Problems with blocky anime encode (from DVD source)

[3ncrypted]

I am trying to encode an anime episode that I ripped from DVD, but the end result is "blocky". I've tried Xvid and Divx as the codec. The "blockyness" shows up on my PC and on my standalone. Most of the video looks very nice, but the blocks show up mostly around the characters face, text (during intro), and any motion.

I'm using AutoGK V.1.96. The DVD source is 720x480 NTSC. In autogk I specify that I want a custom size of 400mb, and I use MP3 (128) for sound, and use auto width. I've used Xvid and Divx. The end result is always 720x544.(not sure why end result is larger) I've been searching and reading posts asking about "blocky" results, so I'll go ahead and let you know that it shows up on my CRT monitor, my TV's(non-HD & HD), and my LCD monitor. The anime I'm encoding is a newer anime, so the animation is very clean and sharp. Like I said above, the majority of the video is very nice. If I could just get rid of the blocks, it would be perfect.

[jggimi]

Bitrate is also important information, and can certainly affect perceived quality. But rather than searching for specific values ... why not just ....

:logfile:

[3ncrypted]

Ok..here is the log. Thanks for your help.

[jggimi]

Thanks. I didn't see anything in the log that would point to a problem with "blockiness." -- I assume that every frame used the maximum bitrate possible. However, it's possible, since AGK did decide to increase resolution larger than D1, that you are seeing artifacts from the resizing upwards. AGK has done this because it will not be able to reach anywhere close to the 400MB file size you are trying to get to.

You might post a sample image; that may help narrow down the problem.

Here are a few things I saw in the log:[8/26/2005 3:54:11 PM] Source has percentage of interlacing in motion areas: 28.51
[8/26/2005 3:54:11 PM] Source has percentage of telecined patterns: 69.36
[8/26/2005 3:54:11 PM] Source has percentage of progressive patterns: 29.79
[8/26/2005 3:54:11 PM] Source has percentage of interlaced patterns: 0.85
[8/26/2005 3:54:11 PM] Source is considered to be hybrid (mostly FILM).
[8/26/2005 3:54:11 PM] Looking for optimal hybrid thresholds.Anime is often complex content to deal with. This may have nothing to do with the artifacts you are seeing, but it is something to keep in mind anyway. Usually, Anime from theatrical releases is Telecined. Anime from TV, on the other hand, is more varied. The content may have differing cells per second utilized, and the processes used to make the DVD transfer vary as well.

AGK has determined that this content is neither fish nor fowl -- a hybrid. Part of it appears to be Telecined from film, part of it appears to be progressive, and a small percentage appears to be neither Telecined nor progressive. This sort of analysis report tells me that the source was probably straight-to-video rather than from a theatrical film transfer.[8/26/2005 3:54:20 PM] Output will contain 33739 framesThat's the length of a TV episode, my earlier guess is confirmed.[8/26/2005 3:56:59 PM] Audio size: 22,110,552 bytes (21.09 Mb)
[8/26/2005 3:56:59 PM] Overhead: 2,179,072 bytes (2.08 Mb)
[8/26/2005 3:56:59 PM] Video size: 395,140,776 bytes (376.84 Mb)
[8/26/2005 3:56:59 PM] Target bitrate is: 2246kbpsThat's a fairly high bitrate for MPEG-4 from DVD sources....here's the proof further down in the log:[8/26/2005 3:58:49 PM] Compressibility percentage is: 371.97
[8/26/2005 3:58:49 PM] Switching b-frames off
[8/26/2005 3:58:49 PM] Chosen resolution is: 720x544 ( AR: 1.32 )
[8/26/2005 3:58:49 PM] Predicted comptest value is: 247.40 Even with the highest quality possible, the output would have only take up about 100 MB of the 376 MB you've got allocated to video. AKG increased resolution to the maximum it could go, and turned off an MPEG compression feature called Bidirectional Encoding, in order to try to increase the effective bitrate. Still, AGK estimates that the video portion of the .avi file will only consume about 152MB.

[3ncrypted]

First... thanks so much for your help. Your last reply has helped me better understand the log file. I was mainly using 400mb as the file size because I wanted the quality to be 100%, and since I'm a mpeg4 noobie, I didn't realize how much I'd over shot the file size.

I've since run the file thru AutoGK again, and this time I used the 233mb preset as the file size. The strange part is that the "blockyness" is gone, but the resolution is still 720x544. The end result was very nice tho. I watched a few minutes of it on my non-hd 53" tv and it looked very..very good. There was a scene with water that had a few blocks, but that was all. Can you look at this new log file and possibly tell me what fixed the "blocky" problem? Just wanted to know because I'm going to start encoding more of these, and I'd like to figure out a size/quality goal that I can stick with. I'd like to keep 6ch audio when available, so I'm also trying to figure out a size to go with that will keep quality at 100% and still allow ac3 audio. I see with this new log file that the compressibility percentage is 109.72 . I'm wondering how much ac3 audio would knock that down.

Thanks again.

[jggimi]

I didn't see anything in this log that would take care of whatever image problem you've been seeing. Note the following:[8/27/2005 8:11:59 PM] Compressibility percentage is: 109.72
[8/27/2005 8:11:59 PM] Chosen resolution is: 720x544 ( AR: 1.32 )
[8/27/2005 8:11:59 PM] Predicted comptest value is: 86.06This time, Bidirectional encoding was used, there was no comment about switching b-frames off.

As I mentioned above, providing an image with the problem would be useful.

[Sharktooth]

AutoGK 1.96 uses quants from 1 to 31 and an old xvid version. Since your settings require low quants to fit the filesize, probably that problem is the (in)famous xvid trellis overflow bug with very low quants (1).
Try updating AutoGK to the latest version (which contains also the latest xvid compile) and see if it helps.

[jggimi]

:goodpost:

[3ncrypted]

I went ahead and encoded the next episode (still with AutoGK 1.96) with the same settings that had finally worked well for the first episode, however upon completion this episode DID have the "blocky" problem when completed. Log file is attached. The blockyness shows up on standalone more than on the PC.

I've just installed the new AutoGK v2.16 Beta and I am encoding this 2nd episode with the exact same settings to see if it's fixed in this version. I will let you know when it's done.

Thanks jggimi and Sharktooth. :thanks:

[3ncrypted]

Well I don't guess the problem is limited to anime only. I used Autogk 2.16 beta to compress a movie to 1,400mb. The end result looks fine on my PC(actually great), but is very blocky on my stand alone.(log attached)