In the past the transfer function was implied by the colorspace. However, it is an independent entity in its own right. Add support for explicitly choosing the transfer function. This change will allow us to represent linear RGB (as is used by openGL), and it will make it easier to work with decoded video material since most codecs store the transfer function as a separate property as well.
Showing the changes to include/uapi (2 of 4 files). Show all
Unified · Split
| @@ -24,6 +24,7 @@ · 23 unmodified lines | ||
| 24 | 24 | * @colorspace: colorspace of the data (from enum v4l2_colorspace) |
| 25 | 25 | * @ycbcr_enc: YCbCr encoding of the data (from enum v4l2_ycbcr_encoding) |
| 26 | 26 | * @quantization: quantization of the data (from enum v4l2_quantization) |
| 27 | + * @xfer_func: transfer function of the data (from enum v4l2_xfer_func) | |
| 27 | 28 | */ |
| 28 | 29 | struct v4l2_mbus_framefmt { |
| 29 | 30 | __u32 width; |
| @@ -33,7 +34,8 @@ struct v4l2_mbus_framefmt { · 3 unmodified lines | ||
| 33 | 34 | __u32 colorspace; |
| 34 | 35 | __u16 ycbcr_enc; |
| 35 | 36 | __u16 quantization; |
| 36 | − __u32 reserved[6]; | |
| 37 | + __u16 xfer_func; | |
| 38 | + __u16 reserved[11]; | |
| 37 | 39 | }; |
| 38 | 40 | |
| 39 | 41 | #ifndef __KERNEL__ |
| @@ -240,6 +240,42 @@ enum v4l2_colorspace { · 239 unmodified lines | ||
| 240 | 240 | ((is_sdtv) ? V4L2_COLORSPACE_SMPTE170M : \ |
| 241 | 241 | ((is_hdtv) ? V4L2_COLORSPACE_REC709 : V4L2_COLORSPACE_SRGB)) |
| 242 | 242 | |
| 243 | +enum v4l2_xfer_func { | |
| 244 | + /* | |
| 245 | + * Mapping of V4L2_XFER_FUNC_DEFAULT to actual transfer functions | |
| 246 | + * for the various colorspaces: | |
| 247 | + * | |
| 248 | + * V4L2_COLORSPACE_SMPTE170M, V4L2_COLORSPACE_470_SYSTEM_M, | |
| 249 | + * V4L2_COLORSPACE_470_SYSTEM_BG, V4L2_COLORSPACE_REC709 and | |
| 250 | + * V4L2_COLORSPACE_BT2020: V4L2_XFER_FUNC_709 | |
| 251 | + * | |
| 252 | + * V4L2_COLORSPACE_SRGB, V4L2_COLORSPACE_JPEG: V4L2_XFER_FUNC_SRGB | |
| 253 | + * | |
| 254 | + * V4L2_COLORSPACE_ADOBERGB: V4L2_XFER_FUNC_ADOBERGB | |
| 255 | + * | |
| 256 | + * V4L2_COLORSPACE_SMPTE240M: V4L2_XFER_FUNC_SMPTE240M | |
| 257 | + * | |
| 258 | + * V4L2_COLORSPACE_RAW: V4L2_XFER_FUNC_NONE | |
| 259 | + */ | |
| 260 | + V4L2_XFER_FUNC_DEFAULT = 0, | |
| 261 | + V4L2_XFER_FUNC_709 = 1, | |
| 262 | + V4L2_XFER_FUNC_SRGB = 2, | |
| 263 | + V4L2_XFER_FUNC_ADOBERGB = 3, | |
| 264 | + V4L2_XFER_FUNC_SMPTE240M = 4, | |
| 265 | + V4L2_XFER_FUNC_NONE = 5, | |
| 266 | +}; | |
| 267 | + | |
| 268 | +/* | |
| 269 | + * Determine how XFER_FUNC_DEFAULT should map to a proper transfer function. | |
| 270 | + * This depends on the colorspace. | |
| 271 | + */ | |
| 272 | +#define V4L2_MAP_XFER_FUNC_DEFAULT(colsp) \ | |
| 273 | + ((colsp) == V4L2_XFER_FUNC_ADOBERGB ? V4L2_XFER_FUNC_ADOBERGB : \ | |
| 274 | + ((colsp) == V4L2_COLORSPACE_SMPTE240M ? V4L2_XFER_FUNC_SMPTE240M : \ | |
| 275 | + ((colsp) == V4L2_COLORSPACE_RAW ? V4L2_XFER_FUNC_NONE : \ | |
| 276 | + ((colsp) == V4L2_COLORSPACE_SRGB || (colsp) == V4L2_COLORSPACE_JPEG ? \ | |
| 277 | + V4L2_XFER_FUNC_SRGB : V4L2_XFER_FUNC_709)))) | |
| 278 | + | |
| 243 | 279 | enum v4l2_ycbcr_encoding { |
| 244 | 280 | /* |
| 245 | 281 | * Mapping of V4L2_YCBCR_ENC_DEFAULT to actual encodings for the |
| @@ -409,6 +445,7 @@ struct v4l2_pix_format { · 163 unmodified lines | ||
| 409 | 445 | __u32 flags; /* format flags (V4L2_PIX_FMT_FLAG_*) */ |
| 410 | 446 | __u32 ycbcr_enc; /* enum v4l2_ycbcr_encoding */ |
| 411 | 447 | __u32 quantization; /* enum v4l2_quantization */ |
| 448 | + __u32 xfer_func; /* enum v4l2_xfer_func */ | |
| 412 | 449 | }; |
| 413 | 450 | |
| 414 | 451 | /* Pixel format FOURCC depth Description */ |
| @@ -1907,6 +1944,7 @@ struct v4l2_plane_pix_format { · 1492 unmodified lines | ||
| 1907 | 1944 | * @flags: format flags (V4L2_PIX_FMT_FLAG_*) |
| 1908 | 1945 | * @ycbcr_enc: enum v4l2_ycbcr_encoding, Y'CbCr encoding |
| 1909 | 1946 | * @quantization: enum v4l2_quantization, colorspace quantization |
| 1947 | + * @xfer_func: enum v4l2_xfer_func, colorspace transfer function | |
| 1910 | 1948 | */ |
| 1911 | 1949 | struct v4l2_pix_format_mplane { |
| 1912 | 1950 | __u32 width; |
| @@ -1920,7 +1958,8 @@ struct v4l2_pix_format_mplane { · 7 unmodified lines | ||
| 1920 | 1958 | __u8 flags; |
| 1921 | 1959 | __u8 ycbcr_enc; |
| 1922 | 1960 | __u8 quantization; |
| 1923 | − __u8 reserved[8]; | |
| 1961 | + __u8 xfer_func; | |
| 1962 | + __u8 reserved[7]; | |
| 1924 | 1963 | } __attribute__ ((packed)); |
| 1925 | 1964 | |
| 1926 | 1965 | /** |