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• avformat/av1 : Document actual behaviour of ff_av1_filter_obus()

  16 janvier 2022, par Andreas Rheinhardt

  avformat/av1 : Document actual behaviour of ff_av1_filter_obus()
  Document that it can be used with a NULL AVIOContext to
  
  get the output size in a first pass.
  Signed-off-by : Andreas Rheinhardt <andreas.rheinhardt@outlook.com>
  

  • [DH] libavformat/av1.h

• Evolution #3819 : Pouvoir demander un module PHP dans paquet.xml

  7 février 2017

  Oui mais…
  1) c’est pas une correction de bug à proprement parler, et
  2) ça fait ajouter une chaine de langue (or on en n’ajoute qu’en 3.2)

• HLS encoded video (ffmpeg) breaks in Safari when segmented via byte-range

  15 juin 2019, par eschie

  Some of my HLS encoded videos via ffmpeg drop the audio when seeking past the buffer. The only way to sync the audio and video up again is to restart the video. What would be causing this ?

  Example Profile :

  bitrate: 4800, profile: 'high', level: '4.1', resolution: 1080, framerate: '24000/1001'

  ffmpeg
  
      '-y' 
  
      '-i' input_file.mov                                                 
  
      '-v' error 
  
      '-map' '0:0'                                                        
  
      '-c:v' libx264                                                  
  
      '-x264opts' f'
  
          keyint=23:                  
  
          min-keyint=23:          
  
          no-scenecut                                                     
  
      '
  
      '-vf' f'scale=-1:1080'
  
      '-preset' 'slow'
  
      '-profile:v' 'high'
  
      '-level' '4.1'
  
      '-b:v' '4800k'
  
      '-maxrate' '4800k'
  
      '-movflags' 'faststart'
  
      '-bufsize' '9600k' 
  
      '-write_tmcd', '0'
  
      '-r' '24000/1001'                                   
  
      output_dir                                                      

  Segmentation CMD :

  FFMPEG 
  
      '-i' output_dir 
  
      '-v' 'error' 
  
      '-acodec' 'copy'
  
      '-vcodec' 'copy'
  
      '-hls_time' '4' #seconds
  
      '-hls_list_size' '0'
  
      '-hls_flags' 'single_file' 
  
      os.path.join(output_dir, f'{run_id}_{bitrate}.m3u8'

  Added : apple’s mediastreamvalidator outputs a few different errors :

  Error: Playlist vs segment duration mismatch
  
  --> Detail:  Segment duration 98.0146, Playlist duration: 4.7968
  
  --> Source:  1559962503399_2200k.m3u8 - 1559962503399_2200k.ts:1746520@0

  Error: Measured peak bitrate compared to master playlist declared value exceeds error tolerance
  
  --> Detail:  Measured: 3182.61 kb/s, Master playlist: 2173.82 kb/s, Error: 46.41%, Combined rendition name: English
  
  --> Source:  ...playlist.m3u8
  
  --> Compare: 1559962503399_2200k.m3u8

  Error: Different target durations detected
  
  --> Detail:  Target duration: 5 vs Target duration: 4
  
  --> Source:  1559962503399_64k.m3u8
  
  --> Compare: 1559962503399_128k.m3u8

  UPDATE 1 :
  I modified the encoding command to utilize tee pseudo-muxer, but it seems the same issue still exists when segmenting HLS as byte-ranges rather than in separate .ts files :

  $ ffmpeg
  
  -hide_banner
  
  -report
  
  -benchmark
  
  -vstats
  
  -i "../Jane_shallowing_Top_v08.mp4"
  
  -dn
  
  -sn
  
  -filter_complex "[0:v]fps=fps=24.000,setpts=(PTS-STARTPTS),split=[vsplit1][vsplit2];[vsplit1]scale=-1:144[video_144];[vsplit2]scale=-1:1080[video_1080]"
  
  -map "[video_144]"
  
  -r:v:0 "24.000"
  
  -c:v:0 "libx264"
  
  -x264-params "keyint=144:min-keyint=144:scenecut=0:open_gop=0"
  
  -preset:v:0 "slow"
  
  -profile:v:0 "baseline"
  
  -refs:v:0 "2"
  
  -b-pyramid:v:0 "strict"
  
  -tune:v:0 "film"
  
  -b:v:0 "96000"
  
  -maxrate:v:0 "56000"
  
  -bufsize:v:0 "6*56000/8"
  
  -vsync:v:0 "cfr"
  
  -bsf:v:0 "h264_metadata=fixed_frame_rate_flag=1"
  
  -map "[video_1080]"
  
  -r:v:1 "24.000"
  
  -c:v:1 "libx264"
  
  -x264-params "keyint=144:min-keyint=144:scenecut=0:open_gop=0"
  
  -preset:v:1 "slow"
  
  -profile:v:1 "high"
  
  -refs:v:1 "2"
  
  -b-pyramid:v:1 "strict"
  
  -tune:v:1 "film"
  
  -b:v:1 "4800000"
  
  -maxrate:v:1 "4800000"
  
  -bufsize:v:1 "6*4800000/8"
  
  -vsync:v:1 "cfr"
  
  -bsf:v:1 "h264_metadata=fixed_frame_rate_flag=1"
  
  -map a:0 -map a:0
  
  -c:a "libfdk_aac"
  
  -ar "48000"
  
  -ab "128k"
  
  -af "aresample=async=1:min_hard_comp=0.100000:first_pts=0"
  
  -f "hls"
  
  -var_stream_map "v:1,a:0 v:0,a:1"
  
  -hls_time "6.000"
  
  -hls_segment_type "mpegts"
  
  -hls_flags "discont_start+temp_file+single_file"
  
  -hls_list_size "0"
  
  -master_pl_name "playlist.m3u8"
  
  -hls_segment_filename "out_%v.ts" "out_%v.m3u8" 

  Segment duration 98.0267, Playlist duration: 6.0000