[FFmpeg-devel] [PATCH] avfilter/vf_zscale: add support for half precision float RGB formats

[James Almer]

Signed-off-by: James Almer <jamrial at gmail.com>
---
 libavfilter/vf_zscale.c | 16 +++++++++++++---
 1 file changed, 13 insertions(+), 3 deletions(-)

diff --git a/libavfilter/vf_zscale.c b/libavfilter/vf_zscale.c
index 7e66c3d6e2..5fe6e555e7 100644
--- a/libavfilter/vf_zscale.c
+++ b/libavfilter/vf_zscale.c
@@ -209,6 +209,7 @@ static int query_formats(const AVFilterContext *ctx,
         AV_PIX_FMT_GBRP, AV_PIX_FMT_GBRP9, AV_PIX_FMT_GBRP10,
         AV_PIX_FMT_GBRP12, AV_PIX_FMT_GBRP14, AV_PIX_FMT_GBRP16,
         AV_PIX_FMT_GBRAP, AV_PIX_FMT_GBRAP10, AV_PIX_FMT_GBRAP12, AV_PIX_FMT_GBRAP14, AV_PIX_FMT_GBRAP16,
+        AV_PIX_FMT_GBRPF16, AV_PIX_FMT_GBRAPF16,
         AV_PIX_FMT_GBRPF32, AV_PIX_FMT_GBRAPF32,
         AV_PIX_FMT_NONE
     };
@@ -582,7 +583,8 @@ static void format_init(zimg_image_format *format, AVFrame *frame, const AVPixFm
     format->subsample_w = desc->log2_chroma_w;
     format->subsample_h = desc->log2_chroma_h;
     format->depth = desc->comp[0].depth;
-    format->pixel_type = (desc->flags & AV_PIX_FMT_FLAG_FLOAT) ? ZIMG_PIXEL_FLOAT : desc->comp[0].depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;
+    format->pixel_type = (desc->flags & AV_PIX_FMT_FLAG_FLOAT) ? (desc->comp[0].depth > 16 ? ZIMG_PIXEL_FLOAT : ZIMG_PIXEL_HALF)
+                                                               : (desc->comp[0].depth > 8  ? ZIMG_PIXEL_WORD  : ZIMG_PIXEL_BYTE);
     format->color_family = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_COLOR_RGB : ZIMG_COLOR_YUV;
     format->matrix_coefficients = (desc->flags & AV_PIX_FMT_FLAG_RGB) ? ZIMG_MATRIX_RGB : colorspace == -1 ? convert_matrix(frame->colorspace) : colorspace;
     format->color_primaries = primaries == -1 ? convert_primaries(frame->color_primaries) : primaries;
@@ -861,11 +863,13 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)
             s->alpha_src_format.width = in->width;
             s->alpha_src_format.height = in->height;
             s->alpha_src_format.depth = desc->comp[0].depth;
-            s->alpha_src_format.pixel_type = (desc->flags & AV_PIX_FMT_FLAG_FLOAT) ? ZIMG_PIXEL_FLOAT : desc->comp[0].depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;
+            s->alpha_src_format.pixel_type = (desc->flags & AV_PIX_FMT_FLAG_FLOAT) ? (desc->comp[0].depth > 16 ? ZIMG_PIXEL_FLOAT : ZIMG_PIXEL_HALF)
+                                                                                   : (desc->comp[0].depth > 8  ? ZIMG_PIXEL_WORD  : ZIMG_PIXEL_BYTE);
             s->alpha_src_format.color_family = ZIMG_COLOR_GREY;
 
             s->alpha_dst_format.depth = odesc->comp[0].depth;
-            s->alpha_dst_format.pixel_type = (odesc->flags & AV_PIX_FMT_FLAG_FLOAT) ? ZIMG_PIXEL_FLOAT : odesc->comp[0].depth > 8 ? ZIMG_PIXEL_WORD : ZIMG_PIXEL_BYTE;
+            s->alpha_dst_format.pixel_type = (odesc->flags & AV_PIX_FMT_FLAG_FLOAT) ? (odesc->comp[0].depth > 16 ? ZIMG_PIXEL_FLOAT : ZIMG_PIXEL_HALF)
+                                                                                    : (odesc->comp[0].depth > 8  ? ZIMG_PIXEL_WORD  : ZIMG_PIXEL_BYTE);
             s->alpha_dst_format.color_family = ZIMG_COLOR_GREY;
         }
 
@@ -909,8 +913,14 @@ static int filter_frame(AVFilterLink *link, AVFrame *in)
         if ((!(desc->flags & AV_PIX_FMT_FLAG_ALPHA)) && (odesc->flags & AV_PIX_FMT_FLAG_ALPHA) ){
             int x, y;
             if (odesc->flags & AV_PIX_FMT_FLAG_FLOAT) {
+                const uint16_t h_one = 0x3C00; // float2half(1.0f)
                 for (y = 0; y < out->height; y++) {
                     const ptrdiff_t row =  y * out->linesize[3];
+                    if (odesc->comp[0].depth == 16)
+                        for (x = 0; x < out->width; x++) {
+                            AV_WN16(out->data[3] + x * odesc->comp[3].step + row, h_one);
+                        }
+                    else
                     for (x = 0; x < out->width; x++) {
                         AV_WN32(out->data[3] + x * odesc->comp[3].step + row,
                                 av_float2int(1.0f));
-- 
2.48.1