Can't "jump" forward/back reliably on some recordings

[dinki]

Hey guys. I'm having an issue where I cannot "jump" forward/backward reliably within XBMC. I am referring to the jumps when you press right/left on the remote and not >> or >>| . When I press right/left, the time advanced or may even go backward at odd intervals. This is only for some recordings. Unfortunately I have not tried this in the native nPVR gui and have deleted the last recording that this happened with before thinking of trying it in the nPVR player.

I have the same problem with multiple XBMC clients (GBox MX2 and RPI running openelec). I am running XBMC Gotham Beta 3 on both XBMC clients though I'm pretty sure this issue occurred with Frodo as well. I am running nPVR 3.1.1 and using sub's pvr addon on XBMC.

Any advice is greatly appreciated. I am attaching logs in the hopes someone can spot an issue. Search the logs for the program 'The Profit' to see the odd jumps. Thanks for the help.

[dinki]

A gentle bump. Can anyone shed some light on why I am having this problem?

[sub]

I'm not sure what to tell you on this one. XBMC's playback isn't as good at seeking in TS files as NextPVR's playback is. It's more prone to not handling well broadcaster's imperfect timelines.

[dinki]

Thanks for the reply. I'm not sure I totally understand what you are saying. It's almost like the ts file has a bad index or something. I've seen this before with avi files where you could watch from beginning to end without problem but when trying to seek within the file it would jump around wildly. I guess I'll have to find an example and ensure that it plays well in the native nPVR gui.

[sub]

AVI/MP4 files have a nice header at the start of the file, which tells the player exactly where to jump for each time code.

TS files don't have this. Instead they just have a timestamp on each packet through out the file. Basic players look at the first timestamp, and the last timestamp to work out the duration based on the file size, and just use that to guesstimate where to jump. Unfortunately that doesn't take into account the fact that the timestamp doesn't always consistently increase through the file. Broadcasters can be stitching shows together etc, without fixing the timestamps, so you can end up with the timestamps resetting part way through the file etc.

[dinki]

Oh wow! That definitely sounds like a problem. This sounds bad. So short of transcoding the TS files into avi/mp4 files there's not much that can be done, right?

[sub]

If it causes problems in your setup, you can try remuxing the files after they're recorded (like from PostProcessing.bat), to give them a nice consistent timeline. There is a couple of utilities that do this, but the names escape me right now.

[dinki]

Thanks again. Are you talking about a tool posted here on the forum or elsewhere? I did a google search and came up with TsRemux at http://www.videohelp.com/tools/TsRemux .. Is that what you're talking about?

*EDIT* Or is it retime http://gbpvr.com/pmwiki/pmwiki.php/Utility/ReTime ?

[sub]

Thanks again. Are you talking about a tool posted here on the forum or elsewhere? I did a google search and came up with TsRemux at http://www.videohelp.com/tools/TsRemux .. Is that what you're talking about?

Yep, tools like this. I've never used them myself though, so can't give you too much advise on their use.

[dinki]

One last thing. If I do something like this in my postprocessing bat file:

move [the code for filename] broken-[the code for filename]
tsremux.exe broken-[the code for filename] fixed-[the code for filename]
move fixed-[the code for filename] [the code for filename]

Will that work once I set the correct variables? I'm guessing it will as I end up with the same name as before so the database doesn't need to be updated, right?