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• fate : add a case for ticket #3229

  12 août 2019, par Zhong Li

  fate : add a case for ticket #3229
  Reviewed-by : Michael Niedermayer <michael@niedermayer.cc>
  
  Reviewed-by : Thilo Borgmann <thilo.borgmann@mail.de>
  
  Signed-off-by : Zhong Li <zhong.li@intel.com>
  

  • [DH] tests/fate/video.mak
  • [DH] tests/ref/fate/mjpeg-ticket3229

• Why is one ffmpeg webm dash stream much larger than the others ?

  5 janvier 2017, par ranvel

  Over the summer, I worked on putting together a script which took a x264 video/mp3 stream and broke it up into the different streams so that it would work via MSE-DASH. (Based heavily on the instructions on the webmproject.org website) Those same scripts have ceased to work, turning a 6GB video into several 25 Gb videos. I kept up with updates of ffmpeg and so I don’t know when it stopped working, but I am guessing it was due to the way that their DASH Webm implementation was updated.

  I found new method which works better, but still has a major problem with one stream. I was hoping someone could explain how this encoding works so that I could understand the underlying cause.

  #!/bin/bash
  
  COMMON_OPTS="-map 0:0 -an -threads 11 -cpu-used 4 -cmp chroma"
  
  WEBM_OPTS="-f webm -c:v vp9 -keyint_min 50 -g 50 -dash 1"
  
  
  
  ffmpeg -i $1 -vn -acodec libvorbis -ab 128k audio.webm &
  
  ffmpeg -i $1 $COMMON_OPTS $WEBM_OPTS -b:v 500k -vf scale=1280:720 -y vid-500k.webm &
  
  ffmpeg -i $1 $COMMON_OPTS $WEBM_OPTS -b:v 700k -vf scale=1280:720 -y vid-700k.webm & 
  
  ffmpeg -i $1 $COMMON_OPTS $WEBM_OPTS -b:v 1000k -vf scale=1280:720 -y vid-1000k.webm &
  
  ffmpeg -i $1 $COMMON_OPTS $WEBM_OPTS -b:v 1500k -vf scale=1280:720 -y vid-1500k.webm  

  The transcode is not yet complete, but you can see where this is headed :

  -rw-r--r--  1 user  staff    87M Jan  4 23:27 audio.webm
  
  -rw-r--r--  1 user  staff    27M Jan  4 23:42 vid-1000k.webm
  
  -rw-r--r--  1 user  staff   285M Jan  4 23:42 vid-1500k.webm
  
  -rw-r--r--  1 user  staff    15M Jan  4 23:42 vid-500k.webm
  
  -rw-r--r--  1 user  staff    20M Jan  4 23:42 vid-700k.webm

  The 1500k variant is disproportionately larger than the other streams.

  The other problem is that when I use a shorter video, lets say eight or nine minutes, the above configuration runs as expected and everything is perfect. I don’t know where the limit for this is since each test costs a lot of processing power and time, but if it’s less than ten minutes, it works and if its longer than an hour, it produces massive files.

• Change file format from flv to anything android will play

  19 octobre 2011, par Bilthon

  I need to take this file which encoded is in h264 but in a flv container and just put it in a mp4, 3gp or whatever file format the android MediaPlayer will understand.

  I want to do this natively. As I will not be decoding nor encoding anything I think I will not be wasting a lot of power (am I wrong ?)

  I followed the instructions from here http://www.roman10.net/?p=394 and could sucessfully compile and use ffmpeg and use it with mp4 and 3gp files.

  But when it comes to flv files it fails. I understand there is no format definition for flv files in that specific port of ffmpeg for android.

  There is no libavformat/flv.h header file for instance.

  Maybe that's why this works :

  extern AVInputFormat ff_mov_demuxer ;
  av_register_input_format(&ff_mov_demuxer) ;

  While this fails :

  extern AVInputFormat ff_flv_demuxer;
  
  av_register_input_format(&ff_flv_demuxer);

  Question is, is there a light at the end of the tunnel ? has someone done something similar ? is it useful ? I mean, I can always just throw the flv media file into a flash player and voila.. the thing is that this would be a parcial solution, as it will not work for all those folks running slower devices that can't yet run Flash.

  Nelson

  PS. Just in case. Here's some info about the file I'm talking about :

  ffmpeg -i rio.flv 
  
  ffmpeg version N-32624-gea8de10, Copyright (c) 2000-2011 the FFmpeg developers
  
    built on Sep 15 2011 23:31:42 with gcc 4.5.2
  
    configuration: --enable-libfaac --enable-libmp3lame --enable-librtmp --enable-libtheora --enable-libx264 --enable-libxvid --enable-gpl --enable-nonfree
  
    libavutil    51. 16. 0 / 51. 16. 0
  
    libavcodec   53. 15. 0 / 53. 15. 0
  
    libavformat  53. 12. 0 / 53. 12. 0
  
    libavdevice  53.  3. 0 / 53.  3. 0
  
    libavfilter   2. 42. 0 /  2. 42. 0
  
    libswscale    2.  1. 0 /  2.  1. 0
  
    libpostproc  51.  2. 0 / 51.  2. 0
  
  
  
  Seems stream 0 codec frame rate differs from container frame rate: 2000.00 (2000/1) -> 14.99 (15000/1001)
  
  Input #0, flv, from 'rio.flv':
  
    Duration: 00:01:00.06, start: 0.000000, bitrate: 783 kb/s
  
      Stream #0.0: Video: h264 (Main), yuv420p, 704x480 [SAR 10:11 DAR 4:3], 14.99 tbr, 1k tbn, 2k tbc