YouTube now supports high definition video

Gints Klimanis · November 23rd, 2008, 01:56 PM

Quote:

Originally Posted by Craig Seeman

Vimeo downloads are exactly what I upload so I'm not sure what others are saying here. The Flash playback is certainly compressed but my H264 sources downloads are my original file.

Thanks for the detailed info, Craig. Vimeo told me their compression is 1.6 MBps VBR, though I assume that is the average bitrate. I've asked them for their minimum and maximum rates.

The downloads I'm referring to are FLV "Grabs" by the Orbit video streaming grabber program which allows you to collect the video stream from YouTube, Vimeo, others. I used this to compare video quality. Play both your original and the grabbed" FLV in VLC Media Player so you can save screen shots to a PNG file for easy comparison.

Christopher Lefchik · November 24th, 2008, 11:55 AM

Quote:

Originally Posted by Craig Seeman

What would YouTube's HD data rate be?

I have downloaded the YouTube HD video which the PC World article linked to. Nero ShowTime reports the video stream bitrate when playing as being from under 1 megabit to ~5 megabits, with a ~14 megabit spike near the beginning. The video stream is AVC Level 5.1. The audio is AAC two channel; it's also VBR. I didn't pay as close attention to the audio bitrate, but it is fluctuating above and below 200 kilobits/second.

And it's a 30p file, so it appears YouTube supports HD frame rates other than 24p.

Craig Seeman · November 24th, 2008, 12:22 PM

Gints, 1.6Mbps VBR seems right since I've seen numbers from 1.5 to 1.8Mbps for Vimeo HD.

Christopher, while 1Mbps would be OK (actually low for 720p IMHO) numbers close to 5Mbps and certainly 14Mbps spike would be rough for some people. Of course even 1Mbps is wasted if they're keeping the picture so small.

Personally I'd like to see about 2.5Mbps for HD which would have enough room for fast action. At least my area that speed is still below DSL for all but the lowest level. DSL in my area is 3Mbps - 8Mbps, Cable is 10Mbps - 30Mbps give or take. There's still some "budget" DSL at 768kbps and 1.5Mbps but those are becoming rarer in my area.

Christopher Lefchik · November 24th, 2008, 12:31 PM

Quote:

Originally Posted by Gints Klimanis

The downloads I'm referring to are FLV "Grabs" by the Orbit video streaming grabber program which allows you to collect the video stream from YouTube, Vimeo, others. I used this to compare video quality. Play both your original and the grabbed" FLV in VLC Media Player so you can save screen shots to a PNG file for easy comparison.

Did you download the 73 megabite MP4 high definition file from YouTube, and not the lower quality FLV "HQ" file?

There are three video files that can be downloaded from YouTube for the Where is Matt video.

1. Standard quality—320x180, Sorenson H.263 video codec, VBR up to at least 700 kilobits/second, MP3 audio codec at 64 kilobits/second (single channel). FLV container. Filesize for Matt video is 11 megabites.

2. HQ quality—480x270, Sorenson H.263 video codec, VBR up to at least 1.5 megabits/second, MP3 audio codec at 96 kilobits/second (single channel). FLV container. Filesize for Matt video is 32.7 megabites.

3. HD resolution—1280x720, H.264/AVC Level 5.1 video codec, VBR up to at least 5 megabits/second, AAC audio codec, VBR up to at least 270 kilobits/second (2 channels). MP4 container. Filesize for Matt video is 73.5 megabites.

Christopher Lefchik · November 24th, 2008, 12:41 PM

Quote:

Originally Posted by Craig Seeman

Gints, 1.6Mbps VBR seems right since I've seen numbers from 1.5 to 1.8Mbps for Vimeo HD.

Christopher, while 1Mbps would be OK (actually low for 720p IMHO) numbers close to 5Mbps and certainly 14Mbps spike would be rough for some people.

Again, that is VBR. The 14 megabit spike was for a split second. I'm not sure exactly what the average would be for the rest of the video, but from the numbers I saw 2.5-3.0 megabits may not be too far off.

Quote:

Originally Posted by Craig Seeman

Of course even 1Mbps is wasted if they're keeping the picture so small.

Very true. I'd say YouTube needs to work on their viewing options for HD resolution. If nothing else, there's currently the full screen option.

Craig Seeman · November 24th, 2008, 01:05 PM

And YouTube Full Screen mode goes to 1920x1080 on my monitor. There's no way to turn scaling off to see 720p on the HD clip. 2.5Mbps wouldn't be bad if you could actually view it at 720p. It didn't look like an H264 encode at 2.5Mbps even scaled to 1080.

Christopher Lefchik · November 24th, 2008, 01:35 PM

Quote:

Originally Posted by Craig Seeman

And YouTube Full Screen mode goes to 1920x1080 on my monitor. There's no way to turn scaling off to see 720p on the HD clip. 2.5Mbps wouldn't be bad if you could actually view it at 720p. It didn't look like an H264 encode at 2.5Mbps even scaled to 1080.

Try this link at the full screen option. Is there any difference?

Craig Seeman · November 24th, 2008, 02:16 PM

Yes, that's exactly what I did. I added &fmt=22 and went full screen and my first response was bleh! The titles look sharp there's significant issues. Camera shake is tough on a codec and this doesn't handle it well at all. Solids (or maybe the subtle gradients within) look bad too. Lots of areas look softer than they should at that data rate. Don't forget it's being scaled to 1920x1080 on my system though but It still wouldn't be great at 720.

Look at some of the Vimeo HD videos posted by DVInfo users at full screen (720p scaling). Even some of the more challenging source material holds up well. I believe Vimeo is still using On2VP6 Flash and H264 should be as good if not better and yet YouTube looks worse. Not all H264 is created equal though. These days MainConcept's codec is the best with Dicas very close behind. Apple's isn't that great by comparison although Compressor does multipass encodes (more than 2). Maybe YouTube is only doing a single pass encode? It doesn't look good though at full screen.

Craig Seeman · November 24th, 2008, 02:33 PM

Double Post deleted.
Hmm first post gave me a browser error so I tried again and didn't even get the double post warning.

David Knaggs · November 24th, 2008, 07:39 PM

I uploaded a 2 minute trailer to YouTube about 6 months ago and, after reading this thread, decided to check it out by adding "&fmt=22" to its address.

It stood up surprisingly well when I went to full screen. Some of the smaller letters on the titles were noticeably "blocky", the very first shot was captured in SD (so not a true test), but all of the following shots, which were originally captured in 720p24 looked very, very nice.

The trailer clip that I originally uploaded was about 74 MB and the compression I'd applied was done with Apple's Compressor using the "H.264 for Apple TV" preset, which has the description "H.264 1280x720 video @ 5Mbps". I also added letterbox bars on top and bottom to bring it to a 4:3 aspect ratio (as earlier experience showed me that YouTube would otherwise stretch 16:9 footage to a 4:3 box).

The HD version downloaded from YouTube was about 34 MB, so YouTube had further compressed it by a bit over 50%.

I suspect that the reason the footage stood up so well was because most of the compression applied to it was kept in the 1280 X 720 range. I don't know how 1080i footage would fare (due to the drastic re-sizing plus the fact that it's interlaced). I suspect that source footage of 1280 X 720 progressive may prove to be the "sweet spot" for a very good result with YouTube HD.

Craig Seeman · November 24th, 2008, 08:00 PM

The preset you use is a good general target for 720 HD upload. I customize things but use the same general target for Vimeo.

You should not have to letterbox though. If you upload square pixels (which HD is), YouTube will add the letterbox. If you add it, you're wasting bits on that black which YouTube will wast further bits to display. Don't letterbox. 1280x720 should be fine. I've been doing 640x360 for SD downconvert for YouTube upload and they look quite good. If your source is Standard Def 16:9 though, you have anamorphic (non square) pixels and you'd need to convert that or YouTube will often squash.

Tyler Franco · November 24th, 2008, 10:47 PM

Looks like YouTube is getting closer to an official "launching" their HD, judging by the way they made all the players bigger and in widescreen format.

YouTube - Where the Hell is Matt? (2008)

Craig Seeman · November 24th, 2008, 11:03 PM

Major improvement taking some advantage of frame size. In the YouTube display it's not bad at all. I'm still seeing major macroblocking, keyframe jumps, from full screen playback. I wish I could turn off scaling.

What I did is take YouTube page and put it on my 46" 1080p display (DVI to HDMI) and went full screen. It wasn't quite "full screen" (had white left/right boarders) but at that size it was playing at 1080 which is scaled up from the 720. I'd like to see scaling off but at it's "in box" display it certainly looks competitive to Vimeo.

I wonder if they're doing 720p30 (Vimeo does poor frame rate conversion from 30 or 25 to 24).

I wish I could post my own test footage scaled to 720p30 (or maybe even p60) and see how it handles.

Craig Seeman · November 24th, 2008, 11:09 PM

BTW that change in player size doesn't seem specific for that demo video.

I'm seeing the new frame size on my own YouTube Channels! KEWL!

Tyler Franco · November 24th, 2008, 11:37 PM

It appears as though YouTube keeps 30p, 30p (unlike Vimeo). This is a big leap for YouTube, although Vimeo still has the advantage of downloading the original source file.

November 24th, 2008, 02:33 PM	#24
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Double Post deleted. Hmm first post gave me a browser error so I tried again and didn't even get the double post warning. Last edited by Craig Seeman; November 24th, 2008 at 02:34 PM. Reason: Double post

November 24th, 2008, 07:39 PM	#25
David Knaggs Major Player Join Date: Apr 2006 Location: Melbourne, Australia Posts: 826	Surprisingly good quality I uploaded a 2 minute trailer to YouTube about 6 months ago and, after reading this thread, decided to check it out by adding "&fmt=22" to its address. It stood up surprisingly well when I went to full screen. Some of the smaller letters on the titles were noticeably "blocky", the very first shot was captured in SD (so not a true test), but all of the following shots, which were originally captured in 720p24 looked very, very nice. The trailer clip that I originally uploaded was about 74 MB and the compression I'd applied was done with Apple's Compressor using the "H.264 for Apple TV" preset, which has the description "H.264 1280x720 video @ 5Mbps". I also added letterbox bars on top and bottom to bring it to a 4:3 aspect ratio (as earlier experience showed me that YouTube would otherwise stretch 16:9 footage to a 4:3 box). The HD version downloaded from YouTube was about 34 MB, so YouTube had further compressed it by a bit over 50%. I suspect that the reason the footage stood up so well was because most of the compression applied to it was kept in the 1280 X 720 range. I don't know how 1080i footage would fare (due to the drastic re-sizing plus the fact that it's interlaced). I suspect that source footage of 1280 X 720 progressive may prove to be the "sweet spot" for a very good result with YouTube HD.

November 24th, 2008, 12:22 PM	#18
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Gints, 1.6Mbps VBR seems right since I've seen numbers from 1.5 to 1.8Mbps for Vimeo HD. Christopher, while 1Mbps would be OK (actually low for 720p IMHO) numbers close to 5Mbps and certainly 14Mbps spike would be rough for some people. Of course even 1Mbps is wasted if they're keeping the picture so small. Personally I'd like to see about 2.5Mbps for HD which would have enough room for fast action. At least my area that speed is still below DSL for all but the lowest level. DSL in my area is 3Mbps - 8Mbps, Cable is 10Mbps - 30Mbps give or take. There's still some "budget" DSL at 768kbps and 1.5Mbps but those are becoming rarer in my area.

November 24th, 2008, 01:05 PM	#21
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	And YouTube Full Screen mode goes to 1920x1080 on my monitor. There's no way to turn scaling off to see 720p on the HD clip. 2.5Mbps wouldn't be bad if you could actually view it at 720p. It didn't look like an H264 encode at 2.5Mbps even scaled to 1080.

November 24th, 2008, 02:16 PM	#23
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Yes, that's exactly what I did. I added &fmt=22 and went full screen and my first response was bleh! The titles look sharp there's significant issues. Camera shake is tough on a codec and this doesn't handle it well at all. Solids (or maybe the subtle gradients within) look bad too. Lots of areas look softer than they should at that data rate. Don't forget it's being scaled to 1920x1080 on my system though but It still wouldn't be great at 720. Look at some of the Vimeo HD videos posted by DVInfo users at full screen (720p scaling). Even some of the more challenging source material holds up well. I believe Vimeo is still using On2VP6 Flash and H264 should be as good if not better and yet YouTube looks worse. Not all H264 is created equal though. These days MainConcept's codec is the best with Dicas very close behind. Apple's isn't that great by comparison although Compressor does multipass encodes (more than 2). Maybe YouTube is only doing a single pass encode? It doesn't look good though at full screen.

November 24th, 2008, 08:00 PM	#26
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	The preset you use is a good general target for 720 HD upload. I customize things but use the same general target for Vimeo. You should not have to letterbox though. If you upload square pixels (which HD is), YouTube will add the letterbox. If you add it, you're wasting bits on that black which YouTube will wast further bits to display. Don't letterbox. 1280x720 should be fine. I've been doing 640x360 for SD downconvert for YouTube upload and they look quite good. If your source is Standard Def 16:9 though, you have anamorphic (non square) pixels and you'd need to convert that or YouTube will often squash.

November 24th, 2008, 10:47 PM	#27
Tyler Franco Regular Crew Join Date: Feb 2008 Location: Columbus, OH Posts: 172	Looks like YouTube is getting closer to an official "launching" their HD, judging by the way they made all the players bigger and in widescreen format. YouTube - Where the Hell is Matt? (2008)

November 24th, 2008, 11:03 PM	#28
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	Major improvement taking some advantage of frame size. In the YouTube display it's not bad at all. I'm still seeing major macroblocking, keyframe jumps, from full screen playback. I wish I could turn off scaling. What I did is take YouTube page and put it on my 46" 1080p display (DVI to HDMI) and went full screen. It wasn't quite "full screen" (had white left/right boarders) but at that size it was playing at 1080 which is scaled up from the 720. I'd like to see scaling off but at it's "in box" display it certainly looks competitive to Vimeo. I wonder if they're doing 720p30 (Vimeo does poor frame rate conversion from 30 or 25 to 24). I wish I could post my own test footage scaled to 720p30 (or maybe even p60) and see how it handles.

November 24th, 2008, 11:09 PM	#29
Craig Seeman Inner Circle Join Date: Feb 2004 Location: Brooklyn, NY, USA Posts: 3,841	BTW that change in player size doesn't seem specific for that demo video. I'm seeing the new frame size on my own YouTube Channels! KEWL!

November 24th, 2008, 11:37 PM	#30
Tyler Franco Regular Crew Join Date: Feb 2008 Location: Columbus, OH Posts: 172	It appears as though YouTube keeps 30p, 30p (unlike Vimeo). This is a big leap for YouTube, although Vimeo still has the advantage of downloading the original source file.