firewire or y/c out

[Wayne Vollweiler]

Some people say firewire is better from DV tape because you’re keeping an all digital signal path. The bad part of that is a) no proc amp controls on input and b) color space is 4:1:1 (4:2:0 in PAL). This comes into consideration if you are doing a lot of compositing. The s-video line (even though its being converted from digital to analog a) gives you proc amp control on input and b) is upconverted to 4:2:2 color space. This is a little misleading because there still isn’t “enough” color to do real high end compositing, but you might see a little difference if you pull a chromakey from the s-video signal. Hope that helps.
Wayne

[Floh Peters]

[Wayne V.] “The s-video line (even though its being converted from digital to analog a) gives you proc amp control on input and b) is upconverted to 4:2:2 color space. This is a little misleading because there still isn’t “enough” color to do real high end compositing, but you might see a little difference if you pull a chromakey from the s-video signal. “

Actually the Media 100 i FireWire input is also upsampled to 4:2:2 when the signal moves into the Media 100 codec chip. Everything inside Media 100 i (unlike HD or sw) is in the “native” Media 100 i codec, which is 8bit 4:2:2 independant of which input you do use. But uprezzing a 4:1:1 (or 4:2:0 signal) does not make much sense unless you recompress it (e.g. for effects, transitions, anything that needs to render). A keyer does not gain anything from converting a signal recorded at 4:2:0 into a 4:2:2 or 4:4:4:4 signal.

[Bill Page]

So, aside from the proc amp control, how much better is the captured pix quality of ‘firewire in’ compared to ‘y/c in’ (into the M100)?

[Bobby Mosaedi]

simply put, you will have the least amount of picure loss and quality if you do firewire in and out. i use firewire in so i get the best picture quality possible when outputting to beta. and if there are any of you still digitizing analog video at 640×480, just stop. start all your programs at 720×486. this will allow you to mix your dv footage with analog video.

firewire is great, i just wouldnt use it as way of controlling my deck. if your deck has rs422 control, use that instead, but still use the DV port for video + audio.

if your need to control the gain from your audio on your dv tape, id digitize analog audio set at 48k, so you can set your levels properly if they are not good on the tape.

is there a way to disable 640×480 options in the hardware settings? i want to prevent people here from making those mistakes when trying to mix analog footage and DV footage.

[Jenny]

Okay, well I did my own tests.

I digitized my last job with y/c and re-digitized it again with firewire DV. First of all, when digitizing with y/c I really missed having the deck control or time code I had with DV. The digitizing did not automatically stop at the end of video like it does when digitizing with DV, y/c stopped at end of tape.

Next I put both clips on time line and cut between. I noticed dramatic differences. The y/c audio was much too low, also the video was more saturated, darker and no detail in blacks. Over all, I prefer the DV firewire.

Thanks to everyone who responded.