Add most basic way of piping through PQ video encoding.

No metadata implemented yet.

assets/shaders/util/rgb_to_yuv.comp

@@ -17,11 +17,10 @@ layout(push_constant) uniform Registers
     float dither_strength;
 } registers;
 
-// BT709. Row-major.
-const mediump mat3 rgb_to_yuv = mat3(
-    vec3(0.2126, 0.7152, 0.0722),
-    vec3(-0.114572, -0.385428, 0.5),
-    vec3(0.5, -0.454153, -0.0458471));
+layout(set = 0, binding = 3) uniform Transform
+{
+	mat3 rgb_to_yuv;
+};
 
 #define D(x) ((x) - 0.5)
 const mediump float dither[] = float[](
@@ -46,4 +45,4 @@ void main()
         imageStore(uLuma, ivec2(coord), ycbcr.xxxx);
         imageStore(uChroma, ivec2(coord), ycbcr.yzyz);
     }
-}
+}

video/ffmpeg_encode.cpp

@@ -1014,8 +1014,18 @@ bool VideoEncoder::Impl::init_video_codec_av(const AVCodec *codec)
 	}
 
 	video.av_ctx->color_range = AVCOL_RANGE_MPEG;
-	video.av_ctx->colorspace = AVCOL_SPC_BT709;
-	video.av_ctx->color_primaries = AVCOL_PRI_BT709;
+
+	if (options.hdr10)
+	{
+		video.av_ctx->colorspace = AVCOL_SPC_BT2020_NCL;
+		video.av_ctx->color_primaries = AVCOL_PRI_BT2020;
+		video.av_ctx->color_trc = AVCOL_TRC_SMPTE2084; // PQ
+	}
+	else
+	{
+		video.av_ctx->colorspace = AVCOL_SPC_BT709;
+		video.av_ctx->color_primaries = AVCOL_PRI_BT709;
+	}
 
 	switch (options.siting)
 	{
@@ -1736,6 +1746,22 @@ void VideoEncoder::process_rgb(Vulkan::CommandBuffer &cmd, YCbCrPipeline &pipeli
 	push.dither_strength = pipeline.constants.dither_strength;
 	cmd.push_constants(&push, 0, sizeof(push));
 
+	auto *color_transform = cmd.allocate_typed_constant_data<vec4>(0, 3, 3);
+
+	// Minimal crude implementation to get something HDR10 working.
+	if (impl->options.hdr10)
+	{
+		color_transform[0] = vec4(0.2627f, 0.678f, 0.0593f, 0.0f);
+		color_transform[1] = vec4(-0.13963f, -0.36037f, 0.5f, 0.0f);
+		color_transform[2] = vec4(0.5f, -0.459786f, -0.0402143f, 0.0f);
+	}
+	else
+	{
+		color_transform[0] = vec4(0.2126f, 0.7152f, 0.0722f, 0.0f);
+		color_transform[1] = vec4(-0.114572f, -0.385428f, 0.5f, 0.0f);
+		color_transform[2] = vec4(0.5f, -0.454153f, -0.0458471f, 0.0f);
+	}
+
 	auto start_yuv_ts = cmd.write_timestamp(VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT);
 	cmd.dispatch(pipeline.constants.luma_dispatch[0], pipeline.constants.luma_dispatch[1], 1);
 	auto end_yuv_ts = cmd.write_timestamp(VK_PIPELINE_STAGE_COMPUTE_SHADER_BIT);

video/ffmpeg_encode.hpp

@@ -82,6 +82,7 @@ class VideoEncoder
 		bool realtime = false;
 		const char *encoder = "libx264";
 		bool low_latency = false;
+		bool hdr10 = false;
 
 		struct
 		{