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Old 18th November 2009, 13:53   #21  |  Link
Flux
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Is it only me or Youtube converts all HD resolution videos to 30 fps? This was not the case couple months ago. It accepted at least 25 fps and 23.976 fps without forced conversion.
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Old 18th November 2009, 13:55   #22  |  Link
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While they're adding things that most people can't play back, I'd really like to see 50fps and 60fps capability. Not for 1080p - just for normal+HQ modes (and maybe 720p HD mode).

For home movies, YouTube HQ would be a good source for a DVD (or DVD-like quality) - but only if 50fps was available. Otherwise everything gets the fake-flimic stutter look of 25p.

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Old 19th November 2009, 16:21   #23  |  Link
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Some people have got 50/60fps normal quality videos on YouTube via some trickery, but the resolution and bitrate are too low IMO. I don't think it's possible with HQ video.

I think a more viable option (considering bandwidth) would be to handle interlaced SD video properly, but I don't know if it would be possible to implement some form of bob deinterlacing with the Flash player.
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Old 19th November 2009, 18:29   #24  |  Link
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Here's more of a challenge: stream 1080p with an end-to-end latency of under 50ms.
Unpossible. Especially where I live (out in the middle of nowhere) You would basically have to be using the same ISP as the broadcaster for it to even be feasible.
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Old 20th November 2009, 10:55   #25  |  Link
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Some people have got 50/60fps normal quality videos on YouTube via some trickery, but the resolution and bitrate are too low IMO.
Thanks - I didn't know that, but Google found from relevant threads.

Looks like that YouTube loophole is closed now - and I agree - the quality was lousy!

Decent quality 60fps SD would require a lower bitrate than the 720p HD they do now, so why not provide it as an (official) option?

(maybe the flash video player plug-in just can't keep up for most people? but that's also true for 1080p, and they've just launched that!)

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Old 20th November 2009, 12:03   #26  |  Link
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LOL I have to wonder if my countries internet infrastructure could handle all this bandwidth. They were complaining when the BBC launched the iPlayer
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Old 20th November 2009, 13:05   #27  |  Link
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1920x1080p60 with no chroma subsampling, quality compared to x264 CRF 18 encode and <100 ms latency. A distant dream for "crystal clear" video chatting.
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Old 20th November 2009, 20:05   #28  |  Link
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@Flux:

For the second time in this thread - chroma subsampling is NOT a bad thing!! It's only a bad thing during post-production, where mathematical precision is necessary.

For final distribution encoding, even converting RGB to YV12 is perceptibly lossless, provided the proper process is followed to convert back to RGB (i.e. decent upsampling, correct matrix etc).

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Old 23rd November 2009, 11:44   #29  |  Link
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I think that's going a bit far. If you have super fine chroma details, RGB>YV12 certainly isn't perceptually lossless. If you're encoding the output of a PC screen, it can make quite a difference. It's not so visible on typical video from a camera - usually invisible, but not always.

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Old 26th November 2009, 03:20   #30  |  Link
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Possible, sure.

I did download the PNG sequence for Big Buck Bunny, and did some comparison on the RGB24 source vs YV12 -> RGB24, and was quite unable to spot a difference in normal viewing modes. Looking at R, G, and B components was another story, of course!

I'd agree there's potential for obvious difference with screen capture.

Also, it's very important to do good chroma upsampling on playback!!

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Old 2nd December 2009, 13:53   #31  |  Link
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chroma subsampling is NOT a bad thing!!
Missing half the color information isn't bad?

I mean I understand we're less sensitive to color and all, but I can clearly see pixelation in some videos on YouTube, especially in bright reds.
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Old 2nd December 2009, 14:55   #32  |  Link
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I mean I understand we're less sensitive to color and all, but I can clearly see pixelation in some videos on YouTube, especially in bright reds.
That's probably bitrate starvation, or possibly poor decoding.

Chroma-subsampling makes the chroma a little soft - not blocky or pixelated (if decoded correctly).

Many encoders trash the chroma channels as they run out of bitrate, giving a blocky look on chroma edges. This isn't caused by 4:2:0 chroma, and could still happen with low bitrate 4:4:4 chroma.

Cheers,
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Old 2nd December 2009, 18:51   #33  |  Link
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That's probably bitrate starvation, or possibly poor decoding.

Chroma-subsampling makes the chroma a little soft - not blocky or pixelated (if decoded correctly).
It's flash's YV12->RGB converter that's the problem. Nothing to do with encoding or decoding.
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Old 2nd December 2009, 21:37   #34  |  Link
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Yep. This is such a common problem, it's disgusting it still exists with many video apps...

:@

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Old 2nd December 2009, 21:43   #35  |  Link
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It's flash's YV12->RGB converter that's the problem. Nothing to do with encoding or decoding.
Thanks for the tip. I notice the same thing if I uncheck High Quality YV12 to RGB conversion in FFDShow.
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Old 3rd December 2009, 12:17   #36  |  Link
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Is there any quality differences between ffdshow High Quality YV12 to RGB conversion and Media Player Classic HC YV12 Chroma Upsampling shader?
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Old 8th December 2009, 15:47   #37  |  Link
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Is it only me or Youtube converts all HD resolution videos to 30 fps? This was not the case couple months ago. It accepted at least 25 fps and 23.976 fps without forced conversion.
youtube has always converted videos to stupid framerates. This is why I like vimeo (too bad not much content variety on there). And 1080 at such low bitrates looks terrible anyways. They're just doing it to advertise it. I hope they don't get rid of the option for 720p because it's a much better middle ground. I won't be uploading 1080 videos anytime soon unless the overall internet evolves into hyperspeed and youtube jacks up the bitrate, which is unlikely soon.

But anyways, I've been using greasemonkey and a gnome-mplayer script to replace the flash player (on linux). With that and vdpau, any hd video on there can be handled smoothly (except videos with the ad scheme, which seems to break things). Or at least it would be, but right now gtk seems to cause a bug which makes vdpau unusable on gnome-mplayer.

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Old 9th December 2009, 09:23   #38  |  Link
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youtube has always converted videos to stupid framerates. This is why I like vimeo (too bad not much content variety on there).
Vimeo messes with frame rates!

For most of its life, it's been 24p.

Upload 25p or 30p, and it drops frames to get it down to 24p. Not acceptable IMO. I have to slow down my 25p content (and then increase the pitch of the audio!) to make it work well on Vimeo!

Cheers,
David.
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Old 9th December 2009, 10:15   #39  |  Link
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mmmh, I've just uploaded my first video since, what, 8 months ?
720x480@29.97fps (h264.mp4)
I downloaded it & it's been converted to 540x360@60fps
WTF ??!!

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Old 9th December 2009, 18:10   #40  |  Link
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Vimeo messes with frame rates!

For most of its life, it's been 24p.

Upload 25p or 30p, and it drops frames to get it down to 24p. Not acceptable IMO. I have to slow down my 25p content (and then increase the pitch of the audio!) to make it work well on Vimeo!

Cheers,
David.
I think it's 24000/1001, and at least it's more natural to a lot of content. Most of the video I work with is in this form. youtube otoh, just turns everything that's SD into nonsensical frame rates and I think into plain NTSC rate 29.970 for HD.
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