inconsistent resolution calculation in batch

[srotman]

I'm a new user but have quickly picked up AutoGK. My first project is encoding all of the first season of Fox's 24. My problem arises when I have set AutoGK to batch encode the first 8 episodes of the show. At the moment, I'm not using ANY hidden options.

My settings are as follows:
Audio: English AC3 2ch (the only one available)
Subtitles: No Subtitles
Output Size: 1/2 CD (350Mb)
Output Audio: 128kbps VBR MP3
Resolution: Auto
Codec: XVID

Using these settings I let AutoGK go at it with the first 8 episodes that are ripped directly from the original DVD's and all have the EXACT SAME RESOLUTION AND FRAMERATE!!!

My question is: Why is it that AutoGK has decided to convert all episodes that come as NTSC 29.97fps to NTSC 23.976fps (not a big issue) and most annoyingly, why is it not consistent with its calculation of the final avi file's resolution? Out of the 8 episodes, the final files are as follows:

Episode 1-3: 608x352
Episode 4: 688x400
Episode 5: 704x400
Episode 6-7: 720x416
Episode 8: 608x352

I have tried setting a fixed width, but then it keeps the width and the height of all the final avi's fluctuates. I understand AutoGK is supposed to make the best choice, but when all 8 sources are practically the same, isn't there something wrong?

[jggimi]

Hello, and welcome to the forum.

...all have the EXACT SAME RESOLUTION AND FRAMERATE!!!

All your sources have the exact same resolution, true. 720x480. That's because they are NTSC, and all NTSC DVDs are 720x480. All your sources are also 29.97, because that is the framerate of broadcast NTSC.

...Why is it that AutoGK has decided to convert ... 29.97fps to ...NTSC 23.976fps...?

Because AGK has determined that the NTSC video was Telecined.Telecining is the process of capturing either 35mm or 16mm film onto video. The film is designed to be projected at 24fps, and needs to get to 29.97fps for NTSC video.Reversing that process is called Inverse Telecining, or IVTC. When you do this to NTSC video, you end up with a framerate of 23.976fps, very close to 24fps. For much more information, please see www.doom9.org/ivtc-tut.htm.

...why is it not consistent with its calculation of the final avi file's resolution?

Because each and every episode has a different compressibility. They have different amounts of motion, camera movement, bright vs. dark areas... and other factors that affect compressibility. If they all had fixed output size and fixed resolutions, each episode would have a widely different image quality for you.

You have chosen an output size for each episode. AGK has determined a peak resolution for each video, based on that output size and the episode's compressibility.

...I have tried setting a fixed width, but then it keeps the width and the height of all the final avi's fluctuates...

The height should vary based upon the Display Aspect Ratio of the DVD, and the amount of letter boxing determined to be used; which may differ from episode to episode, depending on how AviSynth's AutoCrop filter detects letter boxing. This detection level can be modified with AGK's hidden options.

[srotman]

OK... so basically everything that I am experiencing is normal and I have nothing to worry about. In fact, my results are as expected and I can continue with the rest of the season's episodes because everything looks good?

(Please say yes, these VOB files just sitting around on my hard drive are killing me)

Thanks!
(I'm just looking for reassurance before I go ahead and delete the source VOB's because I don't have the original DVD's anymore)

[jggimi]

...I don't have the original DVD's anymore...

Then this does not qualify as Fair Use. See: The Piracy and Copyright section of Doom9's Disclaimer (http://www.doom9.org/index.html?/disclaimer.htm) Forum Rule #6 (http://forum.doom9.org/forum-rules.htm)Thread closed.