diff options
author | Ruiling Song <ruiling.song@intel.com> | 2019-01-22 14:27:01 +0800 |
---|---|---|
committer | Ruiling Song <ruiling.song@intel.com> | 2019-03-22 09:33:28 +0800 |
commit | d0f3798b4e7f9ec3142f74946f7de41b9e3485cb (patch) | |
tree | a8746039ab680a4a6a54f4cba040402f34437b1d /libavfilter/colorspace.c | |
parent | 61cb505d18b8a335bd118d88c05b9daf40eb5f9b (diff) |
lavfi/colorspace: move some functions to common file
These functions can be reused by other colorspace filters,
so move them to common file. No functional changes.
Signed-off-by: Ruiling Song <ruiling.song@intel.com>
Diffstat (limited to 'libavfilter/colorspace.c')
-rw-r--r-- | libavfilter/colorspace.c | 71 |
1 files changed, 71 insertions, 0 deletions
diff --git a/libavfilter/colorspace.c b/libavfilter/colorspace.c index c6682216d6..19616e4f12 100644 --- a/libavfilter/colorspace.c +++ b/libavfilter/colorspace.c @@ -93,6 +93,77 @@ void ff_fill_rgb2xyz_table(const struct PrimaryCoefficients *coeffs, rgb2xyz[2][1] *= sg; rgb2xyz[2][2] *= sb; } +static const double ycgco_matrix[3][3] = +{ + { 0.25, 0.5, 0.25 }, + { -0.25, 0.5, -0.25 }, + { 0.5, 0, -0.5 }, +}; + +static const double gbr_matrix[3][3] = +{ + { 0, 1, 0 }, + { 0, -0.5, 0.5 }, + { 0.5, -0.5, 0 }, +}; + +/* + * All constants explained in e.g. https://linuxtv.org/downloads/v4l-dvb-apis/ch02s06.html + * The older ones (bt470bg/m) are also explained in their respective ITU docs + * (e.g. https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.470-5-199802-S!!PDF-E.pdf) + * whereas the newer ones can typically be copied directly from wikipedia :) + */ +static const struct LumaCoefficients luma_coefficients[AVCOL_SPC_NB] = { + [AVCOL_SPC_FCC] = { 0.30, 0.59, 0.11 }, + [AVCOL_SPC_BT470BG] = { 0.299, 0.587, 0.114 }, + [AVCOL_SPC_SMPTE170M] = { 0.299, 0.587, 0.114 }, + [AVCOL_SPC_BT709] = { 0.2126, 0.7152, 0.0722 }, + [AVCOL_SPC_SMPTE240M] = { 0.212, 0.701, 0.087 }, + [AVCOL_SPC_YCOCG] = { 0.25, 0.5, 0.25 }, + [AVCOL_SPC_RGB] = { 1, 1, 1 }, + [AVCOL_SPC_BT2020_NCL] = { 0.2627, 0.6780, 0.0593 }, + [AVCOL_SPC_BT2020_CL] = { 0.2627, 0.6780, 0.0593 }, +}; + +const struct LumaCoefficients *ff_get_luma_coefficients(enum AVColorSpace csp) +{ + const struct LumaCoefficients *coeffs; + + if (csp >= AVCOL_SPC_NB) + return NULL; + coeffs = &luma_coefficients[csp]; + if (!coeffs->cr) + return NULL; + + return coeffs; +} + +void ff_fill_rgb2yuv_table(const struct LumaCoefficients *coeffs, + double rgb2yuv[3][3]) +{ + double bscale, rscale; + + // special ycgco matrix + if (coeffs->cr == 0.25 && coeffs->cg == 0.5 && coeffs->cb == 0.25) { + memcpy(rgb2yuv, ycgco_matrix, sizeof(double) * 9); + return; + } else if (coeffs->cr == 1 && coeffs->cg == 1 && coeffs->cb == 1) { + memcpy(rgb2yuv, gbr_matrix, sizeof(double) * 9); + return; + } + + rgb2yuv[0][0] = coeffs->cr; + rgb2yuv[0][1] = coeffs->cg; + rgb2yuv[0][2] = coeffs->cb; + bscale = 0.5 / (coeffs->cb - 1.0); + rscale = 0.5 / (coeffs->cr - 1.0); + rgb2yuv[1][0] = bscale * coeffs->cr; + rgb2yuv[1][1] = bscale * coeffs->cg; + rgb2yuv[1][2] = 0.5; + rgb2yuv[2][0] = 0.5; + rgb2yuv[2][1] = rscale * coeffs->cg; + rgb2yuv[2][2] = rscale * coeffs->cb; +} double ff_determine_signal_peak(AVFrame *in) { |