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• How to make file .mpd for adaptive streaming supported on iOS device

  3 août 2020, par thxbox

  I would like to do DASH Adaptive Streaming in Ubuntu server. I used ffmpeg and MP4Box to convert video to .mpd file.

  


  Below is command that I use for convert and to generate a file

  


  ffmpeg -i myvideo.mp4 \
-vcodec libx264 \
-profile:v main -level 3.1 \
-preset medium \
-crf 23 \
-x264-params ref=4 \
-acodec copy \
-movflags +faststart myvideo-output.mp4


  


  MP4Box -dash 4000 \
-rap -bs-switching no 
-profile live \ 
-out myvideo-output.mpd \
-segment-name my_video_segment_ myvideo-output.mp4#audio myvideo-output.mp4#video


  


  in browser side, I implemented dash.js to video player.
the problem is it works on Chrome, Firefox and Safari on Desktop/iPad but it not works on some all iPhone.

  


  How to solve it ?

  


• ffmpeg audio stream retiming for infinite input

  26 février 2020, par Aeon

  I have a ffmpeg process that reads input data from stdout infinitely.
  Its input data are mkv (matroska) containers (sent to stdin by another process), each container contains 4 audio streams (without any video) - 3 ACC streams and 1 FLAC stream. The output of this process is dash muxer.

  ffmpeg -hide_banner -re -fflags +getpts -avoid_negative_ts make_non_negative -stream_loop -1 -f matroska -i pipe: -map 0 -c:a copy -strict -2 -f dash -use_timeline 1 -use_template 1 -seg_duration 5 -dash_segment_type mp4 manifest.mpd

  The problem occurs after the first muxing of obtained mkv file. When it’s time to mux the next one from pipe, I get following messages :

  [matroska,webm @ 000001d3050bba40] Found unknown-length element with ID 0x18538067 at pos. 0x54c766 for which no syntax for parsing is available.
  
  [matroska,webm @ 000001d3050bba40] Seek to desired resync point failed. Seeking to earliest point available instead.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:0; previous: 881714, current: 51200; changing to 881715. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:1; previous: 881714, current: 51200; changing to 881715. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:2; previous: 881714, current: 51200; changing to 881715. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:3; previous: 884005, current: 51200; changing to 884006. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:3; previous: 884006, current: 51244; changing to 884007. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:3; previous: 884007, current: 51244; changing to 884008. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:3; previous: 884008, current: 51288; changing to 884009. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:3; previous: 884009, current: 51288; changing to 884010. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:3; previous: 884010, current: 51332; changing to 884011. This may result in incorrect timestamps in the output file.
  
  [dash @ 000001ac98349080] Non-monotonous DTS in output stream 0:3; previous: 884011, current: 51332; changing to 884012. This may resul
  
  ...

  and dash muxer simply stops generating new segments. I do understand that it’s an issue with timestamps, but I don’t know how to fix that.

  I’ve tried to use -fflags +getpts - no success.
  use_wallclock_as_timestamps 1 solves the "Non-monotonous DTS..." issue, but brings in a bunch of issues with playback, like freezing, breaking, etc., so the playback becomes completely unlistenable.
  Something strange also happens to the SegmentTemplate node of the manifest - its timescale attribute is set to 44100, although there should be 1000000 (-frag_duration 1 is ignored in this case)

  Question : I’m asking for your help in re-timing, i.e. generating the correct timestamps for dash muxing for each new incoming file in the pipe.

• Ffmpeg hardware acceleration unsupported formats betwen tranpose and auto_scaler_0

  11 août 2021, par Eduard6421

  I am trying to develop a transoding service which makes use of nvidia hardware acceleration capabilities ( The gpu used in this process is a Tesla T4) ; I want to generate a mpeg-dash playlist for my video so that i can stream it ;

  


  ffmpeg -y -hwaccel cuda -hwaccel_output_format cuda -i mobil1.mp4 -c:v h264_nvenc -c:a aac  \
-map v:0 -b:v:0 1000k -maxrate:0 1500k -bufsize:0 2500k -filter:v:0 "scale_npp=1920:1080:force_original_aspect_ratio=decrease" -map 0:a -b:a 128k \
-f dash dash.mpd


  


  But when mobile videos are uploaded ( which have rotation metadata ) I encounter the following error :

  


  Impossible to convert between the formats supported by the filter 'transpose' and the filter 'auto_scaler_0'
Error reinitializing filters!
Failed to inject frame into filter network: Function not implemented
Error while processing the decoded data for stream #0:0


  


  How can i solve this issue ?