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Old 8th November 2022, 22:25   #61  |  Link
kurkosdr
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Originally Posted by rwill View Post
Configuration was:
Code:
./xvid_encraw.exe -i tos_720x300_8b.yuv -type 0 -csp i420 -w 720 -h 300 -framerate 24.0 -bitrate 900 -pass1 \
-full1pass -max_key_interval 300 -quality 6 -vhqmode 4 -bvhq -masking 2
./xvid_encraw.exe -i tos_720x300_8b.yuv -type 0 -csp i420 -w 720 -h 300 -framerate 24.0 -bitrate 900 -pass2 \
-max_key_interval 300 -quality 6 -vhqmode 4 -bvhq -masking 2 -o mpeg4.m4v

./y262.exe -in tos_720x300_8b.yuv -size 720 300 -threads 1 2 -profile main -level high -chromaf 420 -rcmode 1 \
-mpout stats.p1 -bitrate 900 -vbvrate 2000 -vbv 600 -quant 3 -quality 100 -frcode 2 -arinfo 1 -nump 18 -numb 2 \
-flatmat -videoformat 709
./y262.exe -in tos_720x300_8b.yuv -size 720 300 -threads 1 2 -profile main -level high -chromaf 420 -rcmode 2 \
-mpin stats.p1 -mpout stats.p2 -bitrate 900 -vbvrate 2000 -vbv 600 -quant 3 -quality 100 -frcode 2 -arinfo 1 \
-nump 18 -numb 2 -flatmat -videoformat 709
./y262.exe -in tos_720x300_8b.yuv -size 720 300 -threads 1 2 -profile main -level high -chromaf 420 -rcmode 2 \
-mpin stats.p2 -mpout stats.p3 -bitrate 900 -vbvrate 2000 -vbv 600 -quant 3 -quality 100 -frcode 2 -arinfo 1 \
-nump 18 -numb 2 -flatmat -videoformat 709 -out mpeg2.m2v
I was surprised by how good your MPEG-2 video looks for the bitrate, so I decided to analyse it, and I noticed that you used a 57-frame GOP on average. You can't do this on DVD-Video, DVD-Video uses a max GOP length of 18 for NTSC and 15 for PAL. This gave your encode a major efficiency boost that you won't get when encoding DVD-Video compliant MPEG-2.

So, to recap, the space-efficiency advantages of using Divx avi over DVD-Video are:
1. Ability to use widescreen at the low resolution of 640x360 (DVD-Video forces you to use a relatively high 720x576/480 resolution if you want widescreen)
2. Whatever efficiency gains MPEG4 ASP offers over MPEG2 due to the better coding tools
3. Further efficiency gains due to using a max I-frame distance of up to 240 (instead of 15 or 18 for DVD-Video)

Also, you can ship either an avi file or an ISO for Divx avi, with DVD-Video you must always ship an ISO (a pet-peeve of mine).

So, back to the original question: Is XVID still used? Answer: Yes, it is still used to make Divx avi files to upload to the internet, because most people don't want to download a 4GB file for SD content (when downloading video for their non-H264 devices).

I know, necroposting (don't care), but I was bored the other day at work and was browsing for car DVD players, and I noticed that they still sell car DVD players that don't support H.264 but do support Divx avi. Yes, in 2022!! And someone bought this player on 30 December 2021 according to Amazon reviews. So, the installed base of car DVD players that don't do H.264 but can do Divx avi is not diminishing but actually expanding! Why can't they support H.264? I guess H.264 needs a more powerful chip while MPEG4 ASP decoding is a standard feature on all DVD chips made for the past decade. Also, MPEG4 ASP royalties are lower or non-existent.

So, my point is, MPEG4 ASP in avi files is not going away. Good or evil, learn to love it. This means Xvid is not going away for quite a while either.

Last edited by kurkosdr; 9th November 2022 at 12:53.
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Old 9th November 2022, 04:54   #62  |  Link
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I was surprised by how good your MPEG-2 video looks for the bitrate, so I decided to analyse it, and I noticed that you used a 57-second GOP on average. You can't do this on DVD-Video, DVD-Video uses a max GOP length of 18 for NTSC and 15 for PAL. This gave your encode a major efficiency boost that you won't get when encoding DVD-Video compliant MPEG-2.
But no one is talking about DVD but you? This is like saying the default -keyint of 250 of x264 is not BD compliant? Keep it mind that the intent was a comparison between a a good Mpeg-2 and a good Mpeg-4 encoder and not between distribution standards.

And its 57 frames and not seconds. You might have also noticed while analyzing the stream that y262 is laking a scenecut detection and as such does not place keyframes on shot changes - giving XVID an advantage.

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Originally Posted by kurkosdr View Post
So, to recap, the space-efficiency advantages of using Divx avi over DVD-Video are:
And there you are talking about DVD again. No one talked about DVD compliance, we talked about video compression standards and their implementation.

This is it then. People here make less sense every day. I am taking a time out from Doom9.
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Old 9th November 2022, 12:57   #63  |  Link
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And its 57 frames and not seconds.
The 57-second thing was a typo (sorry, originally meant to express it in seconds). Fixed now.

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But no one is talking about DVD but you? This is like saying the default -keyint of 250 of x264 is not BD compliant? Keep it mind that the intent was a comparison between a a good Mpeg-2 and a good Mpeg-4 encoder and not between distribution standards.

And there you are talking about DVD again. No one talked about DVD compliance, we talked about video compression standards and their implementation.
For consumer electronics backwards compatibility (which is the only reason you should use anything older than H.264), MPEG2 is DVD or SVCD, and both restrict max distance between I-frames:
http://www.mplayerhq.hu/DOCS/HTML/en...t-vcd-dvd.html

So, for pre-H264 hardware, realisticaly it's either DVD, SVCD, or Divx Home Theater profile, and I answered why Divx Home Theater holds a space-efficiency advantage over DVD. SVCD doesn't do widescreen so I didn't even consider it, but points #2 and #3 in my previous post still apply. And point #2 applies to MPEG2 vs MPEG4 ASP in general.

I know the thread veered off a bit, that's why I realigned it with the original question ("Is XVID still used?") in my previous post. The answer is: XVID is still used to encode Divx Home Theater-compliant files. And Divx Home Theater is still used where small sizes are needed and compatibility with pre-H264 hardware is also needed, due to its space-efficiency advantage over DVD.

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This is it then. People here make less sense every day. I am taking a time out from Doom9.

Last edited by kurkosdr; 9th November 2022 at 13:28.
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Old 10th November 2022, 02:16   #64  |  Link
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For consumer electronics backwards compatibility
No one is talking about consumer electronics.
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Old 10th November 2022, 06:07   #65  |  Link
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Hey nice plane in the picture.

It is taking off like XVID compatible consumer electronics in underdeveloped countries in the year 2022 of our lord.

Speaking of airplanes, Mpeg-1/2 Video is still used in In-flight Entertainment Systems (IFEs). I even was approached in 2020 by people still doing Mpeg-1 Video encodings for IFEs because of my Mpeg-1/2 encoder as commercial solutions have been largely abandoned and the ffmpeg encoder is crappy and apparently not specification compliant.

In Really Modern IFEs Mpeg-4 ASP is used of course. Now you might think this is another use case for XVID. No. XVID like x264 kinda does violate profile limits unless very correctly configured. And then the picture does not look so good anymore. That's because XVID files are supposed to be decoded on a PC without hardware constraints.

Also nice story there with your car DVD player. I would not interpret much into it though, there are always greater retards. More current people have moved on though, to smartphones, tablets and Smart TVs.
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Old 11th November 2022, 03:21   #66  |  Link
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No one is talking about consumer electronics.
You defacto are when talking about anything older than H.264. Even broadcasters who are using MPEG2 are doing it to maintain compatibility with existing MPEG2 receivers. And so are DVD publishers using DVD-Video instead of something like AVCHD or BD9, they are doing it to maintain compatibility with existing consumer electronics DVD players. That's the vast majority of demand for encoders for pre-H264 standards right there.

And anyway, the original question was "Is XVID still used?", so I have to explain to OP that it's used mostly to target non-H264 consumer electronics devices nowadays and its relative merits over DVD-Video that those devices also support.

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Also nice story there with your car DVD player. I would not interpret much into it though, there are always greater retards. More current people have moved on though, to smartphones, tablets and Smart TVs.
I am not in the market for one right now and not planning to be. It all started when browsing Philips' website for something else, and then out of curiosity I wanted to see what kind of media players their name is being plastered on nowadays (hint: not very good ones, it's budget DVD players and car DVD players). Then I veered off to Amazon to see if similar non-H264 players are sold by other brands (apparently they are, a lot). You can try to stop other people from buying these things and also try to convince other people to throw away any such players they already have, so that XVID disappears. I will be waiting. Until then, XVID will be with us for a long time. So, to answer the original question, XVID is still used and will be for a long time.

Last edited by kurkosdr; 11th November 2022 at 04:25.
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Old 11th November 2022, 19:57   #67  |  Link
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Originally Posted by kurkosdr View Post
.......
backwards compatibility (which is the only reason you should use anything older than H.264)
You are wrong.
Now and then I still do some DivX reencodes of hi-quality short (30 minutes maximum) AVC clips which are highly-compressible
(not too sharp and made of low-motion content).
I use a high-bitrate quantization matrix with constant quantizer = 3,
GOP-length = 5 seconds, no B-frames, and so I may get, for example, a 300 MB file (audio included) from a 2 GB AVC source whose GOP-length = 0.5 second.
My storage space is limited and running DivX @ 1920x1080 is faster and simpler than using HEVC, AVC or VC-1,
therefore I choose the easier way whenever I can.
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Old 1st January 2023, 17:35   #68  |  Link
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"Watchable"? 700 MB per 2-hour movie was the standard. Only as movies approached 2.5 hours did you start to see the 2-CD encodes become more common.
700 MB Xvid encodes were the most common, but they weren't very good quality. The best case scenario for them, in terms of a Hollywood movie, was a short (around 90 minutes or so) 2.35:1 movie, which would typically be 640×272. A 2-pass encode with 128 kbps audio didn't have any major compression artifacts at least, but it didn't exactly preserve fine/complex detail like film grain.

Things got worse from there, i.e., a 1.85:1 movie was typically 624×336 (about 20% more pixels to encode), and a 1.33:1 movie was typically 640×480 (about 76% more pixels to encode).

"2-CD" encodes were a thing at least as far back as when I first got a PC / internet access (2001), they were just less common because internet speeds were a lot slower and hard drives were a lot smaller. It didn't usually have anything to do with the length of the movie, but rather with the preferences of the person / release group who encoded it. For example, I doubt that "aXXo" ever released a 2-CD encode, while there were people who always did 2-CD encodes regardless of the length and aspect ratio. 2-CD encodes usually had the untouched AC3 audio from the DVD, usually the 192 kbps 2-channel stream that many, if not most, DVDs included.
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Old 11th January 2023, 18:18   #69  |  Link
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You defacto are when talking about anything older than H.264.
No. Piracy existed before h.264 and it had nothing to do with consumer electronics.
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Old 26th January 2023, 16:30   #70  |  Link
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Compatibility > efficiency

Every time.

Every. Goddamn. Time.
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For consumer electronics backwards compatibility...
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No one is talking about consumer electronics.
What am I missing?
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Old 26th January 2023, 22:42   #71  |  Link
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What am I missing?
You seem to be missing that Katie Boundary's reply was below something about MP3.

Unless music requires a surround format you can buy 44.1kHz Stereo albums for download in MP3 which sound just fine, given their ~250kbps VBR. 44.1kHz Stereo is still somewhat current.

I have not yet seen 2CD Xvid releases of full length movies in (U)HD though. (U)HD is somewhat of a current standard as well.
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Old 27th January 2023, 19:49   #72  |  Link
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You seem to be missing that Katie Boundary's reply was below something about MP3.

Unless music requires a surround format you can buy 44.1kHz Stereo albums for download in MP3 which sound just fine, given their ~250kbps VBR. 44.1kHz Stereo is still somewhat current.

I have not yet seen 2CD Xvid releases of full length movies in (U)HD though. (U)HD is somewhat of a current standard as well.
So? People will download a (U)HD copy for the living room and bedroom and also a Divx avi copy for the car DVD player or TV/DVD player in the kitchen (or other player that doesn't do H.264 or H.265) and have it both ways

Most people here can't understand that:
- Some people will tolerate bad video quality outside the living room and bedroom, because some people just don't care that much.
- DVD players that won't play any kind of H.264 are still being sold today (because H.264 requires better chips and extra royalty payments). You should expect the average DVD player to support DVD-Video and Divx avi and no H.264 (unless it specifically lists HD support, which most don't). See my posts above for an example.

So, to answer the original question: Xvid will still be used for as long as there is a demand for compatibility with non-H.264 hardware, which is still being manufactured and bought by some people even today (no matter how that makes you feel).

Last edited by kurkosdr; 27th January 2023 at 20:22.
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Old 10th February 2023, 22:28   #73  |  Link
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Yes - most of torrent-releases of any new title and broadcast recordings have now xvid-based version of SD resolution with very low bitrate. It is defacto hard standard of media files today. It is sort of natural public voting against zilions non-supported in old hardware players modern codecs with some % of better quality and with requirement to make payment for new hardware or look for software decoder in geeks boxes with updatable firmware/software. Most of real people are simple and like to have plug-and-play media workflow with once for decades purchased simple stable video playback hardware.

The era of computer geeks @home is gone in the past. Very fast in about 20 years - only about 1/5 of a century.

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I mean, we're here talking about H.266 VVC getting ready soon-ish and there are people still encoding in XVID... It definitely makes you wonder...
In practice the residuals of this current dying civilization do not need new non-compatible video codes every 3..5 and even 10 years. The colour analog SDTV work for about half of a century and most users where happy. So may be one new digital codec every half or 1 century may be enough (if civilization do not die too fast and can keep itself stable at the level like 2000 at least a century).

The quality of video codecs reach its 'saturation for general public' at about transition from MPEG-4 ASP to AVC. The MPEG2 was yet about too simple and blocky.

Only moneymakers tried to take more money from general more and more poor public forcing it to move to 265 with 10bit and HD/UHD/HDR/WCG. And general public voting against it using 8bit SDR SD xvid of MPEG-4 ASP with build-it deblocking and a bit more advancing after MPEG-2.

Also a small group of geeks at this planet still tried to make extra/super/ultra/video codec (at some places numbered 266, 267..268+/++) with some more % or part of % of efficiency with 10..100..100000+x more compute resources to encode and _new_ hardware to decode.

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Back then, formats like IMX50 based on MPEG-2 All Intra 50 Mbit/s 4:2:2 were popular for SD files.
In 2006, as little as 2 years after H.264 was introduced, the world moved to HD (and then FULL HD) and Sony made the XDCAM set of standard which is essentially MPEG-2 for both HD and FULL HD.
Guess what happened? Many companies wanted "stability" and adopted it instead of H.264, but that was a big, big mistake. As result, most broadcasters are still using MPEG-2 for FULL HD contents to this very day and are hog-tied to this ancient, no longer supported, unoptimized codec with banding problems and what not.
It is true - some broadcast company in poor country still finally move to HD to the end of 201x and take as standard for file exchange MPEG2 50Mbit/s 4:2:2 LongGOP MXF. Though when in come to broadcast it is downgraded to SD 2 Mbit 4:2:0 h.264.

Last edited by DTL; 10th February 2023 at 23:43.
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Old 11th February 2023, 11:28   #74  |  Link
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I can't understand what the hell DTL is saying.
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Old 13th February 2023, 13:22   #75  |  Link
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I can't understand what the hell DTL is saying.
Looke like DTL just core dumped, don't try to make sense of it.
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Old 13th February 2023, 22:22   #76  |  Link
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Yes - most of torrent-releases of any new title and broadcast recordings have now xvid-based version of SD resolution with very low bitrate. It is defacto hard standard of media files today.
Yeah...

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Most of real people are simple and like to have plug-and-play media workflow with once for decades purchased simple stable video playback hardware.
That is true. Not so long ago (I think it was 2018), the wife of a colleague of mine showed me the playback support of the devices they use to playback stuff for their children in the car while they drive to keep them quiet (when for instance they go to the summer house with their car) and it still showed MPEG-2 and Xvid/DivX support only, so... yeah, there's that.
Of course their car isn't new (and wasn't "new" in 2018 either), but when someone buys a car he expects it to last for several years along with the players inside, so it makes sense.


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The era of computer geeks @home is gone in the past. Very fast
That is sadly depressing...


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The colour analog SDTV work for about half of a century and most users where happy.
Yeah... We might be happy to see lots of stops/nits being recorded in modern cameras without clipped out skies and no banding with 10bit and 12bit etc, but realistically, most consumers don't really care and would have easily been happy to keep watching SD BT601 8bit 100 nits stuff on their TV 'cause "it just works"...


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The quality of video codecs reach its 'saturation for general public' at about transition from MPEG-4 ASP to AVC. The MPEG2 was yet about too simple and blocky.
Honestly, though, we're here discussing about Xvid still being around, but can you imagine how long H.264 will stick around? I mean, it was such a good codec in terms of patents and x264 was such a good encoder that it will probably stick around for years to come and the fact that broadcast companies adopted XAVC Intra Class 300 and 480 for UHD workflows will make it stick around even longer ehehehe.
But even in the consumer world, most of the stuff we see in VOD is still either in H.264 OR has an H.264 fallback stream for compatibility purposes.
I'm not saying that it's a bad thing, on the contrary, but I'm just noticing how long x264 will stick around for years to come. :P

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Only moneymakers tried to take more money from general more and more poor public forcing it to move to 265 with 10bit and HD/UHD/HDR/WCG.
Well... I mean... it's not just money makers, though, isn't it?
I mean, even I don't care much about UHD per se, but there's one thing I'm particularly happy about: more stops in cameras and more nits in contents.
I mean, imagine recording someone with a direct light source and not having to worry about having the sky completely white and clipped out at 100 nits. Nowadays with Sony cameras you can easily record in HLG BT2020 and get your memories in stunning quality and then you can just play back the very same file on your TV etc showing the same amount of nits as the stops recorded by the camera.
Before this was a thing, you had to record in Slog3 and then apply a LUT to go to BT709 SDR 100 nits in the least painful way possible by preserving as much as you could, while if you shot directly in BT709 it would have almost definitely been clipped out.

In a nutshell: I don't think the biggest innovation of 2013 was UHD but rather HDR.

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I can't understand what the hell DTL is saying.
Men and women are often incompatible xD
Just joking, Katie, he might go down a bit of a rabbit hole sometimes with lengthy posts, but so are mine, so we kinda understand each other.
Once you dive into his flow of thoughts, you'll see that he often has some valid points.
Like the recent x264 ASM discussion we had, he made some really valid points.

p.s I'll tell you a secret, he also works with signals through SDI cables, so I like to think that we're SDI buddies XD

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Looke like DTL just core dumped, don't try to make sense of it.
Poor DTL hahahahahahahahaha

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Old 14th February 2023, 20:04   #77  |  Link
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In a nutshell: I don't think the biggest innovation of 2013 was UHD but rather HDR.
Absolutely correct. 1080p HDR is a way bigger upgrade than 2160p SDR.

The rapid adoption of HEVC for premium content was largely driven by support for HDR.

I expect in 10-20 years we'll be thinking of SDR the way we do SD today.
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Old 14th February 2023, 22:36   #78  |  Link
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"keep watching SD BT601 8bit 100 nits stuff on their TV 'cause "it just works"..."

Only extra poor people watch SDR content at 100nits very poor displays (I also use such Philips-china 4K SDR model). Though poor people are most at this planet nowdays. Other can watch colour SDR movies at the daylight at sunlight-viewable displays with 2000..4000+ nits of max(nominal) white. Way better in compare with HDR-capable displays for poor people rated for limited time and limited part of frame peaked brightness to 1000..1500 nits. SDR really not limited to displaying setup of only 100nits and also viewing colour content at so low brightness you limit best colour viewable range to about 10:1 . Below 10nits human vision start to degrades colour saturation and below about 0.1..0.01 it decays to greys only. So to view about 1000:1 dynamic range of 8bit SDR in full colour having dark grey (about 17..18 code value at 8bit limited) at 10nits it is better to have DolbyVision-class 10000 nits fulltime fullframe unlimited display (not very cheap product and eating lots of power). And viewing conditions about mid-shaded daylight about 1000..5000+lux average room lighting (also only very poor people have very dim lighting about 1xx lux or lower at evening/night resting at home after all day hard work).
10000nits are really not any great brigthness - the about 0.7 diffuse reflective office paper at direct sunlight 100000lux have brightness about 20000nits and you still not have any headroom for highlights (natural sun highlights can go significantly higher 100000 nits - like in water objects and so on still non-metal mirrors).
So even still not present at poor people market possible HDR-10000 displays still not cover standard daylight diffuse only reflecting scenes with 'natural 1:1 physical brightness mapping'.

"but can you imagine how long H.264 will stick around? I mean, it was such a good codec in terms of patents and x264 was such a good encoder that it will probably stick around for years to come and the fact that broadcast companies adopted XAVC Intra Class 300 and 480 for UHD workflows will make it stick around even longer ehehehe."

In distribution and endusers it mostly probably till the end of current civilization (possibly less 1 century time left, or even much less). h.264 and x264 for AVC-Intra encoding is possibly very poor solution when you try to cosplay some better MJPEG coder with completely different target designed MPEG coder.
As you see todays it end with very poor performance when about somehow optimized by residuals of programmers frame analysis part in x264 run at about 10% of processing time. And may be 80 and more % of time for your I-frames coder cosplay from x264 you run with very non-optimized CAVLC not-video non-image oriented simple raw data compression engine. And more badly it is forced to keep about equal output bitrate with significantly different in complexity frames without permission to simply keep same quality level and fill bitstream with zero stuffing when frame is simple if your application forces you to have constant bitrate.

So it looks in AVC-intra I-frames CBR encoder cosplay the x264 program runs tons of iterative loops of different quantizer blocks encoding and after (slow and not optimized) CAVLC compression tried to see if it reach your target system bitrate any good. Not really nice solution. CAVLC data compressor is unlikely will be optimized because it is already replaced by better CABAC at general poor public usage and your old industry standards for AVC-Intra not allow to use CABAC - bad.
May be for professional industry exists some hardware ASICs for this AVC-Intra CBR encoding. General public unlikely need such slow and not optimal solution with varied quality over frames and slow encoding rate algorithmic solution. So general usage of x264 is crf-based IPB VBR.

" there's one thing I'm particularly happy about: more stops in cameras and more nits in contents."

1. About several decades already may be from begining of rec.601 digital the good quality broadcast-class video cameras had HDR internal processing - it required to have about 600% non-clipped dynamic range above nominal white (for 2/3 chips classic SD camera). Better product may have 1000% and more range above nominal white. At the 'before public HDR standards' time the camera control person may either hit AUTO KNEE option or manually play with KNEE POINT/ KNEE SLOPE adjustments per scene to have _non_standardized_ HDR compression of scene highlights into SDR valid codevalues range (8 or 10bits). So some 'non-standard-HDR' are really work non-advertized over many decades. With good broadcasters using not very cheap low dynamic range cameras. Only because of per-scene manual or auto-compression of dynamic range without signalling about it - the decoder display device can not fully decompress its range close to natural-scene linear. But it displays without hard clipping. The public-HLG HDR is only putting normatives to compression transfer curve of highlights above nominal (diffuse) scene white. So display device can perform better backward decompression of range above nominal white (and display more or less correctly depending on how much power of light do it have).
Also as cameras start move from SD to HD the noise-limited dynamic range become lower so we were need some years of advancing of incamera noise reduction so you again have about 60dB SNR at HD (and may be already in UHD) camera with still providing some headroom untill white clipping to have data for HDR compression.

2. Nits is completely not directly connected to the displaying of SDR or HDR video system. As described above. Nits only depends on how many money can put customer in display device to have none or time/area-limited or unlimited high-nits display. The xvid-coded 8bit SD/HD SDR content may be nicely displayed at good 2000+ nits full-time full-frame unlimited daylight vieweable open air home private person usage display device.
(image from https://www.tomsguide.com/reference/...est-outdoor-tv , may not displayed in forum)
To not live in dim grey visible environment poorly and partly visually coloured and to see full saturated coloured range down to the very darks we need to live in good enough lit areas (or good enough lit indoors).
Sorry for users of HDR-like hardware of area+time limited poor 1000nits cheap displays for poor general public. No usage of AVC or 265,266 or more numbered by geeks codecs can help to display real physical power light and visible colour range if not enough money put to power of hardware light. So WCG+HDR with very dim 1000nits or less poor displays also really not fully correct stuff. The dangerous words 'colour volume' already passed to public market and only good enough powered displays can reach really good visible colour volume (not just encoded in zero-cost digital file of any codecs/bitdepth).

Last edited by DTL; 14th February 2023 at 23:06.
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Old 16th February 2023, 12:12   #79  |  Link
FranceBB
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1. About several decades already may be from beginning of rec.601 digital the good quality broadcast-class video cameras had HDR internal processing - it required to have about 600% non-clipped dynamic range above nominal white (for 2/3 chips classic SD camera). Better product may have 1000% and more range above nominal white. At the 'before public HDR standards' time the camera control person may either hit AUTO KNEE option or manually play with KNEE POINT/ KNEE SLOPE adjustments per scene to have _non_standardized_ HDR compression of scene highlights into SDR valid codevalues range (8 or 10bits)
That is correct if it wasn't for the fact that cameras originally only had around 6 stops which leaves no headroom for highlights. Only after that, they improved beyond the 6 stops and nowadays they're doing what you described internally. But in SD days? No chance.
But even nowadays, some cameras don't really have many stops and therefore they don't have a large enough bracket to get all the frequencies.
This is just an example: look at the sunlight, the camera sensor had too little stops to be able to record the sky and therefore it's clipped out at 0.7V.



This is a classic example and it's something my colleagues and I refer to with "the sheet is too short". With that expression, we mean that the camera has a bracket of x stops and no matter if you move it up or down, you'll always end up sacrificing something, be it the whites or the blacks of the image. In 99.9% of the cases, the person talking (i.e the presenter) is the most important subject, so that one is where the stops focus around and you'll be able to clearly see the face of the person talking, however the sky will be clipped out (in fact it's white). If you did the other way round, you would have preserved the sky, but the face of the presenter would have been completely averaged out in the dark region and you wouldn't be able to see it.

This, again, is all occurring in BT709 SDR 100 nits and it just shows the limits of SDR.
Sure, you could have a feed recorded by HDR cameras in a totally logarithmic curve like Slog3, Clog3, LogC etc and then perform the BT709 mapping, but realistically, for news, this ain't gonna happen.
One day, though, when everything will be HDR, the cameras will be able to record automatically in let's say HLG and then the same feed could be used live without additional mapping or conversions unlike Slog3, Clog3, LogC etc that would require mapping to PQ and you can bet anything that if today this technology was already widespread and implemented and everything was shot and recorded and aired in BT2020 HLG 1000 nits, the sky would have been there and it would have been blue

Last edited by FranceBB; 16th February 2023 at 12:16.
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Old 16th February 2023, 17:28   #80  |  Link
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"keep watching SD BT601 8bit 100 nits stuff on their TV 'cause "it just works"..."

Only extra poor people watch SDR content at 100nits very poor displays (I also use such Philips-china 4K SDR model).
If not having an UHD TV is considered "extra poor", then I guess most people are "extra poor" according to that weird definition.
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