• What is HDV?
  The HDV specification embraces two types of high definition recording, 720p at a video bit rate of 19Mbps, and 1080i at a rate of 25Mbps. A 1080/60i HDV signal (1440 x 1080) is made up of 1080 lines of vertical resolution (number of lines from the top of the screen to the bottom), each line containing 1440 pixels of horizontal resolution, displayed at a rate of 60 interlaced fields, or 30 frames, per second. Standard definition DV records a 480/60i signal (720 x 480) in NTSC countries, which includes the U.S. These resolutions render the HDV uncompressed video bit rate at roughly 4.5x that of consumer DV. In order to reduce the uncompressed video bit rate to DV’s compressed 25Mbps, HDV adopts the same powerful MPEG-2 compression format that is used for digital broadcasts and DVDs. MPEG-2 for HDV combines intra-frame (intra = within frames) compression, used in DV recording with, the more efficient, inter-frame (inter = between frames) compression. Inter-frame compression organizes frames into groups of pictures (GOPs) or frames, where one GOP is equivalent to about 15 frames, or a half-second of video. Each GOP begins with one intra-frame (I-frame) containing a complete frame of video, similar to a frame of DV video, followed by predictive and bi-directional frames which encode only the changes in the incoming video relative to the complete I-frame. By exploring redundancies within each frame, in addition to between frames, the MPEG codec is capable of compression ratios in excess of 20:1, compared to only 5:1 for DV. This means that less than 5% of the uncompressed HDV video signal is actually recorded to tape, compared to 20% with DV. It also means that the impact of missing data with HDV is much greater than with DV. The video bit rates may be similar, but the importance of each recorded bit is not. The interdependency of all the frames in the GOP, to successfully reconstruct the GOP in its entirety, puts greater demands on the tape to maintain bit-for-bit signal integrity during playback. Errors and dropouts can not only compromise the reconstruction of a single frame, but can affect the decoding of the for HDV? Why entire GOP, causing blocks, freeze frames or audio dropouts to occur. HDV needs a high performance tape.
• What is the difference between the Sony and JVC HDV cameras?
• Do I need a new computer to edit HDV?
• How fast does the processor need to be to edit HDV?
• What is an intermediary codec?
• Why don't I want to edit the transport streams?
• What does the intermediary codec do to the transport stream?
• Does the intermediary codec come free with my camera or NLE?
• What is a transport stream? (A ts file?)
• Is the Audio format of HDV any good?
• How do I capture HDV?
• I heard that HDV has .5 second dropouts. Is this true?
• Do I need a new monitor to preview HDV files?
• How does the camera connect to my computer?
• Isn't HDV just too huge a data rate/stream to edit with?
• How do I deliver HDV files to a broadcaster or client?
• I'm confused by HDV and it's colorspace. I'm told it's different than SD. Is this true?
• Can Vegas/Final Cut Pro/Premiere/AVID control my HDV camcorder?
• In Vegas, my HDV images look squeezed. Why?
• In Vegas, I'm not getting 29.97 or 25 fps playback with Cineform intermediary files. Why?
• Is HDV interlaced the same way as DV? Is it upper or lower field first?
• I heard that HDV has bad motion artifacts. What's the scoop?
• Can I edit HDV in real time?
• .:Does the intermediary codec comes free with my camera or NLE?
• What is "Super-HAD?" Sony makes a big deal about it in their advertising.
• When I capture my HDV, its properties are 1440 x 1080 (from the Sony cameras) How come it's not 1920 x 1080; isn't that supposed to be the display size of 1080 HD?

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