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authorNiklas Haas <git@nand.wakku.to>2016-05-30 19:56:58 +0200
committerwm4 <wm4@nowhere>2016-05-30 20:17:33 +0200
commit45c3e0f0d0c836158ab38db53156bb6461ad7437 (patch)
treefa74784173edcbc2771b045947e0d64ed1b44bd9
parent098ff4174c6c9cc59e65c6f09b23b3adaee03983 (diff)
downloadmpv-45c3e0f0d0c836158ab38db53156bb6461ad7437.tar.bz2
mpv-45c3e0f0d0c836158ab38db53156bb6461ad7437.tar.xz
vo_opengl: refactor HDR mechanism
Instead of doing HDR tone mapping on an ad-hoc basis inside pass_colormanage, the reference peak of an image is now part of the image params (alongside colorspace, gamma, etc.) and tone mapping is done whenever peak_src != peak_dst. To get sensible behavior when mixing HDR and SDR content and displays, target-brightness is a generic filler for "the assumed brightness of SDR content". This gets rid of the weird display_scaled hack, sets the framework for multiple HDR functions with difference reference peaks, and allows us to (in a future commit) autodetect the right source peak from the HDR metadata. (Apart from metadata, the source peak can also be controlled via vf_format. For HDR content this adjusts the overall image brightness, for SDR content it's like simulating a different exposure)
-rw-r--r--DOCS/man/vf.rst8
-rw-r--r--DOCS/man/vo.rst7
-rw-r--r--video/filter/vf_format.c4
-rw-r--r--video/mp_image.c7
-rw-r--r--video/mp_image.h1
-rw-r--r--video/out/opengl/video.c50
-rw-r--r--video/out/opengl/video_shaders.c17
-rw-r--r--video/out/opengl/video_shaders.h2
8 files changed, 66 insertions, 30 deletions
diff --git a/DOCS/man/vf.rst b/DOCS/man/vf.rst
index 40c499cb5a..b4e4438f78 100644
--- a/DOCS/man/vf.rst
+++ b/DOCS/man/vf.rst
@@ -312,6 +312,14 @@ Available filters are:
:prophoto: ProPhoto RGB (ROMM) curve
:st2084: SMPTE ST2084 (HDR) curve
+ ``<peak>``
+ Reference peak illumination for the video file. This is mostly
+ interesting for HDR, but it can also be used tone map SDR content
+ to a darker or brighter exposure.
+
+ The default of 0.0 will default to the display's reference brightness
+ for SDR and the source's reference brightness for HDR.
+
``<stereo-in>``
Set the stereo mode the video is assumed to be encoded in. Takes the
same values as the ``--video-stereo-mode`` option.
diff --git a/DOCS/man/vo.rst b/DOCS/man/vo.rst
index 717c4738a9..3b16e74ae8 100644
--- a/DOCS/man/vo.rst
+++ b/DOCS/man/vo.rst
@@ -1061,9 +1061,10 @@ Available video output drivers are:
``target-brightness=<1..100000>``
Specifies the display's approximate brightness in cd/m^2. When playing
- HDR content, video colors will be tone mapped to this target brightness
- using the algorithm specified by ``hdr-tone-mapping``. The default of
- 250 cd/m^2 corresponds to a typical consumer display.
+ HDR content on a SDR display (or SDR content on an HDR display), video
+ colors will be tone mapped to this target brightness using the
+ algorithm specified by ``hdr-tone-mapping``. The default of 250 cd/m^2
+ corresponds to a typical consumer display.
``hdr-tone-mapping=<value>``
Specifies the algorithm used for tone-mapping HDR images onto the
diff --git a/video/filter/vf_format.c b/video/filter/vf_format.c
index ff7389cb7a..109fda4053 100644
--- a/video/filter/vf_format.c
+++ b/video/filter/vf_format.c
@@ -38,6 +38,7 @@ struct vf_priv_s {
int colorlevels;
int primaries;
int gamma;
+ float peak;
int chroma_location;
int stereo_in;
int stereo_out;
@@ -94,6 +95,8 @@ static int reconfig(struct vf_instance *vf, struct mp_image_params *in,
out->primaries = p->primaries;
if (p->gamma)
out->gamma = p->gamma;
+ if (p->peak)
+ out->peak = p->peak;
if (p->chroma_location)
out->chroma_location = p->chroma_location;
if (p->stereo_in)
@@ -142,6 +145,7 @@ static const m_option_t vf_opts_fields[] = {
OPT_CHOICE_C("colorlevels", colorlevels, 0, mp_csp_levels_names),
OPT_CHOICE_C("primaries", primaries, 0, mp_csp_prim_names),
OPT_CHOICE_C("gamma", gamma, 0, mp_csp_trc_names),
+ OPT_FLOAT("peak", peak, 0),
OPT_CHOICE_C("chroma-location", chroma_location, 0, mp_chroma_names),
OPT_CHOICE_C("stereo-in", stereo_in, 0, mp_stereo3d_names),
OPT_CHOICE_C("stereo-out", stereo_out, 0, mp_stereo3d_names),
diff --git a/video/mp_image.c b/video/mp_image.c
index ac3d4ea5e1..d5b97481e8 100644
--- a/video/mp_image.c
+++ b/video/mp_image.c
@@ -568,6 +568,7 @@ bool mp_image_params_equal(const struct mp_image_params *p1,
p1->colorlevels == p2->colorlevels &&
p1->primaries == p2->primaries &&
p1->gamma == p2->gamma &&
+ p1->peak == p2->peak &&
p1->chroma_location == p2->chroma_location &&
p1->rotate == p2->rotate &&
p1->stereo_in == p2->stereo_in &&
@@ -662,6 +663,12 @@ void mp_image_params_guess_csp(struct mp_image_params *params)
params->primaries = MP_CSP_PRIM_AUTO;
params->gamma = MP_CSP_TRC_AUTO;
}
+
+ // Guess the reference peak (independent of the colorspace)
+ if (params->gamma == MP_CSP_TRC_SMPTE_ST2084) {
+ if (!params->peak)
+ params->peak = 10000; // As per the spec
+ }
}
// Copy properties and data of the AVFrame into the mp_image, without taking
diff --git a/video/mp_image.h b/video/mp_image.h
index 0a43093ecb..18d25968c0 100644
--- a/video/mp_image.h
+++ b/video/mp_image.h
@@ -47,6 +47,7 @@ struct mp_image_params {
enum mp_csp_levels colorlevels;
enum mp_csp_prim primaries;
enum mp_csp_trc gamma;
+ float peak; // 0 = auto/unknown
enum mp_chroma_location chroma_location;
// The image should be rotated clockwise (0-359 degrees).
int rotate;
diff --git a/video/out/opengl/video.c b/video/out/opengl/video.c
index 380e768126..f0a2401172 100644
--- a/video/out/opengl/video.c
+++ b/video/out/opengl/video.c
@@ -2198,13 +2198,14 @@ static void pass_scale_main(struct gl_video *p)
// Adapts the colors from the given color space to the display device's native
// gamut.
-static void pass_colormanage(struct gl_video *p, bool display_scaled,
+static void pass_colormanage(struct gl_video *p, float peak_src,
enum mp_csp_prim prim_src,
enum mp_csp_trc trc_src)
{
GLSLF("// color management\n");
enum mp_csp_trc trc_dst = p->opts.target_trc;
enum mp_csp_prim prim_dst = p->opts.target_prim;
+ float peak_dst = p->opts.target_brightness;
if (p->use_lut_3d) {
// The 3DLUT is always generated against the original source space
@@ -2241,21 +2242,31 @@ static void pass_colormanage(struct gl_video *p, bool display_scaled,
if (trc_dst == MP_CSP_TRC_LINEAR || trc_dst == MP_CSP_TRC_SMPTE_ST2084)
trc_dst = MP_CSP_TRC_GAMMA22;
}
+ if (!peak_src) {
+ // If the source has no information known, it's display-referred
+ // (and should be treated relative to the specified desired peak_dst)
+ peak_src = peak_dst;
+ }
- bool need_gamma = trc_src != trc_dst || prim_src != prim_dst;
+ // All operations from here on require linear light as a starting point,
+ // so we linearize even if trc_src == trc_dst when one of the other
+ // operations needs it
+ bool need_gamma = trc_src != trc_dst || prim_src != prim_dst ||
+ peak_src != peak_dst;
if (need_gamma)
pass_linearize(p->sc, trc_src);
- // For HDR, the assumption of reference brightness = display brightness
- // is discontinued. Instead, we have to tone map the brightness to
- // the display using some algorithm.
- if (p->image_params.gamma == MP_CSP_TRC_SMPTE_ST2084 &&
- trc_dst != MP_CSP_TRC_SMPTE_ST2084 && !display_scaled)
+ // Adapt and tone map for a different reference peak brightness
+ if (peak_src != peak_dst)
{
GLSLF("// HDR tone mapping\n");
- int reference_brightness = 10000; // As per SMPTE ST.2084
- pass_tone_map(p->sc, reference_brightness, p->opts.target_brightness,
- p->opts.hdr_tone_mapping, p->opts.tone_mapping_param);
+ float rel_peak = peak_src / peak_dst;
+ // Normalize such that 1 is the target brightness (and values above
+ // 1 are out of range)
+ GLSLF("color.rgb *= vec3(%f);\n", rel_peak);
+ // Tone map back down to the range [0,1]
+ pass_tone_map(p->sc, rel_peak, p->opts.hdr_tone_mapping,
+ p->opts.tone_mapping_param);
}
// Adapt to the right colorspace if necessary
@@ -2268,8 +2279,14 @@ static void pass_colormanage(struct gl_video *p, bool display_scaled,
GLSL(color.rgb = cms_matrix * color.rgb;)
}
- if (need_gamma)
+ if (need_gamma) {
+ // If the target encoding function has a fixed peak, we need to
+ // un-normalize back to the encoding signal range
+ if (trc_dst == MP_CSP_TRC_SMPTE_ST2084)
+ GLSLF("color.rgb *= vec3(%f);\n", peak_dst / 10000);
+
pass_delinearize(p->sc, trc_dst);
+ }
if (p->use_lut_3d) {
gl_sc_uniform_sampler(p->sc, "lut_3d", GL_TEXTURE_3D, TEXUNIT_3DLUT);
@@ -2410,9 +2427,12 @@ static void pass_draw_osd(struct gl_video *p, int draw_flags, double pts,
default:
abort();
}
- // Subtitle color management, they're assumed to be sRGB by default
- if (cms)
- pass_colormanage(p, true, MP_CSP_PRIM_BT_709, MP_CSP_TRC_SRGB);
+ // Subtitle color management, they're assumed to be display-referred
+ // sRGB by default
+ if (cms) {
+ pass_colormanage(p, p->opts.target_brightness,
+ MP_CSP_PRIM_BT_709, MP_CSP_TRC_SRGB);
+ }
gl_sc_set_vao(p->sc, mpgl_osd_get_vao(p->osd));
gl_sc_gen_shader_and_reset(p->sc);
mpgl_osd_draw_part(p->osd, vp_w, vp_h, n);
@@ -2533,7 +2553,7 @@ static void pass_draw_to_screen(struct gl_video *p, int fbo)
GLSL(color.rgb = pow(color.rgb, vec3(user_gamma));)
}
- pass_colormanage(p, false, p->image_params.primaries,
+ pass_colormanage(p, p->image_params.peak, p->image_params.primaries,
p->use_linear ? MP_CSP_TRC_LINEAR : p->image_params.gamma);
// Draw checkerboard pattern to indicate transparency
diff --git a/video/out/opengl/video_shaders.c b/video/out/opengl/video_shaders.c
index d940c415e8..1f37f4fed1 100644
--- a/video/out/opengl/video_shaders.c
+++ b/video/out/opengl/video_shaders.c
@@ -313,15 +313,10 @@ void pass_delinearize(struct gl_shader_cache *sc, enum mp_csp_trc trc)
}
}
-// Tone map from one brightness to another
-void pass_tone_map(struct gl_shader_cache *sc, float peak_src, float peak_dst,
+// Tone map from a known peak brightness to the range [0,1]
+void pass_tone_map(struct gl_shader_cache *sc, float peak,
enum tone_mapping algo, float param)
{
- // First we renormalize to the output range
- float scale = peak_src / peak_dst;
- GLSLF("color.rgb *= vec3(%f);\n", scale);
-
- // Then we use some algorithm to map back to [0,1]
switch (algo) {
case TONE_MAPPING_CLIP:
GLSL(color.rgb = clamp(color.rgb, 0.0, 1.0);)
@@ -331,7 +326,7 @@ void pass_tone_map(struct gl_shader_cache *sc, float peak_src, float peak_dst,
float contrast = isnan(param) ? 0.5 : param,
offset = (1.0 - contrast) / contrast;
GLSLF("color.rgb = color.rgb / (color.rgb + vec3(%f));\n", offset);
- GLSLF("color.rgb *= vec3(%f);\n", (scale + offset) / scale);
+ GLSLF("color.rgb *= vec3(%f);\n", (peak + offset) / peak);
break;
}
@@ -342,20 +337,20 @@ void pass_tone_map(struct gl_shader_cache *sc, float peak_src, float peak_dst,
A, C*B, D*E, A, B, D*F, E/F);
GLSLHF("}\n");
- GLSLF("color.rgb = hable(color.rgb) / hable(vec3(%f));\n", scale);
+ GLSLF("color.rgb = hable(color.rgb) / hable(vec3(%f));\n", peak);
break;
}
case TONE_MAPPING_GAMMA: {
float gamma = isnan(param) ? 1.8 : param;
GLSLF("color.rgb = pow(color.rgb / vec3(%f), vec3(%f));\n",
- scale, 1.0/gamma);
+ peak, 1.0/gamma);
break;
}
case TONE_MAPPING_LINEAR: {
float coeff = isnan(param) ? 1.0 : param;
- GLSLF("color.rgb = vec3(%f) * color.rgb;\n", coeff / scale);
+ GLSLF("color.rgb = vec3(%f) * color.rgb;\n", coeff / peak);
break;
}
diff --git a/video/out/opengl/video_shaders.h b/video/out/opengl/video_shaders.h
index e43efadeb4..0ee3d81fb5 100644
--- a/video/out/opengl/video_shaders.h
+++ b/video/out/opengl/video_shaders.h
@@ -38,7 +38,7 @@ void pass_sample_oversample(struct gl_shader_cache *sc, struct scaler *scaler,
void pass_linearize(struct gl_shader_cache *sc, enum mp_csp_trc trc);
void pass_delinearize(struct gl_shader_cache *sc, enum mp_csp_trc trc);
-void pass_tone_map(struct gl_shader_cache *sc, float peak_src, float peak_dst,
+void pass_tone_map(struct gl_shader_cache *sc, float peak,
enum tone_mapping algo, float param);
void pass_sample_deband(struct gl_shader_cache *sc, struct deband_opts *opts,