vo_opengl: implement more HDR tonemapping algorithms

This is now a configurable option, with tunable parameters.

I got inspiration for these algorithms off wikipedia. "simple" seems to
work pretty well, but not well enough to make it a reasonable default.

Some other notable candidates:

- Local functions (e.g. based on local contrast or gradient)
- Clamp with soft knee (linear up to a point)
- Mapping in CIE L*Ch. Map L smoothly, clamp C and h.
- Color appearance models

These will have to be implemented some other time.

Note that the parameter "peak_src" to pass_tone_map should, in
principle, be auto-detected from the SEI information of the source file
where available. This will also have to be implemented in a later
commit.

1 files changed, 9 insertions, 0 deletions

diff --git a/video/out/opengl/video.h b/video/out/opengl/video.h
index 5d8c938535..01c0cca78b 100644
--- a/video/out/opengl/video.h
+++ b/video/out/opengl/video.h
@@ -103,6 +103,13 @@ enum prescalers {
     PRESCALE_NNEDI3,
 };
 
+enum tone_mapping {
+    TONE_MAPPING_CLIP,
+    TONE_MAPPING_SIMPLE,
+    TONE_MAPPING_GAMMA,
+    TONE_MAPPING_LINEAR,
+};
+
 struct gl_video_opts {
     int dumb_mode;
     struct scaler_config scaler[4];
@@ -112,6 +119,8 @@ struct gl_video_opts {
     int target_prim;
     int target_trc;
     int target_brightness;
+    int hdr_tone_mapping;
+    float tone_mapping_param;
     int linear_scaling;
     int correct_downscaling;
     int sigmoid_upscaling;