Thursday, January 20, 2011

Ripping DVDs to ProRes

ProRes is really great but it has some limitations you should know that can trip you up later.

A friend called me tonight saying they were getting an error in Final Cut they'd never seen before which was this:

"Codec not found. You may be using a compression type without the corresponding hardware card."

I knew this wasn't true after talking to them a bit so I asked from step one what they did and discovered a big gotcha when ripping DVD content to ProRes for use in Final Cut Pro.

They'd used MPEG Streamclip to rip video from a client's DVD of old footage. Since my friend wanted to use the footage in Final Cut they set MPEG Streamclip to export (transcode) the .VOB file to ProRes.

(No, I'm not sure why MPEG Streamclip lists ProRes twice in it's export options. They're likely HQ and non-HQ but I'm certain.)

When it was done the file was great, imported into Final Cut and they happily edited away. Until they needed to render something and saw the above error. Any kind of rendering produced that error which we knew wasn't true because they had used ProRes many, many times before. Something else was different.

Dissecting the project I started to jot down all the settings and media types in the project and ran across something not readily apparent unless you know to check.

The resultant ProRes file from MPEG Streamclip wasn't a compliant size for ProRes. It wasn't either:


If it's neither one of those sizes Final Cut pro runs and cries in a corner. My friend had left MPEG Streamclip to create a file that was 854x480 because next to it, in MPEG Streamclip's options, it reads "(16:9)" which this footage was and their thinking was that since it's a DVD they didn't need to rip it as an HD file.

I suggested they re-rip the bit of video they needed with MPEG Streamclip set to "1280x720 (HDTV 720p)". They did and after substituting the file for the renderless one Final Cut behaved as expected and rendered away.

So if you rip something to ProRes make sure it's a size that ProRes and Final Cut are expecting.

For more info check out this page in the FCP 7 manual.

Audio Out of Phase

Without getting too much into the details as they're complex and vast sometimes (eventually) you'll receive audio that is out of phase, likely 180°, if the audio sounds like it was recorded with the mic in a plastic bucket. Another clue is that it'll sound okay when played back from whatever it was recorded on but be very low volume when played back in Final Cut Pro.

There are myriad ways this can happen but the most common is that the audio was recorded on two separate mic's that were improperly spaced apart so the audio they're recording reaches one mic later than the other and causes a comb filter effect.

One way I've experienced this is when on set someone has the brilliant idea of setting up a "back-up" mic close to but not along side the main mic's and rather than helpfully recording it to a separate channel they mix it in with the the main audio feed. I cringe when someone tells me they have "reference" audio as well on a multi-camera shoot because there's the risk the audio guy (or girl) mixed it all down.

One particularly bad case was when someone mixed in an off-camera (and off-set) "back-up reference" shotgun mic on a c-stand along with a TV host's lav. I know!

The out-of-phase audio you can monkey with is when there are two mic's recording the same audio source but those mic's are placed at unequal distances from that audio source and they're recorded to separate channels. Audio bouncing off a nearby wall or something into one mic can cause a similar problem.

The basic result is that one audio channel is canceling out the other (sorta, it's really just reducing the amplitude). The peaks of one meet the troughs of the other's waveform thereby reducing the clarity and volume of the audio. This page has some good visuals explaining it. You can get an idea of the effect by reversing the leads to one speaker on a stereo and playing a VO (Voice Over); it'll sound "funny".

Final Cut Pro doesn't have a way to fix this readily, but one quick check for phased audio (and a fix kinda) is to simply turn off one channel and listen to it to see if it sounds better. If it does: the audio sounds brighter, louder, clearer, it's likely the audio was recorded out of phase.

A quick fix (meaning if the client is there waiting when the audio sounded great when played back on their camera through headphones) is to turn off one of the channels, duplicate the one remaining above or below itself, and then adjust the audio level a bit. It'll be in mono but you can fake that by offsetting the duplicated channel by a few hundredths of a frame (in the Viewer via moving the In point while you hold down SHIFT).

I may post more about this later in greater detail but I thought I'd mention this since if it pops up it can be pretty flummoxing if you've never seen (heard?) it before.

Tuesday, January 18, 2011

Live Capture HVX-200 to Final Cut Pro

Just a quickie one.

If you have a Panasonic HVX-200 and a FireWire cable and a laptop running Final Cut Pro (an external HD doesn't hurt, even a USB one) you can capture 720 live.

I won a bet today setting it up which is really why I'm mentioning it now (it was -and I'm quoting here- "a free anything" at a nearby coffee house, btw which became a free French Press...'What's that?' the producer said pointing "You said 'a free anything.'").

The trick is to set the HVX to 720 24p (NOT 720 24pn) and set Final Cut to Non-Controllable Device and 720 24p.

Final Cut Server is teh dead?

Maybe. There are lots of rumors flying about but thinking about it wouldn't surprise me that much. It's complex, data hungry (meaning it works best when you have vast archives of stuff) and a little hard to get your head around. I know of only 4 places that actually use Final Cut Server (...not own it, or just installed it to test it out...but actually use it and rely on it daily).

My experience could be lacking though. It's hard to get reliable numbers on units sold et al.. but it's all just rumors anyway. I think Final Cut Server is pretty cool but its usefulness is limited to larger clients in my experience.