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Old 14th June 2021, 00:53   #21  |  Link
FranceBB
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@FranceBB, I'd say it's worth doing a Beamr eval. I'm definitely impressed with their stuff. More than I thought I would be!
Noted.
I went to their website and I noticed that they're part of the streaming video alliance, a group I'm also part of.
Tomorrow I'll check whether I can find one of them in our Slack group and eventually ask for a trial to test the quality. I can't promise anything though 'cause right now I'm pretty busy trying to encode Dolby Atmos into DolbyED2 without using a Dolby Hardware Encoder
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Old 14th June 2021, 01:15   #22  |  Link
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Yeah, that's one. Another one is when a movie is letterboxed (1:85:1/2.35:1/2.40:1 movie in a 1.78:1 frame for example).
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Old 14th June 2021, 09:33   #23  |  Link
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Yeah, that's one. Another one is when a movie is letterboxed (1:85:1/2.35:1/2.40:1 movie in a 1.78:1 frame for example).
You mean the first few blurry picture lines adjacent to the letterbox borders, unless it is all mod16?
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Old 14th June 2021, 17:50   #24  |  Link
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I've made a quick search, Beamr doesn't seem to be free like x264, am i wrong ?
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Old 14th June 2021, 18:36   #25  |  Link
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I've made a quick search, Beamr doesn't seem to be free like x264, am i wrong ?
You are correct. It is a commercial encoder.
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Old 14th June 2021, 19:30   #26  |  Link
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Yeah if you only want free / open source encoders then forget about anything other than x264
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Old 14th June 2021, 20:00   #27  |  Link
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You mean the first few blurry picture lines adjacent to the letterbox borders, unless it is all mod16?
Yeah, exactly. Those AR never have perfect mod16 black bars, so on a bluray encode this means to have almost the whole movie to have blurred lines. Not so problematic when the image is clean, but if there's grain for artistic reasons or due to the filmprint, that's quite visible.
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Old 14th June 2021, 20:20   #28  |  Link
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Yeah, exactly. Those AR never have perfect mod16 black bars, so on a bluray encode this means to have almost the whole movie to have blurred lines. Not so problematic when the image is clean, but if there's grain for artistic reasons or due to the filmprint, that's quite visible.
This taps into my mid-aughts HD-DVD and Blu-ray authoring days.

A common mistake with those encodes was to center in the middle of the 1080 pixels. But 1080 is not mod16 - the mod16 encode is 1088 with the bottom 8 pixels removed. This was a problem with MPEG-2 and VC-1 as it only supported 16x16 macroblocks. Thus proper mod 16x16 framing of a 2.4 title in MPEG-2 or VC-1 isn't 280 top and bottom, but 272 top and 288 bottom.

With H.264, a 4x4 block is only 8x8 with chroma. So you can get away with mod8 from the top and bottom. 280x280 works for 2.4 in H.264.

With 1.85:1 you've got 1038 active pixels out of the 1080 lines, so 42 lines to crop. 42 isn't mod8; you need to round up to 48. Blanking out 24 pixels top and bottom means covering 6 lines of the source, which may be preferable to getting the edge artifacts. Alternatively you could scale the image up to 1040 active pixels and crop 16 top 24 bottom.

For 2.35:1 you've got 817 active pixels. One would mask 132 top and bottom if centering, but those aren't mod8. So, move the image up four pixels and mask 128 top and 136 bottom.
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Old 15th June 2021, 13:03   #29  |  Link
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Yeah, but it's something that can't be done... I mean, there's no reason to "un-center" the image just to have mod16 black bars and help x264, because it's visible by naked eye that in that way the image is not centered anymore (which is bad aesthetically). Plus, other encoders doesn't exhibit this type of flaw and a comparison with the same movie made by another distributor will made the "trick" obvious.

The suggestion seems more or less a workaround to overcome the problem...
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Old 15th June 2021, 17:29   #30  |  Link
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Yeah, but it's something that can't be done... I mean, there's no reason to "un-center" the image just to have mod16 black bars and help x264, because it's visible by naked eye that in that way the image is not centered anymore (which is bad aesthetically). Plus, other encoders doesn't exhibit this type of flaw and a comparison with the same movie made by another distributor will made the "trick" obvious.

The suggestion seems more or less a workaround to overcome the problem...
Yes, it is exactly a workaround. Being able to be mod8 in H.264 is a big help compared to MPEG-2 and VC-1. And HEVC has even more flexible block sizing tricks, and can go down to at least mod4 safely.

And we're talking about shifting 6 pixels max out of 1080. I do not think most consumers would even notice it if you asked them if something was odd about the image.
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Old 15th June 2021, 18:48   #31  |  Link
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You are correct. It is a commercial encoder.
And i've not been able to see a price on their web page (just out of curiosity). When price is not displayed, never a good thing... Often means it's high.
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Old 15th June 2021, 20:03   #32  |  Link
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I do not think most consumers would even notice it if you asked them if something was odd about the image.
I think is just like the dead pixels on an LCD. Once you know they're there, you can't help but see them.
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Old 15th June 2021, 22:16   #33  |  Link
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I think is just like the dead pixels on an LCD. Once you know they're there, you can't help but see them.
How many customers never realize they have overscan on?
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Old 16th June 2021, 00:47   #34  |  Link
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And i've not been able to see a price on their web page (just out of curiosity). When price is not displayed, never a good thing... Often means it's high.
It's a commercial encoder, so yes generally it's probably not cheap

Shoot them an email, there may be a usage model for individuals / small businesses that makes sense. They're good people (and very clever).
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