Recherche avancée

Sur d’autres sites (9032)

• How to use ffmpeg / x264 2-Pass encoding for multiple bitrate output files

  10 septembre 2019, par Jonesy

  While performing a 2-Pass encode to multiple output files I was receiving the error

  



  ratecontrol_init: can't open stats file 1 ffmpeg2pass-2.log


  



  My setup is to do a single first pass and then multiple second pass encodes to output files with different target bitrates using the same first pass results.

  



  ffmpeg -y -i $INPUT_FILE -an -vcodec libx264 -pass 1 -b:v 700k -f rawvideo /dev/null

ffmpeg -y -i $INPUT_FILE -i out-aud.mp4 \
$AUDIO_OPTIONS_P2 -vcodec libx264 -pass 2 -b:v 250k -f mp4 out-250.mp4 \
$AUDIO_OPTIONS_P2 -vcodec libx264 -pass 2 -b:v 500k -f mp4 out-500.mp4 \
$AUDIO_OPTIONS_P2 -vcodec libx264 -pass 2 -b:v 700k -f mp4 out-700.mp4


  



  This sequence resulted in the error listed above. What I discovered thru code-inspection is that ffmpeg/x264 looks for a different set of first-pass files for each second-pass encoding path. The first encoding path uses the set of files originally created

  



  ffmpeg2pass-0.log
ffmpeg2pass-0.log.mbtree


  



  The second encoding path requires first-pass files with the names

  



  ffmpeg2pass-2.log
ffmpeg2pass-2.log.mbtree


  



  The third encoding path requires first-pass files with the names starting with ffmpeg2pass-4*, etc.

  



  My solution was to create soft-links to the originally created set of files with the new names that were required for each pass before running the second-pass command.

  



  ln -s ffmpeg2pass-0.log ffmpeg2pass-2.log
ln -s ffmpeg2pass-0.log.mbtree ffmpeg2pass-2.log.mbtree
ln -s ffmpeg2pass-0.log ffmpeg2pass-4.log
ln -s ffmpeg2pass-0.log.mbtree ffmpeg2pass-4.log.mbtree


  



  This seems to work as it results in the output encodes that I needed. However, I don't know if this method is legitimate. Am I getting sub-optimal encoding results by using a first-pass output for one bitrate (700k) as the input to second-pass encodings for other bitrates ?

  


• FFMPEG, any video to 16:9

  13 décembre 2019, par Universal

  Help me find a command or script that will convert any video to 16:9, h264 and 2500kbps. I have a server where people upload videos of different quality, size and length. It can be either 640x480 or 1216x2160. Ultimately, I need to get any resolution to 16:9 (with black borders, if needs) and bitrate without visible loss of quality, which will be acceptable for online broadcasting.

  I have this command, but it does not check the resolution of the video. And if the video was 560x448 1000kbps and 700mb, then after conversion it will be 1280x720 3000kbps and 1.5gb, that’s not right.

  ffmpeg -i 5.avi -vcodec libx264 -crf 23 -preset veryfast -vf scale=1280:720:force_original_aspect_ratio=decrease,pad=1280:720:(ow-iw)/2:(oh-ih)/2,setsar=1 -tune zerolatency highoutput.mp4

• FFMPEG Encoding in Multiple resoultions for adaptive streaming

  9 janvier 2020, par thatman

  I am using the following ffmpeg script for encoding mp4 video into different resolutions for adaptive HLS/DASH streaming :

   ffmpeg -y -nostdin -loglevel error -i INPUT.mp4 \
  
      -map 0:v:0  -map 0:v:0 -map 0:v:0  -map 0:v:0  -map 0:v:0  -map 0:v:0 -map 0:a\?:0  \
  
      -maxrate:v:0 350k -bufsize:v:0 700k -c:v:0 libx264 -filter:v:0 "scale=320:-2"  \
  
      -maxrate:v:1 1000k -bufsize:v:1 2000k -c:v:1 libx264 -filter:v:1 "scale=640:-2"  \
  
      -maxrate:v:2 3000k -bufsize:v:2 6000k -c:v:2 libx264 -filter:v:2 "scale=1280:-2" \
  
      -maxrate:v:3 300k -bufsize:v:3 600k -c:v:3 libvpx-vp9 -filter:v:3 "scale=320:-2"  \
  
      -maxrate:v:4 1088k -bufsize:v:4 2176k -c:v:4 libvpx-vp9 -filter:v:4 "scale=640:-2"  \
  
      -maxrate:v:5 1500k -bufsize:v:5 3000k -c:v:5 libvpx-vp9 -filter:v:5 "scale=1280:-2"  \
  
      -use_timeline 1  -use_template 1 -adaptation_sets "id=0,streams=v  id=1,streams=a" \
  
      -threads 8 -seg_duration 5 -hls_init_time 1 -hls_time 5 -hls_playlist true -f dash OUTPUT.mpd

  But the script is giving this error :

  Only ’-vf scale=320:640’ read, ignoring remaining -vf options : Use ’,’ to separate filters
  Only ’-vf scale=640:1280’ read, ignoring remaining -vf options : Use ’,’ to separate filters
  Only ’-af (null)’ read, ignoring remaining -af options : Use ’,’ to separate filters

  Please help in resolving the issue. Thanks in advance !