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The End of Video Coding?

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Re: The End of Video Coding?

#121

Post by icebraining »

dick_sucker2 wrote: post #87
kemitche wrote: post #58

Earlier quoted context omitted.

Netflix isn't necessarily trying to reduce the bandwidth on _their_ side. They want to be able to deliver higher quality to users on lower bandwidth connections. The better that goes, the larger their prospective customer base.

That's a big issue in rural areas with microwave links. Everyone who has one of these links is limited by bandwidth and they all want to watch Netflix.

I wonder if there's a market for a "Netflix ISP" - essentially setting up an antenna for local WAN and a microwave antenna, and then asking Netflix for one of their caching appliances.

Re: The End of Video Coding?

#122

Post by acchow »

dingo_bat wrote: post #4

It seems to me that despite the tech, Netflix video quality is really horrible. Youtube is consistently much higher quality, even though Netflix's own "fast.com" tells me my connection is capable of 75Mbps downstream. Which should be enough for crisp 1080p. Multiple times I've been so frustrated with Netflix's quality that I've started a movie, stopped it because it looked like something out of a VCR, torrented the t…

You're having an abnormal experience. In my own home and all my friends', YouTube looks terribly blocky (low bitrate video) compared to Netflix.

Re: The End of Video Coding?

#123

Post by IshKebab »

c2h5oh wrote: post #21
dingo_bat wrote: post #4

It seems to me that despite the tech, Netflix video quality is really horrible. Youtube is consistently much higher quality, even though Netflix's own "fast.com" tells me my connection is capable of 75Mbps downstream. Which should be enough for crisp 1080p. Multiple times I've been so frustrated with Netflix's quality that I've started a movie, stopped it because it looked like something out of a VCR, torrented the t…

Most likely you're watching in 720p. In Chrome, Firefox and Opera you're getting 720p max. To get 1080p you need to be watching in Internet Explorer, Safari or on a Chromebook. To get 4k you need to be watching in Edge and have a 7xxx or 8xxx Intel CPU and HDCP 2.2 enabled display. Source: https://help.netflix.com/en/node/23742

Wow that is ridiculous. I thought Netflix owned most of their content and wouldn't need to kowtow to ridiculous DRM demands like this? Or is this their own doing?

Re: The End of Video Coding?

#124

Post by icebraining »

admax88q wrote: post #36
lev99 wrote: post #30

Earlier quoted context omitted.

> encoding done in a consumer-grade camera / phone. Just brainstorming here, but encoding local photos/videos might be an acceptable task for a cellphone to do when it is fully charged and plugged in.

That would severely limit the amount of photos and video you can capture between charging sessions. Most phones don't have a ton of storage, and raw video/photos are huge.

Plus storage might not be fast enough to store raw video in realtime. And you'd kill it much sooner with all the writing (larger raw files + reencoded files).

Re: The End of Video Coding?

#125

Post by vardump »

tatersolid wrote: post #115
haikuginger wrote: post #13

Earlier quoted context omitted.

Hardware implementations of codecs can be made that perform encode at low power if a certain level of quality/efficiency can be given up. This is already the case for AVC/HEVC on mobile devices where storage and power considerations overwhelm the possible quality and coding efficiency advances that could be available from a highly-intensive, highly-tunable CPU-based encode. In comparison, if you look at digital cinem…

The very popular RED digital cinema cameras have always shot in compressed form using a low-latency wavelet-based codec (presumably with some ASIC or GPU acceleration on board). http://www.red.com/learn/red-101/redcode-file-format http://www.theblackandblue.com/2012/05/02/shooting-red-epic-... What cameras shoot uncompressed 8K HDR video? That doesn’t even seem possible given current SSD bus speeds. Note that many hi…

> What cameras shoot uncompressed 8K HDR video? That doesn’t even seem possible given current SSD bus speeds.

12-bit bayer RGB matrix 8k @24 fps: 7680 * 4320 * 12bit * 24/s = 1.2 GB/s uncompressed. Currently SSDs go up to 3 GB/s. And you could have a RAID 0 array made out of multiple SSDs.

So it is possible. Entirely another matter whether it makes sense.

One hour of video at this bitrate requires 4.3 TB.

Re: The End of Video Coding?

#126

Post by DavidVoid »

c2h5oh wrote: post #21
dingo_bat wrote: post #4

It seems to me that despite the tech, Netflix video quality is really horrible. Youtube is consistently much higher quality, even though Netflix's own "fast.com" tells me my connection is capable of 75Mbps downstream. Which should be enough for crisp 1080p. Multiple times I've been so frustrated with Netflix's quality that I've started a movie, stopped it because it looked like something out of a VCR, torrented the t…

Most likely you're watching in 720p. In Chrome, Firefox and Opera you're getting 720p max. To get 1080p you need to be watching in Internet Explorer, Safari or on a Chromebook. To get 4k you need to be watching in Edge and have a 7xxx or 8xxx Intel CPU and HDCP 2.2 enabled display. Source: https://help.netflix.com/en/node/23742

>In Chrome, Firefox and Opera you're getting 720p max.

You can actually get some content in 1080p in Chrome and Firefox with a browser extension. It is somewhat unreliable however and some videos still get capped at 720p.

Chrome extension (with explanation of how it works): https://github.com/truedread/netflix-1080p

Firefox extension (unfortunately doesn't seem to work at the moment): https://github.com/vladikoff/netflix-1080p-firefox

Re: The End of Video Coding?

#127

Post by MayeulC »

0x09 wrote: post #105
MayeulC wrote: post #100

Are there transmission schemes that can transfer multiple independent streams that add up for better quality? It could be streams containing information about smaller subblocs, etc. If you take a fourrier transform, the more coefficients you include, the more faithful the reproduction is. Splitting the quality level into multiple independent streams could have multiple advantages : - better use of Multicast, as viewe…

This is known as scalable coding and has been included as an extension or profile in at least every ISO and ITU standard since MPEG-2, see for example https://en.wikipedia.org/wiki/Scalable_Video_Coding (this article seems to be specific to H.264)

Thank you a lot for the proper technical term. Do you happen to know if it is widely used in web-based streaming applications (I would be surprised, as I don't think I encountered it before), if ffmpeg supports it (in the case of H.264),and if AV1 includes such an extension?

Re: The End of Video Coding?

#128

Post by foobarrio »

shawn wrote: post #77
wilun wrote: post #70

Earlier quoted context omitted.

I'm not 100% sure if you tried to be ironic or if you really reported that the video was better in 8k than FHD. Because actually, it can be. Although 8k is overkill, 4k will be enough, and 1440p nearly ok on your old 1024x768 monitor. Typically video encoding does some subsampling on some color components. If you play 4k content on a FHD screen, the quality can be better because you will have no subsampling on your F…

It was a stab at irony. True, but the video is already subsampled. That's how it was able to be uploaded at 1080p at all, since the source video is 8k. So 8k vs 1080p shouldn't make any difference on monitors less than M-by-1080 resolution.

It will make different if the encoding compression is different. Not all 1080p streams are equal. A 1080p FHD blueray is around 30mbps. I've read 20mbps h264 being almost indistinguishable from 30mbps blueray. In my own personal test using some Starwards bluerays, a 10mbps looks pretty good compared to the blueray. On YouTube I've seen anywhere from 2-4mbps being used for 1080p and 7+ used for 4k.

A 4k or 8k stream is coming into your computer at 10+mbps and being downsampled to 1080p can very contain more information than a lower quality 1080p stream coming into your computer at 4mbps even after downsampling.

Re: The End of Video Coding?

#129

Post by fandango »

vardump wrote: post #125
tatersolid wrote: post #115

Earlier quoted context omitted.

The very popular RED digital cinema cameras have always shot in compressed form using a low-latency wavelet-based codec (presumably with some ASIC or GPU acceleration on board). http://www.red.com/learn/red-101/redcode-file-format http://www.theblackandblue.com/2012/05/02/shooting-red-epic-... What cameras shoot uncompressed 8K HDR video? That doesn’t even seem possible given current SSD bus speeds. Note that many hi…

> What cameras shoot uncompressed 8K HDR video? That doesn’t even seem possible given current SSD bus speeds. 12-bit bayer RGB matrix 8k @24 fps: 7680 * 4320 * 12bit * 24/s = 1.2 GB/s uncompressed. Currently SSDs go up to 3 GB/s. And you could have a RAID 0 array made out of multiple SSDs. So it is possible. Entirely another matter whether it makes sense. One hour of video at this bitrate requires 4.3 TB.

Did you forget that there are multiple color channels? 12 bit should be 36 bit so even more is needed.

Re: The End of Video Coding?

#130

Post by vardump »

fandango wrote: post #129
vardump wrote: post #125

Earlier quoted context omitted.

> What cameras shoot uncompressed 8K HDR video? That doesn’t even seem possible given current SSD bus speeds. 12-bit bayer RGB matrix 8k @24 fps: 7680 * 4320 * 12bit * 24/s = 1.2 GB/s uncompressed. Currently SSDs go up to 3 GB/s. And you could have a RAID 0 array made out of multiple SSDs. So it is possible. Entirely another matter whether it makes sense. One hour of video at this bitrate requires 4.3 TB.

Did you forget that there are multiple color channels? 12 bit should be 36 bit so even more is needed.

No. That's how practically all of the cameras work. Google RGB bayer matrix.

There's just one color component per pixel, thus 12-16 bits per pixel is enough.

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