lotr encoding help me improve settings

[peterb]

I've done a DVD from the 3-set LOTR DIVX files. I'm using TMPGEnc for the encoding and I would like to have your advice on what I could improve in the process. This is how I do it:

starting files: DIVX. 23 fps, 640 by 272, 24 bit video sample size.

TMPGEnc settings.

Stream Type: Video Only, MPEG-2 Video
Size 704 x 576
Aspect Ratio: 16:9 display
Rate Control Mode: Constant Quality, CQ 75, min bitrate 1000 max bitrate 5000
Profile & Level: MP@ML
Video Format: PAL
Encode mode: Interlace
YUV format: 4:2:0
DC Component Precision: 9 bits
Motion Search precision: High Quality
Video Source Type: Non-Interlace (progressive)
Source aspect ratio: 1:1 (VGA)
Video Arrange Method: Full Screen (Keep Aspect Ratio 2)
GOP Structure: IBBPBBPBBPBBPBB
Quantize Matrix: Default

The result is very good but I think it still can be improved. These are some of my observations:

Sometimes colours are a bit "washed out" Especially in scenes with a lot of dark and grey in them.
Sometimes video is a bit jerky and not so smooth as I would like it. This is expecially noticable on slow flyover scenes, like when the fellowship is leaving Rivendell and Moria. Quick flyovers like over the river at Helms Deep are much better.
Jerkiness is also very apparent on the text with the "screening copy only" message that are scrolling right on the screen.

Any suggustion on how I could improve this ?

[Atlantis]

If you change it to PAL, how do you fix the audio?

[peterb]

Atlantis: I'm not sure I understand your qustion.

I do a direct stream copy of the audio to a AC3 file with virtualdub. Then I fix the header with AC3fix and then import it into maestro and author. Works perfect. For some reason i lose 2 seconds from the start of the file but that's no problem since I just slide the audio part in the timeline so the end is synchronized.

Your question might be related to what would happen if i speed up the movie by approx 4% by just changing the framerate. Since i did transcode it into 25 fps with TMPGEnc the resulting m2v is exactly the same lenght as the AVI input. However it's probably the reason why I get some jerky motion. It seems TMPGEnc just doubles around 1 frame per second wich gives the jerkiness that's most apparen in scenes with a lot of movement.

Since I want to get rid of that motion jerkiness it seems I only have two choices.

1) Keep the movie at NTSC by leaving video at 23.976 fps and enable 3:2 pulldown when playback

2) Speed up the movie and the aoundtrack with the usual 4.2% for NTSC to PAL conversion.

I'm currently trying option 2 and have split the AC3 into 5 WAVs and changed the speed with Besweet/Azid. Then I converted the 5 WAVs back to AC-3 with SoftEncode and ended up with a 2.51.12 long AC-3 soundtrack instead of the original 2.58.33.

I'm also transcoding the video with 10 bit DC component precision and Very High Quality and 2 pass VBR instead. Should be done within the next 12 hours or so.

I will also experiment with getting the video of the SVCD:s instead of the DIVX but i don't know if that will make any difference. Since the DIVX has better horisontal resolution and the quality of the DIVX is very good I think that SVCD actually might produce worse results.

[peterb]

next 12 hours was optimistic. 24 hours seems more like it.

[Atlantis]

It's better you stay in NTSC. Encoding an NTSC source to PAL and trying to keep the original length is a bad idea. It will create duplicate frames.

[peterb]

the transcoding is finally finished and results are very good. The jerkiness disapperad when I changed the speed of the movie instead of keeping the lengt. Adjusting the length of the audio as descibed eralier worked perfectly. No problems synchronizing. Since the file produced was smaller than I expected I will try again using VBR avg 2000 kbps instead of 1600 as earlier. I want to find the maximum size and still be able to fit it on one dvd-r and have room for menus etc. Since I will be away for a few days I might as well leave the PC working anyhow.

Atlantis: You are absolutely right that it's a bad idea to try to convert to PAL and keeping the lenght. That's what I found out the hard way. But since this test went so well I will probably end up converting to PAL and speeding it up. Since I'm in sweden I will probably have friends borrowing this film that have TV:s that don't support NTSC.