[theora-dev] further debugging of my ogg/theora decoder

Ralph Giles giles at xiph.org
Wed Nov 12 11:28:45 PST 2008


On Wed, Nov 12, 2008 at 2:50 AM, salsaman <salsaman at gmail.com> wrote:

>  I would like to know if theora uses clamped or unclamped YUV.

I don't know what you mean by that. Theora supports two calibrated
colour spaces, one equivalent to NTSC and one equivalent to PAL. Most
videos I've seen use the 'uncalibrated' option when allows full range
in all three 8-bit Y'CrCb channels, and doesn't say how that should be
converted to RGB.

These are TH_CS_ITU_REC_470M, TH_CS_ITU_REC_470BG, and
TH_CS_UNSPECIFIED, respectively, set/read through the colorspace
element of the th_info struct.

Is that what you meant?

 -r


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