Question about H.264

I don't understand.

The Canon 5D (and others) use H.264 as an acquisition format, I believe. But I had understood that H.264 is heavily compressed and, presumably, is not 4:2:2 or higher. Correct? Is it 4:2:1 or (gulp) 4:2:0.? Myabe I am bonkers and it is 4:4:4. Nothing would surprise me.

It may be that there are different flavors of H.264 that I don't know about, but what I don't get is that these people are shooting on a camera with a pretty big sensor, getting the shallow depth of field they want and generally feeling hip shooting with a stills camera - but if the color space is poor, why don't they ever mention this? I just hear how great it is blah blah.

I am too embarrassed to reveal the depths of my ignorance to these people, so am covertly coming to the denizens of LAFCPUG for education.

Perhaps I have misunderstood the nature of the delights of H.264. To me, it is the codec that I use to upload stuff for clients to see on YouTube.

If anyone has a minute, I would appreciate someone 'splainin' this.

Many thanks,

All the best,

Harry The Idiot.

The Canon 5D is a good camera for certain situations. The video recording mode was merely started out as an add on feature, but it quickly gained in popularity and Canon was obliged to conform it more towards video standards.

It's cool because it allows interchangeable lenses to provide the "film like" shallow DOF look, and also because of the size of the sensor, it perhaps allows for shooting in lower light (not sure if this is true especially with the line skipping). However, as it was not designed as a video camera per se, how it makes an image at 24/25 frames per second may be a little questionable. The Canon camera skips lines, resulting in lower than expected resolution when compared to the still images shot at the same resolution from the same camera, and the sensor has a slow sensor readout, which results in rolling shutter artifacts, making post production tricky. The camera shoots to h.264, 4:2:0 and is heavily compressed, But when you want a small camera that can provide a filmic look without breaking the bank and you don't want to spend all that time tweaking the image in post, the 5D is a great camera for that.



www.strypesinpost.com

Thanks for the reply, Strypes.

So it really is 4:2:0. I have heard of the overheating problem. The whole thing sounds like a pain in the neck to me .

Thanks again,

Harry.

It is a good buy if you're tight on budget, just that you have to be careful especially with your subjects as well as shooting conditions. You have much less room in post production than you would have with let's say the RED camera. It looks pretty good unprocessed. Perceived "look" and actual resolution are two different things. You are ultimately producing for people who are watching your film, and not to pass a camera stress test. Definitely something I would use within a 10k cam budget. I won't bother doing too much post, as I would expect the shot to disintegrate under smoothcam, slow mo and heavy grading. But as Stu Maschwitz said on twitter, may your films find an audience who won't care about what camera you shot on.



www.strypesinpost.com

I am working on a project that is almost perfectly suited to the 5D. Shooting behind the scenes at a Interior Design/Decor Web Magazine shoot. The photographer is using a 5D, the BTS crew is using a 5D and I have cobbled together a 2nd unit audio system consisting of a Zoom H4N with lav and a boom. So far the shoots have been tightly controlled and the DOP is a pro cinematographer (features, episodics) doing a family favour so everything is well lit and controlled within the limits of the 5D. Interior decor mags are all bokeh and depth of field photos these days so the style of the Canon cameras fits the look of the webmag.

It's only destined for the web and I think it will look pretty damn good for the budget, which is nil. It's an all-in-the-family affair so we're happy to help.
I am using this project to experiment with some workflows. On the first one I'm using 5DtoRGB and the included batch script. I'll look into Andreas' and Bouke's suggestions for the next project.
I am keeping a tight rein on this as the only person working on the footage so, worst case scenario, I can reconvert using almost any method and relink by name if I have to.

FYI
We used an iPad slate on set and it was great. I used to track IDs from the H4N as take numbers so syncing is a breeze. There are a bunch of iPad slate utilities and while I haven't tested them for true mission critical apps on a multiday feature shoot, quickies like this were fine for the iPad. TOD TC, a flash/beep, highly detailed info neatly displayed on the slate.

ak
Sleeplings, AWAKE!

I agree that the 5D makes lovely pics and is worth the hassle on a budget. We also use 7Ds and 60Ds in our workflow, and it's the lenses that make the difference.

Another great thing about them is they can go almost anywhere as they are so small. I know a bunch of students who were proposing mounting one above a shower in a small bathroom, and we use them inside cars, which is traditionally very difficult with, say, a Betacam rig.

You can hack them somehow to shoot very flat, apparently to give you more room for grading, but in my opinion this is a bit of a waste of time, because they shoot a very fashionably crushed-black high-contrast picture, and the hacks I have seen looked like a lot more post work than necessary, especially given they are 4.2.0.

The major problems are

? Sound. Using a separate sound recorder is advised. And then of course you're on double system sound and have to do syncing.
? Transcoding. Lots more time and disk space required before the edit.
? Run and gun camos, who buy a cheap camera and nothing else (sound, tripod, lighting) and think they can keep up with the big guys for quality. I guess this is like the 'FCP is killing the editing business!' thing.

another point or two about shooting H264:

it's not great to grade. you don't have the latitude you'd have with "real" camera footage.
its been compared to shooting reversal in the old days: you have to get your exposures right.

but what you get out of it can look great.

my girlfriend who is a cinematographer has a 5D, but uses it only occasionally for shooting moving images:
mainly time-lapse with an intervalometer (I guess she could be shooting RAW, in that case)
occasional pickups,
and it's also come in very handy for more "discrete" filming, when a larger camera would get in the way.


nick

"it's also come in very handy for more "discrete" filming, when a larger camera would get in the way. "
"they can go almost anywhere as they are so small"
snap!

And so cheap. I mean, even if you lost an entire rig with a good lens, you could pretty much write it off under a good budget. So great for dangerous conditions. Of course, they have a very distinct look though, so using them as dangermouse b cam might be quite obvious, depending on your other cameras.

> I guess this is like the 'FCP is killing the editing business!' thing.

I've been on avid for the best part of the last few weeks. Some things come back like the recollection scene in apocalypse now, things like creating a bin and calling it "title junk". It's a bit of horses for courses, and there are things which FCP is far superior in, and it's not just the price. I like a bit in both and there are peeves in both NLEs. However, if I had a decent budget, I won't pick a RED cam or an Alexa over a 5D.



www.strypesinpost.com

Harry, as you surmised, H.264 comes in a wide variety of flavors. There can be 4:2:2 H.264. Canon chose to use 4:2:0. Also H.264 coding isn't always heavily compressed. It depends (mostly) on the bitrate chosen. This might be 2 Mb/s for a YouTube piece, or 35 Mb/s for a Blu-ray disc, or using the Compressor preset for QT file in codec H.264 around 95 Mb/s. Canon chose a bitrate of around 44 Mb/s for HD video. You can't expect much more when capture will be on a compact flash card.

Dennis Couzin
Berlin, Germany

Ahhh ... I see. You (dcouzin) have confirmed my fumbling suspicions. So the higher the bitrate the less the compression, I take it?

And all this 4:2:0 or 4:2:2 or 4:4:4 stuff is the allocation of luma and color space and a separate issue from the bit rate. I had previously thought that those 4xx numbers were inextricably linked to the bitrate.

Thank you very much for clarifying all this nonsense. Well, sorta.

Best wishes and thank you all for the replies.

Harry.

> Canon chose a bitrate of around 44 Mb/s for HD video.

Rather, 24 Mbs. From memory, the EBU recommends production in mpeg 2 compression of 50 Mbs at full raster for HD transmission, but that aside, I believe most of the quality hit does not come from the codec, but rather the slow sensor readout, which require loads of engineering hacks just to produce an hd frame size. Pretty much a marvel for its price.



www.strypesinpost.com

>So the higher the bitrate the less the compression, I take it?

Yes and no. A higher the bitrate, means the compression algorithm is less aggressive. Chroma subsampling (and for that matter, subsampling) is also another method to keep the bit rate down. Most compression schemes intelligently round off and discards pixels. Subsampling discards resolution in a simpler but more predictable manner. Chroma subsampling discards color information, which in most cases is imperceptible to the human eye without subjecting the image to further post processing.



www.strypesinpost.com

PS.

Hey, Strypes ...

You say:

"The Canon camera skips lines, resulting in lower than expected resolution"

It "skips lines". Wot's that?

Thank you,

Harry Again.

Quote
strypes
Rather, 24 Mbs

I got my 44 Mb/s figure from a statement in a Canon 5D white paper: "...a 4GB memory card can record approximately 12 minutes of movies at Full HD resolution..." (page 18; repeated on page 19). There are 8 bits in a byte and 60 seconds in a minute. Your figure of 24 Mb/s would be very skimpy for Full HD, considerably less than Blu-ray. 44 Mb/s on the other hand more or less satisfies the 50 Mb/s recommendation you cite, since H.264 is somewhat more efficient compression than the cited MPEG-2.

I suggest you double check your 24 Mb/s, realizing that spec sheets (and this white paper also) are written by half-knowledgeable marketing people, and that 12 minutes in 4GB is a more difficult fact for them to mangle than the bitrate figure.

Dennis Couzin
Berlin, Germany

Just as a throw away the last episode of "House" was shot on a 5D mk ll it's a great camera with limitations, but it's amazing in low light.

Most workflows involve transcode to prores for editing there is a canon plugin for FCP for log and transfer.

For the price of the camera it's un-beatable there are loads of adapter rings to put almost any lens you want.

If you check the web Zacuto did a shoot out between 35mm film cam/5D/7D and Nikons all viewed on cinema screen, very interesting.


Derek

I've seen some very pretty HD Nikon D3S stuff. The field isn't Canon's alone anymore, although they're still far less expensive.

The D3S shoots AVI (!) at 720P to an HD Compact Flash card.

- Loren

Today's FCP 7 keytip:
Play from Playhead to Out Mark with Shift-P !

Your Final Cut Studio KeyGuide? Power Pack.
Now available at KeyGuide Central.
www.neotrondesign.com

I shoot with the 5D regularly ... I do record audio externally via an H4n, but I feed the H4n into the camera and often use the audio recorded in-camera (although... mixed via the H4n) for versions up to and including final export. The audio trouble isn't as bad as it once was.

Trying to mount all the crap that you used to stick on a broadcast camera onto the 5D.... now that's a challenge.

FYI the new low budget terms are: "It's just for the web", "Doc Style", "film Nior" and "we want to shoot it on the 5D".

Mike Watson Wrote:
-------------------------------------------------------
> I shoot with the 5D regularly ... I do record
> audio externally via an H4n, but I feed the H4n
> into the camera and often use the audio recorded
> in-camera (although... mixed via the H4n) for
> versions up to and including final export. The
> audio trouble isn't as bad as it once was.
>
> Trying to mount all the crap that you used to
> stick on a broadcast camera onto the 5D.... now
> that's a challenge.

Same here I use a Tascam DR2d for audio then use Pluraleyes to sync.
Had to buy a Jag35 cage for the 5D to mount audio and HDMI monitor

Derek

So... is it necessary (quality-wise) to transcode to ProRes first? I just shot a music vid with the 5DMKII that is for tv broadcast (SD). Should I just edit with the files as is from the camera (H.264) or would you wizards recommend (or demand) that it be first converted to Prores (HQ or LT). Drivespace and transcoding time are no concern... just quality.
Oh, also, while editing I would like to be able to preview effects (Sapphire film effects, slo-mo's etc) without having to first render every time.
I was just doing some testing with the native H.264 footage and EVERY little tweak to the footage requires a render (which really slows the flow).
Thanks!!

Luna Antonioni

I'm using Mac OS 10.6.7, FCP 7.0.3, a 17" MacBook Pro (2.5Ghz Intel Core 2 duo, 4GB 667 MHz DDR2 SDRAM) , 2TB Rocstor external drive.

> Should I just edit with the files as is from the camera (H.264)

Absolutely not. H.264 will not only perform poorly (slow access, prone to crashes and freezes, etc.), but some people have reported nightmares like exported movie files not matching the edits they did in the timeline, simply because they'd tried to edit with H.264.

Always convert first.


www.derekmok.com

Cool, thanks Derek! That's what I need to hear. Is there some white page or resource as to the correct (optimal) method/settings?
Also, I had two cameras shooting... one camera shot at 30 fps (he didn't have the latest firmware). I shot at 24... should I make his 24? Sorry, I know these are rookie questions... new with this (awesome) 5D.
Thanks!!!!!!!!!
L