MX02 & Prores LT anomalies...
by peter tooke
on
Oct 24, 2009 at 9:30:59 pm
Hi,
Sorry, but a long post-
I have spent the day capturing and recapturing an 8 minute clip trying to sort out some irregularities before I commit to capturing the remaining 10 hours of tape. Here is my setup:
Macbook Pro 2.53 Ghz Intel Core 2 Duo with express slot, 4 gigs RAM
OSX 10.6.1, FInal Cut Pro 7.0
MX02 installed with latest software/drivers.
Convergent Design HD-Connect MI with HDMI in, SDI out, RS422 (to MX02), fw (from camera).
Caldigit VR 3TB raid as media drive via FW 800.
This was all set up to bring in (via SDI) HDV 1080i material client shot on Sony HCR9... because of GOP weirdness and TC breaks when trying to ingest via firewire. Which kept giving me huge gaps in the timeline. So, read Shanes recent post about this common problem and SDI it is. Now out of the camera's HDMI, into the CD MI box and then SDI out of there into the MXO2's SDI in...
But sometimes the captures freezes / hiccups for a second here and there when bringing it in via the ProRes LT easy set up. Try & capture the same clip again, and it doesn't. Then again and it does. At similar spots which play fine on the camera tape... But I am able to bring the entire clip in as one piece, something I was not able top do before. So the SDI workflow certainly works here.
Now I notice something that may or may not be important: In the the log & capture window, while capturing to the ProRes LT codec, the video preview window does not play smoothly. I mention this because I also have captured the exact same clip but trying instead via DVCProHD 1080i / 59.94 setup- and the video preview in the capture window runs smooth as could be. And after trying two passes, not a hiccup in the capture either. It just seems less taxing on the system... given the preview window clue.
So finally my question: Even though Matrox has added ProRes LT 1080i capture to intel Macbook pros to their approved scenarios... and even though the DVCPro codec takes more bandwidth than ProRes LT, is my system still somehow not up to ProRes LT? I read about Shane getting regular ProRes 422 fine on his 2.4ghz macbook, so looking for suggestions / solutions.
Is there something I can do to make what I have run better?
Or ( as I run out of time ) is bringing in everything as DVCPro HD ( 8 bit that it is) not so different from Prores LT? For the record, I have inspected the same clip as both Prores LT and DVCProHD at 200% and toss a coin on which is better, at least to my eyes.
I had wanted to go the ProRes route because of other material to be integrated ( Canon5D MKII h.264 which I received a drive full of ) and seems about everyone on these forums recommends that.
Also, one more thing of interest. In the MX02 easy setups, when capturing prores LT the device control defaults to Sony r2-422 29.97, and DVCPro HD easy set up it defaults to Pansonic RS-422 29.97.
The Prores 422 LT capture was exactly 2 seconds off of camera TC, such as it is, while the DVCPro HD capture on the money. So, I changed the Prores device control to Panasonic, and at least the TC matches.
Thanks a lot.
Peter
Re: MX02 & Prores LT anomalies... by Andy Mees on Oct 25, 2009 at 1:08:43 am
So finally my question: Even though Matrox has added ProRes LT 1080i capture to intel Macbook pros to their approved scenarios... and even though the DVCPro codec takes more bandwidth than ProRes LT, is my system still somehow not up to ProRes LT?
Well, although the data rate of ProRes LT and DVCPRO HD are roughly equal, the compression algorithm applied for ProRes is far more complex, so it is likely not an issue of bandwidth so much as an issue of raw computing. Your system ought to be up to the task of realtime compression to ProRes LT but something is obviously giving it conniptions ... what other apps/processes do you have running? Is Mail being checked in the background? Anti-virus software? You might want to open up /Utilities/Activity Monitor and then monitor that during ProRes LT capture to see if there is anything obvious happening when you get these glitches.
Or ( as I run out of time ) is bringing in everything as DVCPro HD ( 8 bit that it is) not so different from Prores LT?
Annoying if you had your heart set on ProRes LT, but DVCPRO HD is an excellent and reliable option for laptop capture, and as noted, is much less taxing on the system.
For the record, I have inspected the same clip as both Prores LT and DVCProHD at 200% and toss a coin on which is better, at least to my eyes.
There you go.
I had wanted to go the ProRes route because of other material to be integrated ( Canon5D MKII h.264 which I received a drive full of ) and seems about everyone on these forums recommends that.
That's because its flavour of the month. All those currently flying the "ProRes as Intermediate" flag seemed perfectly happy flying the "DVCPRO HD as Intermediate" flag before ProRes was introduced. I'm not suggesting that DVCPRO HD is better at all, ProRes does indeed offer a more modern codec with full raster higher quality compression at a higher bit depth ... but that does invalidate working in DVCPRO HD as an intermediate, as countless hours of broadcast HD can attest.
Also, one more thing of interest. In the MX02 easy setups, when capturing prores LT the device control defaults to Sony r2-422 29.97, and DVCPro HD easy set up it defaults to Pansonic RS-422 29.97.
The Prores 422 LT capture was exactly 2 seconds off of camera TC, such as it is, while the DVCPro HD capture on the money. So, I changed the Prores device control to Panasonic, and at least the TC matches.
That is weird! How about if you skio the CD MI altogether and go HDMI into MXO2 with FW from camera direct to your MBP for deck control?
Re: MX02 & Prores LT anomalies... by peter tooke on Oct 25, 2009 at 2:01:25 pm
Hi Andy-
Thanks so much for taking up the post and replying.
1) I did use activity monitor and watched as I captured yet once again the same 8 minute clip. No other apps open except it, FCP and Loader ( a Digital Heaven FCP utility). CPU usage remained around 150% for FCP application, 10% or so for system.... but a relatively constant 20% unused. And once again, capturing via the aforementioned Prores LT setup, i got a hiccup at the same spot. Exactly - frame to frame. Now clearly there is a little 'something' on the tape that sends the Prores LT capture ON MY SYSTEM ( or so I guess) into a stupor about 1 out of two tries: not seen on tape, not yet experienced via DVCPRO HD capture, no jumps on the activity monitor to give a clue.
2) To test re the TC weirdness, i took your suggestion to bypass the CD MI altogether and instead capture via a) HDMI out of the camera into the MXO2 and b) firewire from camera directly into laptop ( actually from back of Caldigit VR ).
But I was not allowed to have both FW HDV deck control AND Prores LT capture at the same time: you get this notice, "To capture HDV source material. both the Capture and Device Control presets must be configured for HDV; otherwise, to capture in another format, both must no be configured for HDV".
OK.
So for kicks I captured as HDV material via HDMI, via HDV FW control. But now the capture breaks at a tape glitch ( this one seen on tape ), and when starting / capturing again afterwards, lose a large gap of the scene: exactly why I began all this MX02 SDI workflow to avoid... & which I could have done quite nicely via FW out, FW in. Plus I now have HDV material...
Interestingly, the place where the ProRes LT hiccup occurred above was not a bother for the HDV capture this way.
Also - the TC information is exactly 1 frame offset from the Pan RS-422 device control protocol. Which is the correct one? hard to tell given the control on the camera.
So, looks like a DVCPro HD workflow. I just bought the MXO2 & CD MI precisely to help this workflow, and I guess at least good for giving me entire tapes ( without break up / gaps...).
Is there any reason to believe that things would be different if I was capturing from a VTR, like the HVR15 or HVR 25? Neither have SDI, nor rs-422 control, but they do have HDMI out and my CD M I box can handle that.
Re: MX02 & Prores LT anomalies... by Andy Mees on Oct 25, 2009 at 2:42:25 pm
1) I did use activity monitor ... i got a hiccup at the same spot ... no jumps on the activity monitor to give a clue.
Drat ... but that does at least point to something from the source that may be causing the glitch, tho why only with ProRes LT remains a mystery.
2) To test re the TC weirdness, i took your suggestion to bypass the CD MI altogether ... was not allowed to have both FW HDV deck control AND Prores LT capture at the same time
Doh!, forgot about that ... you need to set the camera/deck for iLink downconversion, which forces the output over firewire to be normal DV. Then you set your Device Control preset to Firewire.
Re: MX02 & Prores LT anomalies... by Timothy Payton on Nov 4, 2009 at 5:19:19 pm
I was excited about using DVCPRO HD instead of ProRes LT, so i did a quick comparison test shown at 200% (click for a full sized image)
Of course saturated colors, especially red, which awful on HDV are actually smoothed out in DVCPRO HD (check out the brakelights), but luminance detail is much better in ProRes LT (The Important Sticker). Both were 1440x1080.
