csputils: add missing gamma support

We have MP_CSP_TRC defined, but it wasn't being used by practically
anything. This commit adds missing conversion logic, adds it to
mp_image, and moves the auto-guessing logic to where it should be, in
mp_image_params_guess_csp (and out of vo_opengl).

Note that this also fixes a minor bug: csp_prim was not being copied
between mp_image structs if the format was not YUV in both cases, but
this is wrong - the primaries are always relevant.

1 files changed, 33 insertions, 0 deletions

diff --git a/video/csputils.c b/video/csputils.c
index 90eec39d36..cbd9734819 100644
--- a/video/csputils.c
+++ b/video/csputils.c
@@ -65,6 +65,13 @@ const char *const mp_csp_prim_names[MP_CSP_PRIM_COUNT] = {
     "BT.470 M",
 };
 
+const char *const mp_csp_trc_names[MP_CSP_TRC_COUNT] = {
+    "Autoselect",
+    "BT.1886 (SD, HD, UHD)",
+    "sRGB (IEC 61966-2-1)",
+    "Linear light",
+};
+
 const char *const mp_csp_equalizer_names[MP_CSP_EQ_COUNT] = {
     "brightness",
     "contrast",
@@ -142,6 +149,21 @@ enum mp_csp_prim avcol_pri_to_mp_csp_prim(int avpri)
     }
 }
 
+enum mp_csp_trc avcol_trc_to_mp_csp_trc(int avtrc)
+{
+    switch (avtrc) {
+    case AVCOL_TRC_BT709:
+    case AVCOL_TRC_SMPTE170M:
+    case AVCOL_TRC_SMPTE240M:
+    case AVCOL_TRC_BT1361_ECG:
+    case AVCOL_TRC_BT2020_10:
+    case AVCOL_TRC_BT2020_12:    return MP_CSP_TRC_BT_1886;
+    case AVCOL_TRC_IEC61966_2_1: return MP_CSP_TRC_SRGB;
+    case AVCOL_TRC_LINEAR:       return MP_CSP_TRC_LINEAR;
+    default:                     return MP_CSP_TRC_AUTO;
+    }
+}
+
 int mp_csp_to_avcol_spc(enum mp_csp colorspace)
 {
     switch (colorspace) {
@@ -181,6 +203,17 @@ int mp_csp_prim_to_avcol_pri(enum mp_csp_prim prim)
     }
 }
 
+int mp_csp_trc_to_avcol_trc(enum mp_csp_trc trc)
+{
+    switch (trc) {
+    // We just call it BT.1886 since we're decoding, but it's still BT.709
+    case MP_CSP_TRC_BT_1886:     return AVCOL_TRC_BT709;
+    case MP_CSP_TRC_SRGB:        return AVCOL_TRC_IEC61966_2_1;
+    case MP_CSP_TRC_LINEAR:      return AVCOL_TRC_LINEAR;
+    default:                     return AVCOL_TRC_UNSPECIFIED;
+    }
+}
+
 enum mp_csp mp_csp_guess_colorspace(int width, int height)
 {
     return width >= 1280 || height > 576 ? MP_CSP_BT_709 : MP_CSP_BT_601;