Sur d’autres sites (10502)

• Compressing a Video for HLS Streaming

  12 mars 2018, par jAndy

  I’m in the situation where I have a source file (very high quality, direct output from FCPX) which is in 1080p resolution.

  I use ffmpeg to create a 240, 360, 480 and 720 version to have an adaptive stream quality via HLS, so far so good. My question is about the strategy I’m using.
  Right now, I always use the original file as input for ffmpeg. I was wondering if it wouldn’t be a better idea to convert from 1080 to 720 with full compression algorithms and after that, just re-scale from 720 to 480, 360 and 240.

  I’m not really into video compression and ffmpeg, so I’d just like to hear some expert opinions on this approach. Is there any advantage to always go "all the way" (original file -> compressed/rescaled file) ?

• Converting mp4 to multiple resolutions using FFMPEG

  2 avril 2018, par Edwin Flataunet

  I am developing a E-Learning website where people can upload videos.

  When someone uploads a video, they usually upload it in 1080p full HD which is good.
  Now the issue is that when people watch the videos, they are only in 1080p and some people have bad internet (including myself) so watching a video in 1080p is not optimal.

  So I assume that converting the video to different formats (720p, 360 etc..) is the best way to go here.
  So I tried using FFMpeg, and it works, but its really slow, especially since some videos are over 10 minutes long and over 1gb in size.

  I use this command in FFMPEG :

  ffmpeg -i video.mp4 -vf scale:1280:720 -strict -2 output.mp4

  This works, but its really slow.

  Is there any better way to do this ? Since some people upload 5-10 videos and every video has to be in 3 different formats (1080p(original) 720p, 360p).

  Can someone give me some guidelines how to tackle this issue, as this kind of stops the website from progressing atm.

  Thanks

• ffmpeg : concat and encode with one command

  15 mars 2018, par Massimo Vantaggio

  I have a script that automates encode and concat a series of input video files.
  I’m trying to get encode and concat in a single command.

  At the moment it does not work causing immense empty pauses in the final video output.

  I would like to get the result with concat demux instead of concat protocol because it is much harder to automate in a script

  Do you know if it is possible to archive this result with concat demux ?
  Thanks a lot !

  Massimo

  ENCODE / CONCAT 1080p

  for f in ./*.mp4; do echo "file '$f'" >> list.txt; done
  
  
  
  ffmpeg -f concat -safe 0 -y -i list.txt -i ../logo/logo.png -c:a aac -b:a 384k -ar 48000 -ac 2 -af aresample=async=1000 -c:v libx264 -x264opts keyint=50:min-keyint=50:no-scenecut -bf 0 -r 25 -b:v 4800k -maxrate 4800k -bufsize 3000k -profile:v main -crf 22 -filter_complex "[0:v][1:v]overlay=main_w-overlay_w-10:10,scale=1920:1080,setsar=1" ../buffer/1080set.mp4

  It seems to add long pause at low frame-rate :

  [mov,mp4,m4a,3gp,3g2,mj2 @ 0x7fb03f05e600] Auto-inserting h264_mp4toannexb bitstream filter

  frame= 9745 fps= 13 q=27.0 size= 186368kB time=00:18:52.56 bitrate=1348.0kbits

  frame= 9745 fps= 13 q=27.0 size= 186368kB time=00:18:56.57 bitrate=1343.3kbits/

  frame= 9745 fps= 13 q=27.0 size= 186368kB time=00:19:00.65 bitrate=1338.5kbits/

  frame= 9745 fps= 13 q=27.0 size= 186368kB time=00:19:02.29 bitrate=1336.5kbits/

  More than 1000 frames duplicated

  Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '1.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 512
  
      compatible_brands: isomiso2avc1mp41
  
      creation_time   : 2016-02-27T22:25:49.000000Z
  
      encoder         : HandBrake 0.10.5 2016021100
  
    Duration: 00:06:29.87, start: 0.000000, bitrate: 3447 kb/s
  
      Stream #0:0(und): Video: h264 (High) (avc1 / 0x31637661), yuv420p(tv, bt709), 768x432, 3282 kb/s, 25 fps, 25 tbr, 90k tbn, 180k tbc (default)
  
      Metadata:
  
        creation_time   : 2016-02-27T22:25:49.000000Z
  
        handler_name    : VideoHandler
  
      Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 159 kb/s (default)
  
      Metadata:
  
        creation_time   : 2016-02-27T22:25:49.000000Z
  
        handler_name    : Stereo
  
  
  
  Input #1, mov,mp4,m4a,3gp,3g2,mj2, from '2.mp4':
  
    Metadata:
  
      major_brand     : M4V 
  
      minor_version   : 1
  
      compatible_brands: M4V mp42isom
  
      creation_time   : 2016-02-27T18:52:37.000000Z
  
    Duration: 00:07:16.93, start: 0.000000, bitrate: 1184 kb/s
  
      Stream #1:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, smpte170m), 768x432, 991 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
  
      Metadata:
  
        creation_time   : 2016-02-27T18:52:37.000000Z
  
        handler_name    : Mainconcept MP4 Video Media Handler
  
        encoder         : AVC Coding
  
      Stream #1:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 189 kb/s (default)
  
      Metadata:
  
        creation_time   : 2016-02-27T18:52:37.000000Z
  
        handler_name    : Mainconcept MP4 Sound Media Handler
  
  
  
  Input #2, mov,mp4,m4a,3gp,3g2,mj2, from '3.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42mp41
  
      creation_time   : 2017-06-27T17:58:17.000000Z
  
    Duration: 00:05:05.05, start: 0.000000, bitrate: 2622 kb/s
  
      Stream #2:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, smpte170m), 768x432, 2301 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
  
      Metadata:
  
        creation_time   : 2017-06-27T17:58:17.000000Z
  
        handler_name    : Alias Data Handler
  
        encoder         : AVC Coding
  
      Stream #2:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-06-27T17:58:17.000000Z
  
        handler_name    : Alias Data Handler
  
  
  
  Input #3, mov,mp4,m4a,3gp,3g2,mj2, from '4.mp4':
  
    Metadata:
  
      major_brand     : mp42
  
      minor_version   : 0
  
      compatible_brands: mp42mp41
  
      creation_time   : 2017-06-27T17:53:32.000000Z
  
    Duration: 00:06:47.36, start: 0.000000, bitrate: 3144 kb/s
  
      Stream #3:0(eng): Video: h264 (Main) (avc1 / 0x31637661), yuv420p(tv, smpte170m), 768x432, 2819 kb/s, 25 fps, 25 tbr, 25k tbn, 50 tbc (default)
  
      Metadata:
  
        creation_time   : 2017-06-27T17:53:32.000000Z
  
        handler_name    : Alias Data Handler
  
        encoder         : AVC Coding
  
      Stream #3:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 317 kb/s (default)
  
      Metadata:
  
        creation_time   : 2017-06-27T17:53:32.000000Z
  
        handler_name    : Alias Data Handler