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• react native : only mp4 files

  9 janvier 2021, par yesterday

  I have an react-native app for both android and ios. In this app, users can upload a video (from the cameraroll or directly from the camera). I'm using react-native-camera for this.

  


  On android, the video output is mp4. On ios, the video output is mov.

  


  I'm using react-native-video to display the videos.

  


  On android, there is no problem, but on IOS, the mov videos are played with a switched orientation. You can find a bug report here about this. There are also some other reports where this issue is discussed. Some people state that it's fixed with ios 14.2 (some even say with 14.1), but for me, the issue still exists. I even opened a topic myself for this myself, on the react-native-camera repo : https://github.com/react-native-camera/react-native-camera/issues/2994. You can see some screenshots there.

  


  I found out that, when playing mp4-video's on IOS, this problem does not occur. I figured out that, by converting all mov-files to mp4-files, I would overcome this problem.

  


  My current strategy is like this :

  


  

  • record a movie in mov-format (or get one from the cameraroll)

  


  • copy this file to a "readable" location with react-native-fs copyAssetsVideoIOS.

  


  • convert this mov-file to an mp4-file using FFMPEG. Command : -i input.mov  -preset ultrafast -vcodec h264 -acodec mp2 output.mp4.

  


  • delete the first mov copy.

  


  • upload the mp4-file to the server for display.

  


  


  This strategy works, and an extra is that I now only have mp4-files on my server storage (both from android and ios). I'm using the preset ultrafast in my ffmpeg command because otherwise it takes a long time to convert a 30 second mov-file to an mp4-file, and I don't see a big loss in quality.

  


  The question is : I'm scared that converting every mov-file to an mp4-file will take a lot of resources from the device. There problably is a reason that react-native-camera creates mov-files instead of mp4-files on ios, and now I'm converting them. Will my strategy have an impact on (future) behavior of the videoplayer ?

  


• ffmpg - Overlay merged video from a bunch of small videos on another video

  31 août 2022, par Krishna Chebrolu

  I have a situation where 3-4 small 5secs video clips to be merged and placed at a specific point in time of another video within a fixed frame of 800x600.

  


  For example, main video is of 40 secs of 1280x720 resolution and have 4 small clips of 5 secs each to be placed in a frame of 800x600 from 10 to 30 secs one after the other (or) merge them before placing within the frame.

  


  I tried multiple filters and failing to get the required output.

  


  ffmpeg -y -i bg.mp4 -i c0.mp4 -i f.mp4 -filter_complex "split [main][tmp]; [tmp][1:v][1:a][2:v][2:a]concat=n=2:v=1:a=1[tmp1]; [main][tmp1] overlay=enable='between(t,10,24)':x=50:y=50[v]; [v]drawtext=enable='between(t,26,29)':font='DejaVu Serif':text='Kris Cheb':x=(w-tw)/2:y=((h-text_h)/4): fontsize=80: fontcolor=white, drawtext=enable='between(t,27,29)':text='Awesome Work..':x=(w-tw)/2:y=(((h-text_h)/3)+20): fontsize=38: fontcolor=white, drawtext=enable='between(t,27,29)':text='Congratulations!!':x=(w-tw)/2:y=(((h-text_h)/2)+10): fontsize=38: fontcolor=white"[v] -map [v] out.mp4


  


  Of course, in the above command, I'm yet to add scale with force_original_aspect_ratio=decrease filter and associated attributes.

  


  Could someone please suggest how to achieve this with ffmpeg ?

  


  Thanks

  


  [EDIT-1] :

  


  To overcome this issue, as an alterative, I had split bg.mp4 into multiple segments intro.mp4, outro.mp4 & frame.png and concatenated them with the following command, which is working fine. Of course, there is slight deviation from original requirement of placing c0.mp4 & f.mp4 as overlay in the middle segment and now frame.png is being used as overlay on these middle segment clips.

  


  ffmpeg -y -i intro.mp4 -i c0.mp4 -i f.mp4 -i outro.mp4 -i frame.png &#xA;-filter_complex "[0:v][0:a][1:v][1:a][2:v][2:a][3:v][3:a]concat=n=4:v=1:a=1[vv][a];&#xA;[vv][4:v]overlay=enable=&#x27;between(t,4,16)&#x27;:x=0:y=0[v];&#xA;[v]drawtext=text=&#x27;NAME&#x27;: font=&#x27;Serif&#x27;:fontsize=70: fontcolor=white: x=((w-tw)/2):y=(((h-text_h)/4)&#x2B;10):enable=&#x27;between(t,16,20)&#x27;, &#xA;drawtext=text=&#x27;TEXT2&#x27;:font=&#x27;Serif&#x27;:fontsize=40: fontcolor=black:x=((w-tw)/2): y= ((h/2)&#x2B;30):enable=&#x27;between(t,16,20)&#x27;,&#xA;drawtext=text=&#x27;<text3>&#x27;:font=&#x27;Serif&#x27;:fontsize=40: fontcolor=black:x=((w- &#xA;tw)/2):y=((h/2)&#x2B;70):enable=&#x27;between(t,16,20)&#x27;[v]" -vsync 2 -map &#xA;[v] -map [a] out.mp4&#xA;</text3>

  


  But, need help in replacing the audio of middle segment clips c0.mp4 & f.mp4 with the audio from bgm.mp3 which will be given as a new input.

  


  Appreciate all the help..

  


• ffmpeg fails with an Assertion when concatenating mp4

  10 décembre 2014, par Bernardo

  I’m trying to concatenate 7 files using a file.

  file '/var/www/html/la_verdad_nos_une/assets/videos/COL1.mp4'
  
  file '/var/www/html/la_verdad_nos_une/assets/videos/COL2.mp4'
  
  file '/var/www/html/la_verdad_nos_une/assets/videos/COL3.mp4'
  
  file '/var/www/html/la_verdad_nos_une/assets/videos/COL4.mp4'
  
  file '/var/www/html/la_verdad_nos_une/assets/videos/COL5.mp4'
  
  file '/var/www/html/la_verdad_nos_une/assets/videos/COL6.mp4'
  
  file '/var/www/html/la_verdad_nos_une/assets/videos/COL7.mp4'

  The when I use this command

  sudo ffmpeg -f concat -i /var/www/html/la_verdad_nos_une/assets/videos/1000037.txt -c copy /var/www/html/la_verdad_nos_une/assets/videos/1000037abc.mp4  2>&1

  I get

  ffmpeg -f concat -i /var/www/html/la_verdad_nos_une/assets/videos/1000037.txt -c copy /var/www/html/la_verdad_nos_une/assets/videos/1000037abc.mp4  2>&1
  
  ffmpeg version N-61041-g52a2138 Copyright (c) 2000-2014 the FFmpeg developers
  
    built on Mar  2 2014 05:45:04 with gcc 4.6 (Debian 4.6.3-1)
  
    configuration: --prefix=/root/ffmpeg-static/64bit --extra-cflags='-I/root/ffmpeg-static/64bit/include -static' --extra-ldflags='-L/root/ffmpeg-static/64bit/lib -static' --extra-libs='-lxml2 -lexpat -lfreetype' --enable-static --disable-shared --disable-ffserver --disable-doc --enable-bzlib --enable-zlib --enable-postproc --enable-runtime-cpudetect --enable-libx264 --enable-gpl --enable-libtheora --enable-libvorbis --enable-libmp3lame --enable-gray --enable-libass --enable-libfreetype --enable-libopenjpeg --enable-libspeex --enable-libvo-aacenc --enable-libvo-amrwbenc --enable-version3 --enable-libvpx
  
    libavutil      52. 66.100 / 52. 66.100
  
    libavcodec     55. 52.102 / 55. 52.102
  
    libavformat    55. 33.100 / 55. 33.100
  
    libavdevice    55. 10.100 / 55. 10.100
  
    libavfilter     4.  2.100 /  4.  2.100
  
    libswscale      2.  5.101 /  2.  5.101
  
    libswresample   0. 18.100 /  0. 18.100
  
    libpostproc    52.  3.100 / 52.  3.100
  
  [concat @ 0x3f9c440] Estimating duration from bitrate, this may be inaccurate
  
  Input #0, concat, from '/var/www/html/la_verdad_nos_une/assets/videos/1000037.txt':
  
    Duration: 00:00:00.35, start: 0.000000, bitrate: 10 kb/s
  
      Stream #0:0: Video: h264 (Baseline) (avc1 / 0x31637661), yuv420p(tv, bt709), 568x320, 751 kb/s, 29.97 fps, 29.97 tbr, 19200 tbn, 38400 tbc
  
      Stream #0:1: Audio: aac (mp4a / 0x6134706D), 44100 Hz, mono, fltp, 65 kb/s
  
  Output #0, mp4, to '/var/www/html/la_verdad_nos_une/assets/videos/1000037abc.mp4':
  
    Metadata:
  
      encoder         : Lavf55.33.100
  
      Stream #0:0: Video: h264 ([33][0][0][0] / 0x0021), yuv420p, 568x320, q=2-31, 751 kb/s, 29.97 fps, 19200 tbn, 19200 tbc
  
      Stream #0:1: Audio: aac ([64][0][0][0] / 0x0040), 44100 Hz, mono, 65 kb/s
  
  Stream mapping:
  
    Stream #0:0 -> #0:0 (copy)
  
    Stream #0:1 -> #0:1 (copy)
  
  Press [q] to stop, [?] for help
  
  Assertion next_dts >= 0 failed at /root/ffmpeg-static/src/ffmpeg/libavformat/movenc.c:619

  The funny thing is with the same files it have worked. Since there is no further explanation I was wondering if anyone can point me into the right direction.