Content generation guidelines

[zangue]

Hi,

I'm trying to use the simulator with vod dataset from http://www-itec.uni-klu.ac.at/ftp/datasets/DASHDataset2014 to test live source with multiple representations without success: the vod content analyzer would always failed at some point.

I have noticed that it is because it requires some set of informations to be present at MPD and media segment level, e.g, manifest attributes like period id, represenation contentType among other. It also seems to parse the media segments to get some infos from metadata/boxes.

So my questions is: are they any guidelines for content generation to make sure there is enough infos for the vod analyzer to run successfully. Or could you guys make available what tools and configs you used to generate data available at http://vm2.dashif.org/dash/vod/testpic_2s/ ?

Thanks

[FranS73]

Hi,

Any updates on this? I'm facing the same problem, specially when the analyzer parses the media segments.

Any help would be highly appreciated!

Thanks!

[zangue]

Hi @FranS73

A solution that worked for me was to use ffmpeg and Bento4 to generate MPEG-DASH content. I then adjusted the output to meet the content limitations requirements. The manifest should then be updated to reflect the new directory structure and segment naming. Also add the contentType attribute to each adaptation set of the presentation.

I plan to make a more detailled HowTo and open a PR to update the docs.

I hope this will help.

Best

[FranS73]

Hi @zangue

Thank you very much for the answer! I managed to make it work with Bento4, adjusting the output as you said 👍 but only for videos with the same duration for all segments.

The thing is that the last segment of my videos has different duration. Right now, I'm trying to use SegmentTimeline to handle it but the vod analyzer throws an error; I will keep looking into it.

Also, I'm afraid that some players won't accept the discontinuity between the last video segment and the first one when looping...

Have you used videos with different segment durations? Any advice?

Best

[zangue]

@FranS73 Glad to hear it helped.

The simulator has support for segment timeline. You can leave your content as it and have the simulator serve it with segment timeline MPD by adding an option to the URL as follows:

http://<host>:<port>/livesim/segtimeline_1/<content>/<manifest>.mpd

Dash.js by default can handle discontinuity of up to 15 ms. I guess you can have your content played by it if the discontinuity doesnt exceed that threshold.

However, a straightforward solution would be to exclude the last segment from the loop by editing the .cfg of the content to set nr_segments_in_loop to N-1 segments.

Best

[FranS73]

Hi @zangue

Editing the .cfg did the trick, thank you!!

About the segment timeline, I did a quick test with the option you suggested but it didn't work; the player freezes after some time (even the dash.js reference player). Anyway, with the .cfg edit I don't need this right now, so I will look into it again when needed and report back any finding.

Thank you very much for your help!

Best

[nammajamma]

Hi,

I couldn't quite get pass the segment analyzer as it errors on "too much drift in the duration of the segments."

I've transcoded a source using the bento4 + ffmpeg toolset mentioned in this thread. Are there other things I might try? Appreciate any pointers.