fftools/ffplay: use swapchain_colorspace_hint to get better HDR support

For example, the default surface configuration on macOS is:
VK_FORMAT_A2B10G10R10_UNORM_PACK32 + VK_COLOR_SPACE_PASS_THROUGH_EXT

With HDR10 content and swapchain_colorspace_hint, the surface
configuration updated to:
VK_FORMAT_A2B10G10R10_UNORM_PACK32 + VK_COLOR_SPACE_HDR10_ST2084_EXT

Signed-off-by: Zhao Zhili <zhilizhao@tencent.com>

fftools/ffplay_renderer.c

@@ -697,6 +697,7 @@ static int display(VkRenderer *renderer, AVFrame *frame)
     struct pl_frame target = {0};
     RendererContext *ctx = (RendererContext *) renderer;
     int ret = 0;
+    struct pl_color_space hint = {0};
 
     ret = convert_frame(renderer, frame);
     if (ret < 0)
@@ -709,6 +710,8 @@ static int display(VkRenderer *renderer, AVFrame *frame)
         return AVERROR_EXTERNAL;
     }
 
+    pl_color_space_from_avframe(&hint, frame);
+    pl_swapchain_colorspace_hint(ctx->swapchain, &hint);
     if (!pl_swapchain_start_frame(ctx->swapchain, &swap_frame)) {
         av_log(NULL, AV_LOG_ERROR, "start frame failed\n");
         ret = AVERROR_EXTERNAL;