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

[Marton Balint]

On Thu, 24 Oct 2019, Ole Andre Birkedal wrote:

> 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.

If the incompatibility you experience can be fixed by using option 2, then 
I'd rather not add a flag for option 1... I don't have a strong preference 
though.

Regards,
Marton

>
> 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
>> > > > 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".
>> >
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