[mythtv-users] Editing out commercials

Muddy muddy at muddysmind.com
Thu Oct 30 17:59:36 EST 2003


Not sure if this will help you or not. I've been playing around with
avidemux and love it. I talked to the creator of it who suggested some
tips that payed off.
I'm using your basic bt878 card (ati tv wonder) and it's turning out
nice recordings.
Here is how I'm recording and ripping.
Mythtv is setup as 480x352, Codec mpeg-4, bitrate 2300, max quality 2
minimum quality 12, max diff 3, Enable High-Quality Encoding, Audio
Uncompressed @ 44100. 
Then in Avidemux I pretty much follow their "capture to svcd" guide. My
video is svcd processed @ Constant Quantizer=7 max bitrate 2300, audio
is ffmpeg audio @ 192kbps, and I do not crop per the guide as it gives
me wild color splashes in my video. I only use deinterlace and sharpen
for my filters.The half hour shows I have been ripping end up somewhere
around 350MB in size. The quality is quite good.



- 

On Tue, 2003-10-21 at 19:09, D Banerjee wrote:
> Sounds like you're missing the I frame after the next cut - mpeg is mpeg, if
> your data stream starts on an I frame it should render correctly. When you
> seek to I frame you may need to skip backwards one frame before making the
> cut. Ontopic here - mythtv can already seek to keyframes in edit mode.
> Should be pretty simple to write something that will simply concatenate
> segments..
> 
> ----- Original Message -----
> From: "James L. Paul" <james at mauibay.net>
> To: "Discussion about mythtv" <mythtv-users at mythtv.org>
> Sent: Tuesday, October 21, 2003 6:48 PM
> Subject: [mythtv-users] Editing out commercials
> 
> 
> > -----BEGIN PGP SIGNED MESSAGE-----
> > Hash: SHA1
> >
> > Perhaps this is somewhat off-topic here, but Isuspect other MythTV users
> > might have similar interests or experience doing what I want to do.
> >
> > Context:
> > I'm only talking about MPEG2 here, specifically the streams that the
> > PVR-250 and such spew forth. Has anybody here suggestions for removing
> > commercials from recorded TV shows? I did this with various windows
> > tools and MPEG1 for years under Windows, and haven't found any reliable
> > tools in the past couple years of looking under Linux.
> >
> > Goal:
> > Take a MPEG2 stream recorded by PVR-250 under MythTV, edit out
> > commercials, result in a MPEG2 stream usable for CVD or DVD. I don't
> > want to re-encode. I want to simply do GOP or I-frame cuts and get a
> > valid usable stream. Demuxing/remuxing is tolerable if audio sync
> > doesn't drift. Assume that the stream specs are already appropriate for
> DVD.
> >
> > What I've tried recently:
> > This week I tried avidemux, (and avidemux2, what's the difference?) but
> > could not get anything usable at all. I tried GOPchop, and everything
> > after the first cut is broken. I used mpgtx to demux the GOPchopped
> > file, so I could try gop_fixup to fix the broken time indexes left by
> > GOPchop, but gop_fixup didn't do anything at all, not even walk the file
> > or change a single bit.
> >
> > I used mplayer to note all the in/out points of the commercial breaks
> > and tried using mpgtx to split and join the file. Everything is broken
> > after the first cut. I tried leaving all the segments unjoined but only
> > the first segment was palatable to mplex and dvdauthor.
> >
> > What I ended up doing:
> > I had one show on the History Channel I wanted to get to my parents
> > right away, so I left all the commercials in and simply set chapter
> > marks at the end of each commercial break. Not what I wanted to do at
> > all. I used dvdauthor and mkisofs to generate the DVD ISO.
> >
> > Questions:
> > Is there a tool (under Linux) that I've missed that can do I-frame or
> > GOP cuts in an MPEG2 program stream and result in a correct and usable
> > file? (GUI or not.)
> >
> > Is there something better than mplex to generate a DVD compatible MPEG2
> > stream from element .m2v and .mp2 files? If not, is there a way to get
> > mplex to NOT split the output file at the 2G limit? (Using "-S 0" simply
> > doesn't do anything, it still wants to split the file.)
> >
> > Is there a tool better than dvdauthor for generating a DVD file
> > structure from MPEG2 file(s)?
> >
> > Thanks for any advice!
> > -----BEGIN PGP SIGNATURE-----
> > Version: GnuPG v1.2.1 (GNU/Linux)
> > Comment: Using GnuPG with Thunderbird - http://enigmail.mozdev.org
> >
> > iD8DBQE/lbfMT8BYaKRUpkQRAi+pAJ0Ywp22+BO7A+sCjt3FO8LBmIzQmACeOizW
> > E4/0IfqmiRkrYkimfIt9FAI=
> > =By0A
> > -----END PGP SIGNATURE-----
> >
> >
> 
> 
> ----------------------------------------------------------------------------
> ----
> 
> 
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