Automated Cutting and Transcoding Guide Using Mencoder

[agerdin]

stattik, how do I combine 2 or more profiles? I have tried using "+" but I am not sure thats it?

Can you give an example of twopass and HD?

\\Anders

[-stattik-]

Assuming the show name is Prison Break

SET twopass_patterns="+twopass" "Prison Break"
SET hdtv_patterns="+hdtv" "Prison Break"

It's case sensitive so verify how GBPVR creates the file name. You can add as many show as needed. Technically, the script should detect if the input is HD.

Here are the conditions that will automatically flag the recording as HD:

If the aspect ratio is 16:9
If the video is greater than 1270

Hope this helps

[agerdin]

stattik,

I got things working now except for the twopass profile. I am looking to transcode some of my recordings into an acceptable divx quality. To do this I am using the twopass profile and the setting use_twopass_size=yes, but irregardless of what value I use for twopass_15_min_size the file is of the same size and the quality is not good enoguh. Actually, the file is identical even if I set use_twopass_size=no Just to illustrate I transcoded a movie with the size setting to 166 which is almost double the size per default. I am also using in comskip mode. The version of mencoder is the latest P4 build from http://ffdshow.faireal.net/mirror/mplayer/ (mplayer2007.03.31.P4.7z) as per your earlier suggestion.

I am attaching the log, the script I am using and the gspot information I get.

If you have the chance to look at this I would appreciate it.

\\Agerdin

[-stattik-]

Hi agerdin,

I looked at the logs. The script seems to work correctly. It sets the suggested size to 1245392kB

Code:

xvid: 2Pass Rate Control -- 2nd pass -- total size=1245392kB

My guess is that xvid doesn't need more than what it used to encode the file.

There's a few things you can try.

One thing you can try is to increase the output resolution with the two pass. 640x480 would work or you could choose the same resolution as the original.

Here's another option. Are you looking for a specific size when transcoding? If not, I'd try a fixed quant encode. The quality will be smiliar to a two pass but the size may differ. A quant of 3 is the default, but you can use 2 if you want higher quality. (SET fixed_quant=2)

You could try another version of mencoder as well. I haven't tested 3.31 yet. I'm still using 2.10.


Tell me how it turns out.

[agerdin]

stattik, thanks for your help. I ended up using quant = 2 and kept it to the original size 720x576. That will do for now. I also temporary reverted back to 2.10 of the mencoder but with no difference. However, I still think there are room for improvements since the quality using autoGK or straight virtualdub gives me better quality???

I am also wondering how the profile "letterbox" is working, I would assume it tries to remove the black bars on top and at the bottow, but how does it know where to cut or is this configurable?

\\Agerdin

[-stattik-]

stattik, thanks for your help. I ended up using quant = 2 and kept it to the original size 720x576. That will do for now. I also temporary reverted back to 2.10 of the mencoder but with no difference. However, I still think there are room for improvements since the quality using autoGK or straight virtualdub gives me better quality???

I would take a clip and run it though all apps, then run the different outputs though gspot. Perhaps post them here and I'll take a look at them. Are you using xvid for the other apps as well? I can probably get a little more quality out of mencoder after seeing the gspot outputs. I plan on adding some x264 encoding in a future version of the script but I haven't started that yet. That should add some more quality as well.

I am also wondering how the profile "letterbox" is working, I would assume it tries to remove the black bars on top and at the bottow, but how does it know where to cut or is this configurable?

The script takes the vertical resolution and applies a simple algorithm to it to remove the black borders.

[psicotron3]

I´m trying to add your batch file as a transcoding profile in gbpvr.

Everything works fine. But when I tell gbpvr to stop the transcoding, memcoder continues to run!!

It does the same way if I use "start /wait /low" "call" on nothing to call mencoder from within the batch file.

when I change "start /wait /low" to "call" in my windows schedule job it works great and kills everything at the specified end time of the job.

Is there a way to make gbpvr do the same? This is the only thing that keeps me from using it as a custom conversion profile.

[-stattik-]

So you substituted the "start /wait /low" with "call" and mencoder still runs after you stop the transcode from within GBPVR?

I don't know how GBPVR stops the transcode. With that knowledge we could find out why mencoder still runs after the transcode is "stopped."

[blizard]

How do I use your script stattik? I have read this thread and wiki, but got lost on the way. Where do I start?

I have not yet used comskip or any other features except for AutoGK and now recently tried GBPVRs auto transcode to XviD. AutoGK make a very good quality AVI for the target of file size, but to the cost of encoding time. I compared AutoGK and GBPVRs FFDSHOW and the latter was faster, but it also had some problem with cubic looking text.

My original MPEG2 are recorded at 8000 kbps to have the highest quality as source.

I would like to try to cut out commercials to shorten transcode time and to get a better file size. Transcode for even smaller files size before watching the show. As I understand it your script offer these option and can do this with no human interference when it is set up correctly.

Would be thankful to know where I can find your script and how to use it. I have downloaded comskip79_95.zip, but will first read more on how to use it before I install it.

/blizard
____
I use K-Lite Mega codec package which also contains FFDSHOW and Xvid MPEG-4 Video Decoder for endocing/decoding with CoreAAC and CoreAVC for pure decoding usage.

My CPU are Athlon64 X2 4200+, so any codec that can take advantage of optimization of this CPU would be great.

[psicotron3]

So you substituted the "start /wait /low" with "call" and mencoder still runs after you stop the transcode from within GBPVR?

I don't know how GBPVR stops the transcode. With that knowledge we could find out why mencoder still runs after the transcode is "stopped."

I´ve found on another thread someone talking about running comskip on the conversions menu. Can´t find the thread anymore, but he falled into the same problem.

I looks that gbpvr kills the process it started and left anything else.

Maybe sub can help us here.

And about the sugestion I made for using cbr (constant bitrate) in the DVP-642, after some tests I found out that the generated xvid is TOO large, almost twice the size it have with "abr". So I think you can let the dvp-642 option as it is now.