[vlc-devel] [PATCH] MKV: don't update the playback PTS from unused tracks

[Steve Lhomme]

On Mon, Mar 2, 2015 at 12:23 PM, Steve Lhomme <robux4 at gmail.com> wrote:
> On 02/03/2015 12:11, Rémi Denis-Courmont wrote:
>>
>> Le 2015-03-02 14:02, Steve Lhomme a écrit :
>>>
>>> Fixes #11847
>>>
>>> This file has bad interleaving and shows the progress of broken
>>> tracks that are not in use.
>>> With this patch we only show the progress for the track(s) in use
>>
>>
>> In my understanding, the demuxer should only use the ES state as an
>> optimization. This is especially useful for filtering with RTSP, DVB or
>> MMS.
>>
>> Having the timeline depend on the selected track seems like a terrible
>> idea for somewhat obvious reasons.
>
>
> Yes, but this is a global value that's kept during playback. Right now it
> can even go backward in time if a packet with an old timestamp is
> encountered. And that's the value to report where we are during playback.
>
> If the user selects another track it's going to be bogus all of a sudden.
> The value will stay as it is until new (selected) packets with new
> timestamps are encountered. The only case it wouldn't work is if the user
> selects no track to play at all. But then, we don't care about timestamps...

So do we consider it's okay to have the displayed time going backwards
during playback ? If not it should either be fixed in the demuxer (if
Matroska is the only one doing that) or maybe have a safeguard
globally when getting the current DEMUX_GET_POSITION.

Steve