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Old 17th May 2006, 17:05   #41  |  Link
juerginst
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Great!!!
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Old 9th September 2006, 07:16   #42  |  Link
IndieRockSteve
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Quote:
Originally Posted by Sharktooth
1500kbps is a good starting point for sources with good compressibility at 1280x720 @ 23.976fps.
Higher bitrates are needed if noise or grain is present or if compressibility is lower (action movies for example).
Obviosly that's subjective... but artifacts on HD stuff are much less visible.
Use a quality preset (like HQ-Slower for MeGUI) or if encoding time is a problem just rise the bitrate and use a faster preset.
Interesting. I want to do 1080i->1080p encodes of my HDTV captures, I'm less concerned with file size than I am with quality though. Whats a good bitrate to start at for this? Which of the matrices in your sig should I try with my encodes?

thanks! (and thanks for all your posts on this forum, lots of good reading!)
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Old 9th September 2006, 07:27   #43  |  Link
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If you're not concerned by the filesize, use a one pass crf encoding. Try value from 18 to 26, and choose the biggest value whose quality you still find acceptable. Then stick to that crf for all your encoding.
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Old 28th September 2006, 08:55   #44  |  Link
Romeo_by
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Does anybody can advice a source info about creating custom matrices or may be explain basicly how to do it?
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Old 28th September 2006, 09:25   #45  |  Link
Audionut
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Second result from a custom search.
http://forum.doom9.org/showthread.ph...ghlight=matrix
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Old 23rd April 2008, 14:56   #46  |  Link
RickA
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I know this is an old thread and I do not mean to resurrect it. I just wanted to thank you for this matrix Sharktooth. Tried to PM you this instead but it said your message box was full up.

What a great matrix you have created here. It really helped clear up the 'blockiness' I was getting in dark scenes of low detail. Such as the intro to Alien as they are spelling out the letters and panning across the planet. Even with Constant Quality of 17 and a sufficiently high bitrate I still had ugly blocky artifacts before using this matrix. I realize h264 has a tendency to go blocky in low detail and low lit areas, but EQM AVC-HR really cleared those up for me.

Since this matrix works so well on darkly lit low detail movies I take it that it is also fine to use on well lit low detail movies... as a precautionary measure? I'm new to h264, been playing with MeGUI and AutoMKV for a few weeks. My goal is to put my dvds on the computer hard disk for playback via tv and home sound system - a video jukebox if you will. A file size reduction of @30% and near source quality is what I am aiming for.

Once again, sorry for posting in an old thread. I debated whether to start a new thread just to say 'Thankyou' for the work you have done.

Cheers,
Rick
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Old 23rd April 2008, 15:06   #47  |  Link
Sharktooth
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thanks for your kind words.
as the description says, EQM AVC-HR requires high bitrate and tends to force the codec to assign more bits in certain areas.
this behaviour has been discussed with the x264 devs and is not optimal, but indeed it helps a lot to avoid blocking.
yes, it works good even on "lit" details and if you feel confortable with how it looks, then feel free to use it but remember it needs more bits, that means if you encode in CRF or CQ it will take more disk space than normal.
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Old 24th April 2008, 15:26   #48  |  Link
RickA
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Greetings Sharktooth,

Thanks for responding to my EQM AVC-HR post. I am not fully sure on what you mean when you said 'if you feel comfortable with how it looks' would you please expand more on that? My newbie eyes have only detected a reduced blockiness of h264 in dark, low detailed areas. I have just started testing with your matrix. Is there something else I am missing with using your matrix and should be aware of? You also mention the matrix behavior and h264 as not being optimal. Are you referring to compressing the file size, or picture quality?

As far as the increased file size by using your matrix that is not as much of a concern for me as keeping video quality as close to source as possible. I am basically making a movie jukebox by putting my dvd's onto computer for playback via tv and home sound system. If I get near 30% file size reduction I am happy.

Thanks again.

Cheers,
Rick
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Old 13th May 2008, 16:38   #49  |  Link
mpiper
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Sharktooth,

I just downloaded your custom matrices, but being new to x264, I don't want to randomly use them with no idea of their purpose.

Can you possibly provide us with a simple description of suggested uses? Something like min/max bitrate, anime/clean/grainy source, fastmotion w/ high detail, details vs. banding, etc.

Thank you in advance!
Mike
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Old 13th May 2008, 17:05   #50  |  Link
ToS_Maverick
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read two posts above yours:

Quote:
Originally Posted by Sharktooth View Post
thanks for your kind words.
as the description says, EQM AVC-HR requires high bitrate and tends to force the codec to assign more bits in certain areas.
this behaviour has been discussed with the x264 devs and is not optimal, but indeed it helps a lot to avoid blocking.
yes, it works good even on "lit" details and if you feel confortable with how it looks, then feel free to use it but remember it needs more bits, that means if you encode in CRF or CQ it will take more disk space than normal.

for even more information, start at the beginning of this thread.

and there's another thread about matrices, if you're eager to read:
http://forum.doom9.org/showthread.php?t=117041
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Old 17th July 2008, 10:57   #51  |  Link
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Do we have a "compressibility test" for MPEG4-AVC?
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Old 17th July 2008, 11:28   #52  |  Link
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would it make sense?
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Old 17th July 2008, 13:14   #53  |  Link
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Somehow, unless we have some general rules describing terms like "high bitrate", "difficult materials", etc. for MPEG4-AVC (say, with respect to x.264). I am asking myself questions like "how would this movie look like if I encode it into xxxMB using x.264?" I think something like a compressibility test would help.
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Old 17th July 2008, 17:29   #54  |  Link
Sharktooth
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compressibility test is like for xvid. except you have to use CRF 18 istead of CQ2.
also the avc matrices are really becoming obsolete and useless (at least for x264) since VAQ and Psy-RDO,

Last edited by Sharktooth; 17th July 2008 at 17:32.
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Old 18th July 2008, 00:26   #55  |  Link
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If we are doing a sampled compressibility test, do we need to discard the frames of "artificial" scene changes?
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Old 18th July 2008, 16:32   #56  |  Link
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as a rule of thumb it would be better to discard them but the theoretical right way is just rising the patial comp.test compression value/percent by e few points to compensate the difference of partial encode scenechanges number vs the final encode scenechanges effective or approximated number.
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Old 5th April 2009, 06:56   #57  |  Link
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Would you like to give some idear or papers about how to train a custom quantization matrix?
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Old 5th April 2009, 14:02   #58  |  Link
Sharktooth
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http://en.wikipedia.org/wiki/Quantiz...ge_compression
how to "train" depends on what you want to obtain once you got "how" quantization matrices work.

Last edited by Sharktooth; 5th April 2009 at 14:08.
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