[mythtv] [mythtv-commits] Ticket #10007: Video lags audio (sync) by ~400ms on hd pvr 1212 h264 recordings (only) after firmware update.

[Asher Schaffer]

On Thu, Aug 25, 2011 at 7:53 AM,  <noreply at mythtv.org> wrote:
> #10007: Video lags audio (sync) by ~400ms on hd pvr 1212 h264 recordings (only)
> after firmware update.
> -----------------------------------------+----------------------------
>     Reporter:  gdelx001@…               |      Owner:  markk
>         Type:  Bug Report - General     |     Status:  new
>     Priority:  minor                    |  Milestone:  unknown
>    Component:  MythTV - Video Playback  |    Version:  0.24.1
>     Severity:  medium                   |   Keywords:  video lag sync
> Ticket locked:  0                        |
> -----------------------------------------+----------------------------
>  This didn't happen before a recent firmware update on the HD PVR taking it
>  from version 0xf to 0x17 (May 2009->July 2011 release date), leading me to
>  _speculate_ that some assumptions made by MythTV about h264 streams are no
>  longer met, that Hauppauge tightened or expanded their adherence to spec,
>  which VLC can tolerate and MythTV can't.
> --
> Ticket URL: <http://code.mythtv.org/trac/ticket/10007>
> MythTV <http://code.mythtv.org/trac>

I confirm that this is firmware related, updated to 0x17 and the
problem is there, reverted to an earlier version and it is fine.
There actually appear to be 2 problems.

I have one HDPVR attached to and RNG100 which has the problem
described in the ticket, audio is offset by ~400ms or so, plays back
fine in vlc, but mplayer and myth have issues.

The other HDPVR is connect to a DCT6200, that also plays back fine in
vlc, but with myth it stutters continuously.

I have tested this using both vdpau and software with the same
results, the hdpvrs are both using Component/SPDIF.  I am guessing the
problem is either with the h264 implementation with this firmware, or
upstream in ffmpeg.  Is there any data I can provide that would be
helpful to localize the issue, or should I be speaking with the ffmpeg
group?