Pretty much all the techniques there are used in MPEG-2. I would have like to hear about the H.264 improvements.
H.264 is Magic (2016)
61–70 of 229 posts
Re: H.264 is Magic (2016)
#62Fabrice Bellard's BPG image format uses H.265's keyframe compressor: https://bellard.org/bpg/ Here is a side-by-side visual comparison: http://xooyoozoo.github.io/yolo-octo-bugfixes/#ballet-exerci... Amazing. I ported his BPG decoder to Android ARM for a pornographic app. See my comment history for details. It reduced data transfer by more than 60%.
Isn’t that exactly what HEIC is?
It seems that way - I read this [1] which does a high level comparison of the technologies. It does seem like BPG is patent encumbered by the underlying H265 algorithms (aka HEVC) [2]
[1] https://www.zyxtech.org/2019/06/13/what-is-heic-heif-plus-a-...
[2] https://en.wikipedia.org/wiki/High_Efficiency_Video_Coding
Re: H.264 is Magic (2016)
#63Fabrice Bellard's BPG image format uses H.265's keyframe compressor: https://bellard.org/bpg/ Here is a side-by-side visual comparison: http://xooyoozoo.github.io/yolo-octo-bugfixes/#ballet-exerci... Amazing. I ported his BPG decoder to Android ARM for a pornographic app. See my comment history for details. It reduced data transfer by more than 60%.
What's the patent status? As far as I know, H265 is patent encumbered(and not actually supported on a large chunk of Android devices for the same reason) , so including this somewhere might invite legal trouble.
I was under the impression most implementations rely on hardware support. Hardware vendors pay the royalties then software just hands it off. Afaik that's how it works in most browsers and many modern CPU/GPUs support hardware decoding h265
Re: H.264 is Magic (2016)
#64Fabrice Bellard's BPG image format uses H.265's keyframe compressor: https://bellard.org/bpg/ Here is a side-by-side visual comparison: http://xooyoozoo.github.io/yolo-octo-bugfixes/#ballet-exerci... Amazing. I ported his BPG decoder to Android ARM for a pornographic app. See my comment history for details. It reduced data transfer by more than 60%.
Isn’t that exactly what HEIC is?
HEIC is this plus a kitchen sink of features for digital camera rolls, which aren't useful on the web, all wrapped in a ton of legacy ISO BMFF complexity reaching as far as Classic Mac Quicktime. BPG structure is much more minimal and pragmatic.
However, BPG is unnecessary nowadays. Modern browsers support AVIF, which is HEIF+AV1, so basically HEIC with the painfully patented bit swapped for a freely licensed one.
Re: H.264 is Magic (2016)
#65Earlier quoted context omitted.
This account exists ONLY to talk about that app. Every one of my projects is isolated from the others by using different accounts, etc. We should all be meticulous about compartmentalizing our online identity. This app uses an unusual image codec (BPG) which illustrates that if you control the encoder and decoder, you can choose a format with no mainstream support. I think it is a good point.
> We should all be meticulous about compartmentalizing our online identity. I disagree and I believe the HN guidelines do as well: > Throwaway accounts are ok for sensitive information, but please don't create accounts routinely. HN is a community—users should have an identity that others can relate to.
Do you believe the person posting is guilty of "creating accounts routinely"? Or just one for this app and one 'main' account?
I don't see an issue with creating multiple accounts as long as they're not used for abuse, e.g. spam or trolling, or cause technical issues, e.g. creating millions of accounts. I mean if done right you'd never know or care.
Re: H.264 is Magic (2016)
#66The article starts off with talking about "raw" video containing 3 bytes for every pixel. However, most video is YUV, which is typically 1.5 bytes/pixel. https://en.wikipedia.org/wiki/YUV
Most video I deal with is YUV (YCbCr) 422 at 30 bits per 2 pixels
Re: H.264 is Magic (2016)
#67PSA: For images, there's a finally successor to jpeg: JPEG XL (.jxl) - has lossy and lossless mode; is progressive (you can download just the first parts of the bitstream to get a lower resolution image; and other benefits!) https://jpegxl.info/
"Your browser does not support JPEG XL"; I'm sure it's cool technology but whoever is behind it needs to hire developers and advocates to push code to Webkit / Blink to add support for it, else it won't get mainstream adoption.
Re: H.264 is Magic (2016)
#68Does anything interesting happen if you take the frequency domain representation of an image, represent the frequency domain as an image itself, and compress that with some sort of image compression? For example, encode the frequency domain representation as a low quality JPEG, and then undo the steps to turn it back into the "original". How do the JPEG artifacts on the frequency domain manifest in the resulting imag…
You can try with Imagemagick ( https://legacy.imagemagick.org/Usage/fourier/#im_fft ) : for quality in 50 75 90 95 99 ; do # FFT convert source.png -fft +depth +adjoin source_fft_%d.png # compress FFT magnitude and phase convert source_fft_0.png -quality $quality source_fft_magnitude.jpg convert source_fft_1.png -quality $quality source_fft_phase.jpg # IFFT convert source_fft_magnitude.jpg source_fft_phase.jpg -ift o…
Thanks, this is great. I found it works a lot better if you leave the magnitude alone and only mess with the phase.
The image is still recognisable even at quite harsh compression of the phase file, but almost totally unrecognisable at even minor compression of the magnitude file.
Re: H.264 is Magic (2016)
#69Fabrice Bellard's BPG image format uses H.265's keyframe compressor: https://bellard.org/bpg/ Here is a side-by-side visual comparison: http://xooyoozoo.github.io/yolo-octo-bugfixes/#ballet-exerci... Amazing. I ported his BPG decoder to Android ARM for a pornographic app. See my comment history for details. It reduced data transfer by more than 60%.
That's amazing, thanks for sharing. Going in rather uninformed, I expected it to 'look better' by typical smoothing tricks and whatnot...but no. It has -tons- more detail...looking at little things like wrinkles in the socks and shirt and whatnot. Impressive.
Re: H.264 is Magic (2016)
#70> "a technical walkthrough" > "Suppose you have some strange coin - you've tossed it 10 times, and every time it lands on heads. How would you describe this information to someone? You wouldn't say HHHHHHHHH. You would just say "10 tosses, all heads" - bam! You've just compressed some data! Easy. I saved you hours of mindfuck lectures." Ahh, my favorite kind of technical walkthrough. Love it
I think you could find this interesting: https://www.youtube.com/watch?v=aF1Yw_wu2cM