Arggh! Table of File Sizes? Please?

Grazie wrote on 7/17/2007, 11:54 PM
chilllll

G'morning, would somebody please give me an INTERNET site or one of our OWN replies here ( I've done searching here!) which indicates the file size per minute for SOME of our regular renderings?

Something like:

AVI = XXXXmb/minute
MPG = YYYYmb/minute
MOV = ZZZZmb/minute

.. yeah? That kinda thing>

TIA

Grazie


Comments

John_Cline wrote on 7/18/2007, 12:51 AM
Well, that's kind of hard to define. AVI and MOV are simply containers and the file size per minute depends on the compression method, frame size in pixels and frame rate. Not all video codecs have a constant bitrate. Video formats, like DV, do have a constant bitrate and the image quality varies from frame to frame depending on how complex the video is. DV is 3.6 megabytes per second or 216 megabytes per minute or 12.66 gigabytes per hour. Since HDV has the same constant bitrate as DV, the same numbers apply.

With other codecs, like MJPEG, you can set a desired quality level and the size of each frame varies depending on its complexity. HUYYFUV, LAGARITH and Cineform have a fixed quality level and they will also vary with image complexity.

The file size of MPEG2 per minute is determined entirely by whatever bitrate you set, either a constant bitrate or an average bitrate. MPEG2 can also be set to a specific image quality and the bitrate will vary to hit the target quality level.

So, with the exception of HDV, DV and a few other constant bitrate codecs (or MPEG2 set to a constant of fixed average bitrate), it is sometimes difficult to pin down an exact file size per minute.

John
Grazie wrote on 7/18/2007, 1:20 AM
Well, that's kind of hard to define

I think you are being awfully polite to me! LOL! And yes, before I summon the total wrath upon my head or bottom, from my friends here, I knew that. And consequently WHY there ain't a table!

However . .

SD-DV, just captured, lying on a disc is about 216mb/min equiv to 12.96GB per hour?

Then the next BEST comparison would be uncompressed plain-vanilla AVI? What would THAT be?

Bottom line here, I'm trying for myself and "another", to have an "overview" which - and you've quite rightly pointed out - to be of some semblance of usefulness. A type of litmus/"suck 'n see" ruff guide. Maybe then not let us go down the "exact" option but say it in rough ratios? Would that be of any value or of intelligent insight?

But, John, thanks for the kindly response.

Best regards

Grazie
John_Cline wrote on 7/18/2007, 1:53 AM
OK, uncompressed PAL SD...

720x576 = 1,244,160 bytes per frame x 25 frames/sec = 31,104,000 bytes per second plus 384,000 bytes for the 48k 16bit stereo audio* = 31,488,000 bytes per second. That's 1,889,280,000 bytes per minute. 1.75952911376953 gig a minute! One hour of uncompressed PAL-SD with audio is 113,356,800,000 bytes or 105.571746826172 gigabytes

NTSC...

720x480 = 1,036,800 bytes/frame x 29.97 fps = 30,792,960 bytes/second plus 384,000 for the audio is 31,176,960 byes per second. 1,870,617,600 bytes per minute. 112,237,056,000 bytes per hour or 104.528903961182 gigabytes.

John

* In a Type-2 .AVI file, which is what Vegas uses, there are actually two copies of the audio track stored in the AVI file, even though a second's worth of 48k 16bit stereo audio is 192,000 bytes, it becomes 384,000 bytes when stored in the AVI.

For what it's worth, a DV stream with audio is:

30,195,712 bits/sec
28.796875 megabits/sec
3,774,464 bytes/second
3,686 kilobytes/second
3.599609375 megabytes/sec
Grazie wrote on 7/18/2007, 2:24 AM
Thank you John.

G
riredale wrote on 7/18/2007, 10:04 AM
I've always heard that m2t files are the same size as DV, but in my experience they come in at about 11GB/hr (slightly smaller).
rs170a wrote on 7/18/2007, 10:11 AM
Let me add that (NTSC @ 720 x 480) MOV files are the same size as DV-AVI files.
I did a 2-day shoot last month and the company I worked with recorded the show (using FCP) to an external (Mac-formatted) hard drive.
MacDrive made it very easy to bring these files into Vegas :-)

Mike