>Could someone explain exactly when and where the NTSC setup (Y'+16) >should be added?
The "+16" is not NTSC setup. It is simply footroom in the Y'CbCr encoding scheme for digital pixel data. NTSC setup is part of the spec for *analog* transmission. >This much I think I know: > >For NTSC DV, it is supposed to be added at the final analog output, >say at the camera when output to TV. To get the same effect when True --- and it's got nothing to do with DV. The North American NTSC analog black level is 7.5 IRE above the blanking level (which is 0 volts). >playing on the computer, it needs to be added digitally somewhere in >the chain, but preferably near the end. I've also read repeatedly False --- setup is not something you see in the digital domain; if the computer has an NTSC video output, the hardware will add it. If not, it won't, and doesn't need to. >that it should NOT be added before any processing, which makes sense >as it pushes Y up against the upper bound. Despite this, from >examining output and the code, it looks as about half the software out >there adds the setup. kino/smil2yuv (by default) and transcode do, >lav2yuv and ffmpeg don't (if I recall properly). Are you talking about the +16 offset/base-level in Y', or NTSC setup? Assuming the former, half the software out there is broken, and does not properly process Y'CbCr --- either by neglecting the +16, or by doing weird things with it. File bug reports. >What I don't know: > >When converting DV to mpeg2 (for DVD, say), does the setup get added >before conversion, after conversion, or never? Does the DVD player Never --- DV to MPEG-2 is digital-to-digital, and never had any "setup" to begin with. It always has, however, a black-level of Y'=16. >add the setup just like my DV camera would, or does mpeg2 expect to >have the setup built it? Yes, the DVD player hardware adds the setup if it is correctly configured for your TV. > yuvplay does not add the setup, but should >it (or should it be a flag)? Neither --- it simply hands the (assumed correct) Y'CbCr data over to the SDL library. *That* library needs to correctly convert it to R'G'B' for display --- and SDL probably still doesn't do that. >I'm starting to understand why everyone hates NTSC... Except the Japanese, I guess, since Japanese NTSC uses 0v setup (i.e. none). I believe there is a dipswitch on the Canopus DVC-100 for setup; if you are processing analog material from the US, you would want that set to "Yes, setup, please." It's a question of how the analog signal is interpreted; it's all the same once it is digital (thankfully). -matt m. ------------------------------------------------------- This sf.net email is sponsored by:ThinkGeek Welcome to geek heaven. http://thinkgeek.com/sf _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
