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

Nick Rout nick.rout at gmail.com
Thu Jun 4 19:58:20 UTC 2009


On Thu, Jun 4, 2009 at 7:19 PM, Douglas Wagner <douglasw0 at gmail.com> wrote:
>
>
> 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)
>>> >>> 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."
>>> _______________________________________________
>>> mythtv-users mailing list
>>> 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.
>

Yes thats a very fine feature, I used to use projectx for the same
task but the UI is better in projectx

> Thanks VERY much for all the help.
>

our pleasure :-)


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