Finding errors in H.264 video

PoBear

New member
Hi

Hope I'm posting in the right place.

Running the latest version of TVSuite on a trial key but very impressed so far.

I record HD films from Freeview in the UK on a PC with suitable card.

Being an Over The Air system it can be subject to interference due to the weather etc. causing errors in the video, as a result I often record a film multiple times to try and get a clean version.

I'm trying to get an end copy with minimum errors by editing together clean clips from each recording, I can cut the clips and join them in VR but I need an easy way of detecting where the errors are in video so that I can (in theory) edit around them. What I don't want to have to do is watch each recording frame by frame so I can note where the errors are

Errors most often manifest as lost frames causing either a static image for several seconds, blank screen or pixellisation.

I'm unclear what the QuickSTream Fix does and whether this would help, any thoughts?

If VR can't help, does anybody have any recommendations?

Many thanks
 

cp2

Member
I use TSUMuxer. As it demuxes the file it finds any sync errors and where the re-sync has been carried out.

I suspect that there is a better solution involving VideoRedo itself but in the meantime...
 

Winnewup

Member
Hello,
I use VRD to do exactly the edits on recorded films you described. Sometimes there are errors in the recording but it is easy to find them in the logfile (perhaps you have to change the diagnostic level) if the output dialog gives any hint to an error. But be careful: if the output dialog says that there are only some audio frame errors it is better to have a look in the logfile, because most of the time there are video errors too, but these aren't displayed in the output dialog.
If you have found the errors in the logfile you can easy do your corrections (replace the part with errors) if you have another recording of the film with the same video and audio content with the joiner. It works good, but sometimes you have to modify the cut points a few frames to get cuts without pixelation (especially on I-frames).
VRD works much better than other programs I tried over the years. The HD-output is much better because only the necessary parts are recoded. Other programs often do a complete recoding, because the defined profiles don't fit exactly to the video you want to edit.
The synchronization (video/audio) is good too and there is a good support/forum.
The program doesn't have multi-track timeline or thousands of effects to make new vids but it is easy to use and is worth its money.
Frank
 
Last edited:

PoBear

New member
Thanks for the replies. I processed a file that I new had errors I the video stream but none of these showed up in the log, so I'm back to square one.
 

Winnewup

Member
Hello,
did you change the diagnostics level to "Medium" or "Advanced"? "Medium" works good for me and finds nearly all of the errors.
(Tools\Options\General Parameters\...)
If not please try again. If it doesn't find the errors, perhaps one of the admins has an idea.
Frank
 

PoBear

New member
I ran some more tests with the debug level set to Medium and Advanced and I'm not seeing any errors in the video stream.

How are you processing the videos to get the logs you are seeing?
 
Last edited:

Winnewup

Member
Hello,
I just set marks for begin and end and save the file (mostly ts-stream). If there are any errors it is shown in the dialog at the end of processing. If there are errors shown I have a look into the logfile ("help\Display VideoReDo.log").
Are you sure that there are real streamerrors in the file you captured? Or is the stream itself good and there are errors in the content of the file? (maybe the capturecard saves a correct videofile). In this case you would have to watch the whole film to find errors in the content. I don't know a programm that would be able to find such errors.

If there are real stream errors VRD doesn't find with the methods I described it would be a chance if one of the experts could help you.

Frank
 

PoBear

New member
OK thank you.

I've got two versions of the same film, both are showing audio errors but nothing for the video stream however one has quite a few dropped frames, bizarrely the one that reported the higher audio errors is the one with the fewer video ones.

I've looked at apps that would check the video stream but they are far too complicated looking at individual frames.

I guess I'm trying to do something that is not possible.
 

Dan203

Senior Developer
Staff member
We don't really keep track of the position of the bad frames, just a running total. You might be able to use the log, but the data is not easy to parse.
 

cp2

Member
We don't really keep track of the position of the bad frames, just a running total. You might be able to use the log, but the data is not easy to parse.
So, I'm going to restate my previous comment. I use TSUMuxer to demux the source file and report the time code(s) where it found it necessary to resequence audio and video channels. It does also offer you a second opinion. If the time codes fall inside areas removed during editing ignore it.
Usually I go to the indicated time code and see a "glitch" in the source file. Occasionally TSUMuxer reports no errors and, being sometimes pragmatic, I let it go.
 
Top Bottom