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• ffmpeg with multiple live inputs [closed]

  9 juin 2013, par maddanio

  we are trying to get ffmpeg to combine multiple live streams into one. In principle we got it to work by mosaicing the streams like so :

  ffmpeg -rtsp_transport tcp -r 25 -i rtsp ://root:password@192.168.178.91:554/axis-media/media.amp \
  -rtsp_transport tcp -r 25 -i rtsp ://root:password@192.168.178.92:554/axis-media/media.amp \
  -filter_complex "[0:0]pad=iw*2:ih[a] ;[a][1:0]overlay=w" ...

  the problem though is that ffmpeg seems to start the input streams at significantly different times, so that there is about a 1 second shift between the streams, that remains throughout. Now we do have correct time stamps (pts) on both streams. Can we somehow tell ffmpeg to respect those and use them to align the streams correctly ?

• escaping FFmpeg whitespace in Android

  21 octobre 2015, par MoshErsan

  I’ve a video file stored on the device SD-Card and its path contains a whitespace

  /storage/emulated/0/TestVideos/Media/My Video/VID-20151020-WA0019.mp4

  and when I try to process the video with FFMPEG with this command

  -y -i '/storage/emulated/0/TestVideos/Media/My Video/VID-20151020-WA0019.mp4' -vf scale=480:-1 -ss 0:00:00 -t 0:00:22 -async 1 -strict -2 -threads 2 /storage/emulated/0/temp_VID-20151020-WA0019.mp4

  FFMpeg throws an error :

  '/storage/emulated/0/TestVideos/Media/My: No such file or directory

  I tried to escape the white space in different ways :

  • "/storage/emulated/0/TestVideos/Media/My Video/VID-20151020-WA0019.mp4"
  • '/storage/emulated/0/TestVideos/Media/My Video/VID-20151020-WA0019.mp4'
  • /storage/emulated/0/TestVideos/Media/My%20Video/VID-20151020-WA0019.mp4
  • /storage/emulated/0/TestVideos/Media/My%1Video/VID-20151020-WA0019.mp4
  • "/storage/emulated/0/TestVideos/Media/My%20Video/VID-20151020-WA0019.mp4"
  • '/storage/emulated/0/TestVideos/Media/My%20Video/VID-20151020-WA0019.mp4'

  none of them worked.

  how to escape the whitespace in file path to make work with FFMpeg ?

• Making colour of MP4 video consistent in Chrome

  21 septembre 2021, par OneWorld

  I see a difference in the colour of a video between different machines using different browsers. I was wondering what the cause of the difference is ?

  


  I use FFMPEG to create the video. I sent the video to three different people with slightly different machines, and slightly different Chrome versions, to try and see where the differences are.

  


  The FFMPEG output from the video is as follows :-

  


  ffmpeg version 3.2.2-static http://johnvansickle.com/ffmpeg/  Copyright (c) 2000-2016 the FFmpeg developers
  built with gcc 5.4.1 (Debian 5.4.1-4) 20161202
  configuration: --enable-gpl --enable-version3 --enable-static --disable-debug --disable-ffplay --disable-indev=sndio --disable-outdev=sndio --cc=gcc-5 --enable-fontconfig --enable-frei0r --enable-gnutls --enable-gray --enable-libass --enable-libfreetype --enable-libfribidi --enable-libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libopenjpeg --enable-libopus --enable-librtmp --enable-libsoxr --enable-libspeex --enable-libtheora --enable-libvidstab --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxvid --enable-libzimg
  libavutil      55. 34.100 / 55. 34.100
  libavcodec     57. 64.101 / 57. 64.101
  libavformat    57. 56.100 / 57. 56.100
  libavdevice    57.  1.100 / 57.  1.100
  libavfilter     6. 65.100 /  6. 65.100
  libswscale      4.  2.100 /  4.  2.100
  libswresample   2.  3.100 /  2.  3.100
  libpostproc    54.  1.100 / 54.  1.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'red_and_yellow_uat.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf57.56.100
  Duration: 00:00:03.00, start: 0.000000, bitrate: 84 kb/s
    Stream #0:0(und): Video: h264 (Constrained Baseline) (avc1 / 0x31637661), yuv420p(tv, unknown/bt709/bt709), 1080x1080, 81 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : VideoHandler


  


  From the same UAT rendered Video, with screenshots taken in Chrome from person 1, person 2, person 3, and person 4, and using GIMP colour picker on my machine from the screenshots, the results for red, and yellow are as follows.

  


  Person 1:- #A83833  and  #FFCB2E  Chrome Version 92.0.4515.131 (Official Build) (64-bit)
Person 2:- #AB3334  and  #FFCA38  Chrome Version 92.0.4515.107


  


  (Note : these colours Match / are very close to the original).

  


  Both these machines above are 64 bit Ubuntu machines, using Ubuntu 18.04.5 LTS
We both use the gnome screenshot tool in Ubuntu to take the screenshot, which creates an 8bit PNG.

  


  Person 3:-    #B14039  and  #FED303  Chrome Version 93.0.4577.63 (Official Build) (x86_64)
Person 4:-    #B2403A  and  #FFD201  Chrome Version 92.0.4515.159 (Official Build) (x86_64)


  


  Mac screenshots are taken using cmd shift 4, and generate an 8bit PNG file.

  


  Person 3 Machine Spec :-
Machine :- Macbook Pro (2019)
OS : macOS Big Sur Version 11.5.2
Processor :- 2.6Ghz Intel Core i7 processor. 32bit architecture (typing arch in her tty terminal returns i386).
Graphics :- Intel UHD Graphics 630 1536

  


  Person 4 Machine Spec :-
Machine :- Macbook Pro (Retina, 2015)
OS :- MacOS Mojave, Version 10.14.6
Processor :- 2.5GHz, Intel Core i7
Graphics :- AMD Radeon R9, M370X 2 GB Intel Iris Pro 1536 MB

  


  Person 1 screenshot

  


  

  


  Person 2 screenshot

  


  

  


  Person 3 screenshot

  


  

  


  Person 4 screenshot

  


  

  


  Any suggestions anyone has to make these colours consistent would be much appreciated. Would love to know why it happens also ? If anyone can explain ?