HDV/1920 x 1080/ 1440 x 1080 / NLE Question

Discussion in 'Amateur Video Production' started by Jeff, Aug 5, 2007.

  1. Jeff

    Jeff Guest

    Question for the experts,

    Since the HDV spec is 1440 x 1080 once HDV is recorded onto tape, What at
    advantage does the canon hv20 or the new JVC 3 chipper have by claiming FULL
    HD?

    If its 1440 x 1080 once it's on tape then it cant be captured by a NLE such
    as premiere cs3 or vegas 7 as anything else.

    So what is the advantage of 1920 x 1080?

    I read that 1920 x 1080 can be obtained only if you are bypassing the signal
    recorded onto tape and going staight from the ccd to capture.

    Tahnks,

    Jeff
     
    Jeff, Aug 5, 2007
    #1
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  2. Jeff

    Mike Kujbida Guest


    Contrary to popular belief, HDV is "FULL HD".
    It's got a pixel aspect ratio of 1.33 which, when multiplied by 1440,
    comes out to 1920.
    I don't know about Premiere but Vegas (esp. Vegas 7) handles the HDV
    format very easily.

    Mike
     
    Mike Kujbida, Aug 5, 2007
    #2
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  3. Jeff

    nappy Guest




    Hmmm.. It has an appropriate aspect ratio but as far as I am concerned the
    only thing that is full HD is 1920x1080.

    Anything else is..

    HDV , DVCAMPRO HD, etc..
     
    nappy, Aug 5, 2007
    #3
  4. Jeff

    Frank Guest

    Are you sure that you're in the right group? :)
    Just for clarification, you're referring to the HDV 1080i spec, which
    records non-square pixels to tape, with a recorded frame size of 1440
    by 1080. The HDV 720p spec records square pixels to tape, with a frame
    size of 1280 by 720. 720p HDV records the full raster. 1080i HDV
    doesn't.
    Not familiar with the "JVC 3 chipper". Have a model number? Unless
    they've announced something of which I'm not aware, all of the JVC HDV
    camcorders are 720p, and all of them have full 1280 by 720 sensors and
    record full 1280 by 720 frames to tape.

    The Canon HV20 still records 1440 by 1080 frames to tape, not 1920 by
    1080 frames. Having sensors with 1920 pixels (probably more correctly
    called photo sites) per scan line gives the DSP (digital signal
    processor) more data to work with. The advantage is that with more
    "source pixels", potentially a better looking image will be produced.

    The Sony HVR-Z1 series camcorders, for example, have image sensors
    with but 960 active pixels per scan line, so there's a lot of
    interpolation going on. The Sony HVR-V1 series also lacks full raster
    sensors, but the photo sites are placed on a diagonal. A wise man once
    said that there are many ways to skin a cat - or capture video, it
    seems.

    Panasonic recently announced two new camcorders, both of which are
    3-CCD 1080i AVCHD-format products. Although both models can record
    full frame 1920 by 1080 video, as I understand it, the image sensors
    have but 520,000 effective pixels. That's about 25 percent as many
    pixels as are needed to capture a 1920 by 1080 frame, so I can only
    assume that there's a *whole* lot of interpolation going on.

    To further muddy the waters, Hitachi recently announced two new
    camcorders that record MPEG-4 Part 10 H.264 AVC video to 7.8 GB 8 cm
    Mini-BD (Blu-ray Disc) media. Both models, as I understand it, have
    5.3 million pixels on their (single CMOS) image sensors, more than
    enough for 1080i video (which has 2,073,600 pixels per frame),
    although both models use EIS (electronic image stabilization) and not
    OIS (optical image stabilization), so those extra pixels are needed.
    In the highest quality recording mode, these camcorders record full
    raster 1920 by 1080 frames. In the lower quality mode, anamorphically
    squeezed 1440 by 1080 frames are recorded (just as in 1080i HDV), thus
    lowering the datarate and increasing the recording time.
    In a straight FireWire transfer operation, yes, that's true, but on
    models with an HDMI output, you get a 1920 by 1080 signal over the
    HDMI link. Also, on a fast machine, you could ingest via FireWire and
    save non-compressed, full raster video to disk if you wished,
    expanding each frame to 1920 pixels in width in the process. Then,
    after the transfer is complete, you can edit the full-raster,
    uncompressed frames.
    Everything else being equal, more pixels equals a better looking
    image.
    Well, it's not literally "straight from the CCD", but HDMI will
    essentially give you that.
     
    Frank, Aug 6, 2007
    #4
  5. Jeff

    Jeff Guest

    Frank: you said:

    In a straight FireWire transfer operation, yes, that's true, but on
    models with an HDMI output, you get a 1920 by 1080 signal over the
    HDMI link. Also, on a fast machine, you could ingest via FireWire and
    save non-compressed, full raster video to disk if you wished,
    expanding each frame to 1920 pixels in width in the process. Then,
    after the transfer is complete, you can edit the full-raster,
    uncompressed frames.


    Just to clarify, 1920 x 1080 via HDMI, but not though Tape, ONLy direct from
    the sensor or such.

    I mean 1920 x 1080 cant be recorded onto tape in the HDV standard, right?

    Thanks al ot

    jeff
     
    Jeff, Aug 6, 2007
    #5
  6. Jeff

    Frank Guest

    That's correct. The HDV specification calls for the recording of 1440
    by 1080 frames to tape. I hesitate to call it a "standard", by the
    way, since having never been submitted to any standards body for
    approval, it's really more of just a specification. AVCHD even more
    so. It's just a couple of press releases.

    Of course, there are various external HDD (hard disk drive)
    attachments available for use with HDV (and other) camcorders from
    companies such as Focus Enhancements and Shining Technologies, just to
    name two, but they record the 1440 by 1080 signal produced by the
    camcorder's FireWire port.

    Don't feel bad about the recorded frame size being just 1440 pixels
    wide. That's the way it's been with HDCAM for years now. And that's
    why I had mentioned those Panasonic and Hitachi camcorders in my
    earlier reply. It doesn't mean all that much when they both record
    1920 by 1080 frames and one of them has sensors that capture so few
    pixels to start with. There are marketing issues at work here, too,
    you know.

    Technical specifications of one camcorder versus another camcorder or
    one format versus another format aside, the ultimate test is always
    going to be how well any individual product meets its user's needs
    (including the economic issues) and how well the user understands how
    to get the most out of the product that they're using. And that
    includes just how well the footage is handled throughout the entire
    post production workflow.
    You're very welcome, and hope that this answers your question.
     
    Frank, Aug 6, 2007
    #6
  7. Jeff

    Jeff Guest

    Just a follow-up question, I know through Frank here and others that tape is
    limiited to 1440 x 1080.

    Is the hard disk drive format limited to 1440x 1080 too or can that record
    1920 x 1080 ? (JVC
    GZ-HD7)

    Jeff
     
    Jeff, Aug 9, 2007
    #7
  8. Jeff

    Frank Guest

    1080i HDV is always stored with a frame size of 1440 by 1080,
    regardless of the type of recording media being employed. If it's not
    1440 by 1080, then it's not HDV.

    For a given datastream to be considered 1080i HDV, other criteria must
    be met as well. For example, the data must be encoded in CBR (constant
    bit rate) mode.
    The JVC GZ-HD7 offers multiple, user-selectable recording modes. In
    its highest-quality mode, it can record full 1920 by 1080 interlaced
    frames using long-GOP MPEG-2 video compression in an MPEG-2 TS
    (Transport Stream) wrapper at a VBR (variable bit rate) datarate of 30
    Mbps (26 Mbps average). Audio in this mode is lossy compressed MPEG-1
    Layer II. Five hour's worth of content can be stored to its internal
    60 GB HDD (hard disk drive) when utilizing this particular recording
    mode. This recording mode is not HDV-compatible (the frame size is too
    large (size matters!), the datarate is too high, and it's VBR-encoded
    instead of CBR-encoded, just to name three reasons).
     
    Frank, Aug 9, 2007
    #8
  9. Jeff

    Jeff Guest

    Frank,

    Can Premier CS3 or Vegas edit 1920 x 1080?

    Lastly, is 1920 x 1080 for all intents and purposes considered HD since its
    not HDV?

    jeff
     
    Jeff, Aug 9, 2007
    #9
  10. Jeff

    Frank Guest

    If you're considering the JVC GZ-HD7, I would respectfully suggest
    that you check with some GZ-HD7 owners to find out what they edit
    with.

    There are some MPEG-specific editors out there such as TMPGEnc MPEG
    Editor, VideoReDo Plus, and Womble that might be better suited to the
    job than the typical mainstream video editing application.
    Certainly. HDV is just one of several HD formats. Some others are
    DVCPRO HD, HDCAM, HDCAM SR, XDCAM HD, XDCAM EX, and AVCHD.
     
    Frank, Aug 9, 2007
    #10
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