Bit depth of VHS video, capture cards?

dima · #1 08-01-2019, 04:56 AM

How many bits (in terms of color) (bit depth) has video material captured by VirtualDub and ATI AIW USB (AVI; YUV - YUY2 4: 2: 2) [PAL, 720 x 576] through the HuffYUV codec ?
8, 10, 12 or maybe still different ?

lordsmurf · #2 08-01-2019, 05:08 AM

Most cards capture 8.
Some can do 10 or 10 or more, but it's really pointless.

VHS is equivalent to about 6-bit dithered.

dima · #3 08-01-2019, 05:22 AM

And how much does ATI AIW USB capture ?
12 ?

Even if it is 12, it is over-measure and does not add anything for the quality of captured material from the VHS cassette ?

lordsmurf · #4 08-01-2019, 05:35 AM

Theatre chips (ATI AIW) are 8-bit.

dima · #5 08-01-2019, 05:54 AM

Thank you for reply.

dima · #6 08-01-2019, 06:17 AM

For example: I have an AVI file (HuffYUV; YUV - YUY2 4:2:2) captured by VirtualDub and ATI AIW USB.
By opening this file for editing in VirtualDub and wanting to save it in Video - Color Depth and in Decompression format I choose: 4:2:2 YCbCr (YUY2) and the same format in: Output format to compressor / display also I should choose that do not lose anything of the color quality (no conversion) ?

When loading a file into VirtualDub, this program does not convert a given file into some of its color format, it just reads the data from the AVI file ? That means: at no stage if we do not choose this manually: VirtualDub will not convert the colors to the source material(to(or for) different than source "colors") ?

sanlyn · #7 08-01-2019, 06:34 AM

Quote:

Originally Posted by dima

For example: I have an AVI file (HuffYUV; YUV - YUY2 4:2:2) captured by VirtualDub and ATI AIW USB.
By opening this file for editing in VirtualDub and wanting to save it in Video - Color Depth and in Decompression format I choose: 4:2:2 YCbCr (YUY2) and the same format in: Output format to compressor / display also I should choose that do not lose anything of the color quality (no conversion) ?

When loading a file into VirtualDub, this program does not convert a given file into some of its color format, it just reads the data from the AVI file ? That means: at no stage if we do not choose this manually: VirtualDub will not convert the colors to the source material(to(or for) different than source "colors") ?

By default, VirtuaLDub acts like most editors: it converts input to uncompressed RGB24 for display. Also by default, it outputs uncompressed RGB24 unless you specify otherwise. If you are working in YUY2 or YV12, etc., and want to save your output to one of those color spaces, you must set color depth and compressor to avoid an unwanted RGB conversion on output, and set the processing mode to "Video..." -> "fast recompress".

If you are applying VirtualDub filters to the output, set the processing mode to "Video.." -> "full processing mode", then set your output color depth and compressor as desired.

Almost all other editors work in the same way.