[FFmpeg-devel] [PATCH] Support for zulu timezone format for PDT in HLS playlists

[Ole Andre Birkedal]

This is something that Akamai requires for their MSL4 product when ingesting HLS and using it to generate clips on their CDN. It's also something required by one of our customers, but we don't know the exact reason of why they require this.
I'll update the patch with a better commit message explaining these things.

Having a setting for choosing to use UTC and then by default presenting it in the Z format is a good idea! Always using UTC should not be on by default though, even if I think that's the best way to present timestamps, there could be users who depend on it being non-UTC.

So to recap
1) By default USE Zulu time on +0000 UTC timestamps in PDT, but can be configured OFF.
2) Add an option for using UTC timezone in PDT, by default OFF.

Just realising that this also bleeds into the CMAF muxer in DASH, will investigate what can be done to support similar settings there.

Thanks for the feedback,
Ole Andre Birkedal

‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
On Wednesday, October 23, 2019 2:50 PM, Marton Balint <cus at passwd.hu> wrote:

>
>
> On Wed, 23 Oct 2019, Marton Balint wrote:
>
> > On Wed, 23 Oct 2019, Ole Andre Birkedal wrote:
> >
> > > Thanks for the feedback, attached new complete patch with code changes +
> > > added documentation for it
> >
> > Please also explain why this might be required in the docs. In the commit
> > message please name the specific vendor/device which is not parsing zero
> > offset correctly.
> > I wonder if it would make sense to set this flag by default (doing that
> > can be a separate patch) if it improves compatiblity.
>
> One more idea is that maybe we should introduce a flag which always puts
> the timestamp in UTC instead? Otherwise your approach only works if the
> local time is UTC, no?
>
> Thanks,
> Marton
>
> > Thanks,
> > Marton
> >
> > > Ole
> > > ‐‐‐‐‐‐‐ Original Message ‐‐‐‐‐‐‐
> > > On Wednesday, October 23, 2019 4:32 AM, Steven Liu lq at chinaffmpeg.org
> > > wrote:
> > >
> > > > > 在 2019年10月22日，18:37，Ole Andre Birkedal birkedal at extab.net 写道：
> > > > > Some HLS players prefer UTC+0 timestamps in PROGRAM-DATE-TIME to end in a
> > > > > Z instead of +0000, this patch adds a hlsflag to enable that feature.
> > >
> > > > > Example command:
> > > > > ffmpeg -i input.mp4 -c copy -hls_flags +program_date_time+zulu_timezone
> > > > > output.m3u8
> > >
> > > > > Example PDT output:
> > > > > #EXT-X-PROGRAM-DATE-TIME:2019-10-22T10:27:54.000Z
> > > > > Ole Andre
> > > > > Birkedal<zulu_timezone.patch>_______________________________________________
> > >
> > > > Document doc/muxer.texi please.
> > > >
> > > > > ffmpeg-devel mailing list
> > > > > ffmpeg-devel at ffmpeg.org
> > > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
> > > > > To unsubscribe, visit link above, or email
> > > > > ffmpeg-devel-request at ffmpeg.org with subject "unsubscribe".
> > > >
> > > > Thanks
> > > > Steven
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> > > > ffmpeg-devel at ffmpeg.org
> > > > https://ffmpeg.org/mailman/listinfo/ffmpeg-devel
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> >
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