Tvheadend

Well, it almost works...

If the stream is error-less, then it works perfectly. The only drawback is that there's seemingly no way to keep the DVB subtitles, which isn't really an issue for me.

However, if there is an error, then avidemux borks with a "too short" complaint; most likely cause is "missing or incorrect timestamps (pts/dts)". ProjectX isn't fixing the error for me just yet, so maybe I'll need to run some files through Handbrake anyway just to bludgeon the errors into submission (assuming this one isn't corrupt beyond repair). A small price to pay if it saves me 8 hours on most/some/any files, though...!

Okay, using this as a diary/scratchpad - you never know, it may be helpful for someone else! - here are my conclusions so far:

1. If the stream is error-free, avidemux will chop it neatly. Keyframes are every second or so on my .ts streams.
2. If the stream has errors, avidemux will fail ("video too short" - most likely pts/dts errors).
3. avidemux works better with .mkv and .ts output containers than .mp4 - these sometimes have weird lengths and/or you can't seek properly through them.

In terms of fixing the file:

1. TSmuxer introduces sync problems.
2. ProjectX doesn't work with H.264 video streams.
3. Recoding it in Handbrake fixes the streams but takes ages
4. Simply remuxing into mkv with mkvmerge also seems to fix the timing, and doesn't introduce any sync errors

So:

1. If it's error-free: avidemux, trim and output to mkv, job done.
2. If it has errors: remux into mkv with mkvmergegui, then into avidemux to trim and back out to mkv

I'm half inclined to remux everything into mkv as a post-processing script to save a bit of time, since avidemux should then always accept the output.

I'd still rely on Handbrake rather than avidemux's x264 video filter if I need to process the stream further - e.g. cropping an overhanging DOG off the top of the image - but that's by the by.

Or, of course,

2. If it has errors, use avidemux to find the appropriate cut points and then just use a simple EDL file, leaving the original untouched.

This is probably the best, as it's really hard to fix timing issues if the data is corrupt or not there. While remuxing does a decent job, I've noticed some stuttering of the video as it keeps synched, which isn't apparent in the TS file. I'm assuming that the error correction is sufficient to bludgeon its way through errors on the original.

Prof,

I haven't read your full thread. But I used to just use avconv (with a wrapper script) to manually cut (top and tail only, most stuff I record is on channels without commercials during the feature) and remux to MKV (manually as in I would determine the cut points in VLC etc...). The only change I've made recently is to switch to TS due to some recent problems with BBC services.

I've only recorded a handful of things with ads inline and thus far haven't even bothered to cut them. But my plan is probably just to cut the individual chunks and then use the XBMC naming convention (-partX) to have XBMC auto stitch them together on playback rather than worry about properly re-stitching the files. Although I think if you concat .ts files, ffmpeg just about copes (sometimes).

I no longer bother with any transcoding. The only thing I used to transcode (and probably still would) is DVD to H264, but then I very rarely buy DVDs these days. If I do buy stuff I prefer to get blu-rays.

Adam

Thanks, Adam. Yes, most of my stuff is advert-free as well - so I'm really just clipping off the recording pre- and post-amble for neatness and family-friendliness. There's the odd commercial-riddled C4HD film or stuff for the kids that needs more attention, but not much.

I'm landing on the EDL as the simplest way of "trimming" ts files, and leave it at that. Life's too short, after all, and XBMC has better EDL support than the original mplayer et al (e.g. HH:MM:SS.sss as reported in avidemux instead of 3600*HH+60*MM+SS calculations). I've also spent far too long with VLC trying to seek cut points, only to find them half a second out. And don't get me started on comskip.

I may choose to transcode to trim off the channel DOG on letterbox films. Otherwise, the only re-encoding I've had to do is where tvheadend recorded a seemingly-duff primary audio track; Handbrake repaired that even if VLC and XBMC struggled with the original.