Using QT Pro as a capture device?

Discussion in 'Digital Video' started by Kingsly, Mar 12, 2006.

  1. Kingsly macrumors 68040

    Kingsly

    #1
    Will QT Pro record the same resolution as my camera? I'm pretty sure the answer is "yes" but I want to make sure before I start using it as a capture device.
    My idea is to use my MBP as a direct to HDD capture device, eliminating that evil thing I like to call DV tape (and capturing, ick!).
    I would have my XL-1 plugged into my MBP via FireWire and have either a USB 2.0 (fast enough?) or another Firewire HDD (via the Express/32 slot? Daisy chained with the XL?) and use QT pro to record. Also, It will double as a monitor.
    Will that work?
     
  2. LethalWolfe macrumors G3

    LethalWolfe

    Joined:
    Jan 11, 2002
    Location:
    Los Angeles
    #2
    AFAIK no it will not. I just looked at QT pro and the recording res is only 240*180 compressed to MPEG-2 or H.264. Why not use iMovie or Final Cut (if you have it) to capture directly? Also, I don't know how well the FW daisy chain will work (USB 2.0 is no good). Some devices play nice daisy chained others do not. So you'll just have to experiment and see if your devices will play nice or not.


    Lethal
     
  3. Kingsly thread starter macrumors 68040

    Kingsly

    #3
    Oh yeah, I just realized that I can use FCP to capture live! Thanks.
    I'll try daisy chaining the HDD to the XL-1. Out of curiosity, why wont USB 2.0 work? Isn't it faster than FW?
     
  4. LethalWolfe macrumors G3

    LethalWolfe

    Joined:
    Jan 11, 2002
    Location:
    Los Angeles
    #4
    In actual use USB 2.0 is slower than FW400, even though it's faster on paper.


    Lethal
     
  5. Kingsly thread starter macrumors 68040

    Kingsly

    #5
    Darn. Do you know of a good, inexpensive, FW400 Express/32 card?
     
  6. Anonymous Freak macrumors 601

    Anonymous Freak

    Joined:
    Dec 12, 2002
    Location:
    Cascadia
    #6
    Odd, QTPro will record at 'device native' if I so desire... (DVcam or iSight.) The iSight in the MacBook Pro apparently has a native format of YUV422, 640x480, 15fps, 75.54 mbits/sec. And, of course, DV (when directly imported) is 640x480, 29.97fps, 29.80 mbits/sec.

    Especially if you want to edit later, it's best to record in 'device native'. (It should be a third choice in QTP preferences, along with the mentioned MPEG-4 and H.264.

    Although, as mentioned, FC or iMovie are better capture mediums.

    I can record directly to a USB 2.0-connected laptop drive (4200 RPM, even,) with no frame loss. I usually capture to a FW daisy-chained system, to one of two 7200 RPM 80 GB hard drives that are daisy chained to each other, and with the camera!
     
  7. Kingsly thread starter macrumors 68040

    Kingsly

    #7
    Good. It sounds like I can daisy chain the camera through the HDD with no dropped frames. Thanks!
     
  8. LethalWolfe macrumors G3

    LethalWolfe

    Joined:
    Jan 11, 2002
    Location:
    Los Angeles
    #8
    How I overlooked the "native capture" option I have no idea.


    I'm glad your setup works for you (and hopefully the OPs will work for him). From personal experience and reading other's experiences on video forums I know that the performance of FW daisy chains and USB 2.0 can be questionable which is why I don't recommend them w/o caveat.


    Lethal
     
  9. RedTomato macrumors 68040

    RedTomato

    Joined:
    Mar 4, 2005
    Location:
    .. London ..
    #9
    USB's high quoted speeds are only for maximum BURST speed, i.e. can't be relied on continously.

    FW is IIRC a bus to bus device meaning it has gauranteed and continous bandwith on that firewire channel.

    FW400 is about 30 to 40 MB/sec so DV's 3.5 MB per second will fit comfortably. Daisychaining your camera so it's on the same channel is 7MB/sec on the channel which should be OK.

    For HD, I think it's somewhere around 30-50MB/sec which fills up a single FW400 channel, so to record to external disc, yes you would need a second channel. I think that's where you got your PCMICA card idea from, but it's not needed for plain miniDV.

    I record from my DV camera to my Powerbook all the time, capturing to the PB HD in iMovie, and it automatically seperates and logs the clips for me, no problem and no dropped frames.

    I was dreaming about buying the Panasonic AG-HVX200 - that seems to output 100Mps at full quality 60fps 1080p HD, and some people are saying it's too much for firewire. The situation doesn't seem very clear on that score at the moment.

    For pretty much any other camera on the market, Firewire will do fine for simultanously recording and capturing to HD on the same channel.

    .. RedTomato ..
     
  10. Kingsly thread starter macrumors 68040

    Kingsly

    #10
    Thanks for that breakdown of FW and USB. Now I understand and that answers my questions. Thanks once again.
     
  11. GanChan macrumors 6502

    Joined:
    Jun 21, 2005
    #11
    Don't you have to have the XL1 in either Record or Pause mode to send signal? That would mean that it will "fall alseep" in Pause mode after about 5 minutes, so you'd pretty much have to be rolling tape to keep the output going to your laptop. Which would kind of defeat the "going tapeless" thing. Right?
     
  12. Anonymous Freak macrumors 601

    Anonymous Freak

    Joined:
    Dec 12, 2002
    Location:
    Cascadia
    #12
    If you want to do it that way, record to the tape, too. It's a good automatic-backup, if nothing else. (And if you really don't want to mess with tapes, then just record over it.)
     
  13. Kingsly thread starter macrumors 68040

    Kingsly

    #13
    Thats my plan. ;)
    And no, the XL does not have to be recording to send a FW signal. I have used it as a [rather large] iSight.
     
  14. GanChan macrumors 6502

    Joined:
    Jun 21, 2005
    #14
    So it doesn't fall asleep on you without a tape rolling in it? The FW stays on?

    My reason for wanting to go straight to a laptop would be to avoid downtime for tape changes....I'll have to run some experiments....
     
  15. Anonymous Freak macrumors 601

    Anonymous Freak

    Joined:
    Dec 12, 2002
    Location:
    Cascadia
    #15
    I can't say for certain on the XL, but my Sony camcorder, with power plugged in, will go to sleep in 10 minutes if I leave it in video standby mode (but it will send the signal through FireWire,) but it won't even go to sleep if I put it in still photo mode. (Plus it sends a slightly better image through FireWire in still photo mode.) On battery, it goes into sleep in 10 minutes of inactivity regardless of mode.
     
  16. GanChan macrumors 6502

    Joined:
    Jun 21, 2005
    #16
    It works. I can go FW direct to computer by leaving the tape transport door open.

    The weird thing is, Final Cut Pro and Quicktime Pro both allow me to close the inner tape compartment while leaving the outer door hanging open, but iMovie just gives me a blue "no tape" screen unless I actually put a tape in. And if I do that, the XL1 goes into its regular Standby routine and falls asleep....:rolleyes:

    Still, Quicktime Pro recognizes the Canon DV and lets me import at native quality. I can then convert it from .mov to .dv and drag it right into FCP. (FCP doesn't like the .mov for some reason -- maybe because it's 640x480).
     

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