GH4 GH4 codec

David W. Jones said:
But since you don't deliver anything, you just use what camera you are given, one might ask if your initial question is relevant? ;)
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Did I say it was relevant to anything? I was just shooting the breeze, thinking out loud and chatting.

I'm amazed that tech requirements were never discussed on a BBC shoot - unless others in your team covered them - there must have been contracts surely?

Steve
 
steve phillipps said:
I'm amazed that tech requirements were never discussed on a BBC shoot - unless others in your team covered them - there must have been contracts surely?

Steve
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Not a BBC shoot.

Production houses all over the world provide commercials to the BBC.

We were required to deliver on standard definition DigiBeta, even though we shot on a Red Epic. Kind of silly the BBC makes such a big deal about meeting their high quality standards, and then requests SD commercials.

This might be helpful, maybe not…. https://tech.ebu.ch/docs/r/r118.pdf
 
David W. Jones said:
Not a BBC shoot.

Production houses all over the world provide commercials to the BBC.

We were required to deliver on standard definition DigiBeta, even though we shot on a Red Epic. Kind of silly the BBC makes such a big deal about meeting their high quality standards, and then requests SD commercials.

This might be helpful, maybe not…. https://tech.ebu.ch/docs/r/r118.pdf
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Are you talking about BBC America?

I think people are assuming you're talking about BBC transmitted in England. (which doesn't have any commercial advertising at all)

I can't imagine BBC america care that much about what format they receive commercials in, feature length TV programmes they definitely do care about what format it's shot on.
 
Ask yourself, what is bringing home more resolution, color info, and overall data; The tapebased varicam at 30fps, 720p (50mbps at 4:2:2) or the GH4 at 100MBPS shooting 4k 4:2:0 and then downsizing to 1080? The cost of the bodies is irrelevant. Side by side, the GH4 will likely make the old ENG cam look pretty bad. Moreover, when you've got what a broadcaster wants, they don't often ask a lot of questions about formats and such. Most folks at the networks honestly don't know enough to even properly ask.
 
Cosimo Bullo said:
Ask yourself, what is bringing home more resolution, color info, and overall data; The tapebased varicam at 30fps, 720p (50mbps at 4:2:2) or the GH4 at 100MBPS shooting 4k 4:2:0 and then downsizing to 1080? The cost of the bodies is irrelevant. Side by side, the GH4 will likely make the old ENG cam look pretty bad. Moreover, when you've got what a broadcaster wants, they don't often ask a lot of questions about formats and such. Most folks at the networks honestly don't know enough to even properly ask.
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Played straight from camera onto the screen, yes the GH4 may well look better, but that's what I said earlier in the thread, the problem isn't how it looks in camera it's what it will look like after it's been mangled in the transmission chain. And you seem to have your numbers and acronyms a bit muddled there - the GH4 is not 100 MBPS (that would be megaBYTES) it's 100 mbps (megaBITS), and the Varicam is 100mb/s Intra frame. Hard to compare the codecs directly of course but the general rule of thumb is I believe that Long GOP codecs are roughly twice as efficient, but that would still mean the GH4 is waaaaay more compressed than the Varicam.
If you mean by "when you've got what a broadcaster wants" that no-one will care if you have some unique never-to-be-repeated footage then of course that's true, but for general day to day programme making they do have rules and tech standards which you have to abide by if you want to keep working - you can't just shoot a BBC1 HD drama on a VX1000 or an iphone and not tell anyone and expect to get away with it!
Steve
 
Well, considering I've shot for the BBC with the VX1000 (for doc, not drama) that doesn't add up (but that was WAY back in the day...)

The problem with your logic is that you're looking at 1/4 of the GH4 res (25mbps per 1080 worth of real estate) and comparing it with say the EX3, and in that case, yes, that 1/4 of the GH4 is more compressed, but the GH4 shoots 4k, and when you then output the 4k master at 1080 you will have fewer compression artifacts, etc that you would from the 35mbps EX3.

Moreover, I owned a RED ONE for a while and I can honestly say the GH4 keeps up with the footage from that beast quite well in general, and is better in low light (original RED sensor). The cam starts in about 1 second, quickly moves between 4k and 108060p, and can live on my shoulder, clanging around with my D810 through whatever I put it through. We have left the time of the expensive cam always being the one to go to. In the era of gopros shooting 4k, and GH4s and A7S's shooting world class footage for sub $3k the most important element is grabbing the right tool for the job, and that will often be a camera much smaller and less expensive than we old-timers are used to shooting on. Your client wants your footage to look extraordinary, how you go about doing that will become less and less of a concern to them.
 
Cosimo Bullo said:
Well, considering I've shot for the BBC with the VX1000 (for doc, not drama) that doesn't add up (but that was WAY back in the day...)
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Well, I did say for BBC1 HD, which didn't even exist WAY back in the day, so I think it does still add up.

I suppose the only way we'll know is when tech specs are finalised. I just know that the past is littered with people thinking and saying that their lovely cameras make fantastic images and then being surprised when they fall well below the specs of the broadcasters. I was one of them, in the days when we shot Super 16 and it looked so gorgeous, it was hard to accept when we were told it wasn't good enough for HD transmission.

Steve
 
steve phillipps said:
As the EBU minimum codec for broadcast spec for HD is 50 mb long GOP or 100 mb I frame, presumably for 4k this codec needs to be 4x the data rate (at least)?
Looking at the GH4 it has this, at first glance, impressive 100mb/sec long GOP codec, but presumably that equates to a pretty poor, non-broadcast-spec 25 mb codec in HD.
Steve
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This assumes that perceptual encoding is linear with frame size. That's an incorrect assumption.

Fran
 
Fran Guidry said:
This assumes that perceptual encoding is linear with frame size. That's an incorrect assumption.

Fran
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I never said it was a correct assumption - that why I said "presumably" rather than stating it as a fact. If you have any further information and maths to demonstrate the actual relationship please feel free to share, I'm very receptive to being educated.

Steve
 
Working on both linear and on-demand channels, shooting footage and producing broadcast masters, the type of camera you're shooting with doesn't matter much to the broadcast folks, as long as your master is within their specs. We've shot b-roll with hacked GH2s, GH3s and 4k GH4s and I've seen them intercut nicely with other cameras (RED included) for broadcast segments and commercials.
 
steve phillipps said:
Quite obviously that is highly dependent on who the broadcaster is - some are clearly far more demanding than others.

Steve
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I've never had Media Prep nor the Media Library ask me what camera(s) I shot the master with. It's the DP or Production Team who's responsible for choosing the right tool for the task.
 
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drewski310 said:
I've never had Media Prep nor the Media Library ask me what camera(s) I shot the master with. It's the DP or Production Team whose responsible for choosing the right tool for the task.
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Quite obviously that is highly dependent on who the broadcaster is - some are clearly far more demanding than others.

Steve
 
steve phillipps said:
Quite obviously that is highly dependent on who the broadcaster is - some are clearly far more demanding than others.

Steve
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Haha...ok. FYI, we have access to all cameras on our Production Team. Like I said, you choose the right tool for the task. How many broadcast masters have you delivered?
 
Does that have any relevance? I don't deliver - I just shoot, and shoot with what I'm given or told to shoot with - all the programmes I've ever worked on have had tech minimum requirements. Quite obviously that is highly dependent on who the broadcaster is - some are clearly far more demanding than others.
Steve
 
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steve phillipps said:
Does that have any relevance? I don't deliver - I just shoot, and shoot with what I'm given or told to shoot with - all the programmes I've ever worked on have had tech minimum requirements.
Steve
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It's relevant because you're trying to equate the acquisition specs of your camera with the delivery specs of the broadcast master. That's the responsibility of the editor to ensure the master is broadcast compliant. Editors have to be able to ingest footage from all sorts of sources - think about those crime reality shows, like Dateline NBC in the US for example. They're pulling footage from security cameras, 911 recordings, smartphones, etc. for their b-roll. None of it is "broadcast spec", and yet they produce a 100% broadcast compliant master suitable for network airing.
 
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