Sample Rate Mismatch?

Discussion in 'Digital Video' started by .:*Robot Boy*:., Dec 7, 2005.

  1. .:*Robot Boy*:. macrumors 6502

    Jan 21, 2005
    New Zealand
    So, I've just been given an editing project and I'm having some headaches.

    Basically, I've been given a mini DV tape by a guy who's cheap, no-name DV camera won't export DV (only stills and analogue video). I've borrowed a Canon DM-XM1 from a friend so that I can import the video into my PowerBook and edit it.

    The problem I'm having is that the audio (both the imported audio and the audio played back on the camera itself) is atrocious! It clicks and goes all static-y. Also, towards the end of the footage, the dialogue is out-of-sync. I've tried importing into both Quicktime 7 Pro and iMovie (I'm gunna have a go with FCP 4.5 next) and I'm having the same problem in both applications.

    I've watched it on the guy's crappy DV camera and it's fine, but playback on the Canon is terrible.

    From what I can tell, the audio was recorded onto the DV tape at 12-bit 32KHz... I think... Could it be that the Canon is trying to play back the audio at a higher sample rate?

    I'm totally confused here :confused:.
  2. WinterMute Moderator emeritus


    Jan 19, 2003
    London, England
    The Canon is probably trying to dither the missing bits, and not having a good time doing it.

    Try reseting the Canon's audio to 12-bit 32Khz and see if that rectifies the problems, otherwise connect the analog outputs from the crappy camera to the canon's inputs and convert to Firewire in the Canon.
  3. 2jaded2care macrumors 6502

    Jun 13, 2003
    I don't have the latest iMovie yet, but I don't think the version I have will accept 12 bit (32KHz) audio. If it would even let you try to capture it, it would sound like you describe since it's expecting 16 bit (48 KHz) audio.

    You'd have to do as Wintermute suggests and send the analog signal through the Canon (set for 16 bit audio) and out the FW to the Mac. I don't think setting the Canon for 12 bit will help unless iMovie HD now accepts that.

    Next time, tell the guy to save everyone some headaches and set his camcorder to record 16 bit audio. The 12 bit audio setting (and recording in LP instead of SP) always causes problems.

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