   2.  9.100 /  2.  9.100
libpostproc    54.  7.100 / 54.  7.100
3

The scale filter will adjust the sample aspect ratio to maintain the original display aspect ratio, which is 16:9 for your input. Use the SAR filter to reset the SAR after scaling.

ffmpeg -i 1.mp4 -vf scale=2000:100,setsar=1 2.mp4
  • Thanks a lot, it's working. – Abelisto Nov 2 at 8:54
  • 1
    @Abelisto, you may see this answer, too, for detailed description of SAR, PAR, and DAR. – MarianD Nov 10 at 23:45

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.