Uncompressed vs NTSC DV!

[jgastelb]

OK, so this may sound too obvious but I wanted to know if there are going to be visible differences between rendering uncompressed (default template) and NTSC DV 24p with 2-3-3-2 pulldown?

I went ahead and rendered NTSC DV 24p for a client and he wanted uncompressed. I don't know what was wrong with me that day but I confused the two and gave him that files saying it was uncompressed. Unfortunately, my computer was having the blue screen of death and it was not letting me access the VEG files anymore so I had to reinstall windows xp and I'm stuck with the NTSC. Will there be any visible differences when he blows it up as opposed to using an uncompressed file as his final source?

I had read somewhere that using the 2-3-3-2 pulldown was best when thinking about re-editing something but somehow I thought it was uncompressed or the quality would be close to lossless. Am I way off???

Jgastelb

 

[scannon]

What is DV? (courtesy of Adam Wilt)

DV is an international standard created by a consortium of 10 companies for a consumer digital video format. The companies involved were Matsushita Electric Industrial Corp (Panasonic), Sony Corp, Victor Corporation of Japan (JVC), Philips Electronics, N.V., Sanyo Electric Co. Ltd, Hitachi, Ltd., Sharp Corporation, Thompson Multimedia, Mitsubishi Electric Corporation, and Toshiba Corporation. Since then others have joined up; there are now over 60 companies in the DV consortium. DV, originally known as DVC (Digital Video Cassette), uses a 1/4 inch (6.35mm) metal evaporate tape to record very high quality digital video. The video is sampled at the same rate as D-1, D-5, or Digital Betacam video -- 720 pixels per scanline -- although the color information is sampled at half the D-1 rate: 4:1:1 in 525-line (NTSC), and 4:2:0 in 625-line (PAL) formats. (See below for a discussion of color sampling.)
The sampled video is compressed using a Discrete Cosine Transform (DCT), the same sort of compression used in motion-JPEG. However, DV's DCT allows for more local optimization (of quantizing tables) within the frame than do JPEG compressors, allowing for higher quality at the nominal 5:1 compression factor than a JPEG frame would show. See Guy Bonneau's discussion of DV vs MJPEG compression for more details, or download the DVCAM Overview documents (PDFs) from http://www.sony.ca/dvcam/brochures.htm for a nice tutorial on compression.
DV uses intraframe compression: Each compressed frame depends entirely on itself, and not on any data from preceding or following frames. However, it also uses adaptive interfield compression; if the compressor detects little difference between the two interlaced fields of a frame, it will compress them together, freeing up some of the "bit budget" to allow for higher overall quality. In theory, this means that static areas of images will be more accurately represented than areas with a lot of motion; in practice, this can sometimes be observed as a slight degree of "blockiness" in the immediate vicinity of moving objects, as discussed below.
DV video information is carried in a nominal 25 megabit per second (Mbits/sec) data stream. Once you add in audio, subcode (including timecode), Insert and Track Information (ITI), and error correction, the total data stream comes to about 29 Mbits/sec or 3.6 MBytes/sec. Roger Jennings' papers run through the detailed numbers.

Quality on a scale of 1- 10

D-5 (10-bit uncompressed digital) - 10
D-1 (8-bit uncompressed digital) - 9.9
Digital Betacam, Ampex DCT - 9.7
D-9 (Digital-S), DVCPRO50 - 9.6
DV, DVCAM, DVCPRO (D-7), Digital8 - 9.0
MII, Betacam SP - 8.9
1" Type C - 8.7
3/4" SP - 6.5
3/4", Hi8, SVHS - 5.5
Video 8, Betamax - 4.0
VHS - 3.5
EIAJ Type 1, Fisher-Price Pixelvision - 1.0

That said, don't confuse frame rate 29.976, 23.976, or 23.976 with 2:3 0r 2:3:3:2 pulldown with uncompressed. DV is a compression scheme for video using 5:1 intraframe compression and a 4:1:1 colorspace.

Unless you capture from the camera to the deck directly via SDI or your camera uncompresses video on playback via some type of YUV out your captured files are already compressed.

Hope this helps

S Cannon

 

[jgastelb]

WOW!!! That was a mouthful. Thanks for that wealth of information. The footage was simply transferred from an external hard drive to my computer. Some of it was heavily compressed from a web source, some was 16mm digitized to quicktime (uncompressed, I believe) and other was HVX footage that I think was shot at 1080i. Not sure about the last one. I was trying to fit the file into one data file dvd but I was really assuming lossless quality for some reason.

Some people say that the quality loss is so virtually minimal when using ntsc dv and that they use it so as not to have huge file sizes. At least, I'm finding that.
Jgastelb

 

[GenJerDan]

In your case, uncompressed might have been better.

In most cases (shooting DV to begin with), there's not enough difference to matter unless you did some outrageous CC and effects. After all, the source was already DV, so going uncompressed isn't going to add any goodness to it.