diff options
Diffstat (limited to 'video/out/gpu/video_shaders.c')
-rw-r--r-- | video/out/gpu/video_shaders.c | 96 |
1 files changed, 38 insertions, 58 deletions
diff --git a/video/out/gpu/video_shaders.c b/video/out/gpu/video_shaders.c index 315e15cc89..0fff8f05f2 100644 --- a/video/out/gpu/video_shaders.c +++ b/video/out/gpu/video_shaders.c @@ -567,75 +567,55 @@ static void pass_inverse_ootf(struct gl_shader_cache *sc, enum mp_csp_light ligh // under a typical presentation gamma of about 2.0. static const float sdr_avg = 0.25; -// The threshold for which to consider an average luminance difference to be -// a sign of a scene change. -static const int scene_threshold = 0.2 * MP_REF_WHITE; - -static void hdr_update_peak(struct gl_shader_cache *sc) +static void hdr_update_peak(struct gl_shader_cache *sc, + const struct gl_tone_map_opts *opts) { - // For performance, we want to do as few atomic operations on global - // memory as possible, so use an atomic in shmem for the work group. - GLSLH(shared uint wg_sum;); - GLSL(wg_sum = 0;) - - // Have each thread update the work group sum with the local value + // Update the sig_peak/sig_avg from the old SSBO state + GLSL(sig_avg = max(1e-3, average.x);) + GLSL(sig_peak = max(1.00, average.y);) + + // For performance, and to avoid overflows, we tally up the sub-results per + // pixel using shared memory first + GLSLH(shared uint wg_sum;) + GLSLH(shared uint wg_max;) + GLSL(wg_sum = wg_max = 0;) GLSL(barrier();) - GLSLF("atomicAdd(wg_sum, uint(sig_max * %f));\n", MP_REF_WHITE); + GLSLF("uint sig_uint = uint(sig_max * %f);\n", MP_REF_WHITE); + GLSL(atomicAdd(wg_sum, sig_uint);) + GLSL(atomicMax(wg_max, sig_uint);) - // Have one thread per work group update the global atomics. We use the - // work group average even for the global sum, to make the values slightly - // more stable and smooth out tiny super-highlights. + // Have one thread per work group update the global atomics GLSL(memoryBarrierShared();) GLSL(barrier();) GLSL(if (gl_LocalInvocationIndex == 0) {) GLSL( uint wg_avg = wg_sum / (gl_WorkGroupSize.x * gl_WorkGroupSize.y);) - GLSL( atomicMax(frame_max[frame_idx], wg_avg);) - GLSL( atomicAdd(frame_avg[frame_idx], wg_avg);) + GLSL( atomicAdd(frame_sum, wg_avg);) + GLSL( atomicMax(frame_max, wg_max);) + GLSL( memoryBarrierBuffer();) GLSL(}) - - const float refi = 1.0 / MP_REF_WHITE; - - // Update the sig_peak/sig_avg from the old SSBO state - GLSL(uint num_wg = gl_NumWorkGroups.x * gl_NumWorkGroups.y;) - GLSL(if (frame_num > 0) {) - GLSLF(" float peak = %f * float(total_max) / float(frame_num);\n", refi); - GLSLF(" float avg = %f * float(total_avg) / float(frame_num);\n", refi); - GLSLF(" sig_peak = max(1.0, peak);\n"); - GLSLF(" sig_avg = max(%f, avg);\n", sdr_avg); - GLSL(}); + GLSL(barrier();) // Finally, to update the global state, we increment a counter per dispatch - GLSL(memoryBarrierBuffer();) - GLSL(barrier();) + GLSL(uint num_wg = gl_NumWorkGroups.x * gl_NumWorkGroups.y;) GLSL(if (gl_LocalInvocationIndex == 0 && atomicAdd(counter, 1) == num_wg - 1) {) - - // Since we sum up all the workgroups, we also still need to divide the - // average by the number of work groups GLSL( counter = 0;) - GLSL( frame_avg[frame_idx] /= num_wg;) - GLSL( uint cur_max = frame_max[frame_idx];) - GLSL( uint cur_avg = frame_avg[frame_idx];) - - // Scene change detection - GLSL( int diff = int(frame_num * cur_avg) - int(total_avg);) - GLSLF(" if (abs(diff) > frame_num * %d) {\n", scene_threshold); - GLSL( frame_num = 0;) - GLSL( total_max = total_avg = 0;) - GLSLF(" for (uint i = 0; i < %d; i++)\n", PEAK_DETECT_FRAMES+1); - GLSL( frame_max[i] = frame_avg[i] = 0;) - GLSL( frame_max[frame_idx] = cur_max;) - GLSL( frame_avg[frame_idx] = cur_avg;) - GLSL( }) - - // Add the current frame, then subtract and reset the next frame - GLSLF(" uint next = (frame_idx + 1) %% %d;\n", PEAK_DETECT_FRAMES+1); - GLSL( total_max += cur_max - frame_max[next];) - GLSL( total_avg += cur_avg - frame_avg[next];) - GLSL( frame_max[next] = frame_avg[next] = 0;) - - // Update the index and count - GLSL( frame_idx = next;) - GLSLF(" frame_num = min(frame_num + 1, %d);\n", PEAK_DETECT_FRAMES); + GLSL( vec2 cur = vec2(float(frame_sum) / float(num_wg), frame_max);) + GLSLF(" cur *= 1.0/%f;\n", MP_REF_WHITE); + + // Use an IIR low-pass filter to smooth out the detected values, with a + // configurable decay rate based on the desired time constant (tau) + float a = 1.0 - cos(1.0 / opts->decay_rate); + float decay = sqrt(a*a + 2*a) - a; + GLSLF(" average += %f * (cur - average);\n", decay); + + // Scene change hysteresis + GLSLF(" float weight = smoothstep(%f, %f, abs(cur.x - average.x));\n", + (float) opts->scene_threshold_low / MP_REF_WHITE, + (float) opts->scene_threshold_high / MP_REF_WHITE); + GLSL( average = mix(average, cur, weight);) + + // Reset SSBO state for the next frame + GLSL( frame_max = frame_sum = 0;) GLSL( memoryBarrierBuffer();) GLSL(}) } @@ -659,7 +639,7 @@ static void pass_tone_map(struct gl_shader_cache *sc, GLSLF("float sig_avg = %f;\n", sdr_avg); if (opts->compute_peak >= 0) - hdr_update_peak(sc); + hdr_update_peak(sc, opts); GLSLF("vec3 sig = color.rgb;\n"); |