Garbage in recorded MPEG stream, How to troubleshoot bad recording? Options

[Guest_Tellyaddict_*]

I haven't seen this problem described anywhere else, so here's my first post:

I'm happily using VisionDTV to watch live broadcasts from all 6 transponders here in Sydney - Quality and Strength are generally over 85% and picture is perfect (from rabbit ears!).

However, playback of any recorded stream is almost unwatchable -it's full of macroblock errors almost as if the signal is dramatically weaker when recording. Back on live TV it's fine though.

I've tried recording with VisionDTV 2.42a and WebScheduler and the result is the same.

System config:
Shuttle SN85G4 XPC
Athlon 64 3200
1GB Corsair RAM
VisionPlus DVB-t
ATI Radeon 9600 128MB
Seagate Barracuda SATA 200GB HDD

I've seen some discussion about problems with SATA drives, but I've tried recording to a firewire attached 80GB external PATA drive and got the same results

Any suggestions? I can email a short clip of the recorded video if it helps.

Thanks!

[Guest_JoeyBloggs_*]

Oh let me guess. You are trying to playback the recordings with Windows Media Player ???

[Guest_Tellyaddict_*]

Playback on Windows Media Player and VisionDTV doesn't even show the frames with the bad macroblocks - they just skip the frames.

PowerDVD and Media Player Classic both show all the frames, garbage included. I've also opened the .mpg files up with VirtualDubMod and looked at individual frames. The garbage really is there, so I don't think it's an artifact of dodgy on-the-fly decoding.

[auenf]

Playback on Windows Media Player and VisionDTV doesn't even show the frames with the bad macroblocks - they just skip the frames.

VisionDTV is the correct way to play it back, you can use other apps after you have demuxed the mpg thru projectx (then mux again using a different app) to get rid of the errors.

Enf...

[Guest_JoeyBloggs_*]

I would have said that you would want Signal QUALITY > 95% for watchable video. But not really sure why you are seeing differences between live and replay unless the various software is using different codec's that are handling errors differently ~

I note that you only list the single SATA drive, so Windows is installed on it ~ Just recording to PATA might not exclude SATA problems if Windows is paging to the SATA drive at the same time ~

No wireless LAN, Keyboard, Mouse etc ?

[Guest_Tellyaddict_*]

Ah yes - I'm using this machine as an HTPC, so it has a Logitech Bluetooth Keyboard/Mouse and a Netgear WG121 USB wireless LAN adaptor.

Do you mean that they could be interfering with the incoming signal? It's possible, but you'd expect the live picture would also be less than perfect.

Right now signal qualiy is 98% on all transponders strength is 84% to 87% - live picture is perfect as usual and recordings look like someone is sprinkling them with errors!

I suspect that it's something to do with activity on the SATA interface screwing up the decoding on the VisionPlus card, so I'll try and set the system up with just a PATA drive.

If it does turn out to be SATA related, I'm a bit concerned that the accepted fix for these kind of problems seems to be "don't use SATA drives" - isn't this really a bug in the DTV or SATA drivers that should be fixed??

[darro]

If it does turn out to be SATA related, I'm a bit concerned that the accepted fix for these kind of problems seems to be "don't use SATA drives" - isn't this really a bug in the DTV or SATA drivers that should be fixed?? 

I think you will find that most people have found the problem is not with the SATA drive, but with the e-cheapo controllers found on most MBs. There are a number of posts here that describe SATA drives working with add-in controllers.

Cheers
Darren

[Guest_Tellyaddict_*]

My Shuttle only has one PCI slot (with the VisionPlus in it) so an add-on controller card is not a solution for me!

From what I've read, only VIA and Silicon Image make built-in SATA controllers for Athlon 64 motherboards and both of them have this problem. This sucks! Surely this can be fixed by proper drivers? Who do I complain to? Shuttle? NVidia (chipset)? Silicon Image??

[Guest_JoeyBloggs_*]

Well I would isolate the problem first before complaining to anyone Rip out the wireless stuff and/or the SATA drive and find out what's actually causing the problem...

[Guest_Tellyaddict_*]

I think I've just proved it's SATA that's to blame: I hooked up an external 80GB PATA drive via USB2.0 and it records with WebScheduler perfectly... just so long as there's no activity on the SATA drive.

I forced some SATA activity by searching the drive and this introduced no end of corruption in the MPEG stream when I played the file back. As soon as the search stopped the recorded stream was fine again. Looks like any activity on the SATA interface b*ggers up the VisionPlus decoding.

So - is the SATA activity hogging the PCI bus or is it just producing radio interference?

Anyone got any hints on how to shield the SATA cable to eliminate that possibility??

[auenf]

I think I've just proved it's SATA that's to blame:  I hooked up an external 80GB PATA drive via USB2.0 and it records with WebScheduler perfectly... just so long as there's no activity on the SATA drive.

I forced some SATA activity by searching the drive and this introduced no end of corruption in the MPEG stream when I played the file back.  As soon as the search stopped the recorded stream was fine again.  Looks like any activity on the SATA interface b*ggers up the VisionPlus decoding.

So - is the SATA activity hogging the PCI bus or is it just producing radio interference? 

Anyone got any hints on how to shield the SATA cable to eliminate that possibility??

the problem is that the SATA controller is a PCI based controller, where a SATA controller that is integrated into the southbridge of the chipset (like the Intel ICH-5) doesnt use the PCI bus.

the Nforce3 SFF you are using uses the Silicon Image SATA controller, and some report that the promise SATA controller doesnt flood the PCI as much as the SI does.

pretty much your stuck with that SATA controller unless you use a PATA hdd instead.

Enf...

[Guest_SEl_*]

I have used Visionplus card in melbourne for serveral months and found it very good. I think for good reception a log peridic TV antenna is necessary. As you mensioned rubbish in is rubbish out.

[Guest_samueldavis_*]

Quote:
"VisionDTV is the correct way to play it back, you can use other apps after you have demuxed the mpg thru projectx (then mux again using a different app) to get rid of the errors."

I bought my Vision DTV to record TV and then burn it to DVD+Rs.

Does anyone know where I can get "ProjectX", and can anyone suggest any ways to burn the files onto DVD.


Many Thanks

[nate]

Does anyone know where I can get "ProjectX"

http://www.oozoon.de/
or
http://members.aon.at/johann.langhofer/index.htm

[Guest_sammo2828_*]

I'm experiencing something similar:

I have an Asus A7N8X-E Deluxe motherboard with integrated SATA controller. Showshifter 3.02 beta with Spectrum BDA drivers seem to be working when there is not much hard drive activity. However, when there are lots of reads/writes then the video and audio becomes stuttery and choppy. In general, viewing is okay, but recording is bad.

The only thing I can contribute is that hard drive activity doesn't seem to affect the quality under Linux. I tried Fedora Core 2 with new entries in modprobe.conf and used dvbstream piped to xine. The audio and video seemed to be fine even when I was doing some pretty intensive file searches. (this doesn't mean that you should quickly delete windows and install Linux - it is not without its own problems too!)

So, maybe it's a SATA driver issue under Windows?

If anyone else has tried the VisionPlus with integrated SATA in both Linux and Windows, it'll be good to hear from u too.

Cheers!

[Guest_sammo2828_*]

From what I've read, only VIA and Silicon Image make built-in SATA controllers for Athlon 64 motherboards and both of them have this problem.  This sucks!  Surely this can be fixed by proper drivers?  Who do I complain to?  Shuttle?  NVidia (chipset)? Silicon Image?? 

Hi

Do you have a link to the things you have read about integrated SATA controllers and VisionPlus?

The ones I could find are:

http://forums.dvbowners.com/index.php?show...indpost&p=16521
http://forums.dvbowners.com/index.php?show...indpost&p=15147

In my previous post (above), I said that hard drive activity doesn't seem to affect the audio / video quality under a Linux installation. I guess that sort of shows that proper drivers can fix it ..

--edit--

okay, under linux, i just did some more intensive file copying on the hard drive while watching tv and got some garbage output .. i kept copying bigger files and eventually the video and audio froze completely, and i had to manually kill the processes .. it also looks like SD channels are less susceptible than HD channels ..

overall, when there is hard drive activity, HD channels are more sensitive than SD channels. Also, Windows is more sensitive than Linux.

[Guest_sammo2828_*]

Hi all again,

GOOD NEWS! Especially for integrated SATA hard drive users.

After a really frustrating night of trying to get my visionplus card working without jerky audio and video during recording, I finally made a bit of progress ..

It seems that if the visionplus card shares the same IRQ as the SATA controller then there'll be problems. Go to Device Manager and View by Resources. Then check if it is using the same IRQ (mine was IRQ 18 for SATA controller and DTV Audio/Video devices).

So I tried changing PCI slots (which I think is mentioned elsewhere on this forum) and now I have *viewable* tv, and can even record.

I'll post more results later ...