Player load the whole mpeg dash webm file

[KhodyrevDS]

I'm trying to play mpeg dash webm file https://dev2-portal.videonotion.com/web/guest/preview?v=5757f876-c575-4969-a37d-450d7c65d015
After start playing the whole video downloading (For example, I see in the response Content-Range:bytes 433-9781613/9781614). It's too much (about 9 mb) so it's loading too long.

How I can affect to this?

Video encoded by ffmpeg with this instruction http://wiki.webmproject.org/adaptive-streaming/instructions-to-playback-adaptive-webm-using-dash

[KhodyrevDS]

Checked with shaka player, it is playing fine.

ffmpeg command

ffmpeg -i in.mp4 -c:v libvpx -threads 4 -vf setdar=dar=0,setsar=sar=0,scale=trunc(oh*a/2)*2:1080 -b:v 524288 -minrate, 524288 -maxrate 524288 -bufsize 1835k -an -pix_fmt, yuv420p
 -movflags faststart -keyint_min 96 -g 96 -frame-parallel 1 -f webm -dash 1 -strict -2 out.webm -y

[davemevans]

The problem is that the EBML parser in general, and - importantly here - the cue parser is very strict and not at all permissive.

FFMPEG is including CueRelativePosition elements in the CueTrackPosition elements, and the strict parser doesn't expect these so fails, returning a single cue which is deemed to cover the entire presentation.

Matroska marks CueRelativePosition as not valid in webm [1], and mkvalidator agrees, but the webm spec implies they are ok [2], so the parser probably should handle them (and other unknown tags).

I've made a patch that makes the parser more permissive in cue parsing, and the content referenced above now loads correctly. @KhodyrevDS can you test davemevans@340e082?

I also tested the webm streams in #1732 (comment) and they continue to play as expected.

[1] https://www.matroska.org/technical/specs/index.html
[2] https://www.webmproject.org/docs/container/#CueRelativePosition

[KhodyrevDS]

It's working greate