Quote:
Originally Posted by sanlyn
Your capture is 720x480 frame sized, losslessly compressed with huffYUV in a YUY2 colorspace. ... However, on the way to Virtualdub your video was apparently lossy encoded to YV12 MPEG by the capture device. You have lossless media in the AVI, but you have a quality loss concerning the earlier stage of MPEG encoding.
...
You would have had the same capture if you had allowed the ASUS capture card to store the lossy MPEG recording into your computer as MPG files, then opened the MPEG recordings in Avisynth or Virtualdub and filtered and saved them as lossless YV12 for intermediate working files. That sounds like a roundabout way of doing it and isn't a lossless process -- unless there is some way you allowed VirtualDub to hook into that ASUS card's capture drivers before the unit encoded to lossy MPEG, which I doubt VirtualDub could do. |
Most "MPEG hardware encoder" cards that VirtualDub can access do provide true uncompressed 4:2:2 via the DirectShow driver, as a bonus of their desire to offer a fast, "lag-free" preview of the incoming video.
Without a sample on hand to verify one way or the other, it shouldn't be assumed that this ASUS card compresses and then decompresses its DirectShow 4:2:2 offering.
One oddity is the Hauppauge WinTV-PVR-150, where the stream available to VDub uses a proprietary 4:2:0 pixel format with a unique FOURCC -- but not compressed to MPEG. I may have a Japanese card that operates as you describe; I can't recall anymore.
