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Old 7th January 2004, 21:30   #1  |  Link
SeeMoreDigital
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Proposed Hi-Def encoding 'Codec Shoot-Out' discussion

Ok I've started this thread as an extension to Doom9's most excellent latest 'Codec Shoot-Out' and this thread started by twist3d as a response to the afore mentioned 'Codec Shoot-Out'.

Well, for those members and visitors who followed twist3d's thread, I posted this observation (as well as others) and Doom9 posted this response (as well as others)!

Anyway, I think it's fair to say we are both now interested in the next evolutionary step for the current codec manufacturers to aspire to, which is High-Definition encoding.

So if anybody has any suggestions regarding the standardisation of such a test together with proposed methods, please post the information here.

Cheers

EDIT: Just put 'Proposed' at the beginning of the title - that's all!
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Last edited by SeeMoreDigital; 13th January 2004 at 22:37.
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Old 8th January 2004, 01:26   #2  |  Link
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One question, why?
The codec should scale with resolution. I encode HDTV to Xvid and it does wonderfully, I have also tried wme9 and it does good also, the main reasons I went with Xvid were AC3 compatibility, stability (wme9 crashed alot when I used it), and ease of use for the encoding tools.

I do 42 minute tv shows in 700-1024 megs typically. And movies usually go for 4-6 gigs.
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Old 8th January 2004, 09:20   #3  |  Link
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In Australia we have some decent hdtv. I dont have that great reception but I have got a 1440x1088 mpeg2 clip that works out ~100mb/min. Thats way too high to store on a dvd so if i wanted to keep it at a high resolution I would need about a third of the bitrate to store a movie on a dvd-r.

Maybe the codecs can be stretched to a half hd dvd rip.

I have done zero testing on this, I may do some tonight.
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Old 8th January 2004, 10:35   #4  |  Link
SeeMoreDigital
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Quote:
Originally posted by Versa
One question, why?
The codec should scale with resolution. I encode HDTV to Xvid and it does wonderfully, I have also tried wme9 and it does good also, the main reasons I went with Xvid were AC3 compatibility, stability (wme9 crashed alot when I used it), and ease of use for the encoding tools.

I do 42 minute tv shows in 700-1024 megs typically. And movies usually go for 4-6 gigs.
This is exactly the kind of information that may be of interest to others!

So, you've ascertained that capturing with the WME9 encoder did not work reliably enough for you. But it might be interesting to find out why. And if others have had more success!

What image pixel frame size are you using for your captures?
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Old 8th January 2004, 12:30   #5  |  Link
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OK played around a bit with some codecs

Bitrates: 5000kbps and 2500kbps, this would equate to 1 or 2, two hour movies per dvd. My clip was much shorter.

Resolution: 1440x704 (interlaced anamorphic mpeg2 source, cropped with avisyth 2.5)

TomsMoComp and lanczos resize.

Xvid, best out of the lot, comparable quality to a 2 cd dvd rip, (per pixel size that is) @ 5000kbps, still very good quality @ 2500 - some blocks. My guess is a lot more quality could be obtained I used the default settings. probably 2500 could be comparable to a 1cd rip. [a third slower than divx5]

Divx5.1.1, second. Just a little worse, still very good. I did not use b frames, gmc or qpel. Also no psy. Standard speed. [Fastest encoding time]

tie for third depending on how you like things:

blurred; divx3, just tried this one for fun. turned out not so bad, bitrate did not affect quality that noticably. Plenty of blurring, smears and little edge atifacts. [almost as fast as divx5]

blocky; wmv9, heaps(!) of macroblocks. I dont use wmv9 that much but used the highest quality (ie slowest settings) went out and had dinner because it was so slow. Very disappointing [Slowest by a factor of 10]


I have never used rv9 and have only looked at vp6 for a few minutes so I didnt try these codecs.


I think the hardest part about a codec shoot out would be some standardized sources. I have no idea where you could find some.

Last edited by vio; 8th January 2004 at 12:33.
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Old 8th January 2004, 14:21   #6  |  Link
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Hi vio

Can I have a little more info about your source please? You mentioned that it's 1440x1088 which equates to an 4:3 image!

Does your source contain any black mattes or is it all image?

Is it a 4:3 image or is it 16:9

Before things get too confused I think it may be best to stick to the following 'full frame' image pixel frame sizes when encoding: -

For 16:9 sources use either 1280x720p or 1920x1088i
For 4:3 sources use either 960x720p or 1440x1088i

Obviously some 16:9 sources may not be all image (ie they might also contain black mattes) and as such have aspect ratios of their own, such as 1.85:1, 2.35:1, 2.40:1 etc.

In which case you could elect to crop away the mattes and use the following image pixel frame sizes: -

For 720p sources at 1.85:1 you could crop to 1280x688
For 720p sources at 2.35:1 you could crop to 1280x544
For 720p sources at 2.40:1 you could crop to 1280x528

For 1080i sources at 1.85:1 you could crop to 1920xx1040
For 1080i sources at 2.35:1 you could crop to 1920xx 816
For 1080i sources at 2.40:1 you could crop to 1920xx 800

Cheers
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Old 8th January 2004, 19:10   #7  |  Link
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Quote:
So if anybody has any suggestions regarding the standardisation of such a test together with proposed methods, please post the information here.
idea 1: I think that highdef-tests shouldn't be done with already lossy & compressed material, like dvd's. (it's like recompressing mp3 and making audio quality tests). what do you think?

idea 2: maybe closer to the user interest would be anamorphic encodes at dvd-resolution or little lower?
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Old 8th January 2004, 19:33   #8  |  Link
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Quote:
idea 1: I think that highdef-tests shouldn't be done with already lossy & compressed material, like dvd's. (it's like recompressing mp3 and making audio quality tests). what do you think?
And we're back to the source problem. Where would you get an uncompressed high def master of a movie to encode? You can't take the T2 DVD because it's already been WMV9 compressed. How good is HDTV? Do you get studio quality 10+mbit average, 20mbit tops sources without any transmission errors?
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Old 8th January 2004, 19:44   #9  |  Link
SeeMoreDigital
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Quote:
Originally posted by twist3d
idea 1: I think that highdef-tests shouldn't be done with already lossy & compressed material, like dvd's. (it's like recompressing mp3 and making audio quality tests). what do you think?
Yes, that is a good idea. However, it's not going to be that easy for us all to obtain the same source files for testing. I've just downloaded the latest T2 trailers from the M$ web site. One is at 720p the other is at 1080p (wow, we now have 1080p as well as 1080i) and each of these is around 100MB!

Quote:
Originally posted by twist3d
idea 2: maybe closer to the user interest would be anamorphic encodes at dvd-resolution or little lower?
Ah! One of the main advantages behind high-def is its use of 'true 16:9 frame' sizes and not 'anamorphic (1.25:1 or 1.50:1) frame' sizes, like the ones we currenly have with DVD.

That said, one of the problems we have with HDTV is the confusing amount of trasmission standards (around 20 or so I think). There is even a 864x480p standard ie a 'true 16:9 frame' version of NTSC.

Another advantage of not encoding using anamorphic frames is that the images will always appear at the correct aspect ratio when viewed!

Cheers
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Last edited by SeeMoreDigital; 8th January 2004 at 19:47.
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Old 8th January 2004, 19:58   #10  |  Link
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Why would you encode 'uncompressed high def masters'?

What's wrong with the T2 1080p (1440x816) and the Corel Reef 1080p WMV9 encodings from the microsoft site?

edit: sorry I didn't read SeeMoreDigital's post

On this site: http://206.159.116.24/public.htm, hdtv captures (~15Mb, including 2.0 AC3) are posted regularly.

Last edited by Wilbert; 8th January 2004 at 20:00.
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Old 8th January 2004, 20:11   #11  |  Link
SeeMoreDigital
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Quote:
Originally posted by Wilbert
Why would you encode 'uncompressed high def masters'?
There will be a time when forum members may want to convert their HDTV Mpeg2 captured broadcasts to say WMV9, Mpeg4, RV9 etc using larger image pixel frame sizes than the ones many of us currently use when 'backing up' our DVD's

Quote:
Originally posted by Wilbert
What's wrong with the T2 1080p (1440x816) and the Corel Reef 1080p WMV9 encodings from the microsoft site?

On this site: http://206.159.116.24/public.htm, hdtv captures (~15Mb, including 2.0 AC3) are posted regularly.
There is nothing wrong with any of these encodes, they look great. But even the WMV9 version of T2 exceeds 6GB and therefor will not fit onto a single layered DVD~R!

Cheers
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Old 8th January 2004, 20:30   #12  |  Link
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I guess you misunderstood my post.

Quote:
There will be a time when forum members may want to convert their HDTV Mpeg2 captured broadcasts to say WMV9, Mpeg4, RV9 etc using larger image pixel frame sizes than the ones many of us currently use when 'backing up' our DVD's
Of course, that's the reason for this test. But since when are 'HDTV Mpeg2 captured broadcasts' uncompressed?

Quote:
There is nothing wrong with any of these encodes, they look great. But even the WMV9 version of T2 exceeds 6GB and therefor will not fit onto a single layered DVD~R!
What I meant, is that you could use them in your test. Of course, it might be that you can find better candidates.

I think it makes only sense, if you encode them using a lower resolution.
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Old 8th January 2004, 20:43   #13  |  Link
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Quote:
Originally posted by SeeMoreDigital
What image pixel frame size are you using for your captures? [/B]
I use full frame 1280x720 (@24 or 30 fps depending) for 720p broadcasts and I deinterlace and bicubic resize down to 1280x720p for 1080i broadcasts.

I managed to fit toystory hdtv to 1.5 gigs and mission to mars down to 3 gigs, looking very good, but I think I am going to up the filesize a little for the next movies. The hardest compression was 2.5 hours of hdtv hockey that was 18 gigs mpeg2, I could only get it down to 6 gigs.
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Old 8th January 2004, 21:03   #14  |  Link
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I think that only the live transmissions can have the real quality of HDTV. The movies are DVD's at high bitrate and bigger resolutions.
So, for what we need more space for the same movie? Great quality? I don't think so, just wasting space.
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Old 8th January 2004, 21:17   #15  |  Link
SeeMoreDigital
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Quote:
Originally posted by Wilbert
Of course, that's the reason for this test. But since when are 'HDTV Mpeg2 captured broadcasts' uncompressed?
Ofcourse you are correct, they are already compressed. But they are massive too!


Quote:
Originally posted by Wilbert
What I meant, is that you could use them in your test. Of course, it might be that you can find better candidates.

I think it makes only sense, if you encode them using a lower resolution.
Absolutely. I did just this with the T2 clip. I lowered the bitrate of the original clip so the resulting encode would have a file size suitable for for storage on a single sided DVD-R!

At 152mins, the WMV9 version of T2 Extreme would make a great test source. Shame it's encrypted.... bummer!
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Old 8th January 2004, 21:40   #16  |  Link
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SeeMoreDigital, all the digital tv I get is 16:9.

Clip is 1440x1088, a bit of letter boxing so cropped down to 1440x1036. And Aspect Ratio is 2.025 so then resized to 1440x704, not perfect AR but closet mod16.

I can get access to alot of 1080i tv, but I dont know whether its 576i upconverted or just a bad source. The TV guides dont say. The clip I tested is a true 1080i source but I have to move my antenna to get it.
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Old 9th January 2004, 08:32   #17  |  Link
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Well.. having a WMV9 source sure would itch me.. I'd consider that an unfair beginning.. I'd expect the source to be available in a format that is not one of the codecs to be tested. A high bitrate MPEG-2 HDTV broadcast seems the most suitable source imho.

Quote:
The movies are DVD's at high bitrate and bigger resolutions.
That is not quite correct. In fact, most studios today make one high def digital master of a movie (unfortunately I don't recall the resolution and actual format.. but it's at least as good as what you can get via HDTV). From that, they make the HDTV broadcast, DVD and DVB broadcast. It is all the same source. So, DVD is a resized and recompressed version of the original digital master. Taking the HDTV version would get us much closer to the actual source.
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Old 9th January 2004, 15:49   #18  |  Link
SeeMoreDigital
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Quote:
Originally posted by Doom9
Well.. having a WMV9 source sure would itch me.. I'd consider that an unfair beginning.. I'd expect the source to be available in a format that is not one of the codecs to be tested. A high bitrate MPEG-2 HDTV broadcast seems the most suitable source imho.
Agreed. Unfortunately, Euro1080 our European HD broadcaster, no longer transmits such images 'in the clear' (a case of real bad timing). So I am looking into the prospect of purchasing the necessary PCI card and card reader. The good news is, Euro1080 is available to anybody throughout Europe with none of the usual 'out of country' licensing restrictions.

Quote:
Originally posted by Doom9
That is not quite correct. In fact, most studios today make one high def digital master of a movie (unfortunately I don't recall the resolution and actual format.. but it's at least as good as what you can get via HDTV). From that, they make the HDTV broadcast, DVD and DVB broadcast. It is all the same source. So, DVD is a resized and recompressed version of the original digital master. Taking the HDTV version would get us much closer to the actual source.
Agreed again. Even in my old telecine days, the equipment I had access to, in order to create analog tape transfers (from film), were capable of producing higher quality images than any of the early DVD's I own.

However, there's no denying that DVD has taken off faster than anybody in the industry could ever have hoped for. And as a result the new transfer equipment and techniques used to transfer the film image to DVD have improved too. I guess one of the main reasons why todays DVD images look so good is because the production of the DVD is planned at the same time as the film. Also having direct access to the original film (instead of the copies) is the biggest plus of all!

Owners of the T2 Extreme DVD will get an insight of how 'film to digital' transfer techniques have changed after reading the sleeve notes. In fact the newly created digitised master (which at 24fps equals film speed) contains so much detail and resolution that only a very small percentage is carried over to the Mpeg2 DVD... To underline what I'm talking about, here's a direct quote from the sleeve notes.. "Because the video compression for DVD strips away nearly 98% of the original bits used on the uncompressed DVD master, THX reviews every shot to verify that the compression matches the source as closely as posible..."

98% eh, I don't think we'll be downloading this source master for our lossy tests then!

Cheers
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Old 9th January 2004, 17:02   #19  |  Link
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I can only think of one source of uncompressed digital video off the top of my head - video games. Too bad they wouldn't be very comparable to live-action or animated content. Unless somebody has either a really nice digital camcorder, or somebody has access to a transfer device, I imagine it won't be easy getting higher-than-HDTV quality stuff to encode.

EDIT: That 98% figure is incredible. If we assume the maximum DVD bitrate is 9.8Mbps (That is correct, isn't it?), then the master would be 490 Mbps/61.25MBps.

Last edited by sxd; 9th January 2004 at 17:07.
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Old 9th January 2004, 19:26   #20  |  Link
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I looked at suitable transport streams I have:

1) matrix trailer (~17 Mbps, 1920x1088, 88s)

2) performance of Michella Branch (~18 Mbps, 1920x1080, 53s)

What do you think about it?
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