avfilter/scale_vulkan: add dynamic crop region and aspect ratio match

The scale_vulkan filter initializes the shader once, with the crop
region set by the original frame. However, subsequent frames may
specify a different crop region than the first frame. This change
updates the cropping to match the behavior present on the other
hardware frame scale filters.

The scale filter should also allow negative values
that respect aspect ratio, similar to other scale filters.

Signed-off-by: Koushik Dutta <koushd@gmail.com>

libavfilter/vf_scale_vulkan.c

@@ -46,6 +46,10 @@ typedef struct ScaleVulkanContext {
     /* Push constants / options */
     struct {
         float yuv_matrix[4][4];
+        int crop_x;
+        int crop_y;
+        int crop_w;
+        int crop_h;
     } opts;
 
     char *out_format_string;
@@ -121,10 +125,6 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
     FFVkSPIRVCompiler *spv;
     FFVulkanDescriptorSetBinding *desc;
 
-    int crop_x = in->crop_left;
-    int crop_y = in->crop_top;
-    int crop_w = in->width - (in->crop_left + in->crop_right);
-    int crop_h = in->height - (in->crop_top + in->crop_bottom);
     int in_planes = av_pix_fmt_count_planes(s->vkctx.input_format);
 
     switch (s->scaler) {
@@ -159,6 +159,10 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
 
     GLSLC(0, layout(push_constant, std430) uniform pushConstants {        );
     GLSLC(1,    mat4 yuv_matrix;                                          );
+    GLSLC(1,    int crop_x;                                               );
+    GLSLC(1,    int crop_y;                                               );
+    GLSLC(1,    int crop_w;                                               );
+    GLSLC(1,    int crop_h;                                               );
     GLSLC(0, };                                                           );
     GLSLC(0,                                                              );
 
@@ -205,8 +209,8 @@ static av_cold int init_filter(AVFilterContext *ctx, AVFrame *in)
     GLSLC(1,     ivec2 size;                                                 );
     GLSLC(1,     ivec2 pos = ivec2(gl_GlobalInvocationID.xy);                );
     GLSLF(1,     vec2 in_d = vec2(%i, %i);             ,in->width, in->height);
-    GLSLF(1,     vec2 c_r = vec2(%i, %i) / in_d;              ,crop_w, crop_h);
+    GLSLC(1,     vec2 c_r = vec2(crop_w, crop_h) / in_d;                     );
-    GLSLF(1,     vec2 c_o = vec2(%i, %i) / in_d;               ,crop_x,crop_y);
+    GLSLC(1,     vec2 c_o = vec2(crop_x, crop_y) / in_d;                     );
     GLSLC(0,                                                                 );
 
     if (s->vkctx.output_format == s->vkctx.input_format) {
@@ -286,6 +290,11 @@ static int scale_vulkan_filter_frame(AVFilterLink *link, AVFrame *in)
     if (!s->initialized)
         RET(init_filter(ctx, in));
 
+    s->opts.crop_x = in->crop_left;
+    s->opts.crop_y = in->crop_top;
+    s->opts.crop_w = in->width - (in->crop_left + in->crop_right);
+    s->opts.crop_h = in->height - (in->crop_top + in->crop_bottom);
+
     RET(ff_vk_filter_process_simple(&s->vkctx, &s->e, &s->shd, out, in,
                                     s->sampler, &s->opts, sizeof(s->opts)));
 
@@ -327,6 +336,11 @@ static int scale_vulkan_config_output(AVFilterLink *outlink)
     if (err < 0)
         return err;
 
+    ff_scale_adjust_dimensions(inlink, &vkctx->output_width, &vkctx->output_height, 0, 1);
+
+    outlink->w = vkctx->output_width;
+    outlink->h = vkctx->output_height;
+
     if (s->out_format_string) {
         s->vkctx.output_format = av_get_pix_fmt(s->out_format_string);
         if (s->vkctx.output_format == AV_PIX_FMT_NONE) {