Automated Cutting and Transcoding Guide Using Mencoder

[pBS]

anyone know how to get mencoder to cut only on i-frames?
[i remember seeing that somewhere recently but can't find it anywhere]
it would fix all the av-sync issues on transcodes..
have you tried adding -idx to make the resulting file skip better?
seems to work for me...
seems that if a cut isn't on an i-frame the audio goes ever-so-slightly out of sync from then on..
any ideas?

[pBS]

finally found it and it does seem to work... -hr-edl-seek
it makes mencoder read the whole file straight thru,pausing only encoding at cut points....from a mplayer man page:
****
-hr-edl-seek (EDL only)
Use a more precise, but much slower method for
skipping areas. Areas marked for skipping are not
seeked over, instead all frames are decoded, but
only the necessary frames are encoded. This allows
starting at non-keyframe boundaries.
NOTE: Not guaranteed to work right with '-ovc
copy'.
****
it fixes the blocky cutpoints and it fixed sound sync on my encodes and the -idx really does help the seeking..
i couldn't find it in the regular manual page but they say it is kinda outdated..
just thought i'd share the info...working excellently now,almost ready to redo ALL my files..
here's my encoder line,i get 40fps on 1.8ghz P4...so far they burn well to dvd too..
:edit
Oops,i forgot to adjust for non-dvd source, you have to use :ildct to preserve the telecine info in the mpeg,cuz the captures are coming from the interlaced s-video inputs,they are captured at 29.97 fps and film content is already telecined before they broadcast it...also you can use :ilme and :mbd=2 to enhance quality and compression but at a non-realtime framerate..
******
mencoder.exe %name% -edl "%~dpn1.edl" -hr-edl-seek -of mpeg -mpegopts format=dvd -oac lavc -ovc lavc -lavcopts vcodec=mpeg2video:ildct:vqscale=4:keyint=16:vmax_b_frames=2:dia=2:acodec=mp2:autoaspect:abitrate=128:turbo -noskip -o "output.mpg"

[sbp]

Hi Stattic

Have you found out how to encode my clip without loosing sync.
I have tried several setting but still without succes.
Mencoder complain about a lot of dublicate frames. I have tried the -mc 0 and -noskip, didn't work.
I can see that you have this: 24000/1001 -o, is that for PAL also?

Regards
Steen

[-stattik-]

Hi sbp,

I haven't had a chance to test it lately because I've been really busy but I should have some time this weekend. A recent compile of mencoder was released by celtic_druid on the 1st that I'd like to try. Perhaps it will fix your problems. 24000/1001 is FPS for film. For PAL I would use -ofps 25.

Here's the link to the new mencoder compile:

http://www.aziendeassociate.it/cd.asp?dir=/mplayer

[-stattik-]

Steen I believe I've found a fix to the avsynch issues.

Replace the tandard config line with this:

start /low /wait %mencoder_path% %name% -edl "%~dpn1.edl" -ovc xvid -xvidencopts bitrate=900:me_quality=6:chroma_me:noqpel:chroma_opt:vhq=4:bvhq=1:trellis:hq_ac:gmc:quant_type=mpeg:max_key_interval=240%turbo% -oac mp3lame -lameopts mode=2:cbr:br=128 -vf filmdint,softskip,scale=512:384,hqdn3d=3:2:3:3 -ofps 24000/1001 %test% -mc 0 -o "%~dpn1.avi"

This fixed the synch isues for me when testing your file. If it works for you I'll release an update to the script.

[wtg]

Hi sbp,

I haven't had a chance to test it lately because I've been really busy but I should have some time this weekend. A recent compile of mencoder was released by celtic_druid on the 1st that I'd like to try. Perhaps it will fix your problems. 24000/1001 is FPS for film. For PAL I would use -ofps 25.

Here's the link to the new mencoder compile:

http://www.aziendeassociate.it/cd.asp?dir=/mplayer

The Athlon 64 build doesn't work for me... I get an error saying it can't find intl.dll, which isn't part of the archive.

Also, any idea what the changes are supposed to be in this build vs. the earlier Nov build? There doesn't seem to be anything that says.

[wtg]

Steen I believe I've found a fix teh avsynch issues.

Replace the tandard config line with this:

start /low /wait %mencoder_path% %name% -edl "%~dpn1.edl" -ovc xvid -xvidencopts bitrate=900:me_quality=6:chroma_me:noqpel:chroma_opt:vhq=4:bvhq=1:trellis:hq_ac:gmc:quant_type=mpeg:max_key_interval=240%turbo% -oac mp3lame -lameopts mode=2:cbr:br=128 -vf filmdint,softskip,scale=512:384,hqdn3d=3:2:3:3 -ofps 24000/1001 %test% -mc 0 -o "%~dpn1.avi"

This fixed the synch isues for me when testing your file. If it works for you I'll release an update to the script.

So it's the %turbo% and -mc 0 options that changed here? What do they do? (Besides of course what you said, which is fix the avsynch issue )

[tpgbpvr]

Anyone have a good profile for ipod mp4 for mencoder? I am at a loss.

Any help appreciated.

the specs from apple are:
MPEG-4 video: up to 2.5 mbps, 480 x 480, 30 frames per sec., Simple Profile
with AAC-LC up to 160 Kbps, 48 Khz, stereo audio in .m4v, .mp4 and .mov file
formats

Thanks

[-stattik-]

The Athlon 64 build doesn't work for me... I get an error saying it can't find intl.dll, which isn't part of the archive.

Also, any idea what the changes are supposed to be in this build vs. the earlier Nov build? There doesn't seem to be anything that says.

I've only tested the Athlon XP build. I'll try the Athlon64 build tonight.

As far as changes go, this is what I gleaned from CVS:

http://www1.mplayerhq.hu/cgi-bin/cvsweb....5&r2=1.276

There isn't anything in there that directly affects this script.

[-stattik-]

So it's the %turbo% and -mc 0 options that changed here? What do they do? (Besides of course what you said, which is fix the avsynch issue )

%turbo% was an option that was added in a previous release. Enabling it in the settings will give you up to 12% faster encoding with a negligible loss in quality.

-mc 0 is the only change. If it works for Steen, I'll add it to an updated script.