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Old 25th October 2017, 09:26   #321  |  Link
mzso
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Originally Posted by dapperdan View Post
In case anyone else was confused like I was, the still image format based on AV1 called AVIF is mentioned (briefly) in a video mostly on other topics, given by Netflix at the Demuxed conference, not in either of the two videos that mention AV1 in their titles:

https://www.youtube.com/watch?v=PSdhW-R9u6s
A timecoded link would have been nice. Or a mention of what was said. Not everyone has time for these long-ass videos.
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Old 25th October 2017, 13:20   #322  |  Link
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It's at 1:30 through to about 4 minues though it pretty much only says "We expect to have a new image format based on [AV1] called AVIF" and about 3 minutes makes clear this is just a I-Frame of AV1 and aimed towards distribution rather than storage.

Last edited by dapperdan; 25th October 2017 at 13:23.
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Old 25th October 2017, 17:44   #323  |  Link
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AV1 status update talk from Gstreamer conference, very similar content to the Demuxed talk.

https://gstconf.ubicast.tv/videos/av...arly-complete/
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Old 25th October 2017, 17:47   #324  |  Link
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A PhD-level internship for working on AV1 at Mozilla is open for applications:

https://careers.mozilla.org/position/gh/881961
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Old 25th October 2017, 21:34   #325  |  Link
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Hope not too many issues crop up in the reference implementation due to the final rush to get things done.
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Old 27th October 2017, 17:36   #326  |  Link
TD-Linux
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I am baffled by the use of such an old x265 build. Even in placebo it'll run a ton faster than the current AV1 reference implementation. So it'd be trivial to rerun the test at the same time the final tests for AV1 are done for a presentation like this.

Are the different command lines used for the different codecs listed somewhere?
Yeah using the old version is not great (which is why I was sure to list it) I want to provide better x265 numbers before presenting numbers with something closer to the "final" codec (the "AV1" here is missing features too). Note it's probably far from the only issue comparing x265 and AV1 - both use very different reference frames and keyframe boosts so doing a comparison with metrics is quite hazard frought. The VP9 numbers are much more comparable. The x265 parameters were:

Code:
--preset placebo --no-wpp --bframes 16 --merange 256--min-keyint 1000 --keyint 1000 --no-scenecut --crf=$x
The bframes and merange options were determined through trial and error to improve x265's metric score. I've run x265 since but haven't tried to re-optimize these on a newer build.

This is done on the AWCY infrastructure. Here are two more recent results, still with the old x265 runs:

https://arewecompressedyet.com/?job=...3A43%3A40.468Z

with --tune psnr

https://arewecompressedyet.com/?job=...3A43%3A40.468Z
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Old 27th October 2017, 19:09   #327  |  Link
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Yeah using the old version is not great (which is why I was sure to list it) I want to provide better x265 numbers before presenting numbers with something closer to the "final" codec (the "AV1" here is missing features too). Note it's probably far from the only issue comparing x265 and AV1 - both use very different reference frames and keyframe boosts so doing a comparison with metrics is quite hazard frought. The VP9 numbers are much more comparable. The x265 parameters were:
An apples-to-apples comparison of a bitstream is impossible. All that really is possible is to compare DMOS of an optimal encode from the best available encoders for each format targeting the same scenario.

Code:
--preset placebo --no-wpp --bframes 16 --merange 256--min-keyint 1000 --keyint 1000 --no-scenecut --crf=$x
No IDR frames and no rate control isn't a real-world scenario. But assuming these are short clips
  • Why a CRF encode? If you want a particular bitrate to compare quality, you should use 2-pass VBR. Iteratively selecting a CRF to get the target file size is just a very slow way to get an identical result.
  • If you stick with single pass, use --rc-lookahead 250
  • You should add --cu-lossless to fully exercise x265 and HEVC features. It can improve efficiency with synthetic elements and when visual lossless.
  • You should add --tskip, which can often improve x265 with fine details.
  • You should try --subme 7; placebo defaults to 5. I don't know if it'll offer practical improvements, but may well for objective metrics when using --tune for those metrics.
  • You should try --me sea or even full if you want Full Placebo. They likely would help a bit with PSNR and objective metrics, although it doesn't seem that useful in the real world.
  • For lower syntax overhead, try--opt-cu-delta-qp.
  • You should be testing with the current release version of x265 for when you are running the comparison. AV1 isn't going to compete against last year's x265! The competition is between the best available encoders at the time of a comparison.

Quote:
The bframes and merange options were determined through trial and error to improve x265's metric score. I've run x265 since but haven't tried to re-optimize these on a newer build.
Those should be fine, albeit super slow. Even placebo only uses merange of 92. Tskip is going to offer a lot better quality @ speed improvement.

Also, none of the metrics I've seen published have particularly good correlation to DMOS. If you can't do a real subjective test, you should at least include VMAF, which is definitely the best available subjective metric today.

Quote:
This is done on the AWCY infrastructure. Here are two more recent results, still with the old x265 runs:

https://arewecompressedyet.com/?job=...3A43%3A40.468Z

with --tune psnr

https://arewecompressedyet.com/?job=...3A43%3A40.468Z
If you are testing SSIM, you need to use --tune ssim and --rd-ssim. --tune PSNR generally gives worse results with SSIM than not using any --tune, as your results show.

But, really, these results don't matter with an old version. There has been a ton of tuning since that x265 build. Ones relevant to placebo 8-bit SDR testing include:
  • Support for non-IDR I-frames (very relevant with --no-keyint)
  • new lambda tables
  • A bunch of syntax simplification tools
There is a temptation to assume there exists a way to compare bitstreams outside of their encoders, but there simply isn't. Which is why I recommend picking a real world scenario and tuning each encoder as best as possible for that scenario. Ignoring rate control, keyframes, and subjective quality excludes critical features always used in real-world encoding, and results in a less relevant real-world test.

And bitrates need to be used where all streams to be tested show some degree of compression artifacting. If any stream is visually lossless for any significant period, we don't know if the bitrate is higher than is needed to be visually lossless. That tends to underestimate the advantage of the more efficient encoder.

Two tests I like are:

VBR:
  • 2-pass VBR
  • peak bitrate 2x average bitrate
  • VBV set to the max of the lowest Profile @ Level for the content frame size and fps
  • Open GOP with adaptive duration of a maximum of 5 seconds

CBR:
  • 1-pass CBR
  • VBV set to 2x bitrate
  • Fixed 2 second Closed GOP

The minimum viable objective metric is VMAF, in my opinion. All the ones currently used for this comparison don't include temporal comparisons(need to catch keyframe strobing and grain swirling!), and all have lots of known defects resulting in poor subjective comparisons. Plus the average of squared errors of individual frames does nothing to pick up on quality variation inside of a clip. A clip that is 3 second great and 3 seconds awful can have a better psnr and ssim as a clip that is consistently mediocre, but consistently mediocre is a much better subjective experience. I understand that is why rate control is deactivated in codec comparisons, but that itself assumes that QP==constant quality, when we know it isn't (which is why CRF was invented).

The better the metrics being used, the more relevant the comparison. And it is also helpful for designers of new bitstreams and encoders to get them focused on optimizing the stuff that really matters. The whole sum of squared PSNR and no rate control biases codec development for codecs where fixed QP optimizes for high mean PNSR per frame. And that just isn't something that matters in a real-world encoder with rate control, adaptive quantization, and watched by humans.

It is illustrative to encode with --tune psnr and see the ways that subjective quality degrades when optimizing for that metric. Or just using fixed QP.
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Old 27th October 2017, 23:32   #328  |  Link
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An apples-to-apples comparison of a bitstream is impossible. All that really is possible is to compare DMOS of an optimal encode from the best available encoders for each format targeting the same scenario.
Agreed. I've set up some infrastructure that makes it possible to crowdsource this as well, so I'd like to do so once AV1's done.

Quote:
No IDR frames and no rate control isn't a real-world scenario. But assuming these are short clips
Yup, they are only 60 frames long and intentionally don't have scenecuts. This is done primarily for performance reasons (it also approximately matches the HEVC test conditions, though whether that should be a goal is questionable). Note that the primary use case of this platform is to quickly iterate small changes - it is a slight abuse to be doing cross codec comparisons...
Quote:
Why a CRF encode?
We're calculating bd-rate, which plots several rate points on a curve and integrates the area difference between them to get an "average" change in rate. Precisely hitting a rate target isn't important. In fact, using VBR is counterproductive as it often adds noise to the results for small changes, and also x265 and libaom's VBR modes aren't really comparable. It might make more sense to use VBR modes for visual comparisons, though (with careful consideration of the buffer models). And possibly with some objective metrics as well, but I think libaom's rate controller will need to be rewritten to have a more x265-like mode before this really produces interpretable results.
Quote:
You should add --cu-lossless to fully exercise x265 and HEVC features. It can improve efficiency with synthetic elements and when visual lossless.
Noted. There a couple of clips in the test set that might benefit.
Quote:
You should add --tskip <snip>
Noted, I'll try iteratively adding them to the current release (previously I've found that that some of these options were less well tested and didn't always offer improvements)

Quote:
Also, none of the metrics I've seen published have particularly good correlation to DMOS. If you can't do a real subjective test, you should at least include VMAF, which is definitely the best available subjective metric today.
I've actually added it already, the main issue I've ran into is that VMAF tends to saturate quickly at higher qualities and actually goes down slighty, this causes bd-rate to be come uncomputable. I need to come up with some sort of solution to this. Select VMAF and individual videos at this link to see the problem: https://arewecompressedyet.com/?job=...3A06%3A32.304Z

I also do want to warn that I've seen VMAF give rather unexpected results. For example, AV1's CDEF filter produced clearly superior results in a subjective test but VMAF shows it as several percent worse. In addition, VMAF hates x264 and x265's AQ modes. The greatest strength of VMAF is that it tends to offer an absolute quality measure across different types of video - but locally it's far from perfect.
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Old 30th October 2017, 08:25   #329  |  Link
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Hope not too many issues crop up in the reference implementation due to the final rush to get things done.
Which is exactly the same I am feeling now.

But I dont think it matters, at least I hope that is the way Open Media Alliance sees it. If they are in it for the long run. AV1 shouldn't really be perfect. But it should be a statement to the world, that it is possible to do video codec this way.

Then I hope they will start drafting a AV2 spec along with a ecosystem around it.

But given the way google does thing, I am not holding my breath.
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Old 30th October 2017, 17:46   #330  |  Link
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Yup, they are only 60 frames long and intentionally don't have scenecuts. This is done primarily for performance reasons (it also approximately matches the HEVC test conditions, though whether that should be a goal is questionable). Note that the primary use case of this platform is to quickly iterate small changes - it is a slight abuse to be doing cross codec comparisons...
Only 60 frame clips? No scenecut makes perfect sense in that case, but I worry about the broad applicability of the results. The VBV is a huge percentage of the bitrate at those low sizes, which can yield a lot of variability of the size of a compliant stream. And a 2-sec GOP is on the low end of typical usage anyway.

Quote:
We're calculating bd-rate, which plots several rate points on a curve and integrates the area difference between them to get an "average" change in rate. Precisely hitting a rate target isn't important. In fact, using VBR is counterproductive as it often adds noise to the results for small changes, and also x265 and libaom's VBR modes aren't really comparable.
Perhaps the implementations aren't comparable, but the problem to solve is the same: maximum quality given a maximum file size and a maximum VBV. So I would think the results are comparable, even if not comparable.

Quote:
It might make more sense to use VBR modes for visual comparisons, though (with careful consideration of the buffer models). And possibly with some objective metrics as well, but I think libaom's rate controller will need to be rewritten to have a more x265-like mode before this really produces interpretable results.
That is a core point. Are we comparing the ability of the bitstream or of the best reference encoder? I'd argue that doing the former is impossible to do well with high precision. But I can see the value in getting a snapshot estimate.

Quote:
I've actually added it already, the main issue I've ran into is that VMAF tends to saturate quickly at higher qualities and actually goes down slighty, this causes bd-rate to be come uncomputable. I need to come up with some sort of solution to this.
If perceptual quality is saturating, than VMAF is yielding appropriate results. From a DMOS perspective, the closer we are to visually lossless, the smaller the relative efficiency of different encoders becomes. We would expect meaningful distortion to flatten out at a certain point. It is kind of ridiculous that PSNR -10 to -30 has the same weight as PSNR -60 to -80, since the former is a huge visual quality difference and the latter is invisible.

Quote:
I also do want to warn that I've seen VMAF give rather unexpected results. For example, AV1's CDEF filter produced clearly superior results in a subjective test but VMAF shows it as several percent worse. In addition, VMAF hates x264 and x265's AQ modes. The greatest strength of VMAF is that it tends to offer an absolute quality measure across different types of video - but locally it's far from perfect.
VMAF isn't perfect. Its test range was relatively limited (1080p down to ~300 Kbps IIRC) and was mainly done with x264. Since it was only trained on x264 style artifacts, types of artifacts only appearing in HEVC and/or AV1 might give weird results.

In theory, the VMAF framework can be used, but using new clips to retrain the ML. In practice, I think VMAF will need and enhanced temporal component to capture a broader range of codecs and scenarios. In particular, I think the current VMAF will underestimate the perceptual experience hit of keyframe strobing, and thus wouldn't capture Open versus Closed GOP differences.

Overall, I think you're making a very good effort here. This is really hard stuff to do well. Fundamentally, there are lots of real-world things we want to predict from metrics that we simply can't predict well. Even DMOS has its limitations, as it takes so long that the results generally don't reflect the abilities of encoder implementations by the time they are published.

And golden eyes have all kinds of biases. I know I am so trained to pick up and classic forms of encoding issues that I notice things real-world customers almost never will.

We continue to slouch towards mediocrity.
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Old 1st November 2017, 11:04   #331  |  Link
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Which is exactly the same I am feeling now.

But I dont think it matters, at least I hope that is the way Open Media Alliance sees it. If they are in it for the long run. AV1 shouldn't really be perfect. But it should be a statement to the world, that it is possible to do video codec this way.

Then I hope they will start drafting a AV2 spec along with a ecosystem around it.

But given the way google does thing, I am not holding my breath.
Google seems to be cooperating well enough with the group(along with everyone else even if they are on opposing sides e.g. Intel/AMD). AV1 is unlikely to have the same major issues like VP9, but it is slowly looking to become more of a stopgap for AV2 due to time pressure. I am seeing a lot of experiments being moved to AV2, which will hopefully be done right once the pressure to rush things out clears after AV1 is released.

Can't complain about the current state that much however, AV1 is still a very good codec

As for the ecosystem, I am hoping for a family of related container formats, something like:
webm - video (AV1/Opus)
webp - picture (AV1 Intra) - throw out VP8
weba - audio (Opus)

It would definitely help to market these codecs and formats a bit more to the general populace. Not sure AVIF is that great to pronounce

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Old 1st November 2017, 13:13   #332  |  Link
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Originally Posted by bstrobl View Post
As for the ecosystem, I am hoping for a family of related container formats, something like:
webm - video (AV1/Opus)
webp - picture (AV1 Intra) - throw out VP8
weba - audio (Opus)

It would definitely help to market these codecs and formats a bit more to the general populace. Not sure AVIF is that great to pronounce
using the extension .webp would be a bad idea. As people may try and view a vp8 .webp file in a view/browser that only supports av1 .webp. They should use the extension .avif. Avif will be good enough for a decade as image compression isn't going to improve that much. JPEG has been around for over 20yrs and avif is only going to be ~65% smaller. There isn't any point making a new image format every ~3yrs, there is a good benefit to making new aom video codecs every 3yrs though.
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Old 1st November 2017, 13:25   #333  |  Link
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I am seeing a lot of experiments being moved to AV2, which will hopefully be done right once the pressure to rush things out clears after AV1 is released.
I will be thoroughly disappointed if AV2 turns out to be another tweakfest for old ideas. I don't think there's a point in creating yet another format to a similar concept. Development would will have ever diminishing returns anyway.

I think AV2 should be something fundamentally different (for the better) and they'll finish it whenever they do.

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there is a good benefit to making new aom video codecs every 3yrs though.
I strongly disagree... In three years they can't even exploit the full potential of a codec format.
It's only good for HW manufacturers, who can resale the same crap, but with a newer HW decoder.

Last edited by mzso; 1st November 2017 at 13:28.
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Old 1st November 2017, 18:51   #334  |  Link
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As for the ecosystem, I am hoping for a family of related container formats, something like:
webm - video (AV1/Opus)
webp - picture (AV1 Intra) - throw out VP8
weba - audio (Opus)
Why not use MPEG-4 program streams for video, HEIF for picture, and MPEG-4 program streams for audio? Dropping in a new codec is a lot easier than full support for a new container format. And we have a LOT of mature muxing, distribution, and playback tech built around MPEG-4 PS.
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Old 1st November 2017, 18:57   #335  |  Link
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using the extension .webp would be a bad idea. As people may try and view a vp8 .webp file in a view/browser that only supports av1 .webp. They should use the extension .avif. Avif will be good enough for a decade as image compression isn't going to improve that much. JPEG has been around for over 20yrs and avif is only going to be ~65% smaller. There isn't any point making a new image format every ~3yrs, there is a good benefit to making new aom video codecs every 3yrs though.
Maybe a 65% size reduction for natural images, which are JPEG's sweet spot. But for sharp-edged and synthetic content like text, line art, screen shots, noise-free gradients, etcetera, JPEG is quite bad. I've been able to get 95% reductions for Manga-style art using HEIF HEVC versus JPEG. I imagine AV1 would be in the same rough ballpark.

The goal isn't just to replace JPEG, but also PNG and GIF. HEIF+HEVC is a superset of all of JPEG, PNG, and GIF, and offers better efficiency than any of them for all their scenarios, and adds a lot of additional scenarios as well (like real PQ Rec. 2020 style HDR). An HEIF+AV1 would likely have similar potential.
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Old 1st November 2017, 21:04   #336  |  Link
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Maybe a 65% size reduction for natural images, which are JPEG's sweet spot. But for sharp-edged and synthetic content like text, line art, screen shots, noise-free gradients, etcetera, JPEG is quite bad. I've been able to get 95% reductions for Manga-style art using HEIF HEVC versus JPEG. I imagine AV1 would be in the same rough ballpark.

The goal isn't just to replace JPEG, but also PNG and GIF. HEIF+HEVC is a superset of all of JPEG, PNG, and GIF, and offers better efficiency than any of them for all their scenarios, and adds a lot of additional scenarios as well (like real PQ Rec. 2020 style HDR). An HEIF+AV1 would likely have similar potential.
heif requires licensing h265 patents though which can be expensive. Avif will be patent free, so much better to use that.
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Old 2nd November 2017, 10:28   #337  |  Link
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Why not use MPEG-4 program streams for video, HEIF for picture, and MPEG-4 program streams for audio? Dropping in a new codec is a lot easier than full support for a new container format. And we have a LOT of mature muxing, distribution, and playback tech built around MPEG-4 PS.

I guess the point is to use simplified containers dedicated to few codecs to ensure a decent chance of compatibility, as dropping in newer codecs onto old containers may cause frustrations in the future. HEIF is also a very large spec from what I can tell, would make sense to use a heavily simplified version to ensure compatibility and reliability for standard web distribution. WebP is still at version 0.6 so something could still be fixed up for version 1.0 rather than ditching the name. Ingraining format names like JPEG can be quite useful sometimes.

Quote:
heif requires licensing h265 patents though which can be expensive. Avif will be patent free, so much better to use that.
The HEIF container itself should not have any associated patent fees, only the HEVC Intra part. Not sure what AVIF brings to the table in this case actually.

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Old 2nd November 2017, 21:48   #338  |  Link
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Originally Posted by benwaggoner View Post
Why not use MPEG-4 program streams for video, HEIF for picture, and MPEG-4 program streams for audio? Dropping in a new codec is a lot easier than full support for a new container format. And we have a LOT of mature muxing, distribution, and playback tech built around MPEG-4 PS.
I'm not sure who is the target of those suggestions.

* For a new image format to gain relevant success, browser vendors will have to reach a consensus. Google and Mozilla are not going to support anything HEVC or MPEG based.

* weba is already the unofficial extension of YouTube's Opus WebM DASH streams. weba/Opus/~160kbps is the highest quality 2ch audio format available (MP4/AAC/256kbps is discontinued).

* For local storage, Matroska works, and will work, just fine with any codec combination.

* Browsers will support AV1/Opus in WebM by default (muxed or separate, including live DASH/WebM streams).
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Old 2nd November 2017, 23:59   #339  |  Link
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Originally Posted by benwaggoner View Post
Why not use MPEG-4 program streams for video, HEIF for picture, and MPEG-4 program streams for audio? Dropping in a new codec is a lot easier than full support for a new container format. And we have a LOT of mature muxing, distribution, and playback tech built around MPEG-4 PS.
We plan to have first class support for ISOBMFF. There is already an Opus-in-MP4 mapping which would make a good pairing.

As far as a still image format, I dunno. HEIF is an option, though it has its own problems (it would be too easy for it to just be a single frame video track, so it's got a totally separate codec mapping).
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Old 8th November 2017, 10:22   #340  |  Link
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Since MABS is able to build aomenc/aomdec as separate encoder/decoder application pair, I wanted to try it once with a small sample (Siemens "foreman", CIF PAL, 300 frames, Derf's Y4M fixed to 25 fps), running on an AMD Phenom-II X4 (other encoders want to use at most SSE2 here).

Basic batch:
Code:
aomenc -v --passes=2 --pass=1 --fpf=foreman_cif.basic.av1.fpf --target-bitrate=300 -o foreman_cif.basic.av1.webm foreman_cif_pal.y4m
aomenc -v --passes=2 --pass=2 --fpf=foreman_cif.basic.av1.fpf --target-bitrate=300 -o foreman_cif.basic.av1.webm foreman_cif_pal.y4m
Pass 1 finishes quickly, only few seconds. Pass 2, instead ... a previous run with a more explicit command line estimated several days to finish. So I reduced the parameter set and tried again. Still:

Code:
>aomenc -v --passes=2 --pass=1 --fpf=foreman_cif.basic.av1.fpf --target-bitrate=300 -o foreman_cif.basic.av1.webm foreman_cif_pal.y4m
Codec: AOMedia Project AV1 Encoder v0.1.0-6495-g63d190aea
Source file: foreman_cif_pal.y4m File Type: Y4M Format: I420
Destination file: foreman_cif.basic.av1.webm
Coding path: LBD
Encoder parameters:
    g_usage                      = 0
    g_threads                    = 8
    g_profile                    = 0
    g_w                          = 352
    g_h                          = 288
    g_bit_depth                  = 8
    g_input_bit_depth            = 8
    g_timebase.num               = 1
    g_timebase.den               = 25
    g_error_resilient            = 0
    g_pass                       = 0
    g_lag_in_frames              = 19
    rc_dropframe_thresh          = 0
    rc_resize_mode               = 0
    rc_resize_denominator        = 8
    rc_resize_kf_denominator     = 8
    rc_end_usage                 = 0
    rc_target_bitrate            = 300
    rc_min_quantizer             = 0
    rc_max_quantizer             = 63
    rc_undershoot_pct            = 25
    rc_overshoot_pct             = 25
    rc_buf_sz                    = 6000
    rc_buf_initial_sz            = 4000
    rc_buf_optimal_sz            = 5000
    rc_2pass_vbr_bias_pct        = 50
    rc_2pass_vbr_minsection_pct  = 0
    rc_2pass_vbr_maxsection_pct  = 2000
    kf_mode                      = 1
    kf_min_dist                  = 0
    kf_max_dist                  = 9999
Pass 1/2 frame  300/301    55384B    1476b/f   36922b/s 3788536 us (79.19 fps)

>aomenc -v --passes=2 --pass=2 --fpf=foreman_cif.basic.av1.fpf --target-bitrate=300 -o foreman_cif.basic.av1.webm foreman_cif_pal.y4m
Pass 2/2 frame   22/3      24753B 1018316 ms 1.30 fpm [ETA  6:55:11]       4F
Pass 2/2 frame   24/5      25314B 1435997 ms 1.00 fpm [ETA  8:18:27]       4F
The output seems to play with ANSI Escape sequences, which Windows 7 cmd may not support on its own...

The ETA will rise the longer I let it ... do whatever it does. Such a speed is ... "concerning", nicely said. And I wonder what the reason could be: Is there a minimum CPU requirement for assembly optimized routines way beyond SSE2? Or is there a possible mis-configuration in the build? Or are the computational efforts so extreme when not capped by a per-frame deadline?

Unfortunately, there is no support in ffmpeg yet (JEEB mentioned some shared variable names with libvpx in IRC), thus no playback in LAV Filters (e.g. in MPC-HC) yet, either. At most it is detected...

Code:
Codecs:
 D..... = Decoding supported
 .E.... = Encoding supported
 ..V... = Video codec
 ..A... = Audio codec
 ..S... = Subtitle codec
 ...I.. = Intra frame-only codec
 ....L. = Lossy compression
 .....S = Lossless compression
 -------
 ..V.L. av1                  Alliance for Open Media AV1
BTW, the low target bitrate of 300 kbps is not the reason, it is just as slow for 3,000. And a deadline goal '--good' did not change the speed either.
__________________

German Gleitz board
MediaFire: x264 | x265 | VPx | AOM | Xvid

Last edited by LigH; 9th November 2017 at 20:51.
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