vo_gpu: fix green shit with float yuv input

This was incorrect at least because the colorspace matrix attempted to
center chroma at (conceptually) 0.5, instead of 0. Also, it tried to
apply the fixed point shift logic for component sizes > 8 bit.

There is no float yuv format in mpv/ffmpeg yet, but see next commit,
which enables zimg to output it. I'm assuming zimg defines this format
such that luma is in range [0,1] and chroma in range [-0.5,0.5], with
the levels flag being ignored. This is consistent with H264/5 Annex E (I
think...), and it sort of seems to look right, so that's it.

3 files changed, 23 insertions, 12 deletions

diff --git a/video/out/gpu/ra.c b/video/out/gpu/ra.c
index c4d3b53284..2874cf1ad2 100644
--- a/video/out/gpu/ra.c
+++ b/video/out/gpu/ra.c
@@ -283,11 +283,10 @@ static const struct ra_format *find_plane_format(struct ra *ra, int bytes,
 // Returns false (and *out is not touched) if no format found.
 bool ra_get_imgfmt_desc(struct ra *ra, int imgfmt, struct ra_imgfmt_desc *out)
 {
-    struct ra_imgfmt_desc res = {0};
+    struct ra_imgfmt_desc res = {.component_type = RA_CTYPE_UNKNOWN};
 
     struct mp_regular_imgfmt regfmt;
     if (mp_get_regular_imgfmt(&regfmt, imgfmt)) {
-        enum ra_ctype ctype = RA_CTYPE_UNKNOWN;
         res.num_planes = regfmt.num_planes;
         res.component_bits = regfmt.component_size * 8;
         res.component_pad = regfmt.component_pad;
@@ -305,9 +304,10 @@ bool ra_get_imgfmt_desc(struct ra *ra, int imgfmt, struct ra_imgfmt_desc *out)
                 res.component_pad < 0)
                 return false;
             // Renderer restriction, but actually an unwanted corner case.
-            if (ctype != RA_CTYPE_UNKNOWN && ctype != res.planes[n]->ctype)
+            if (res.component_type != RA_CTYPE_UNKNOWN &&
+                res.component_type != res.planes[n]->ctype)
                 return false;
-            ctype = res.planes[n]->ctype;
+            res.component_type = res.planes[n]->ctype;
         }
         res.chroma_w = 1 << regfmt.chroma_xs;
         res.chroma_h = 1 << regfmt.chroma_ys;
@@ -330,6 +330,16 @@ supported:
     return true;
 }
 
+static const char *ctype_to_str(enum ra_ctype ctype)
+{
+    switch (ctype) {
+    case RA_CTYPE_UNORM:    return "unorm";
+    case RA_CTYPE_UINT:     return "uint ";
+    case RA_CTYPE_FLOAT:    return "float";
+    default:                return "unknown";
+    }
+}
+
 void ra_dump_tex_formats(struct ra *ra, int msgl)
 {
     if (!mp_msg_test(ra->log, msgl))
@@ -338,12 +348,7 @@ void ra_dump_tex_formats(struct ra *ra, int msgl)
     MP_MSG(ra, msgl, "  NAME       COMP*TYPE SIZE           DEPTH PER COMP.\n");
     for (int n = 0; n < ra->num_formats; n++) {
         const struct ra_format *fmt = ra->formats[n];
-        const char *ctype = "unknown";
-        switch (fmt->ctype) {
-        case RA_CTYPE_UNORM:    ctype = "unorm";    break;
-        case RA_CTYPE_UINT:     ctype = "uint ";    break;
-        case RA_CTYPE_FLOAT:    ctype = "float";    break;
-        }
+        const char *ctype = ctype_to_str(fmt->ctype);
         char cl[40] = "";
         for (int i = 0; i < fmt->num_components; i++) {
             mp_snprintf_cat(cl, sizeof(cl), "%s%d", i ? " " : "",
@@ -382,9 +387,10 @@ void ra_dump_imgfmt_desc(struct ra *ra, const struct ra_imgfmt_desc *desc,
         mp_snprintf_cat(pl, sizeof(pl), "%s", t);
         mp_snprintf_cat(pf, sizeof(pf), "%s", desc->planes[n]->name);
     }
-    MP_MSG(ra, msgl, "%d planes %dx%d %d/%d [%s] (%s)\n",
+    MP_MSG(ra, msgl, "%d planes %dx%d %d/%d [%s] (%s) [%s]\n",
            desc->num_planes, desc->chroma_w, desc->chroma_h,
-           desc->component_bits, desc->component_pad, pf, pl);
+           desc->component_bits, desc->component_pad, pf, pl,
+           ctype_to_str(desc->component_type));
 }
 
 void ra_dump_img_formats(struct ra *ra, int msgl)
diff --git a/video/out/gpu/ra.h b/video/out/gpu/ra.h
index 58bf55357b..4067b52425 100644
--- a/video/out/gpu/ra.h
+++ b/video/out/gpu/ra.h
@@ -531,6 +531,8 @@ struct ra_imgfmt_desc {
     int component_bits;
     // Like mp_regular_imgfmt.component_pad.
     int component_pad;
+    // == planes[n].ctype (RA_CTYPE_UNKNOWN if not applicable)
+    enum ra_ctype component_type;
     // For each texture and each texture output (rgba order) describe what
     // component it returns.
     // The values are like the values in mp_regular_imgfmt_plane.components[].
diff --git a/video/out/gpu/video.c b/video/out/gpu/video.c
index 41c021bd94..22ce0c3f3b 100644
--- a/video/out/gpu/video.c
+++ b/video/out/gpu/video.c
@@ -790,6 +790,8 @@ static void pass_get_images(struct gl_video *p, struct video_image *vimg,
         int csp = type == PLANE_ALPHA ? MP_CSP_RGB : p->image_params.color.space;
         float tex_mul =
             1.0 / mp_get_csp_mul(csp, msb_valid_bits, p->ra_format.component_bits);
+        if (p->ra_format.component_type == RA_CTYPE_FLOAT)
+            tex_mul = 1.0;
 
         img[n] = (struct image){
             .type = type,
@@ -2296,6 +2298,7 @@ static void pass_convert_yuv(struct gl_video *p)
 
     struct mp_csp_params cparams = MP_CSP_PARAMS_DEFAULTS;
     cparams.gray = p->is_gray;
+    cparams.is_float = p->ra_format.component_type == RA_CTYPE_FLOAT;
     mp_csp_set_image_params(&cparams, &p->image_params);
     mp_csp_equalizer_state_get(p->video_eq, &cparams);
     p->user_gamma = 1.0 / (cparams.gamma * p->opts.gamma);