Sur d’autres sites (11956)

• Live Streaming With Dash While Converting MP4 to WEBM

  3 mai 2021, par kisroby

  I need to convert mp4 files to webm in order to stream it using WebRTC (In Chrome I believe only VP8 is supported at the moment).

  


  I'd like to stream it to WebRTC while it's converting, so what I've come up with is to use the DASH streaming technique.

  


  So, my question would be, is that possible to use DASH and convert the segments from H264 to VP8 codec WITHOUT firstly converting the file to webm ?

  


• How to create a live stream in dash format from mp4 file or m3u8 list ? (ffmpeg)

  30 juin 2017, par jorge.luengo

  I have been trying different ways of running dash live streams from mp4 or m3u8 but none of them worked fined. I want to use ffmpeg because of my server conditions.
  This command has been the one that did something but it didn’t work as I expected :

  ffmpeg-3.3.2-64bit-static/ffmpeg -i reencoded24eng.mp4 -vf yadif=0 -r 30 -vcodec libx264 -keyint_min 60 -g 60 -b:v 1000k -ac 2 -strict 2 -acodec aac -ab 64k -map 0:v -map 0:a -f dash -min_seg_duration 2000  -use_template 1 -use_timeline 1 -init_seg_name init-\$RepresentationID\$.mp4 -dash 1  -media_seg_name test-\$RepresentationID\$-\$Number\$.mp4 test.mpd

  The error that the dash-if conformance tool provides is the following one :

  Start XLink resolving

  XLink resolving successful

  Start MPD validation

  MPD validation successful - DASH is valid !

  Start Schematron validation

  location="/[local-name()=’MPD’ and namespace-uri()=’urn:mpeg:dash:schema:mpd:2011’]/[local-name()=’Period’ and >namespace-uri()=’urn:mpeg:dash:schema:mpd:2011’]">
  If the MPD is dynamic the Period element shall have an id.

  location="/[local-name()=’MPD’ and namespace-uri()=’urn:mpeg:dash:schema:mpd:2011’]/[local-name()=’Period’ and >namespace-uri()=’urn:mpeg:dash:schema:mpd:2011’]/*local[1]">
  Common attributes for AdaptationSet and Representation shall either be in >one of the elements but not in both.

  Schematron validation not successful - DASH is not valid !

  BUILD SUCCESSFUL
  Total time : 5 seconds

  Could anyone help me with this ?

• Working example on live streaming using FFMPEG+MP4Box+Dash.js

  27 février 2017, par BartMao

  I’m stucked on this issue for a couple of days, couldn’t find a perfect working example.

  Here’s my current method :

  Step 1.

  ffmpeg -re -i sample.mp4 -threads 0 -y \
  
  -map 0:1 -vn -acodec aac -strict -2 -ar 48000 -ac 2 \
  
  -f segment -segment_time 4 -segment_format mpegts Dash\audio_%d.ts \
  
  -map 0:0 -vcodec libx264 -vprofile baseline -preset veryfast \
  
  -s 640x360 -vb 512k -bufsize 1024k -maxrate 512k -level 31 -keyint_min 25 -g 25 \
  
  -sc_threshold 0 -an -bsf h264_mp4toannexb -flags -global_header \
  
  -f segment -segment_time 4 -segment_format mpegts Dash\video_%d.ts

  Step 2.

  mp4box -add Dash\audio_%d.ts Output\audio_%d.ts.mp4
  
  mp4box -add Dash\video_%d.ts Output\video_%d.ts.mp4

  Step 3.

  mp4box -dash-ctx Output\dash-live.txt -dash 4000 \
  
  -rap -ast-offset 12 -no-frags-default -bs-switching no \
  
  -min-buffer 4000 -url-template -time-shift 1800 \
  
  -segment-name live_$RepresentationID$_ -out Output\live \
  
  -dynamic -mpd-refresh 2 -subsegs-per-sidx -1 Output\audio_%d.ts.mp4:id=audio Output\video_%d.ts.mp4:id=video

  I played the live.mpd generated using Dash.js, the player paused a long time before actually playing, and freeze every time getting a new m4s file.

  Are there any wrong on my commands ? Or it would be great if can provide any other good examples.