How to make better AVI files

[VintageGold]

I've used AutoGK for the better part of 6 months now and have always had a problem with getting my files to look good at smaller file sizes. I have found several TV program series where each episode is only about 350 MB that are presumably captured off TV using a vid cap card or Tivo or something.

If I encode a TV series off of DVD's and set it to 350 MB, the files look like garbage. I have tried several different file sizes, messed around with the Output Resolution (set to fixed width of like 352), and get the best results when the file is larger (between 641 to 700+ MB.)

So my question is two fold:

1.) What accounts for the smaller files sizes these people are achieving?
2.) What, if anything, would I need to do differently to get smaller file sizes?

Currenlty I can fit 7 episodes on a DVD if I use 641 MB file sizes. The colors and dark blocks just get worse if I try to fit 8 or more (498-561 MB file size.)

[CWR03]

You'll probably want to switch to the full Gordian Knot - AutoGK doesn't provide the control needed to produce files of great quality at that size.

[manono]

Hi-

Yes, I agree with CWR03. In GKnot you can apply filters to aid the compressibility.

But, you didn't really give enough information. Are you doing an apples to apples comparison? That is, are you trying to encode the same series for 350 MB that you already saw done well for 350 MB? The reason I ask is that different series compress differently. One might be a half hour series, and another an hour. One might be full screen and the other widescreen. One might be action oriented, and the other dialog driven. One might be film at 23.976fps, and the other video at 29.97fps. All of these factors (and others) are important in helping to determine how well a series compresses for a given resolution and file size.

If these aren't the same series, then I wouldn't set both the resolution and file size, if I were you, when using AutoGK, as that can lead to the bad results you've been experiencing. If you have a look at the results of the compression test, I think you'll see really low numbers.

[VintageGold]

The series I'm currently encoding is Buffy The Vampire Slayer. Average episode length is 44 minutes. Aspect Ratio is 4:3. Frame rate, 29.97 fps. The series I've downloaded that I would compare it too would most likely be Alias, which is very action oriented.

But most of the programs I've seen that are 350 MB are hour long TV programs (about 44 minutes after the commercials are removed). Like I stated before, more than likely these were recorded using a video capture card onto a computer. I imagine the way the product is originally broadcast would have some affect on the compressability of the program.

If you guys thing Gknot is the way to go, I'll check it out and see what kind of results I get. Otherwise, I'm stuck doing episodes at double to filesize to get good (I'm a littel pickier than others) image quality.

If it would be helpful, I can list all the settings I'm using. Please let me know and I'll report back.

[manono]

And are the other ones you've seen done at 23.976fps? I would guess so, since most TV series these days are created on Film. There's a good 20% bitrate savings right there, compared to encoding for 29.97fps. If it really is interlaced 29.97fps originally, well, deinterlacing for AVI will never look all that good.

I would guess that Buffy should also be done for 23.976fps, but I've never worked with it, so I'm not positive. Do you have an AutoGK log file handy for one of the Buffy eoisodes?

Most of those series are edited on video and encoded interlaced at 29.97fps. But most of them can also be IVTC'd back to 23.976fps. There's certainly nothing wrong with encoding for 1 CD and giving it a higher resolution. You want Buffy to look her best, don't you? :)

[CWR03]

I agree with manono - Buffy was filmed, so regardless of the framerate on the DVD your final product should be 23.976fps. There are two ways to do this (with Gordian Knot):

1) Process the video with DGIndex first, set Video > Field Operation to Forced Film, then encode either with no deinterlacing or field deinterlacing, depending on which looks best.

2) Process with Field Operation set to None, then encode using IVTC.

I've had varied success with different TV shows on DVD - some but not all are telecined, so you'll have to test to see which procedure works. Both of the aforementioned procedures yield a 23.976fps video. Adding the reduced framerate to the more effective compression using the full Gordian Knot should give you the results for which you're looking.

[Backflip]

Certainly you'll see quality improvement if you use GKnot and enable atleast VHQ mode of 4 for XviD encoding. This guide is good (a little outdated though. Trellis is now fine to use):

http://www.doom9.org/index.html?/xvid-vdub-11.htm

Main page - http://www.doom9.org/xvid.htm

[VintageGold]

Here's copy of the log file for you to look at.

[7/27/2005 4:33:08 PM] AutoGK 2.13b
[7/27/2005 4:33:08 PM] OS: WinXP (5.1.2600).2
[7/27/2005 4:33:08 PM] Job started.
[7/27/2005 4:33:08 PM] Input dir: H:\Buffy\Season 3\Disc 1\01
[7/27/2005 4:33:08 PM] Output file: I:\Buffy\Season 3\01 Anne.avi
[7/27/2005 4:33:08 PM] Output codec: XviD
[7/27/2005 4:33:08 PM] Audio1: English AC3 2ch
[7/27/2005 4:33:08 PM] Subtitles: none
[7/27/2005 4:33:08 PM] Format: .AVI
[7/27/2005 4:33:08 PM] Target size: 700Mb
[7/27/2005 4:33:08 PM] Custom audio settings: VBR MP3 with average bitrate: 160Kbps
[7/27/2005 4:33:08 PM] Started encoding.
[7/27/2005 4:33:08 PM] Demuxing and indexing.
[7/27/2005 4:34:09 PM] Processing file: H:\Buffy\Season 3\Disc 1\01\VTS_03_1.VOB
[7/27/2005 4:34:09 PM] Processing file: H:\Buffy\Season 3\Disc 1\01\VTS_03_2.VOB
[7/27/2005 4:34:09 PM] Processing file: H:\Buffy\Season 3\Disc 1\01\VTS_03_3.VOB
[7/27/2005 4:34:09 PM] Source resolution: 720x480
[7/27/2005 4:34:09 PM] Found NTSC source.
[7/27/2005 4:34:09 PM] Source aspect ratio: 4:3
[7/27/2005 4:34:09 PM] Analyzing source.
[7/27/2005 4:36:52 PM] Source has percentage of interlacing in motion areas: 43.89
[7/27/2005 4:36:52 PM] Source has percentage of telecined patterns: 98.19
[7/27/2005 4:36:52 PM] Source has percentage of progressive patterns: 1.47
[7/27/2005 4:36:52 PM] Source has percentage of interlaced patterns: 0.34
[7/27/2005 4:36:52 PM] Source is considered to be FILM.
[7/27/2005 4:36:52 PM] Output will contain 64600 frames
[7/27/2005 4:36:52 PM] Decoding audio.
[7/27/2005 4:37:53 PM] Normalizing audio.
[7/27/2005 4:38:43 PM] Encoding audio.
[7/27/2005 4:42:11 PM] Audio1 size: 55,874,784 bytes (53.29 Mb)
[7/27/2005 4:42:11 PM] Overhead: 2,584,064 bytes (2.46 Mb)
[7/27/2005 4:42:11 PM] Video size: 675,544,352 bytes (644.25 Mb)
[7/27/2005 4:42:11 PM] Running compressibility test.
[7/27/2005 4:42:11 PM] Writing the following script to I:\Buffy\Season 3\agk_tmp\01 Anne_comptest.avs
===========================================================
LoadPlugin("C:\PROGRA~1\AutoGK\DGMPGDec\DGDecode.dll")
LoadPlugin("C:\PROGRA~1\AutoGK\filters\autocrop.dll")
LoadPlugin("C:\PROGRA~1\AutoGK\filters\decomb.dll")
LoadPlugin("C:\PROGRA~1\AutoGK\filters\RemoveGrain.dll")

movie = mpeg2source("I:\Buffy\Season 3\agk_tmp\01 Anne.d2v")
cropclip = autocrop(movie,mode=0,wmultof=4,hmultof=4,samples=10,aspect=0,threshold=34,samplestartframe=0,leftadd=0,rightadd=0,topadd=0,bottomadd=0)
fixed_aspect = 0.888888888888889
c_width = width(cropclip)
c_height = round(height(cropclip) / fixed_aspect)
input_par = float(c_width)/float(c_height)
out_width = 640
out_height = round(float(out_width) / input_par)
hmod = out_height - (floor(out_height / 16 ) * 16)
out_height = (hmod > 4) ? (out_height + (16 - hmod)) : (out_height - hmod)
new_aspect = (float(out_width) / float(out_height)) / fixed_aspect
Telecide(movie,order=1,guide=1,post=2).Decimate(mode=0)
autocrop(mode=0,wmultof=4,hmultof=4,samples=10,aspect=new_aspect,threshold=34,samplestartframe=0,leftadd=0,rightadd=0,topadd=0,bottomadd=0)
LanczosResize(out_width,out_height)
RemoveGrain(mode=2)
SelectRangeEvery(300,15)
===========================================================
[7/27/2005 4:47:06 PM] Duration was: 4 minutes 54 seconds
[7/27/2005 4:47:06 PM] Speed was: 10.97 fps.
[7/27/2005 4:47:06 PM] Compressibility percentage is: 137.57
[7/27/2005 4:47:06 PM] Using sharper matrix
[7/27/2005 4:47:06 PM] Chosen resolution is: 720x544 ( AR: 1.32 )
[7/27/2005 4:47:06 PM] Predicted comptest value is: 81.03
[7/27/2005 4:47:06 PM] Running first pass.
[7/27/2005 4:47:06 PM] Writing the following script to I:\Buffy\Season 3\agk_tmp\01 Anne_movie.avs
===========================================================
LoadPlugin("C:\PROGRA~1\AutoGK\DGMPGDec\DGDecode.dll")
LoadPlugin("C:\PROGRA~1\AutoGK\filters\autocrop.dll")
LoadPlugin("C:\PROGRA~1\AutoGK\filters\decomb.dll")
LoadPlugin("C:\PROGRA~1\AutoGK\filters\RemoveGrain.dll")

movie = mpeg2source("I:\Buffy\Season 3\agk_tmp\01 Anne.d2v")
cropclip = autocrop(movie,mode=0,wmultof=4,hmultof=4,samples=10,aspect=0,threshold=34,samplestartframe=0,leftadd=0,rightadd=0,topadd=0,bottomadd=0)
fixed_aspect = 0.888888888888889
c_width = width(cropclip)
c_height = round(height(cropclip) / fixed_aspect)
input_par = float(c_width)/float(c_height)
out_width = 720
out_height = round(float(out_width) / input_par)
hmod = out_height - (floor(out_height / 16 ) * 16)
out_height = (hmod > 4) ? (out_height + (16 - hmod)) : (out_height - hmod)
new_aspect = (float(out_width) / float(out_height)) / fixed_aspect
Telecide(movie,order=1,guide=1,post=2).Decimate(mode=0)
autocrop(mode=0,wmultof=4,hmultof=4,samples=10,aspect=new_aspect,threshold=34,samplestartframe=0,leftadd=0,rightadd=0,topadd=0,bottomadd=0)
LanczosResize(out_width,out_height)
RemoveGrain(mode=2)
===========================================================
[7/27/2005 5:59:18 PM] Duration was: 1 hour, 12 minutes 12 seconds
[7/27/2005 5:59:18 PM] Speed was: 14.91 fps.
[7/27/2005 5:59:19 PM] Expected quality of first pass size: 82.65
[7/27/2005 5:59:19 PM] Running second pass.
[7/27/2005 7:46:04 PM] Duration was: 1 hour, 46 minutes 45 seconds
[7/27/2005 7:46:04 PM] Speed was: 10.08 fps.
[7/27/2005 7:46:04 PM] Job finished. Total time: 3 hours 12 minutes 56 seconds

One thing that may make a big difference is that I plan to watch these on a regular (read - 4:3, non-HD) TV.

Take a look and let me know what you think is going on and what I can try to change to improve things.

I still haven't had a chance to check out GKnot yet. Looking at the page, I guess I'm not sure what to actually download and run? Any suggestions would be great.

[Backflip]

You can improve things by using atleast VHQ of 4, Trellis and keep B-VOP's of 2/1.50/1.00. Set these in the XviD codec itself.

In regards to downloading stuff, ya need Gordian.Knot.Codec.Pack.1.9.Setup and GordianKnot.RipPack.0.35.0.Setup (and GordianKnot.RipPack.0.35.0.Update if you want, but it's not necessary) which can be downloaded from the top of the page - http://www.doom9.org/index.html?/xvid.htm