Detect DVB recording errors

[Supremus]

Sometimes when I record big DVB files, typically 1 hour+, I will sometimes get the occassional picture break-up. I am not entirely sure what causes it, but I assume it's down to signal strength issues. I have tried a booster, but it introduced too much noise and caused lock-up issues.

Anyway, it's a rare problem, but it happens. I was wondering if there is a tool that will scan a DVB file (ts, m2v, whatever) and report any errors. If it's a long recording, it's a pain to have to watch the whole thing to see if something went wrong, particularly if it's something I wasn't planning to watch for a while. Neither PVAstrumento or ProjectX report these errors. The problem usually manifests itself as a few corrupt blocks in the image or a short picture freeze, depending on which software I use to play them back.

[Soopafresh]

Are you sure ProjectX doesn't report the errors ? You can try Mpeg2repair - it works on Transport Stream files only, and has good error logging capability.

[Supremus]

Nope, I don't get any error messages from ProjectX, but there is clearly a minor corruption issue on playback. MPEGrepair doesn't recognize my TS files. It says it failed to find video PID. I tried creating a TS file of my own using ProjectX, but that didn't work either, so I guess MPEGrepair just doesn't like me.

[SatStorm]

This happens very often,especially when a DVB channel change mode from 4:3 to 16:9, or change audio (from mono to stereo and vice versa).
Other reason is the switch on / off of another channel inside the same TS. It is a well known flaw of MCPC transmissions.
DVB receivers use buffers etc, so you won't notice it, ever. But when you record the stream, those issues pop up.
There is only one cure for the problem: Fix it during the "capture" (transfer is a better term).
Some programs during the capture, drop bad video and audio frames to keep in synch or avoid picture breakups. You won't notice this at the final file in normal situations. This is what dvbrecorder 1.19e does with older Nokia 9xxx receivers (the ones with SCSI ports).
Others automatic split at the point of the problem. Unfortunatelly this can lead to a huge number or splited files

The new "solution" which IMO is not as good as the first used (the one with dvbrecorder) is grabbing all the satellite stream, the so called TS info. That has benefits and flows. Beyond the fact that the files are bigger, you have to run later a second program to "export" the elements of the TS file you wish to keep. Unfortunatelly, the TS files keep the flows inside too. A huge problem.
The solution is to fix the TS file first and then export the elements you wish to keep.
There is no program yet that can do this 100%

I know first hand that womble's mpeg2vcr can sometime handle dvb TS files "as is" and correct issues. You can also "cut" bad frames manually, without notice it during playback. The problem is that only half "broken" TS files can be fixed like that.

After a while, you turn to capture analogue your DVB sources, because you can't deal with those f@#$% issues!

ORRR you get an old trusty Nokia dbox 1 (9x00) like I do the last 6 years and grabbb and grabbb and grabbb without stupid issues! But this is a European thing, you won't be able to use it easy on US/ Australia / etc...

[Supremus]

I actually use a Dbox2, and I am generally very happy with the results, but like I said, sometimes I get the occassional brief freeze or corruption on long recordings, and I rarely have time to go through each one and check for such errors, which is why I hoped there might be a piece of software that effectively scanned for errors, so I could either wait for a repeat or edit out the offending frames.

It does sounds like MPEGrepair would have been up for the job, but since it won't read my TS files, I'm stuck. Maybe I should try and email the author and see if he wants to have a look at one of my TS samples and perhaps fix any compatibility issues. I haven't had any problems with any other apps reading them.

[TBoneit]

Try the latest Beta of VideoReDo. You'll need to get a trial unlock key first (Free) so it will handle the entire file. Then What I do is open VideoReDo, Use the Quickstreamfix that under the tools menu without ever opening the .ts file first. Run Quickstreamfix with the output to another drive for speed. That will output as elementary streams, MPG or VOB format.

At that point it is fixed for me and I can then open in VRD run the commercial detection and edit the file.

Cheers.

[Supremus]

Tried VideoReDo. Not sure what the Quickstream Fix actually fixes, non compliant GOP length perhaps? It certainly didn't report any errors or fix my corruption problem. Thanks for trying, though

[TBoneit]

In general When I Qucikstreamfix a .ts file it will report that it fixed several types of errors. It can fix GOP length too but that will add to the processing time.

If you were using the beta and it didn't help their support may be able to help. Leave a feedback about your problem and they'll probably ask you for a piece of your file to see what is happening and be able to come up with a cure. I had good support even before I purchased it,

Good Luck

[Supremus]

OK, in case anyone has this problem in the future, here's what I did to fix it: I ran the original TS, which MPEG2repair wouldn't accept, through ProjectX to create a new TS file. MPEG"repair was then happy to read the new file and spotted a couple of minor errors, fixed them, and hey presto, after a quick ProjectX DeMux of the fixed TS files I have an error-free MPEG2 file ready to go on DVD.

[Soopafresh]

Nice one. Amazing how powerful that software is, especially for free