I would like to convert my DVD collection to a compressed format for efficient storage on my HTPC. In addition, I would like to retain decent picture quality for viewing on a 1080p HDTV. I have been experimenting with several video conversion programs (AVS video converter, DVDPean, AutoMKV & RipBot264), encoders (Xvid & h264), encoder configuration settings and filters. In all instances, the foreground portion of the video looks crisp & clear but the background portion looks blotchy & pixelated. Is this to be expected or is there a way to clean up the background? If so, how? Here's an example (see circled areas)
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Probably too low of a bitrate from your encoder, if the source was a DVD.
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Some of that could be in your source and therefore could be reduced with a deblocking filter. And some if it will be unaviodable if you require low bitrates. One of the methods used by low bitrate encoders is to remove details, especially in dark areas. The result is macroblock artifacts like you're seeing.
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Like it or not, this is almost unavoidable when using mpg-4 for compression. I have never seen an Xvid or H264 file that didn't have it to some degree, even when high bitrates are used. I believe you are pretty much stuck with it if you use Xvid. H264 at bitrates of around half the source DVD might give you better results.
Read my blog here.
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I am experimenting in this same area -- background giblets or floating chisel chodd is what I
mainly call them when I see them in the background. In fact, I'm running some encoding
scenarios on a short clip (the mummy returns) for posting, cause due to my ananlog cabletv,
there is much noise to attend to first, and then design a unique filter-chain around *this*
particular capture source and then finally encode it to a low-bitrate codec of choice. I was
hoping for h264, preferebly the raw .mp4 version, but i'm not sure yet on the howto parts.
There's still much to iron out before I finalize to something acceptable. I mean, this project
will not be from an already clean dvd/mpeg "digital" source, but rather from a noisy analog one.
What you have to do is find a good (high enough) bitrate to start with, and then observe the
video for various details. You want to find out how low you can reduce the bitrate (or quality
control value) to but still maintain detail.
But, before you begin something like this, you really need to review your dvd collection for its
background attributes to determine if it already has them. I mean, there is no point in going
all out crazy to debug all this if your original (dvd) ource has these artifacts in them aready.
If you've determined that original source has them then you might want to consider reviewing
ways to eliminate or reduce them *before* attempting your xvid/h264 encoding possibilities.
-vhelp 4622 -
As others have suggested, a higher bitrate should eliminate those blocks. For a given bitrate, you will find less blocking with h264 than XviD.
If you want, you can adjust h264's inloop blocking filter, but I doubt this would be necessary for a good DVD source and a decent bitrate -
You know, I think his trouble is prob the source, or his dvd he said. I think the artifacts
are already there to begin with. I finished yet another encode of that sample clip in h264
(w/out audio unfortunately) and for the noisy source that it is (analog cabletv) in the
background scenes, they do not have the artifact mentioned in this discussion. So it must
be this users source that is the root of the problem here
-vhelp 4625 -
Xvid, and to a lesser degree, H.264, work best with detailed or noisy sources if given enough bitrate. They both suffer from blocking (Xvid/Divx are the worst) on large areas of low tonal range - sky, single colour walls etc. It is inherent in the way the compression works. H.264 tries to address it with it's built in deblocking. I have encoded good quality source at stupidly high bitrates (2 - 3K for 640 pixel width source) using both Xvid and Divx and still ended up with blocky clusters in areas of sky and shadowed backgrounds, yet on lower birates I can get crisp images wherever there is patterns or detail. The detail stops the compressor seeing larger flat areas and over compressing them.
Read my blog here.
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I have been running an HTPC for just over 3 years now and have seen it go through many incarnations of what it would be used for and how it would do it...
I originally built my HTPC to do much the same as you want: to store movies in Divx or Xvid format on the system, ready to be played at a push of the remote. I went through much the same as you, never impressed with the quality of the compressed movies. I would guess that once you have become accustomed to the quality of the original DVD a compressed, lossy conversion of the same movie is somewhat dissapointing or else I am just too damn demanding. I played with many settings and software solutions. The higher the bit rate went, the larger the file got, meaning less could be stored on the hard drive. Adding an additional drive became the solution but then I came to the realization that I was moving in the wrong direction. The HTPC was to be a simple and QUIET system. More drives and their associated noise and heat would not help the situation. Rethink time...
I have now settled my HTPC into what has become a very workable and versatile system:
It is used as a music jukebox. All of my audio CD's (approximately 1,200) are ripped to MP3 format and stored on the hard drive, sorted by genre, artist and CD title. I find MP3 to be quite acceptable as a lossy compression format. Assembled playlists are a huge benefit.
It is used as a PVR to record/timeshift cable TV shows in DVD quality MPEG2 format. Shows can be edited and burned to DVD as required. Connects to the internet to obtain up-to-date local TV listings. Makes programing TV shows to record as easy as right clicking and selecting "record this show".
It is used to view live TV and much like a Tivo, can pause live TV or record on demand.
It is used to store digital photograph collections and much like slide projectors of years past can be used to bore the hell out of guests by forcing them to relive a vacation in Eugene, OR.
It connects to digital cameras, MP3 players, Pocket PC's and smart phones to transfer music, video and pictures.
The dilema was movies. What to do? I finally settled on playing the original DVD's. I organized them into a database on the HTPC and keep the discs well organized for easy locating. I play the DVD's on the HTPC and have eliminated the standalone DVD player from my primary home theatre. My entire home theatre now consists of the TV, surround amplifier, HTPC and speakers. The DVD's now occupy an area once used for CD storage. By ripping the CD's to MP3 it solved the storage issues. IMHO CD's seem much more agreeable to compression than DVD.
My 2 cents... -
I'm experimenting with H.264 encoding from DVD rips at present. I did notice the blocking problem on a snow scene but the built in de-blocking filter seems to help a lot. Adding bitrate didn't have as much affect.
For my DVDs, I use a 400 disc Sony changer. The rest of my compressed videos are on a server computer in the back room, accessed by the HTPC over a LAN, and all is fed to a video projector and surround sound system. -
I suppose that choosing a suitable quantize matrix might be
part of the solution to this problem. However the QMs for H264-encoding
are even more mysterious than the "well-known" mpeg-1/2 matrices.
So far, I have not found the courage for starting to understand them. -
Xvid and Divx (the Windows codecs) have playback deblocking options. They don't work quite as well as h.264 deblocking though.
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Thanks for all of the input everyone. Converting to Xvid used to work great until I recently upgraded to a HDTV. Solve one problem and create 3 new ones.
I tried bitrates from 1500-5000 kbps. That didn't solve the problem.
The source video does look a bit noisy. Would you try preprocessing the video with something like VirtualDub before encoding? That was where I was headed next. If that doesn't work I'll probably just store my favorites in original format on the HTPC and the rest on disc. -
Don't use B frames if you don't want macroblocks. B frames are encoded with higher quantizers so they get more macroblock artifacts. Encode in single pass target quantizer mode with a quantizer of 2. But if you do this the resulting AVI file won't be much smaller than the source MPEG. And you'll still get an additional round of DCT ringing artifacts.
To remove macroblock artifacts from your source, use AviSynth's Deblock() filter. Of course, what you're doing smearing out the blocks to smooth the edges, not adding back the detail that was lost in the original compression. You'll still get creepy crawly artifacts because the way the individual frames are smeared varies from frame to frame. -
I just got a great idea ...
RagingSloth, can you upload a small vob, say around 10 megs (I'm still on dial-up) and we
can all have a go at it in encoding it to an Xvid and/or H264 and we can all review each others
methods/results/and things. I think that this would be a great challenge for everybody to help
fine-tune or resolve the these types of artifacts.
(Post the link to an unprocessed dvd snipped vob as soon as possible, thanks)
This will keep us busy figuring this all out, but it will also serve as an adventure.. oh yeah, and fun
The challenge is on..
-vhelp 4527 -
Stupid is, stupid ain't, though I gotta stupid question anyway..
B frames are encoded with higher quantizers so they get more macroblock artifacts.
macroblocks ??
-vhelp 4628 -
--- A memory unblock of a deblock from a bi-product off part of an algo's intended purpose..
To remove macroblock artifacts from your source, use AviSynth's Deblock() filter. Of course, what you're doing smearing out the blocks to smooth the edges, not adding back the detail that was lost in the original compression. You'll still get creepy crawly artifacts because the way the individual frames are smeared varies from frame to frame.
During my exploration of the Median filter I was developing from scratch, in one of my algorithems for
processing the image fields, I stumbled on a positive bi-product of the kaos. And that was a form of
deblocking. In some of my test videos using various algorithms, I found this out. I remember snipping
the routine and dumpping it at the bottom of the (pascal) source code, a place where I like to dump
things for later (and easier) retreaval when time allows and memory serves
--> Image Processing: Temporal / Spacial Median filter -- by vhelp; -- Dec 23, 2007
I would love to look into that routine and see what might/might not come out of it.. only.. the only
problem with that is finding it through all the beta versions I made of the filter. It's a maze of versions
and spin-off to other project designs, etc.
--- regarding codec version installed
I would also suggest (to the originator of this topic) to look into the version of the codec installed
on the computer.. the xvid and h264 codecs. Maybe its the codec or the player that links to the
codec for decoding these videos.
-vhelp 4629 -
Originally Posted by RagingSloth
At the very least run the TV set through the THX Optimizer found on all the Star Wars DVDs, as well as on dozens of others. Also, as Midzuki suggests, using better quantiser matrices can help, but will require larger file sizes for the same quality. -
vhelp: I'll upload a clip asap. Can you recommend a tool to snip the vob file?
manono: The macroblocking is visible on my HDTV and a separate PC monitor. I calibrated my HDTV the best I could using Digital Video Essentials. I'll take a look at the THX Optimizer as well. -
I would also suggest (to the originator of this topic) to look into the version of the codec installed
on the computer.. the xvid and h264 codecs. Maybe its the codec or the player that links to the
codec for decoding these videos.
-vhelp 4629
Here is a test clip per your request:
test_clip.demuxed.m2v -
Originally Posted by redwudz
I would need to daisy-chain 3 of those Sony changers together! -
-I chose ~2500kbps (about 1/2 bitrate of original)
-720x480 (not resized)
-DAR 16:9
-2-pass high quality encode - Virtualdub for XviD, MeGUI for x264 (I can't figure out proper bitrate/sizing for XviD in MeGUI)
-Same .avs script used for both, no filters, default settings
-x264 r808, XviD [version 1.2.0-dev build 2007-07-25]
-Screenshots show more differences as .bmp, but for hosting purposes, reduced to .jpg with 100 quality
XviD
http://www.megaupload.com/?d=0Z01H47H
x264
http://www.megaupload.com/?d=6KHATCDU
Comments: I think x264 is the best quality, and jagabo's magic on the XviD looks better than my stock XviD settings - where you can clearly see blocking similar to the original post
ORIGINAL
XviD-2500kbps
Jagabo Xvid 2800kbps
x264-2500kbps
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To whom this may interest: 8)
Sharktooth's EQM AVC-HR rev.1
This matrix was made for medium-high bitrate backups with High-Profile
AVC encoders that support custom matrices and 8x8 discrete cosine
transform. It also reduces blocking.
Usage:
- high quality backups of DVD material at full resolution (anamorphic)
and bitrates of at least 1300-1400kbps (for average motion and not
noisy/old movies).
- non anamorphic/vertically resized encodes at bitrates of at least
1000kbps.
Standard version (JM, x264 & Encavc beta2-2 compatible):
INTRA4X4_LUMA =
6, 9,13,19,
9,14,20,27,
13,20,28,35,
19,27,35,42
INTRA4X4_CHROMAU =
6,10,15,20,
10,16,21,27,
15,21,28,33,
20,27,33,42
INTRA4X4_CHROMAV =
6,10,15,20,
10,16,21,27,
15,21,28,33,
20,27,33,42
INTER4X4_LUMA =
8,11,15,20,
11,16,21,27,
15,21,28,35,
20,27,35,42
INTER4X4_CHROMAU =
8,11,16,21,
11,17,22,27,
16,22,28,35,
21,27,35,42
INTER4X4_CHROMAV =
8,11,16,21,
11,17,22,27,
16,22,28,35,
21,27,35,42
INTRA8X8_LUMA =
6, 7, 8,10,12,14,16,18,
7, 9,11,13,15,16,18,20,
8,11,14,16,17,19,21,22,
10,13,16,18,20,22,24,26,
12,15,17,20,23,25,28,30,
14,16,19,22,25,29,34,38,
16,18,21,24,28,34,46,52,
18,20,22,26,30,38,52,72
INTER8X8_LUMA =
8, 9,10,12,14,16,19,21,
9,11,13,15,17,19,21,23,
10,13,16,18,20,22,23,25,
12,15,18,21,23,24,26,32,
14,17,20,23,25,27,33,40,
16,19,22,24,27,34,41,52,
19,21,23,26,33,41,53,64,
21,23,25,32,40,52,64,80
according to Rocka's MatrixEditor
08 05 07 09 11 13 14 17
08 08 09 11 13 13 14 17
08 08 11 12 13 14 17 94
09 11 13 13 14 17 94 94
11 11 13 13 14 94 94 94
13 13 14 16 94 94 94 94
13 13 14 94 94 94 94 94
13 14 94 94 94 94 94 94
12 12 13 14 15 16 22 26
12 13 14 15 16 22 26 32
13 14 15 16 22 26 32 94
14 15 16 22 26 32 94 94
15 16 22 26 32 94 94 94
16 22 26 32 94 94 94 94
22 26 32 94 94 94 94 94
26 32 94 94 94 94 94 94 -
--> filename: vhelp.test_clip.demuxed.[v1.0].mp4
EDIT: ahh, screw it.. the link doesn't seem to want to work and I'm out of ideas and energy. So I give up.
Have a good night and weekend, everyone..
-vhelp 4630 -
Greets,
A bit late to the party here but, RagingSloth if you are still working on this... I would second Midzuki's suggestion of trying Sharktooth's EQM AVC-HR matrix. It is a great matrix. Stumbled across it a few days back - thanks in part to Midzuki's suggestion here.
I was having problems converting my dvd of Alien with AutoMKV and getting severe blocking in the opening scene as they pan across the planet while spelling out the title. Even while using Constant Quality of 17 and having sufficient bitrate. I realize it is part of h264's nature to scavage heavily from low detail areas. Yet, with the EQM AVC-HR matrix it cleared all the blocking artifacts up. I was very pleased to see the improvement.
Good luck on your project.
Cheers,
RickRene: Could you not just wound him a little bit?
Hans: Well now, with a 25 pound shell that is not easy.
'Allo 'Allo
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