[mythtv-users] Announcement: Looking for Alpha testers for a generic Lossless cut solution
Doug Vaughan
r.d.vaughan at rogers.com
Thu Oct 11 10:46:00 UTC 2012
Stephen,
I appreciate you getting back to me on this problem video. So far I
have seen these other problems that have a slightly similar ring to them.
1) An HDHomrun recording device with one specific TV station whose
recordings consistently get cut with only the audio track. I have been
provided samples and will be looking at this issue today. Every other
channel that is recorded on the same device works well with Lossless Cut.
2) A specific UK DVB usb device creates recorded files whose audio track
cause mkvmerge to output a flood of "No audio header found" until
mkvmerge has a malloc() error and aborts. I suggested that this user
communicate with the MKVToolNix developers on their forum.
I would like to investigate your situation but can only provide more
help if I get a sample of the video. Please do two things. Update
Lossless Cut to v0.1.4 as a number if important bugs were fixed. Second
provide a sample specific to the video that Lossless Cut cannot process.
I know you already supplied one sample but I understood that to be an
issue over subtitle extraction and not a problem with interpreting track
information. In any event I tried the test described below on the sample
you had supply and the video and audio track was copied without issue. I
would need a recording sample from this other recording to do any more
investigating.
You can try to simplify the investigation with this set of tests.
Basically use mkvmerge to convert your whole video to a mkv file. No
cuts no other Lossless Cut processes. If mkvmerge can successfully take
the recording and copy the tracks to a mkv container then I can likely
fix Lossless Cut.
Try:
> mkvmerge -v -o "test.mkv" "/path to problem/recordedfile.mpg"
> mediainfo "/path to problem/recordedfile.mpg"
> mediainfo "test.mkv"
That will tell you definitively if mkvmerge can handle your recording
and what tracks (video, audio and subtitle) it recognises and copies to
the output mkv container. The two mediainfo commands will shows you what
tracks are in the original recording and what tracks mkvmerge copied to
the new mkv container. Expect the subtitle tracks to be dropped but
focus on the video and audio tracks.
Lossless Cut is totally dependant on mkvmerge to recognise audio and
video tracks. When it cannot Lossless Cut has reached a limit and that
recording device or at least a description on the circumstances needs to
be added to the Unsupported device list or Known limitations section.
Thanks for your help.
Doug
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