Freeze during advertisements!

[jpsa]

Weird one this... if I watch the Tour de France coverage on ITV4, then the video freezes from time to time (the audio keeps running), but only ever during an ad break!

Logs attached -- freezes occurred at 14:12, 14:16, 14:33 and 15:40. In each case I pressed Escape to return to the TV Guide, and reselected Watch.

The logs are from the server, which runs XP and uses the ffdshow decoders (no client was running), but I have also seen the same (or at least similar) problem on a Windows 7 client machine using the Microsoft DTV-DVD decoders.

Any ideas?

[sub]

Have you recorded it? If so I might need to get you to supply a small snippet which covers the ad transition so I can check it out. I suspect it's something to do with local ad insertion (switching to different audio/video pid)

[sub]

Cutchunk can used to cut abut from the larger recording

[jpsa]

I didn't record today, but I'll try to remember to do tomorrow's.

[jpsa]

I've got a .ts file which reliably freezes the video on the XP/ffdshow machine. It's about 30MB, though, so I'm not sure how best to get it to you.

This.ts file doesn't show the problem on the Win7/Microsoft DTV-DVD machine (though there are some stutters, which may or may not be related). I can try to find another extract which does upset that machine, if you like.

[sub]

If you play that recording with other video decoders on XP, does it have the same problem?

[jpsa]

The only other MPEG2 decoders offered on that machine are three Nero ones, and each of those gives an unhandled exception error (object reference not set to an instance of an object) if I try to use them. Is there a particular decoder you'd like me to try?

[sub]

Is there a particular decoder you'd like me to try?

No, but given you said it was working on the Win7 machine, but not XP, it changed my mind and thought it's likely to be something about the encoding that the decoder doesn't like.

I'm happy to try the clip here with a few decoders if you can put it somewhere I can download from, like dropbox, or rapidshare etc.

[jpsa]

The clip is the file y.ts at
https://skydrive.live.com/redir?resid=60...912847!116
It reliably freezes the video on the XP/ffdshow machine about 1m15s from the start.

I think you may be right about it being a decoder issue, because I tried to get another clip which showed the freeze on the client Win7//Microsoft DTV-DVD machine, but have so far failed. Although it does freeze from time to time watching live TV, I can't reproduce the effect when watching the same extract from a recording. Perhaps this is actually a different problem -- I'll try to get some more information.

Thanks for offering to take a look!

[mvallevand]

I ran it through a couple of anaylzers I have and starting at 1:35 there are quite a few errors

Code:

Sequence Frame 2382(15-P) / Time 0:01:35 :
VideoWarning: Discontinuity of (13+) packet(s).  First packet ending at offset 25276600
VideoError: DMV motion prediction not supported. MBA=334(448,144)
VideoError: Motion vector going out of range at MBA=334(448,144)
VideoError: Missing 17 picture slices at MBA=333(432,144)
FileInfo: Last video errors span 274 bytes at file offset 25276405
FileInfo: Last video errors span 0 bytes at file offset 25276877
VideoWarning: Discontinuity of (11+) packet(s).  First packet ending at offset 25279420

Sequence Frame 2426(7-B) / Time 0:01:37 :
VideoWarning: TemporalRef gap of 1013.  Timestamp gap of 0.280000 sec. ending at file offset 25278719

Sequence Frame 2472(15-B) / Time 0:01:39 :
VideoError: Missing 1 slice macroblocks at MBA=67(528,16)
FileInfo: Last video errors span 23 bytes at file offset 26348102

which your decoder might be able to handle well. If you try to skip over ads the skipping in the bad files might be what makes you notice the problems more.

Martin