Struct defining white point location in terms of CIE 1931 chromaticity x and y.

Definition at line 72 of file csp.h.

Function pointer representing a double -> double transfer function that performs either an OETF transfer function, or alternatively an inverse EOTF function (in particular, for SMPTE ST 2084 / PQ).

This function inputs linear light, and outputs gamma encoded light.

See ITU-T H.273 for more information.

Definition at line 91 of file csp.h.

Function pointer representing an ITU EOTF transfer for a given reference display configuration.

Parameters

Lw The white point luminance of the display, in nits (cd/m^2).

Lb The black point luminance of the display, in nits (cd/m^2).

Definition at line 162 of file csp.h.

Retrieves the Luma coefficients necessary to construct a conversion matrix from an enum constant describing the colorspace.

Parameters

csp An enum constant indicating YUV or similar colorspace.

Returns

The Luma coefficients associated with that colorspace, or NULL if the constant is unknown to libavutil.

Definition at line 58 of file csp.c.

Referenced by create_filtergraph(), ff_draw_init2(), ff_fmt_from_frame(), filter_frame(), init(), init_filter(), init_scale_shader(), and tonemap_opencl_init().

Retrieves a complete gamut description from an enum constant describing the color primaries.

Parameters

prm An enum constant indicating primaries

Returns

A description of the colorspace gamut associated with that enum constant, or NULL if the constant is unknown to libavutil.

Definition at line 90 of file csp.c.

Referenced by create_filtergraph(), ff_fmt_from_frame(), ff_icc_profile_generate(), gamut_from_colorspace(), get_rgb2rgb_matrix(), infer_prim_ref(), libjxl_get_primaries(), libjxl_populate_primaries(), and png_get_chrm().

Detects which enum AVColorPrimaries constant corresponds to the given complete gamut description.

See also

enum AVColorPrimaries

Parameters

prm A description of the colorspace gamut

Returns

The enum constant associated with this gamut, or AVCOL_PRI_UNSPECIFIED if no clear match can be identified.

Definition at line 110 of file csp.c.

Referenced by iccdetect_filter_frame(), libjxl_get_primaries(), and populate_avctx_color_fields().

Determine a suitable 'gamma' value to match the supplied AVColorTransferCharacteristic.

See Apple Technical Note TN2257 (https://developer.apple.com/library/mac/technotes/tn2257/_index.html)

This function returns the gamma exponent for the OETF. For example, sRGB is approximated by gamma 2.2, not by gamma 0.45455.

Returns

Will return an approximation to the simple gamma function matching the supplied Transfer Characteristic, Will return 0.0 for any we cannot reasonably match against.

Definition at line 149 of file csp.c.

Referenced by mov_write_gama_tag(), and png_get_gama().

Determine the function needed to apply the given AVColorTransferCharacteristic to linear input.

The function returned should expect a nominal domain and range of [0.0-1.0] values outside of this range maybe valid depending on the chosen characteristic function.

Returns

Will return pointer to the function matching the supplied Transfer Characteristic. If unspecified will return NULL:

Definition at line 400 of file csp.c.

Referenced by decode_block(), decode_init(), and main().

Returns the mathematical inverse of the corresponding TRC function.

Definition at line 426 of file csp.c.

Referenced by main().

Returns the ITU EOTF corresponding to a given TRC.

This converts from the signal level [0,1] to the raw output display luminance in nits (cd/m^2). This is done per channel in RGB space, except for AVCOL_TRC_SMPTE428, which assumes CIE XYZ in- and output.

Returns

A pointer to the function implementing the given TRC, or NULL if no such function is defined.

Note

In general, the resulting function is defined (wherever possible) for out-of-range values, even though these values do not have a physical meaning on the given display. Users should clamp inputs (or outputs) if this behavior is not desired.

This is also the case for functions like PQ, which are defined over an absolute signal range independent of the target display capabilities.

Definition at line 605 of file csp.c.

Referenced by gamut_from_colorspace(), main(), and sws_test_transfer().

Returns the mathematical inverse of the corresponding EOTF.

Definition at line 631 of file csp.c.

Referenced by gamut_from_colorspace(), main(), and sws_test_transfer().