[mythtv-users] Video Editing HELP! (COMPLETE noobie)

Douglas Wagner douglasw0 at gmail.com
Thu Jun 4 07:19:43 UTC 2009


On Thu, Jun 4, 2009 at 12:20 AM, Douglas Wagner <douglasw0 at gmail.com> wrote:

>
>
> On Wed, Jun 3, 2009 at 7:21 PM, Nick Rout <nick.rout at gmail.com> wrote:
>
>> On Thu, Jun 4, 2009 at 11:11 AM, belcampo <belcampo at zonnet.nl> wrote:
>> > Nick Rout wrote:
>> >>
>> >> On Thu, Jun 4, 2009 at 12:40 AM, barbex <barbex at gmail.com> wrote:
>> >>>>
>> >>>> So I loaded avidemux last night and gave IT a shot.  "Better" is a
>> >>>> phrase
>> >>>> that comes to mind, at least it's easy enough to use.  Getting rid of
>> >>>> commercials was pretty easy after indexing, and saving instead of a
>> 12 -
>> >>>> 15
>> >>>> hour process was about 30 minutes...
>> >>>>
>> >>>> That's about as best as I can say.  The video STILL doesn't work, it
>> now
>> >>>> looks like it's playing on x2 and there's still no sound.  I've tried
>> >>>> AVI
>> >>>> and mpeg video saving routines, all a no go.
>> >>>
>> >>> I was going to suggest avidemux as the only program I could find that
>> >>> made any sense to me. And I have successfully cut videos from mpeg
>> >>> files that mythtv recorded into new mpeg files. I remember that I had
>> >>> to pay attention to Transport Stream (TS) versus PS whatever stream
>> >>> and it failed on some files because of errors in the recording. There
>> >>> is some information here:
>> >>>
>> >>>
>> http://avidemux.org/admWiki/index.php?title=Editing_MPEG_capture_(DVB_or_IVTV)<http://avidemux.org/admWiki/index.php?title=Editing_MPEG_capture_%28DVB_or_IVTV%29>
>> >>> about that problem. So far nuv-files have stumped me but only because
>> >>> I got scared of ProjectX.
>> >>>
>> >>> ProjectX seems to be the solution to all and everything when it comes
>> >>> to video and repairing them. I am by no means an expert in this but I
>> >>> would try that next.
>> >>
>> >> I find dvbcut http://dvbcut.sourceforge.net/ to be very good at
>> >> cutting DVB material frame accurate before encoding with avidemux.
>> >
>> > Where can I read "frame accurate" cutting ?
>>
>> Most editors only cut to the nearest I frame, and doesn't have to
>> re-encode anything (as each GOP is maintained).
>>
>> DVBCUT is frame accurate and re-encodes enough to make new I-frames at
>> the beginning of the new GOP.
>>
>> Say you have a sequence of frames that you want to cut out the first
>> three frames.
>>
>> I B B x P B B P
>>
>> Normally you can't do that because the remaining sequence PBBP does
>> not start with an I-frame, the P frame needs the frames before it to
>> be decoded.
>>
>> So dvbcut re-encodes the remaining sequence to create a new GOP
>> starting with an I-frame.
>>
>> Hence on the web page: "It follows a "keyhole surgery" approach where
>> the input video and audio data is mostly kept unchanged, and only very
>> few frames at the beginning and/or end of the selected range are
>> re-encoded in order to obtain a valid MPEG file."
>> _______________________________________________
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>> mythtv-users at mythtv.org
>> http://mythtv.org/cgi-bin/mailman/listinfo/mythtv-users
>>
>
>
> Just wanted to post back to the thread to thank everyone for their posts.
> I'm learning ALOT here.
>
> Playing with avidemux on a video.  After indexing I notice that AVIDEMUX
> detects the frame speed at almost 60 frames / second in the recording
> (59.something), which seems strange since NTSC video is 30.
>
> When I play the file I get VERY scratchy sound, in essence it's as if sound
> is recorded something like every other frame or some such.  When I decrease
> framerate of the video to 30 I get perfect sound, however it is EXTREMELY
> out of sync with the video itself.
>
> I did manage to get rid of the double speed video by decreasing the frame
> rate to 30, but then of course sound is borked.  Simply playing the
> incomming video though avidemux (without doing anyting to it) has sound
> issues...I'm using ALSA:default.
>
> With Kino I get almost 30 minutes (29.somethign) into the video and it
> stops processing...however when playing the little bit I do get it's got
> fine quality sound and is in sync with the video.  Kino doesn't give me
> information on the frame rate or such that it's detected.
>
> I'll look at reading the recording back into Myth and trying the transcode
> steps listed above and see if I can get things going that way.
>
> Thanks all for the help, keep the information comming.
>
> --Douglas Wagner
>

Fast update to the thread.

MAJOR thanks to the person who turned me on to dvbedit above (Nick, thank
you), it works like a charm.  Opened, Indexed, commercial cut, and exported
without any problems or issues at all.

I particularly like the secondary slider allowing you to easily access frame
by frame information close to the frame in the primary slider, that makes it
REALLY handy to work with.

Cutting commercials was a snap and the program was just, well, easy to get
into and use.

One of my videos is now in good shape thanks to those of you on this
thread.  Next things next, I'm going to take a video I've had notorious
trouble with (It's still in MythTV as a TV Show, but prior transcodes have
failed misserably) and try to edit it via Myth.

Thanks VERY much for all the help.

--Douglas Wagner
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