Sony announces new 4K camera systems PMW-F55 and PMW-5

[Mark Kenfield]

Originally Posted by Alister Chapman

Not sure just how practical and useable the 4K XAVC compressed footage from the F55 will be. Sony will be using a lot of the advanced AVC encoding functions to get the best image quality so it will be very processor intensive to decode.

Probably a great time to pick up a used F3. Anyone want one of mine?

Sony posted up a chart somewhere that had a list of decoding times for different Codecs, and it suggested that XAVC actually has a faster decoding time than ProResHQ and DNxHD (with SR Lite perched in the middle of ProRes and DNxHD).

I've no idea whether that will bare out in actual post production workflows, but if it is faster, that reduces my concerns about the more complex compression schemes considerably.

[Sareesh Sudhakaran]

Originally Posted by Mark Kenfield

Sony posted up a chart somewhere that had a list of decoding times for different Codecs, and it suggested that XAVC actually has a faster decoding time than ProResHQ and DNxHD (with SR Lite perched in the middle of ProRes and DNxHD).

That is exciting news. Any idea where the link is? I couldn't find it on google.

[David Heath]

Originally Posted by Sareesh Sudhakaran

That is exciting news. Any idea where the link is? I couldn't find it on google.

I found this - XAVC Sonys implementation of Advanced Video Coding - Sony Community - 36571 - and if you scroll down to Figure 5 I think that's the chart being talked about. (It's what Sony were showing at a roadshow about the F5/55.)

They were at pains to point out that XDCAM 422 50Mbs is likely to be codec of choice for quite a while to come, at least for ordinary current broadcast, and especially for quick turn round material. It seems that decoding the inter-GOP nature is far easier than decoding the H264 part of an AVC/H264 type codec - even if the latter is I-frame only.

Hence the long-GOP nature gives the bitrate:quality ratio desired, but without the computing load of something H264 based.

But for some applications it's essential to be I-frame based, and going to H264 also gives options such as 10 bit and 4k resolution. And on cameras like the F5/55, the latter two aspects become much more significant. Hence expect to see increasing use of XAVC, but don't expect it to replace MPEG-2 overnight by a long way.

[Sareesh Sudhakaran]

Thanks, David. That's an excellent resource.

As far as codecs are concerned, after digibeta, hdcam, dv, hdv and xdcam, I'm inclined to take Sony's word!

[David Heath]

Originally Posted by Sareesh Sudhakaran

As far as codecs are concerned, ..........I'm inclined to take Sony's word!

I have no reason to doubt what they are saying there, though couldn't independently verify it. Yes, I'm inclined to believe it's true.

If I sounded surprised in the previous post, it's because I remember how much extra computer effort it took to edit Standard Def MPEG2 compared to DV, due to the long-GOP nature. That shouldn't surprise anyone.

I suppose if I'd previously been asked to guess, I'd have guessed that the long-GOP nature of XDCAM would probably have about the same extra load as I-frame only H264. (So I'd have expected XDCAM422 and such as AVC-Intra to require similar computing effort to process.) It appears that isn't true, that the AVC nature has more effect than long-GOP, each taken in isolation.

[Sareesh Sudhakaran]

I got the impression that XAVC is an intra frame 100 Mbps codec ready for broadcast, just like xdcam is for interframe. XAVC stops at 59.94 (both i or p). It does not have the option of true 60p or 120p. I wonder why. I can see how shooting RAW at 60p+ would be difficult to write on media, but there is no problem with XAVC at 1 Gbps. This leads me to believe its priority is broadcast, not acquisition.

It goes without saying that marrying intraframe with Long GOP is the height of what the MPEG4 specification is capable of. And Sony is trying to get early adopters of 4K to start using it. I don't understand.

What I gathered from it is: their cameras are producing RAW images at humongous data rates, ACES is the future, and all that 'visual glory' will be preserved by XAVC at 4K. Is that the message?

If so, then why is there a picture of the F65 at 120 fps - XAVC can't handle 120 fps.

As for HD, I don't see why anybody would sacrifice native, Prores or DNxHD 220 Mbps (assuming they are already invested in it) for XAVC. This is the part I don't get. Figure 5 shows the XAVC HD codec with a frame rate slightly under 40 fps, while all the other 'standards' are at about 30 fps. What's the point of having an fps advantage between 30 and 40? Sony themselves claim that xdcam (or any variant) is the fastest and most efficient system.

In Figure 6, Sony slots XAVC for sports and TV Commercials. Why bother, when traditional systems are already more than capable of handling 1080i59.94 (or 50)?

So maybe XAVC for 4K is more 'digestible' for the smaller producer, and the HD part is 'we're doing it so we can' kind of deal. I don't know, I've read it a few times, and I'm still trying to figure this one out.

[David Heath]

Originally Posted by Sareesh Sudhakaran

This is the part I don't get. Figure 5 shows the XAVC HD codec with a frame rate slightly under 40 fps, while all the other 'standards' are at about 30 fps. What's the point of having an fps advantage between 30 and 40? Sony themselves claim that xdcam (or any variant) is the fastest and most efficient system.

As far as figure 5 goes, then note carefully how the diagram is introduced: "Figure 5 shows how different compressed video streams can be decoded on a given computer platform, without resorting to any hardware accelerators"

In other words, the actual fps figures are not ABSOLUTE - they will depend on the computer being used for test. It stands to reason that the more powerful the computer, the higher the figures will be. The figure 5 figures are RELATIVE, they show how the codecs relatively compare on one computer. Use a computer of different power and the figures will differ, but the relative performances are likely to be in the same ratios.

As far as codecs go, then beware the word "efficient". On the one hand it can mean "smallish file size for a given quality", on the other it can mean "doesn't need a lot of computing power". And it's often the case that being efficient in the one sense can mean being inefficient in the other sense!

This is illustrated by comparing AVC-HD with MPEG2 long-GOP. People selling AVC-HD cameras will stress it's relative "efficiency" - which is true in terms of the quality:filesize equation. But in the other sense, AVC-HD is very inefficient in terms of making use of available computing power. You can't have your cake and eat it!

Originally Posted by Sareesh Sudhakaran

I got the impression that XAVC is an intra frame 100 Mbps codec ready for broadcast, just like xdcam is for interframe. XAVC stops at 59.94 (both i or p). It does not have the option of true 60p or 120p.

If so, then why is there a picture of the F65 at 120 fps - XAVC can't handle 120 fps.

Firstly, I don't think any equipment actually does do "true" 60p - to all intents and purposes, practically, 60p and 59.94p are the same thing? It just depends whether you're being precise or rounding up.

And no, I don't agree it's (only) "an intra frame 100 Mbps codec" - it's a family with bitrates up to 960Mbs, and a choice of I-frame or long-GOP. Look at table 3 in the link I posted.

As far as the higher frame rates go, then my interpretation is that whilst the fundamental XAVC spec may stop at 60p (OK, 59.94p, :-) ), then it is still possible to RECORD at higher frame rates in an overcranking sense. So set to XAVC, record at 120fps, end up with a standard 60fps XAVC file at half speed. I stress this is my interpretation - anybody verify that for sure?

[Sareesh Sudhakaran]

Originally Posted by David Heath

As far as figure 5 goes, then note carefully how the diagram is introduced: "Figure 5 shows how different compressed video streams can be decoded on a given computer platform, without resorting to any hardware accelerators"

In other words, the actual fps figures are not ABSOLUTE - they will depend on the computer being used for test. It stands to reason that the more powerful the computer, the higher the figures will be.

I missed that. It is half interframe after all!

Firstly, I don't think any equipment actually does do "true" 60p - to all intents and purposes, practically, 60p and 59.94p are the same thing? It just depends whether you're being precise or rounding up.

59.94p is the limit for the F65 (as well as the Epic). The only camera that claims to do 120 fps in sensor is the Alexa. Arriraw can specifically be streamed to both 59.94p and 60p via dual 3G-SDI. But that's a totally different workflow. I'm not sure about the Phantoms.

In any case, you are right. 59.94 is the limit for workflows in general.

And no, I don't agree it's (only) "an intra frame 100 Mbps codec" - it's a family with bitrates up to 960Mbs, and a choice of I-frame or long-GOP. Look at table 3 in the link I posted.

My mistake. After reading it a few times, my brain just turned into mush.

As far as the higher frame rates go, then my interpretation is that whilst the fundamental XAVC spec may stop at 60p (OK, 59.94p, :-) ), then it is still possible to RECORD at higher frame rates in an overcranking sense. So set to XAVC, record at 120fps, end up with a standard 60fps XAVC file at half speed. I stress this is my interpretation - anybody verify that for sure?

Shouldn't be a problem, but I'm guessing too. I'm sure Sony tied up all the loose ends. Now all we need to know is what computer to buy!

[Brian Drysdale]

Here are the first impressions of the F55 by Ned Soltz and Timur Civan.

Sony F55 Initial Review - Ned Soltz and Timur Civan on Vimeo

[Jack Zhang]

That video skipped the entire audio menu. Also proves that the prototype models are progressive only. Production models may have interlaced, or they may not.

[Dennis Hingsberg]

Is it confirmed that F5/F55 production models will have peaking feature & waveform monitor?

[Alister Chapman]

Peaking yes definately. Waveform, no mention in the manual. I have a camera at home, I'll check later.

The cameras do record 50i/60i (or rather 25i/30i) with Mpeg2, but XAVC is progressive only.

Internally the cameras can record unto 60fps. The F5 can will be able to record raw to the R5 at up to 120fps, the F55 up to 240fps in 2k and 120fps in 4k.

[Dennis Hingsberg]

Your camera is pre-production model though isn't it? I heard it will have waveform or spot meter, but not histogram (which oddly upset a lot of people).

:)

[Alister Chapman]

No mention of waveform in the manual either. Yes the camera I have is pre-production but is hot off the press from Japan and has the latest firmware version which I believe is extremely close to production (it even works with regular SxS cards, which earlier versions did not). Production cameras are on the lines now.

[Dennis Hingsberg]

I just caught a glimpse of the F5/F55 firmware release schedule. It now appears to be official that there will be three subsequent firmware releases after the camera ships.

From what I gather it means on the F5 at least, out of the gate you will only be able to shoot: 4k raw 24/25/30/50/60p max, HD XAVC 10-bit 1-60p, MPEG 422 30p/60i.

2K RAW & XAVC, HFR, S&Q, gamma, LUT, will come much later. Much MUCH later....

See schedule from sony: