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matthrolf
2007-08-07, 01:11 AM
Playing back large files (90+min) files, mpg encoded dvd's, randomly lose audio/video sync. The fix seems to be to skip back and it catches up. Probably does this 10-20 times during a movie, but does not do it when playing a recorded program played from the same volume.

Any ideas?

Thanks,

Matt

stustunz
2007-08-07, 01:18 AM
what mpeg video/audio decoders are you using

matthrolf
2007-08-07, 01:30 AM
Good question... System default because I am using mvp only. I did not know that the installed encoders matter to the mvp because I thought the mvp was simply sent the file data stream and it does the decoding with its hardware decoder.

Matt

mvallevand
2007-08-07, 01:50 AM
I've never played a DVD with emulation mode (I don't even have a DVD in my machine) but like anything doing transcoding on the fly, which I assume happens there's a chance of some sync issues if there isn't enough date in the mvpmc's buffers. I'd try playing with various config.xml settings for a dvd, I'm guessing here I am not in front of my machine, and either decrease the max bit rate a bit, and remove the numeric screen size setting and let mvpmc handle it. Increasing the pre-buffer for transcoding could help too, and mvpmc isn't as sensitive to the Hauppauge dongle to bigger buffer time-outs.

Martin

matthrolf
2007-08-07, 02:21 AM
I'm not doing any transcoding... they are mpg2 files. I have converted MANY dvd's to mpg's.

Matt

mvallevand
2007-08-07, 02:24 AM
I'm not doing any transcoding... they are mpg2 files. I have converted MANY dvd's to mpg's.

Matt

How are you converting the AC3 audio?

Martin

matthrolf
2007-08-07, 02:27 AM
hmm, don't know. It could be encoding it as ac3, since an mpg file can have sound encoded as ac3... I'm betting not. Let me do some research on that and I'll get back to you.

Matt

matthrolf
2007-08-07, 02:29 AM
BTW I'm using "1 click dvd to mpg" as my software... I am going to do some analysys on the resultant files. The Haup dongle didn't have any problem with this that is why I am curious.

(I noticed that I didn't actually answer your question)

Matt

mvallevand
2007-08-07, 02:30 AM
hmm, don't know. It could be encoding it as ac3, since an mpg file can have sound encoded as ac3... I'm betting not. Let me do some research on that and I'll get back to you.

mvpmc will actually play the AC3 audio but the sync will be off a good bit of the time. That's why I figured you are transcoding somehow.

Martin

matthrolf
2007-08-07, 02:34 AM
This is the data off videoredo file properties... Does that help?

Matt


File Name: C:\Users\matthrolf\Desktop\Encoded DVDs\The Good Sheperd.mpg
File Size: 3360271600 ( 3.13 GB )
Program Duration: 02:47:21.16
File Type: PS - MPEG2
Encoding: MPEG 2
Video stream Id: xE0
Encoding Dimensions: 480 x 480
Display Size: 480 x 480
Aspect Ratio: 4/3
Frame Rate: 29.97 FPS
Bit Rate: 2.376 Mbps
VBV_Buffer: 224 KB
Profile: Main/Main
Progressive: Prog or Int
Chroma: 4:2:0
Audio Format: Layer 2
Audio Stream Id: xC0
Audio Bit Rate: 128 Kbps
Audio Sampling Rate: 44100 Hz

mvallevand
2007-08-07, 02:58 AM
Ok, that helps. It looks like a pretty basic svcd file which really shouldn't lose sync. 0xCO for audio will be MP2 Audio. At this bit rate the mux should be full too. So I have a couple of questions

Are you running wired or wireless?

Do you use the mvpmc share to load a command line?

Martin

matthrolf
2007-08-07, 03:00 AM
Wired and wireless... They both behave identically.

No I do not have a share for the dongle. I choose emulation mode from the menu manually... I rather like that :D It keeps the mvp from having an active session on the pvr computer.

Thanks,

Matt

mvallevand
2007-08-07, 03:10 AM
Wired and wireless... They both behave identically.

I figured, this doesn't look like it is bandwidth related. Could you telnet to you mvp, log on as root and issue this command after the #

ifconfig

I am interested in seeing if you are getting high number of errors or collisions.

I am assuming you are running full duplex and not 1/2 which the Hauppauge dongle prefers.



No I do not have a share for the dongle. I choose emulation mode from the menu manually... I rather like that :D It keeps the mvp from having an active session on the pvr computer.

So do I, I am actually surprised at the number of people who like to keep the connection open, taking resources on the server since the connection time is so short.

Martin

matthrolf
2007-08-07, 03:16 AM
# ifconfig
eth0 Link encap:Ethernet HWaddr 00:0D:FE:0C:3F:EC
inet addr:192.168.222.142 Bcast:192.168.222.255 Mask:255.255.255.0
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:644735 errors:6 dropped:0 overruns:6 frame:0
TX packets:336496 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:936662570 (893.2 MiB) TX bytes:0 (0.0 B)
Interrupt:27 Base address:0xd300 DMA chan:1

lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:0 (0.0 B) TX bytes:0 (0.0 B)


The switch to which it is plugged says fdx

matthrolf
2007-08-07, 03:18 AM
That sample set is probably a little too small... Let me repost after I try playing a movie.

Matt

mvallevand
2007-08-07, 03:34 AM
That sample set is probably a little too small... Let me repost after I try playing a movie.

That's a reasonable sample and the six errors wouldn't cause the problem you talk about. Collisions affect performance the most and you don't have any.

Martin

mvallevand
2007-08-07, 03:58 AM
Sub, (if you are reading this thread) in the gbpvr dongle, do you remember if you ever issued an av_sync() commands while the video was playing or did you let the demux handle everything like I do?

Martin

mvallevand
2007-08-07, 11:44 AM
Matt, the sync that I asked sub about is issued on a pause. Does hitting pause/play resync this file?

Martin

HtV
2007-08-07, 03:09 PM
My guess would be that the problemis in the transcoding, I've seen a lot of sync problems with dvd>mpg. You might try videoredo, you can use it as a trial, It has a very nice timestamp fixing routine. Then you would know if it's in the transcoding.

matthrolf
2007-08-07, 04:57 PM
I am not transcoding. They are MPG2 files.

Matt

matthrolf
2007-08-07, 04:59 PM
Matt, the sync that I asked sub about is issued on a pause. Does hitting pause/play resync this file?

Martin

I will find out... Skipping back (i use 30 seconds) usually fixes it.

Matt

HtV
2007-08-07, 07:52 PM
I am not transcoding. They are MPG2 files.

Matt

Ok, what's in a name, I meant the conversion/translation/rename, whatever you want to call it, from vob to mpg. That's a little more complicated than changing the extension from vob to mpg and "stitching" everything together to 1 file.

matthrolf
2007-08-07, 07:54 PM
These files are being created using software specifically designed to translate vob files from the dvd to mpg files and place all files into one file. There WAS no problem playing these files on former versions. There is no problem playing these files form windows media player or vlc.

Matt

HtV
2007-08-07, 08:30 PM
I have seen mpg's before that would play ok in vlc or wmp but not on the mvp, or play only in vlc, or give different durations in different players. etc etc.

mvallevand
2007-08-07, 10:40 PM
You can't compare mvpmc and vlc, since vlc handles errors in the mpeg stream better. I don't use wmp so I assume it's the same. What I think is happening is the "stitching" that Hans is referring to isn't perfect, it is a difficult process, and this is causing the sync error.

I'm surprised that the Hauppauge dongle handles it better but I hope that pause/play test proves successful, because that points to a solution.

Martin

matthrolf
2007-08-08, 06:37 PM
First, the problems mentioned are with the timebase of the file... These checkout fine. I, too, have seen files that exhibit this behavior; these do not.

Secondly, yes, unfortunatly the haup dongle did not have this problem.


I am away from the house for a while I will be able to get more testing done in a couple of days... Sorry for the delay, unplanned business trip.

Thanks for you time,

Matt