Automated Cutting and Transcoding Guide Using Mencoder

[DrDDT]

I also have a quality question:

How can I transcode recorded PAL tv (4:3) to a smaller disksize with the least quality loss?
I'm already removing all the black bars around the picture, but standard xvid settings seem to introduce a slight blurring of some parts of the image.

Transcoding speed is not an issue.

[-stattik-]

I'm trying to come up with a solution to make better usage of the available drive space for recording without loosing quality with re-encoding unless the original source "old".

I'm looking to have stattik_transcode executed at the end of any recording from ParallelProcessing.bat or simply a scheduled job to look for any original recordings older than a definable number of days in addition to having logic that allows the trancoding of "old" recordings only if free drive space is below a defined value.

The current version of the script that was posted here in the thread should do what you want. For instance, you could set it to only transcode files older than a week. Or you can set it to only transcode when drivespace drops below 20 GB free. Of you could do both.

[-stattik-]

I'm recording network HDTV and displaying on a 1080p display. What kind of impact on encoding time and resulting size does it have if I skip scaling down?

There will be a significant impact if you increase resolution. I get about 24FPS using the default settings. If I transcode to 720P @24FS, I get about 5FPS. I haven't tested things out for the best quality/speed ratio yet because I don't have a HDTV yet. Perhaps in a few months that will change.

What FPS would you consider fast enough for encoding? Then we could figure out the best quality for it. The script can also run on multiple PC's at once if needed.

The best overall quality would be to turn off scaling completely.

Code:

SET SDvideo_width=full
SET HDvideo_width=full

That works currently but will depreciate when I add the full_resolution option in the next version. I would also set:

Code:

SET output_fps=ivtc

unless you're PAL.

x264 would also be preferred over xvid if you can play it back smoothly.

Code:

SET video_encoder=x264

It encodes a little slower but it supports multiple CPU's and saves about ~30% on space.

[-stattik-]

I also have a quality question:

How can I transcode recorded PAL tv (4:3) to a smaller disksize with the least quality loss?
I'm already removing all the black bars around the picture, but standard xvid settings seem to introduce a slight blurring of some parts of the image.

Transcoding speed is not an issue.

Here's what I would suggest:

Code:

SET video_encoder=x264
SET full_resolution=no
SET SDvideo_width=full
SET HDvideo_width=full
SET output_fps=auto
SET CPUs=2
SET x264_quality=18

x264 is a a little slower than xvid but you get smaller file size and typically better quality. If you want to stick with xvid, choose fixed_quant=3 or two_pass.
full_resolution will be fully implemented in the next version of the script.
output_fps is auto because you're PAL
be sure to add the amount of CPU cores you have.
x264_quality can go as far as 16 but you probably won't see much improvement from 18. It's not any slower, it just sets the bitrate. The lower the number, the higher the bitrate.

Obviously I would suggest testing this out before putting into production.

Technically there's some more quality you can squeeze out of x264 but there's a large performance hit. (~60%) See how the above works out.

[-stattik-]

I downloaded this from the "reliable" link in the wiki:
http://www.mplayerhq.hu/MPlayer/releases....0pre8.zip

The reliability pertained to DVD parsing. I would recommend the processor-specific builds here:

http://tirnanog.fate.jp/mirror/mplayer/

I use 2007.12.03 currently. I'll post a patched version of the script for PSP's here after I test of the files it's created tonite.

[lstepnio]

I'm encoding HDTV TS and I've been playing around with finding a configuration to keep encoding time reasonable while keeping quality near transparent from typical viewing distances.

I'm testing encoding to 1080i and 720p shows to 1280x720p xvid using fixed_quant=2 with good results with the test encodes so far with around 7fps encoding on my low-end AMD Athlon.

SET video_encoder=xvid
SET keep_ac3audio=yes
SET HDvideo_width=1280
SET HDvideo_height=720
SET fixed_quant=2

What effect does HDvideo_width=full compared to keep_resolution=yes have?

also, container=mkv doesn't seem to work. i don't even see logic in the script for anything except for mp4 and avi.

[h00ch]

The reliability pertained to DVD parsing. I would recommend the processor-specific builds here:

http://tirnanog.fate.jp/mirror/mplayer/

I use 2007.12.03 currently. I'll post a patched version of the script for PSP's here after I test of the files it's created tonite.

Thanks, appreciate all the help. I tried using the P4 latest build but now I get an error about not being able to find "pthreadGC2.dll". Any ideas?

[-stattik-]

Thanks, appreciate all the help. I tried using the P4 latest build but now I get an error about not being able to find "pthreadGC2.dll". Any ideas?

http://ffdshow.faireal.net/mirror/pthreadGC2.dll.7z

Just extract it and put it in your mencoder folder.

[-stattik-]

I'm encoding HDTV TS and I've been playing around with finding a configuration to keep encoding time reasonable while keeping quality near transparent from typical viewing distances.

I'm testing encoding to 1080i and 720p shows to 1280x720p xvid using fixed_quant=2 with good results with the test encodes so far with around 7fps encoding on my low-end AMD Athlon.

SET video_encoder=xvid
SET keep_ac3audio=yes
SET HDvideo_width=1280
SET HDvideo_height=720
SET fixed_quant=2

Sounds good.

What effect does HDvideo_width=full compared to keep_resolution=yes have?

also, container=mkv doesn't seem to work. i don't even see logic in the script for anything except for mp4 and avi.

HDvideo_width=full leaves the resolution as it is. keep_resolution will replace this but it's not fully implemented yet.

I must have removed the mkv container option. I seem to remember that i was getting a/v synch errors. I'll have to revisit it.

[-stattik-]

I downloaded this from the "reliable" link in the wiki:
http://www.mplayerhq.hu/MPlayer/releases....0pre8.zip

Here is an updated version of the 0.5.2a script with the psp profile updated.

It's by no means finished but it will encode PSP-compliant mp4 files. I plan to add some more psp features in the very near future. See how it works with processor-specific builds or the RC2 build..