[mythtv-users] Jerky playback on BBC HD Chennels

[HP-mini]

On Mon, 2013-01-28 at 09:59 +0000, Paul Gardiner wrote:
> On 28/01/2013 03:04, HP-mini wrote:
> > On Mon, 2013-01-28 at 09:15 +1300, HP-mini wrote:
> >> On Sun, 2013-01-27 at 17:25 +0000, Fred Watt wrote:
> >>> On 27/01/13 16:51, Tim Draper wrote:
> >>>> On 25 January 2013 06:52, Fred Watt <fredwattmythtv at gmail.com>
> >>>> wrote:

> 
> Oh hang on. I wonder if this is connected. I get jerky playback if I
> jump back during live tv to the start of the program. It then wont
> recover witout exiting and reentering.
> 
> In any case, it sounds like we just want the commit of 11159 reverted.
> 
> P.

Yes.
I don't have any BBC HD samples but..
I don't think ffmpeg is causing the hdpvr problems because ffplay from
yesterday & couple months ago, play all the hdpvr samples (from tickets)
I have.

Mythplayer (no commit 11159) can play hdpvr okay only if the mess at
start is cut off.
Myth mpegrecorder needs recent commit to improve (but not fixed)..
I think the start mess impacts frame cut accuracy & possibly av sync in
transcodes.

The mythplayer 0.26 seems to be very sensitive to start &
discontinuities of mpegts files. It seems to get frame indexing/ordering
wrong. You can induce same effect with cutlist editor.
It is posible that the missing (lost) "I" frames at the start (in hdpvr
recordings) trigger the intra-refresh "B" frame flag.

Like you say..bookmark/exit/play corrects the jerky playback (for
induced jerky playback not hdpvr recordings).

The start mess is an annoyance & should just be handled because mpegts
allows cutting-joining files.
The problem appears to be mythplayer &/or the way it uses ffmpeg libav.

Brett.