Adding support for hls EXT_X_PROGRAM_DATE_TIME

[r0ro]

Rework from https://github.com/google/shaka-packager/pull/814

Adding support for generation of the EXT_X_PROGRAM_DATE_TIME tag for HLS playlists, with fixed UTC timezone

Add a new hls option: --hls_ext_x_program_date_time <time_offset_ms>

When turned on this option will insert EXT_X_PROGRAM_DATE_TIME in media playlists. Date time is computed from local time adjusted by time_offset_ms.

ex playlist:

stream_0.m3u8

#EXTM3U
#EXT-X-VERSION:6
## Generated with https://github.com/google/shaka-packager version 81dc2360c2-release
#EXT-X-TARGETDURATION:8
#EXT-X-PLAYLIST-TYPE:VOD
#EXT-X-MAP:URI="360p.mp4",BYTERANGE="823@0"
#EXT-X-PROGRAM-DATE-TIME:2020-09-12T00:24:42.994Z
#EXTINF:8.000,
#EXT-X-BYTERANGE:531320@915
360p.mp4
#EXTINF:4.000,
#EXT-X-BYTERANGE:226186
360p.mp4
#EXTINF:8.000,
#EXT-X-BYTERANGE:543230
360p.mp4
#EXTINF:4.000,
#EXT-X-BYTERANGE:218737
360p.mp4
#EXTINF:4.040,
#EXT-X-BYTERANGE:207063
360p.mp4
#EXT-X-ENDLIST

stream_1.m3u8

#EXTM3U
#EXT-X-VERSION:6
## Generated with https://github.com/google/shaka-packager version 81dc2360c2-release
#EXT-X-TARGETDURATION:8
#EXT-X-PLAYLIST-TYPE:VOD
#EXT-X-MAP:URI="1080p.mp4",BYTERANGE="862@0"
#EXT-X-PROGRAM-DATE-TIME:2020-09-12T00:24:42.994Z
#EXTINF:8.000,
#EXT-X-BYTERANGE:2618974@954
1080p.mp4
#EXTINF:4.000,
#EXT-X-BYTERANGE:733878
1080p.mp4
#EXTINF:8.000,
#EXT-X-BYTERANGE:2170779
1080p.mp4
#EXTINF:4.000,
#EXT-X-BYTERANGE:710278
1080p.mp4
#EXTINF:4.040,
#EXT-X-BYTERANGE:514582
1080p.mp4
#EXT-X-ENDLIST

[kqyang]

@r0ro Thanks for the PR. A bit busy right now. I'll try to review it later this week.

[r0ro]

@r0ro Thanks for the PR. A bit busy right now. I'll try to review it later this week.

Hi @kqyang did you get a chance to review this ?

[zuzzurro]

Are there any advances on this topic, by chance?

[hariszukanovic]

Is this merge going to happen?

[Decoydoll]

Hi @r0ro thank you for initiating this PR, are you still following up this PR? Currently i have a use case that is needing this feature, i hope this can be merged soon, thanks!

[r0ro]

Hi @r0ro thank you for initiating this PR, are you still following up this PR? Currently i have a use case that is needing this feature, i hope this can be merged soon, thanks!

I'm not sorry. I believe this would need some rebase against current codebase and some modifications as suggested by @kqyang

[cosmin]

Going to close this for now since nobody is actively working on it, if someone else wants to pick it up please open a new PR on top of the current main branch.