Automated Cutting and Transcoding Guide Using Mencoder

[-stattik-]

I posted the first release of sTranscode here:

http://forums.nextpvr.com/showthread.php?p=361894

[vmq]

If you choose a resolution larger than the input resolution, it will autocrop and not resize just like you want.

That is a nice idea, I only tried the SD setting before so I didn't see that feature.

The original version of the script had custom crop settings for each of the resolutions that I was using. I then realized all the possible resolutions and decided to come up with an automated way to get clean crop settings. Currently, autocrop finds the correct settings for my test sources. If anything, I'd like to improve autocrop over adding custom crop settings.

I also have a modified version of your 0.5.6 script that does exactly that. I found that there are not too many input resolutions that need "manual" crop settings. For me it's 720x480 (analog) and 544x480 (clear-CAM SD) with 4/3 and 16/9. Maybe you can put the manual crop back in and leave it disabled unless autocrop is turned off.

Speaking of autocrop, I needed to change the mplayer command for cropdetect in your _sTranscode.bat:

Code:

start "sTranscode" /B /low /wait "%tool_path%\mplayer\mplayer.exe" %1 %sstep% -vf cropdetect=24:16,scale  -nosound -vo md5sum -benchmark >>"%~dpn1-ct.log"

I took out the -frames 100 and framestep=10, because otherwise I only got three [CROP] lines that were processed by CALL :crop_sort for a 45min recording.

With the patch I get about 45 and the statistics for the right crop get much better. Unfortunately cropdetect still gets it wrong for the file I was testing with. It failed to detect the lower letterbox bar in the recording in the second half of the file. I played with the cropdetect parameter, but that doesn't help. It looks like a bug in mplayer.

Alternately, you could add the exact crop settings in the transcode.ini file (crop_choice=720:352:0:62 ). That will work on every file in that directory.

Yes, that works, but isn't it ugly?

[vmq]

...
Maybe you can put the manual crop back in and leave it disabled unless autocrop is turned off.

Never mind, how about this: (patches attached)

customcrop.txt needs to be copied into the profiles directory. If an input resolution is matched to one of the lines in this file the crop values are used. If a file is identified to be letterbox (via the letterbox_patterns variable) the input resolution is modified with "lbox" ("<width>x<height>lbox") otherwise "full" is line is appended. All this is only done if use_custom_crop is set to yes.

Volker

[-stattik-]

For me it's 720x480 (analog) and 544x480 (clear-CAM SD) with 4/3 and 16/9.

I also test with 704x480, 720p, 1080i, 720x576, 544x576, and a number of odder resolutions that I receive from time to time. Seems not everyone captures in DVD resolution. As long as autocrop identifies pillarboxing, letterboxing, or CinemaScope, I've found the logic picks the best crop values for me every time.

I took out the -frames 100 and framestep=10, because otherwise I only got three [CROP] lines that were processed by CALL :crop_sort for a 45min recording.

Mplayer has trouble seeking in some sources, it also takes some time. Your change probably took a half an hour to scan a 43 min file. That's how long it would take on my PC.

It failed to detect the lower letterbox bar in the recording in the second half of the file. I played with the cropdetect parameter, but that doesn't help. It looks like a bug in mplayer.

Have you tried using comskip to determine cropping? I use comskip for all my shows and let mplayer detect cropping for DVD's since it has a much better time seeking. You're no required to cut if you run comskip either. If you choose no to cut using the edl files, sTranscode will just add chapter markers to the MKV file to identify the commercials.

Yes, that works, but isn't it ugly? [/QUOTE]

It depends on how you look at it. I have a show that is broadcast with pillarboxing AND letterboxing. Both mplayer and comskip can't identify both sets of crops. Without the sTranscode.ini file, I wouldn't be able to insert the correct crop(crop_choice=1424:800:250:140). And I only have to do it once because the rest of the episodes are handled in the same way.

[vmq]

I also test with 704x480, 720p, 1080i, 720x576, 544x576, and a number of odder resolutions that I receive from time to time. Seems not everyone captures in DVD resolution. As long as autocrop identifies pillarboxing, letterboxing, or CinemaScope, I've found the logic picks the best crop values for me every time.

This is true, the aspect detection of comskip and the derived cropping works fine, except that it is not able to detect the needed cropping when you want to remove only a few pixel at the borders, for example my analog letterbox recordings need about 60 pixel to be cut top and bottom (forks fine with the comskip logic) and also 20 pixel on the right and a few on the left. (Yeah, blame Time Warner Cable, but still the comskip logic does not detect this). Mplayer cropdetect can detect the needed cropping on all four sides, unforunately it fails in some cases.

Mplayer has trouble seeking in some sources, it also takes some time. Your change probably took a half an hour to scan a 43 min file. That's how long it would take on my PC.

I cannot comment on having trouble, I only tried a few files and everything was quick. My 43 min testfile, using the mplayer.exe from your "first release of sTranscode" needs about 20sec with my changes, and I got 43 [crop] lines. Works fine - in theory - except that the detection got it wrong in the second part of the file.

Have you tried using comskip to determine cropping? I use comskip for all my shows and let mplayer detect cropping for DVD's since it has a much better time seeking. You're no required to cut if you run comskip either. If you choose no to cut using the edl files, sTranscode will just add chapter markers to the MKV file to identify the commercials.

Yes, comskip works, except for the not detected "small border" problem. That's why I use my manual parameters.

vmq: Yes, that works, but isn't it ugly?

It depends on how you look at it. I have a show that is broadcast with pillarboxing AND letterboxing. Both mplayer and comskip can't identify both sets of crops. Without the sTranscode.ini file, I wouldn't be able to insert the correct crop(crop_choice=1424:800:250:140). And I only have to do it once because the rest of the episodes are handled in the same way.

In principle yes, but my wife sometimes wants different shows (in parallel) while I still record CSI. Problem, when recorded in HD CSI is 16:9, when analog it is 4:3 and needs some small border cropping, but both types are recorded into the same directory by gbpvr. This is probably not a common problem and the sTranscode.ini solution works in all other cases.

Btw, my previous patch can be trivially changed to handle your pilar+letterbox (centercut) recordings. A new centercut_patterns variable and a little code to handle <width>x<height>ccut formats would need to be added.

[-stattik-]

vmg,

I moved our discussion to the sTranscode thread.

http://forums.nextpvr.com/showthread.php...post363051