Since I upgraded to R5A22 I have been getting a strange intermittent audio jitter. It is like the audio jumps forward and back playing over itself several times. It seems to happen worse after a short while playing, but will eventually start behaving again. It's not just on the playback and live tv. I tried cating the /dev/video0 to a file and playing it on both the mythfrontend and also on my windows laptop. It stutters in exactly the same place. I took a sample of the audio so you can hear the type of problem.

Download Sample 2.6MB

I tried installing the TV card in a completely different machine with a fresh install but it does the same.

The system specs of the two systems I have tried are:
1:
ABIT KT7A MB with 1GHz Athlon XP
PVR-250
Soundblaster Live sound card

2:
Dell Dimention 8100
PVR-250
Soundblaster Live Sound card (Different one to above)

The PVR 250 card shows up in lspci as:
Internext Compression Inc iTVC16 (CX23416) MPEG-2 Encoder (rev 01)

It is a UK model one.

if I grep dmsg for tuner I get:


Could an incorrect tuner type be causing the jitter?

have you tried enabling extra audio buffering?

yes, it makes no difference.

if I change the tuner type in /etc/mythtv/modules/ivtv to type 5 (the default detected is type 1) I loose the echo effect, but the recording stutters instead. Type 45 seems to be working better so far, but I have only just started testing it.

Does anyone know what I should actually have the tuner type set to for this machine, and this card type?

Damn, spoke to soon, it's started doing it again

It's wierd the way it is not consistent, it seems to get worse at times, sometimes it is fine. Usually gets bad just as a good bit is comming up, but I guess that is just sod's law in action.

Full lspci shows the card as:

hmm, i think i've got the same problem. i just upgraded from R5A16 to R5A22 and am now getting the stuttering in audio playback.
however, i did change a couple of the default settings during the upgrade. i just noticed that one recording that was default appears to have turned out ok. the one i just got done watching that was 'high quality' was stuttering. so i'm having a look at my recording settings, audio & video.

I have noticed this too. Sometimes TV plays fine and then others the audio is really poor, cracky and stutters.

I also get this when playing back XviD in MythVideo as well. Sometimes they play back fine and sometimes I have to exit then re-play the file!

I have uninstalled alsa and re-compiled it with the latest. I have always had to do this with KnoppMyth as if I don't everything goes haywire when trying to time search forward/backward (in anything!)...

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Knoppmyth R5B7 (previous: R5A10,R5A22)
Pundit-r BIOS 1005 | Celeron D320 2.4Ghz
Pinnacle PCTV Stereo (saa7134)
Hauppage PVR-500
512MB PC3200 RAM
ATI 9100IGP using ATI 8.23.7
250 GB Samsung SATA
Sony DVD-RW
Sapphire (ATI) Remote Wonder