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Request Video Editing Advice?
Based on responses by Creative Cow experts to an earlier post (’30p vs. 60i – And Other Questions’), I have bought a Sony VIXIA HV30 video camera and recorded in 30p, which yields 1440×1080 output when recording on tape – narrower than 1920 but just fine since my subject (two people side by side) will fit. In fact, 1440/1080 is a 4/3 ratio, and one of the outputs I’m aiming for is 4/3 (320×240) since one my purposes is lots of compact files of individual signed sentences for quick viewing on the web. The other purpose is careful detailed analysis of facial expressions (it’s deaf people communicating in sign language), which is why I need high definition. The latter output, of course, would not be intended for the web.
Questions:
1. The VIXIA HV30 manual describes the setting I employed as “High-definition video at 1080i specifications with a progressive frame rate of 30fps.” Is this a mistake? If it’s progressive, shouldn’t they call it 1080p instead of 1080i? What did I really record in?
2. Loaded to Vegas Video Pro 9.0, the Properties of the resulting .m2t (mpeg2) designate it as 1440x1080x12. What does the ’12’ at the end mean?
3. The Properties also say the file is ‘upper field first’. Does this indeed mean that it is not progressive after all, despite what the manual claimed?
Turning to the Project Properties:
4. If I try to match the pixel count of my video file by loading it to an “HDV 1080-60i (1440x1080x32, 29.97fps)” project, I’m not letterboxed, but everything is squished sideways. The pixel aspect ratio is 1.333 (i.e. 4/3), which matches the video file, so why is it squished sideways?
(Also, loaded that way, it’s “upper field first”, which again suggests that it’s not progressive, as indeed the designation 60i would suggest.)
5. What does the ’32’ at the end of 1440x1080x32 mean?
6. Loaded to an “HDV 720-30p (1280x720x32, 29.97fps)”, it’s not letterboxed, the proportions all look right, and the Properties dialog box now says it’s progressive. But have I lost resolution or clarity by going to 1280x720x32??
(Hmmmm… I suspect that 720 being half of 1440 has something to do with the answer, but I’m hoping you can enlighten me as to the details.)
7. And which project format will be easier to build my compact video files from?
I know that’s a lot of questions. Thanks very much for your help.
Peyton
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1 Reply
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First paragraph – Actually, that’s a Canon, not a Sony. (I’m sure that’s a typo).
I’m not an expert on the progressive numbers, but you’re assumption that 1440×1080 is 4×3 assumes square pixels. The Canon H series are all wide-screen camcorders, so those pixels are 0.75:1, not square, and what you recorded is actually 16×9.
I’m guessing the last number (the 32 in 1440x1080x32) would be the number of bits per pixel (to record the color information). I could be wrong.
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