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kcb
7th February 2006, 06:13
Firstly, i use TMPEGEnc to encode to SVCD i have noticed in DGIndex under 'Colorimetry' i have ITU-R BT.470-2. When i examine other samples i've downloaded it says FCC. Which encoder produces FCC Colorimetry? and what exactly is Colorimetry? I've tried searching but it's irrelevant to what i'm after. thanks.
Shinigami-Sama
7th February 2006, 06:46
these downloads you speak of are trailers and other such of like no?

and colorimerty to best of my understanding is the type of colours it uses, like RBG YUV and such
mpucoder
7th February 2006, 07:51
YUV and RGB are color spaces. Colorimetry defines the primary colors, transfer characteristics, and, for YUV, the matrix coefficients. Several standards of colorimetry are supported by mpeg, including ITU-R BT.709, ITU-R BT.470-2 system M (aka FCC, as this defines NTSC colorimetry), ITU-R BT.470-2 system B and G (PAL), SMPTE 170M, and SMPTE 240M (1987). Different standards can be used to define color primaries, transfer characteristics, and matrix coefficients. Which standards are used for each is defined in the colour_description field of the sequence display extension header.
kcb
7th February 2006, 08:04
Hmm i see. Am i right in saying that TMPEGEnc uses YUV ? Hence TU-R BT.470-2, to change it to FCC i would have to run an avisynth script which converts it to RGB therefore giving me a value of FCC?
Wilbert
7th February 2006, 10:51
Hence TU-R BT.470-2, to change it to FCC i would have to run an avisynth script which converts it to RGB therefore giving me a value of FCC?
That's not possible at the moment. Besides the difference between 'ITU-R BT.470-2 system M (aka FCC, as this defines NTSC colorimetry)' and 'ITU-R BT.470-2 system B and G (PAL)' is small and not noticable.

Am i right in saying that TMPEGEnc uses YUV ?
mpeg-2 is always YUV.

For clarity, the matrix coefficients (fcc, BT.470-2, etc ...) are the coefficients in the RGB<->YUV conversion. The player should use these coefficients when displaying (and hence converting it to RGB) it.
mpucoder
7th February 2006, 15:30
The chief difference between PAL and NTSC colorimetry is the assumed gamma of the display. For NTSC this is 2.2, for PAL/SECAM it is 2.8