Questions about Field/Frame based capture

[Phire]

Ok I've got a few questions, some of them may be confusing, but hey .

1. Is there such a card where it captures 704x480 WITHOUT having 2 fields?

2. Do DVDs originally have 2 fields?

3. 640x480 RGB capture is not field based, correct?

4. Is HuffyYUV field based also? and can HuffyYUV reach up to 704x480 or is 640x480 the max? (On a G400)

5. What do professionals use to make VCDs? I don't think they capture and resize? And if they did, wouldn't the VCD have ghosting effects becuase of no deinterlacing? even with Smart Deinterlace filter used, there is still a difference seen. I'm guessing they somehow capture in RGB off some sort of film source?

6. Is field-based capture something the card does or is it based on the codec?

[Dr Mordrid]

1. Not unless you film using a DV cam that is using a progressive scan CCD. Then you can import the non-interlaced frames and use them as an image sequence in your editor.

2. DVD's do use field based video.

3. Wrong. 640x480 is field based. It just omits a portion of the overscan area normally found in 704 or 720 wide D1 video.

4. HuffYUV encodes whatever the video input device feeds it. If this is interlaced video then so be it. As for its max resolution, that depends on what you feed it.

On the Marvel the max res of RGB is 640x480 so that is what HuffYUV will encode. If you use YUY2 its max rez is 704x480 and so that is what HuffYUV encodes with it.

HuffYUV doesn't really care. It just blindly encodes what you feed it.

5. Capturing RGB encoded with HuffYUV makes no sense whatsoever since the Marvel, and most other analog cards, use YUY2 natively (or some other YUV variant) and encode that on the fly to obtain their RGB signal. Therefore, doing a double conversion of YUY2->RGB->HuffYUV is nonsensical when you can do a straight YUY2->HuffYUV conversion with half the CPU loading.

6. It's both part of the NTSC and PAL video standards and a feature of the card to the extent that the card determines which field order is used: fieldA or fieldB. Some cards use fieldA, some fieldB. It doesn't matter which as long as you set your editor up to use what your card provides.

Dr. Mordrid


[This message has been edited by Dr Mordrid (edited 24 November 2000).]