[FFmpeg-user] A/V sync issues & more with MediaPortal recording of ClearQAM

Mr M redpenguinmail at gmail.com
Mon Feb 10 00:38:19 CET 2014

On Thu, Feb 6, 2014 at 3:40 PM, Mr M <redpenguinmail at gmail.com> wrote:

> On Thursday, February 6, 2014, Mr M <redpenguinmail at gmail.com> wrote:
>> On Thursday, February 6, 2014, Carl Eugen Hoyos <cehoyos at ag.or.at> wrote:
>>> Mr M <redpenguinmail <at> gmail.com> writes:
>>> > > Audio streams are switching between silent and
>>> > > non-silent, and I have no idea how (and if) this
>>> > > is signaled.
>>> > Well I can definitely tell you one thing. The second
>>> > audio track (spa) is definitely silent even on the TV
>>> > as I hear nothing when switching to it.
>>> The transport stream contains three audio tracks (0x40,
>>> 0x41 and 0x42), actual audio switches between two of them.
>>> Is your tv really never silent while playing this program?
>>> Carl Eugen
>>> _______________________________________________
>>> ffmpeg-user mailing list
>>> ffmpeg-user at ffmpeg.org
>>> http://ffmpeg.org/mailman/listinfo/ffmpeg-user
>> I just took a look again and during programming and commercials then back
>> again it never went silent.
>> --
>> Sent from Gmail Mobile
> Recordings from MSNBC are claiming only 2 audio streams now. Maybe
> sonething was broken when I was recording last Sunday.

Just an update to this:

I have recorded another show today from this channel, but to be safe I used
another PC with another tuner card just to make sure that the PC or tuner
was not the culprit.

ffmpeg shows:

Input #0, mpegts, from 'Caught on Camera (Twist of Fate -
  Duration: 01:09:58.60, start: 0.071600, bitrate: 4000 kb/s
  Program 137
    Stream #0:0[0x40](eng): Audio: ac3 ([129][0][0][0] / 0x0081), 48000 Hz,
stereo, fltp, 192 kb/s
    Stream #0:1[0x41](spa): Audio: ac3 ([129][0][0][0] / 0x0081), 0
channels, fltp
    Stream #0:2[0x30]: Video: mpeg2video (Main) ([2][0][0][0] / 0x0002),
yuv420p(tv), 704x480 [SAR 10:11 DAR 4:3], max. 4295 kb/s, 29.97 fps, 29.97
tbr, 90k tbn, 59.9
At least one output file must be specified

So one of the audio tracks is gone yet it still looses A/V sync over time.

So it appears to be something with the the cableco signal.

I also spoke with the MediaPortal folks and they stated they do not alter
the signal/stream in anyway when it's recording. I also do not have any
commerical skipping programs or anything of that nature in use.

More information about the ffmpeg-user mailing list