JackOfAllFilmTrades
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Why does a camera have to record at 50Mbps to be considered fit for broadcast?
- Thread starter JackOfAllFilmTrades
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Bassman2003
Veteran
Because broadcasters subject the signal to a lot of abuse to get it to your television and they want to start with a high quality recording.
AndrewGentle
Well-known member
It probably doesn't if you're recording timelapses.
The European Broadcasting Union did some very extensive trials a few years ago to compare various codecs and on the basis of the results published guidelines for broadcasters. Full details at - http://tech.ebu.ch/docs/techreview/trev_2008-Q3_HD-Prod-Codecs.pdf AFAIK it's by far the most thorough comparison so far done, and has the merit of being independent. (Note that 50Mbs is only acceptable for interframe codecs - the minimum is 100Mbs for intra-frame.)
The real point is to ensure not simply that a codec doesn't degrade the picture on first recording - but that subsequent decoding, processing and recoding likewise doesn't degrade the picture, even when done repeatedly. To that end they made sure they shifted the image by a couple of pixels between each decode/recode, and in the case of XDCAM422 made sure that on each cycle a different frame was forced to be the I-frame.
For practical purposes, the key finding for real world users is that both XDCAM422 and AVC-Intra 100 both passed as fully approved for all general HD broadcast acquisition. (XDCAM EX 35Mbs got subsequent broadcast approval for "journalism" applications, so it's reasonable to think of it as the present day HD equivalent to DVCAM)
It's worth repeating the key conclusion :
The real point is to ensure not simply that a codec doesn't degrade the picture on first recording - but that subsequent decoding, processing and recoding likewise doesn't degrade the picture, even when done repeatedly. To that end they made sure they shifted the image by a couple of pixels between each decode/recode, and in the case of XDCAM422 made sure that on each cycle a different frame was forced to be the I-frame.
For practical purposes, the key finding for real world users is that both XDCAM422 and AVC-Intra 100 both passed as fully approved for all general HD broadcast acquisition. (XDCAM EX 35Mbs got subsequent broadcast approval for "journalism" applications, so it's reasonable to think of it as the present day HD equivalent to DVCAM)
It's worth repeating the key conclusion :
JackOfAllFilmTrades
New member
So in other words I can shoot on whatever I want if it doesnt shoot native 50Mbps as long as I record through a Ninja or something that records at at least 50?
Also is this also true for American broadcast standards or just Euro?
Also is this also true for American broadcast standards or just Euro?
Andrew Gupta
Active member
"American broadcast standards" are all over the place -- depending on what you're doing. There's no one single American standard. Last month I was dealing with a broadcast entity in NYC that demanded something similar to the European guidelines stated above, and last week I dealt with a broadcast entity in Baltimore that records (SD) DVCPRO to external recorders, while a competing broadcast entity used AVCHD cameras for local news. Ad agencies have their own standards, and cable systems may (or may not) have their own acceptable formats. Professional distributors may have very high standards that far exceed local broadcast stuff. The honest answer is -- it's a mess.
Meaning -- you want to specifically connect with your form of distribution and know exactly what they request.
If you're shooting stuff on your own and want it to be universally acceptable for any request -- then the safe bet is to shoot the best possible quality of which you are capable -- and then deliver (encode out) to any specific request.
In a very generalized sense, yes, for local broadcast the minimum general standards are 50 Mbps long-gop, and 100 Mbps intra-frame. Those are minimums.
JackOfAllFilmTrades
New member
I see. Last year I was editing a show for local broadcast and they wanted it on 480 DVD deliverable (They dont support HD yet from client submissions for whatever reason). They never cared one bit about bit rate just as long as it played on a DVD and had enough black video on front and back.
HKO
Well-known member
Perhaps not - I think the BBC have camera specs as well for HD as far as resolution, aliasing, lens quality etc goes as well. They look at the whole machine I guess. I mean you can get uncompressed Video from an old sony consumer SR11 on a Ninja but it still may fail their other rigorous tests aside from the codec. If you get an EX1 to a ninja - well then that is bang on. I am sure that if the story is compelling enough though - none of this matters. I have seen really crappy iphone vids make big news if it is relevant. Think of the riots in the Arab spring. Context is everything.
Shooting a nature series or Drama? Better off doing it with an approved camera. Covering the latest breaking news - who cares - just capture it.
Bassman2003
Veteran
There is "Broadcast" and then there is broadcast. The term "Broadcast" in this sense refers to to large, national broadcasting companies with high quality and large budgets. On the other end you have local cable broadcasters who just put any signal up on your TV. A little common sense will tell you who you are dealing with...
TheReverend
Well-known member
It varies wildly from my experience. I've done AVCHD capture and H264 delivery with multiple commercials that have aired in the Twin Cities area. Charter and Comcast both have different requirements for what they will accept, but pretty much no specifications on what you shoot with. Of course, commercials/paid-for-programming is probably dealt with differently than a documentary/piece that they are airing on their dime. I've received commercial content from other high-end broadcasters to use in our commercials, and they sent me a high bitrate 1080p30 H264 file. I kinda thought I would get a ProRes or something, but apparently, whatever. The long-form paid-programming that I send into our local FOX and CW stations both had difficulty airing our HD file, because they don't even have infrastructure for the file sizes. FOX got it worked out, but we still are sending The CW station DVDs, so our content isn't even HD 16x9, but it letterboxed 4:3 :/
My experience is the US, standards are minimal. Shoot something that looks great and deliver in the correct format, and you are good to go.
My experience is the US, standards are minimal. Shoot something that looks great and deliver in the correct format, and you are good to go.
I believe the BBC basically follow the European Broadcasting Union criteria for minimum specs - doc R118: http://tech.ebu.ch/docs/r/r118.pdf They've been known to recently purchase large numbers of Sony PMW500s, Canon XF305s and C300s, and most recently JVC HM650s for self shoot journalist use.
Note that this has the status of *RECOMMENDATIONS* - not rules, certainly not laws. A broadcaster will not be closed down or even fined if they choose not to follow them.
Practically, most see them as fairly pragmatic and sensible and choose to follow the recommendations.It is also well acknowledged that they are for basic "shot for" material, and it's well understood that exceptions may have to made for archive, specialist cameras (Go-Pro etc), and material that is unique. It's exactly as henryolonga says: if it's for news, and all that is available of a major event is phone footage - it'll get used. That does not mean using a phone to shoot for general HD broadcast is therefore OK.
As said, these are formal recommendations in Europe, but I understand that they are being seen as sensible in other countries as well. My own feeling is that if choosing a camera now, it makes sense to go along with them - even if some clients have laxer standards, it means you should be able to satisfy the demands of the more quality conscious. And they do follow on from a lot of research - if you're worried about the end quality of your work, following them can give a lot of peace of mind.
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legrevedotcom
Veteran
And yet Danish national tv often records stuff with an obvious .h264 codec and noone cares....... There's a long line of "we are used to doing it this way...." people who just cant see past numbers.