record time longer than indicated

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David_

New member
I have my DVX200 set to record FHD 1080 All-I 23.98. The display indicates I can record 1 HR and 25 MINS on a 128 GB card. However, I was able to record 3 times that amount of time. Why? Was it because the camera was locked off for a simple interview session and therefore a more easily compressed image?

Thanks.
 
I finally updated my Firmware from 1.81 to 1.84, which has caused the opposite problem: I am now getting now getting an error of too little recording time remaining.

I know that well over 3 hours can be recorded on a 128GB SD card with settings FHD 1080, ALL-I, MOV 23.98.

However, even after the update, when I put in an empty 128 SD card it indicates that it's capacity is only 1 hr 25. Clearly this is wrong as the card can record over 3 hours.

I checked with a 64 GB card and it gave me the same erroneous reading, but cut in half, 42 mins, as expected since it is half the size of the 128.

Why am I getting incorrect reamining recording time even after a firmware update?
 
Last edited:
I just checked Barry Green's e-book and his chart (pg. 66) states you can expect :40 on a 64GB SD card so 1:25 sounds accurate.

FHD ALL-I 200M
16GB 32GB 64GB
10:00 20:00 40:00
 
I just checked again and my camera is set to:

4:2:2 (8bit)
MOV
FHD 1080/23.98p ALL-I 200M

However, even though my camera is set to record at 200MBs, the files created are 50Mbs.

Why could this be happening?
 
David_ said:
I just checked again and my camera is set to:

4:2:2 (8bit)
MOV
FHD 1080/23.98p ALL-I 200M

However, even though my camera is set to record at 200MBs, the files created are 50Mbs.

Why could this be happening?
Click to expand...

How are you determining that the resulting files are 50Mbs?
 
Not a direct answer to your question, but an observation on the naming conventions: the ALL-I codec is only 200mbit when it's recording at 60p, and even then, it's a maximum of 200 megabits, not a minimum or guaranteed amount. When recording 30p, it's going to be a max of 100 megabits, and when recording 24p it's going to be a max of 80 megabits. That's the way Panasonic's intraframe codecs have always worked; example is DVCPRO-HD, which was nominally 100 megabits when shooting 720/60p but 40 megabits when shooting 720/24p. The same amount of data is allocated per frame, so more frames = more megabits getting used up. The "class" of the codec (such as AVC Ultra Class 200) refers to a quality level that's achieved by up to that number of bits, but that class is always based on the notion of encoding 60 fps.

The difference you're observing is likely due to the subject matter not being terribly difficult to encode. The ALL-I codec has a maximum data size that it CAN use, but it is not REQUIRED to use all that data. DVCPRO-HD didn't work that way, it always resulted in the exact same size per frame, but the newer h.264 codecs are always variable bitrate, and it's set to encode to a certain quality level. If it needs to use up the full allotment of (200 mbits / 60 fps = 3.333) 3.333 megabits per frame in order to achieve that quality level, then that's what it will do. But if it can achieve that quality level at 3 megabits per frame, or 2.5 megabits per frame, then it'll do that too. It's a variable bitrate codec, up to 3.333 megabits per frame (or 200 megabits per second).
 
Thanks, Barry.

A related question: In your book on page 62 you write that one can expect results from 100Mps long GOP that would exceed 200Mps ALL-I. However, I don't see 100Mps as a choice in the menu, at least not in 23.98p? I see an option for 100Mp in 59.94p. Is that the 100Mps you mean?

FYI, I initially choose ALL-I hoping that my editing workstation wouuld handle it better, but it didn't. So I am using proxies. Therefore any long GOP is OK, since I will be making proxies anyway. Is the DUAL CODEC 50 better than than 100 non-dual?
 
Yes, the data rate for the long-GoP codecs is dependent on the frame rate and frame size.

Dual Codec 50 makes for very nice 1080 footage when the main Codec is UHD.
 
Just to understand:

There is no 100Mps at 23.98p.

100Mps is only available in 59.94p.

Do I have that right?
 
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