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• Using FFmpeg or Similar to Normalize audio in a video to EBU R128 standard

  12 mai 2020, par MrNeedHelpPlease

  This is my first time here on stack overflow asking question.

  



  I am stuck and really struggling with this. I am trying to make some of my MXF video files to be EBU r128 standard for its audio.

  



  This means that it has to be -23 and not higher than 0.5.

  



  My current process

  



  Watch_folder > Encoding to MXF > Output_folder

  



  I need to makesure when its comes to output folder, those MXF files are EBU R128 Loudness compliant.

  



  What I have done so Far :

  



  FFMPEG :

  



  ffmpeg -i input.mxf -af loudnorm=I=-23:LRA=7:tp=-2:print_format=json -f null -

  



  got the result :

  



  Input Integrated : -15.1 LUFS
Input True Peak : +0.0 dBTP
Input LRA : 17.1 LU
Input Threshold : -26.2 LUFS

  



  Output Integrated : -17.1 LUFS
Output True Peak : -1.5 dBTP
Output LRA : 5.3 LU
Output Threshold : -27.6 LUFS

  



  Normalization Type : Dynamic
Target Offset : +1.1 LU

  



  then i did

  



  ffmpeg -i input.mxf  -af loudnorm=I=-23:LRA=7:tp=-2:measured_I=-15.1:measured_LRA=17.1:measured_tp=0:measured_thresh=-27.6:offset=1.1 -ar 48k -y output.mxf

  



  However, when i put it through the software Eff, it says that its not EBU compliant.

  



  *EDIT :
This also reduces the quality. for example ; my 6 Gb becomes 250 MB and you can tell the quality downgraded

  



  ffmpeg-normalize

  



  I did the following

  



  ffmpeg-normalize input.mxf -c:a pcm_s32le -ar 48000 -o output.mxf
but this gives me errors.

  



  if i do it without the output file type, i get a mkv which will not work for me. i need it to be mxf.

  


• ffmpeg same bit rate in hls file across resolutions

  4 août 2019, par Saurabh

  We are using following command to generate dash and hls file for a given video :

  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:0 2000k -c:v:1 libx264 -filter:v:1 "scale=640:-2"  \
  
          -maxrate:v:2 3000k -bufsize:v:0 6000k -c:v:2 libx264 -filter:v:2 "scale=1280:-2" \
  
          -maxrate:v:3 245k -bufsize:v:3 600k -c:v:3 libvpx-vp9 -filter:v:3 "scale=320:-2"  \
  
          -maxrate:v:4 700k  -bufsize:v:3 1400k -c:v:4 libvpx-vp9 -filter:v:4 "scale=640:-2"  \
  
          -maxrate:v:5 2100k -bufsize:v:3 4200k -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_playlist true -f dash output/output.mpd

  This works and generates hls files also as expected, one sample m3u8 file below :

  #EXTM3U
  
  #EXT-X-VERSION:7
  
  #EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="group_A1",NAME="audio_6",DEFAULT=YES,URI="media_6.m3u8"
  
  #EXT-X-STREAM-INF:BANDWIDTH=129663,RESOLUTION=320x168,CODECS="avc1.64000c,mp4a.40.2",AUDIO="group_A1"
  
  media_0.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=129663,RESOLUTION=640x336,CODECS="avc1.64001e,mp4a.40.2",AUDIO="group_A1"
  
  media_1.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=129663,RESOLUTION=1280x670,CODECS="avc1.64001f,mp4a.40.2",AUDIO="group_A1"
  
  media_2.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=330756,RESOLUTION=320x168,CODECS="vp09.00.11.08,mp4a.40.2",AUDIO="group_A1"
  
  media_3.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=329663,RESOLUTION=640x336,CODECS="vp09.00.21.08,mp4a.40.2",AUDIO="group_A1"
  
  media_4.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=329663,RESOLUTION=1280x670,CODECS="vp09.00.31.08,mp4a.40.2",AUDIO="group_A1"
  
  media_5.m3u8

  Now as you notice, the Bandwidth is same for resolution of 320x168, 640x336 and 1280x670, which might have happened because of nature of video.

  But the issue with this is in iOS’s AVPlayer it always picks the minimum resolution one and never picks the better resolution stream even if it is available because of same bitrate.

  So the question I want to ask is : is there some option available to ensure - I always have some difference in the bitrates of different resolutions or more specific, bit rate always increase(may be just by few bytes) for increasing resolutions.

  ---

  EDIT

  Earlier I was using -b:v option per output instead of -maxrate:v, I was getting following output for same video :

  #EXT-X-STREAM-INF:BANDWIDTH=479663,RESOLUTION=320x168,CODECS="avc1.64000c,mp4a.40.2",AUDIO="group_A1"
  
  media_0.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=1129663,RESOLUTION=640x336,CODECS="avc1.64001e,mp4a.40.2",AUDIO="group_A1"
  
  media_1.m3u8
  
  
  
  #EXT-X-STREAM-INF:BANDWIDTH=3129663,RESOLUTION=1280x670,CODECS="avc1.64001f,mp4a.40.2",AUDIO="group_A1"
  
  media_2.m3u8

  If you see, Bandwidth has increased considerably, for the same video and same video quality, also all the file sizes also increased 4x. as par my understanding with maxrate option, ffmpeg optimises the output and provides only required bandwidth, while with b:v option it forcefully increases the bandwidth to given values without any benefit in terms of quality. So essentially you get same quality video at much higher bandwidth.

  Which is why I want to use maxrate option but with increasing bandwidth. If I manually change the bandwidth to increasing order in the output with maxrate option, adaptive bit rate starts to work in iOS’s AVPlayer.

• Asking ffmpeg to extract frames at the original frame rate [closed]

  26 avril 2019, par Amelio Vazquez-Reina

  On the FFmpeg documentation (here, and here) I read that, by default, FFmpeg chooses to extract frames at 25 frames per second (otherwise you can specify a framerate with the -r option)

  My problem is that I have a folder with dozens of videos, each of them recorded at different frame rates, so my question is :

  Is there a way to ask FFmpeg to extract frames from a video at the "native" frame rate (i.e. the original frame rate at which the video was recorded) ?

  In case it matters, I am working with MP4 files