720P/30PN is Not a DVCPRP recording format???

A

Angelcyk

Well-known member
I've been shooting a few projects lately using either the 720/30PN or 720/24PN mode and found out on page 27 on the manual that states...... The 720/30PN and 720/24PN formates are not included in the DVCPRO HD recording format. If this is not DVCPRO HD, then what format is? DVCPRO-100 or DVCPRO-75? And is there a difference in quality compared to 720/30PN or 720/24PN?

Also on the back of the camera there's a setting called "MCR". Does the "M" stand for media? I'm sure it does but I just want to be clear since it does not state that in the manual.
 
i thought "mcr" was memory card recorder. i could be wrong though....

i don't know about the technicality of the pn mode but when i edit it, the format is dvcpro hd. what else would it be?
 
DVCProHD means many things... most importantly here, it's used (perhaps too informally?) as a tape format, a streaming format, and a data format. Native (PN) modes are not valid as TAPE or STREAMING formats... DVCProHD tape runs at a constant 100mbps, while 720PN has a data rate of 50mbps, and 720pN, 40mbps. Thus, the "over 60" modes which pad the 24p or 30p data streams with extra data to fill out the 100mbps. Streaming over firewire also requires a constant 100mbps stream. This is why there's no firewire output in pN modes.

The quality of 720/24p or 30p (once pulldown is removed) and 720/24pN or 30pN is exactly the same. The non-native modes just pad the data with enough redundant information to provide a constant 100mbps data stream to devices that need it.

So... the DVCProHD CODEC is used for native and non-native modes. But only non-native modes can provide a DVCProHD data stream, or be written to DVCProHD tape.

Make sense?
 
So, the reason why "it's not considered DVCPROHD" is because 720/30PN is being transfered at 50mbps rather than 100mbps> Everyone has told me that there's no quality loss, but I guess it's because it still uses the DVCPro HD "Codec" as you mentioned. This makes sense, thanks for the info!
 
Just curious, if 720PN transfers data at 50mbps then what is the data rate transfer of DVCPro50
24P?
 
The EFFECTIVE data rate of DVCPro50 in 24P is 40mbps. DVCPro50 is interlaced; and introducing the pulldown for 24P (the redundant padding to fill 50mbps) adds 1 frame of redundant information for every 4 unique frames - or in reverse, when removing pulldown, you drop 1 of every 5 frames, or 20% of the data - that is, in other words, 10mbps of the full 50mbps is just padding in 24p.

In an interlaced system, 30p progressive uses the same amount of data as 60i. and 24p uses 80% of the data. That's because in 30p, both fields are still used, just in a different manner than in 60i; and in 24p, 80% of the amount of data is used (4/5 of all fields).

In 60p, each frame is natively progressive, so to get to 30p, you throw half the frames away (for 50% of the 60p data rate), and to get to 24p you throw away 36 out of every 60 frames for an effective data rate that's 40% of the 60p data rate.

Hopefully, the new crop of cameras like the HMC-150, which have no legacy ties to tape formats, will be smart enough to decrease compression rates so as to keep the data rate constant, and thus increase quality when going from 60p or 60i to 24p...
 
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Output how? Via the camera's firewire port? There's no firewire out when capturing in native mode. If you mean from your NLE - most will add pulldown and allow this.
 
ullanta said:
Output how? Via the camera's firewire port? There's no firewire out when capturing in native mode. If you mean from your NLE - most will add pulldown and allow this.
Click to expand...
Sorry, upon output from FCP or worst case senario from an AVID, thanks for answering my question, I got a little nervous reading this thread.
 
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