From 62dfa2ba14d9adbf88e8748a7e1c5ce68f0f8fa8 Mon Sep 17 00:00:00 2001 From: Vittorio Giovara Date: Mon, 10 Jul 2017 10:34:30 -0400 Subject: [PATCH] Add tonemap filter Based off mpv automatic tonemapping capabilities. Signed-off-by: Vittorio Giovara --- doc/filters.texi | 108 ++++++++++++ libavfilter/Makefile | 1 + libavfilter/allfilters.c | 1 + libavfilter/version.h | 2 +- libavfilter/vf_tonemap.c | 354 +++++++++++++++++++++++++++++++++++++++ 5 files changed, 465 insertions(+), 1 deletion(-) create mode 100644 libavfilter/vf_tonemap.c diff --git a/doc/filters.texi b/doc/filters.texi index 8b0c6d920b..502ebd5e45 100644 --- a/doc/filters.texi +++ b/doc/filters.texi @@ -14442,6 +14442,113 @@ Vertical low-pass filtering can only be enabled for @option{mode} @end table +@section tonemap +Tone map colors from different dynamic ranges. + +This filter expects data in single precision floating point, as it needs to +operate on (and can output) out-of-range values. Another filter, such as +@ref{zscale}, is needed to convert the resulting frame to a usable format. + +The tonemapping algorithms implemented only work on linear light, so input +data should be linearized beforehand (and possibly correctly tagged). + +@example +ffmpeg -i INPUT -vf zscale=transfer=linear,tonemap=clip,zscale=transfer=bt709,format=yuv420p OUTPUT +@end example + +@subsection Options +The filter accepts the following options. + +@table @option +@item tonemap +Set the tone map algorithm to use. + +Possible values are: +@table @var +@item none +Do not apply any tone map, only desaturate overbright pixels. + +@item clip +Hard-clip any out-of-range values. Use it for perfect color accuracy for +in-range values, while distorting out-of-range values. + +@item linear +Stretch the entire reference gamut to a linear multiple of the display. + +@item gamma +Fit a logarithmic transfer between the tone curves. + +@item reinhard +Preserve overall image brightness with a simple curve, using nonlinear +contrast, which results in flattening details and degrading color accuracy. + +@item hable +Peserve both dark and bright details better than @var{reinhard}, at the cost +of slightly darkening everything. Use it when detail preservation is more +important than color and brightness accuracy. + +@item mobius +Smoothly map out-of-range values, while retaining contrast and colors for +in-range material as much as possible. Use it when color accuracy is more +important than detail preservation. +@end table + +Default is none. + +@item param +Tune the tone mapping algorithm. + +This affects the following algorithms: +@table @var +@item none +Ignored. + +@item linear +Specifies the scale factor to use while stretching. +Default to 1.0. + +@item gamma +Specifies the exponent of the function. +Default to 1.8. + +@item clip +Specify an extra linear coefficient to multiply into the signal before clipping. +Default to 1.0. + +@item reinhard +Specify the local contrast coefficient at the display peak. +Default to 0.5, which means that in-gamut values will be about half as bright +as when clipping. + +@item hable +Ignored. + +@item mobius +Specify the transition point from linear to mobius transform. Every value +below this point is guaranteed to be mapped 1:1. The higher the value, the +more accurate the result will be, at the cost of losing bright details. +Default to 0.3, which due to the steep initial slope still preserves in-range +colors fairly accurately. +@end table + +@item desat +Apply desaturation for highlights that exceed this level of brightness. The +higher the parameter, the more color information will be preserved. This +setting helps prevent unnaturally blown-out colors for super-highlights, by +(smoothly) turning into white instead. This makes images feel more natural, +at the cost of reducing information about out-of-range colors. + +The default of 2.0 is somewhat conservative and will mostly just apply to +skies or directly sunlit surfaces. A setting of 0.0 disables this option. + +This option works only if the input frame has a supported color tag. + +@item peak +Override signal/nominal/reference peak with this value. Useful when the +embedded peak information in display metadata is not reliable or when tone +mapping from a lower range to a higher range. +@end table + @section transpose Transpose rows with columns in the input video and optionally flip it. @@ -15627,6 +15734,7 @@ zoompan=z='min(max(zoom,pzoom)+0.0015,1.5)':d=1:x='iw/2-(iw/zoom/2)':y='ih/2-(ih @end example @end itemize +@anchor{zscale} @section zscale Scale (resize) the input video, using the z.lib library: https://github.com/sekrit-twc/zimg. diff --git a/libavfilter/Makefile b/libavfilter/Makefile index 06b915fc91..545b871cd7 100644 --- a/libavfilter/Makefile +++ b/libavfilter/Makefile @@ -314,6 +314,7 @@ OBJS-$(CONFIG_THUMBNAIL_FILTER) += vf_thumbnail.o OBJS-$(CONFIG_TILE_FILTER) += vf_tile.o OBJS-$(CONFIG_TINTERLACE_FILTER) += vf_tinterlace.o OBJS-$(CONFIG_TLUT2_FILTER) += vf_lut2.o framesync2.o +OBJS-$(CONFIG_TONEMAP_FILTER) += vf_tonemap.o OBJS-$(CONFIG_TRANSPOSE_FILTER) += vf_transpose.o OBJS-$(CONFIG_TRIM_FILTER) += trim.o OBJS-$(CONFIG_UNPREMULTIPLY_FILTER) += vf_premultiply.o framesync2.o diff --git a/libavfilter/allfilters.c b/libavfilter/allfilters.c index e58c0d5c82..f1dacaffa8 100644 --- a/libavfilter/allfilters.c +++ b/libavfilter/allfilters.c @@ -325,6 +325,7 @@ static void register_all(void) REGISTER_FILTER(TILE, tile, vf); REGISTER_FILTER(TINTERLACE, tinterlace, vf); REGISTER_FILTER(TLUT2, tlut2, vf); + REGISTER_FILTER(TONEMAP, tonemap, vf); REGISTER_FILTER(TRANSPOSE, transpose, vf); REGISTER_FILTER(TRIM, trim, vf); REGISTER_FILTER(UNPREMULTIPLY, unpremultiply, vf); diff --git a/libavfilter/version.h b/libavfilter/version.h index 1d37fd8e4b..5efb648c6d 100644 --- a/libavfilter/version.h +++ b/libavfilter/version.h @@ -30,7 +30,7 @@ #include "libavutil/version.h" #define LIBAVFILTER_VERSION_MAJOR 6 -#define LIBAVFILTER_VERSION_MINOR 98 +#define LIBAVFILTER_VERSION_MINOR 99 #define LIBAVFILTER_VERSION_MICRO 100 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \ diff --git a/libavfilter/vf_tonemap.c b/libavfilter/vf_tonemap.c new file mode 100644 index 0000000000..10308bdb16 --- /dev/null +++ b/libavfilter/vf_tonemap.c @@ -0,0 +1,354 @@ +/* + * Copyright (c) 2017 Vittorio Giovara + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +/** + * @file + * tonemap algorithms + */ + +#include +#include +#include + +#include "libavutil/imgutils.h" +#include "libavutil/internal.h" +#include "libavutil/intreadwrite.h" +#include "libavutil/mastering_display_metadata.h" +#include "libavutil/opt.h" +#include "libavutil/pixdesc.h" + +#include "avfilter.h" +#include "formats.h" +#include "internal.h" +#include "video.h" + +#define REFERENCE_WHITE 100.0f + +enum TonemapAlgorithm { + TONEMAP_NONE, + TONEMAP_LINEAR, + TONEMAP_GAMMA, + TONEMAP_CLIP, + TONEMAP_REINHARD, + TONEMAP_HABLE, + TONEMAP_MOBIUS, + TONEMAP_MAX, +}; + +typedef struct LumaCoefficients { + double cr, cg, cb; +} LumaCoefficients; + + +static const struct LumaCoefficients luma_coefficients[AVCOL_SPC_NB] = { + [AVCOL_SPC_FCC] = { 0.30, 0.59, 0.11 }, + [AVCOL_SPC_BT470BG] = { 0.299, 0.587, 0.114 }, + [AVCOL_SPC_SMPTE170M] = { 0.299, 0.587, 0.114 }, + [AVCOL_SPC_BT709] = { 0.2126, 0.7152, 0.0722 }, + [AVCOL_SPC_SMPTE240M] = { 0.212, 0.701, 0.087 }, + [AVCOL_SPC_BT2020_NCL] = { 0.2627, 0.6780, 0.0593 }, + [AVCOL_SPC_BT2020_CL] = { 0.2627, 0.6780, 0.0593 }, +}; + +typedef struct TonemapContext { + const AVClass *class; + + enum TonemapAlgorithm tonemap; + double param; + double desat; + double peak; + + const LumaCoefficients *coeffs; +} TonemapContext; + +static const enum AVPixelFormat pix_fmts[] = { + AV_PIX_FMT_GBRPF32, + AV_PIX_FMT_GBRAPF32, + AV_PIX_FMT_NONE, +}; + +static int query_formats(AVFilterContext *ctx) +{ + return ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); +} + +static av_cold int init(AVFilterContext *ctx) +{ + TonemapContext *s = ctx->priv; + + switch(s->tonemap) { + case TONEMAP_GAMMA: + if (isnan(s->param)) + s->param = 1.8f; + break; + case TONEMAP_REINHARD: + if (!isnan(s->param)) + s->param = (1.0f - s->param) / s->param; + break; + case TONEMAP_MOBIUS: + if (isnan(s->param)) + s->param = 0.3f; + break; + } + + if (isnan(s->param)) + s->param = 1.0f; + + return 0; +} + +static double determine_signal_peak(AVFrame *in) +{ + AVFrameSideData *sd = av_frame_get_side_data(in, AV_FRAME_DATA_CONTENT_LIGHT_LEVEL); + double peak = 0; + + if (sd) { + AVContentLightMetadata *clm = (AVContentLightMetadata *)sd->data; + peak = clm->MaxCLL / REFERENCE_WHITE; + } + + sd = av_frame_get_side_data(in, AV_FRAME_DATA_MASTERING_DISPLAY_METADATA); + if (!peak && sd) { + AVMasteringDisplayMetadata *metadata = (AVMasteringDisplayMetadata *)sd->data; + if (metadata->has_luminance) + peak = av_q2d(metadata->max_luminance) / REFERENCE_WHITE; + } + + /* smpte2084 needs the side data above to work correctly + * if missing, assume that the original transfer was arib-std-b67 */ + if (!peak) + peak = 12; + + return peak; +} + +static float hable(float in) +{ + float a = 0.15f, b = 0.50f, c = 0.10f, d = 0.20f, e = 0.02f, f = 0.30f; + return (in * (in * a + b * c) + d * e) / (in * (in * a + b) + d * f) - e / f; +} + +static float mobius(float in, float j, double peak) +{ + float a, b; + + if (in <= j) + return in; + + a = -j * j * (peak - 1.0f) / (j * j - 2.0f * j + peak); + b = (j * j - 2.0f * j * peak + peak) / FFMAX(peak - 1.0f, 1e-6); + + return (b * b + 2.0f * b * j + j * j) / (b - a) * (in + a) / (in + b); +} + +#define MIX(x,y,a) (x) * (1 - (a)) + (y) * (a) +static void tonemap(TonemapContext *s, AVFrame *out, const AVFrame *in, + const AVPixFmtDescriptor *desc, int x, int y, double peak) +{ + const float *r_in = (const float *)(in->data[0] + x * desc->comp[0].step + y * in->linesize[0]); + const float *b_in = (const float *)(in->data[1] + x * desc->comp[1].step + y * in->linesize[1]); + const float *g_in = (const float *)(in->data[2] + x * desc->comp[2].step + y * in->linesize[2]); + float *r_out = (float *)(out->data[0] + x * desc->comp[0].step + y * out->linesize[0]); + float *b_out = (float *)(out->data[1] + x * desc->comp[1].step + y * out->linesize[1]); + float *g_out = (float *)(out->data[2] + x * desc->comp[2].step + y * out->linesize[2]); + float sig, sig_orig; + + /* load values */ + *r_out = *r_in; + *b_out = *b_in; + *g_out = *g_in; + + /* desaturate to prevent unnatural colors */ + if (s->desat > 0) { + float luma = s->coeffs->cr * *r_in + s->coeffs->cg * *g_in + s->coeffs->cb * *b_in; + float overbright = FFMAX(luma - s->desat, 1e-6) / FFMAX(luma, 1e-6); + *r_out = MIX(*r_in, luma, overbright); + *g_out = MIX(*g_in, luma, overbright); + *b_out = MIX(*b_in, luma, overbright); + } + + /* pick the brightest component, reducing the value range as necessary + * to keep the entire signal in range and preventing discoloration due to + * out-of-bounds clipping */ + sig = FFMAX(FFMAX3(*r_out, *g_out, *b_out), 1e-6); + sig_orig = sig; + + switch(s->tonemap) { + default: + case TONEMAP_NONE: + // do nothing + break; + case TONEMAP_LINEAR: + sig = sig * s->param / peak; + break; + case TONEMAP_GAMMA: + sig = sig > 0.05f ? pow(sig / peak, 1.0f / s->param) + : sig * pow(0.05f / peak, 1.0f / s->param) / 0.05f; + break; + case TONEMAP_CLIP: + sig = av_clipf(sig * s->param, 0, 1.0f); + break; + case TONEMAP_HABLE: + sig = hable(sig) / hable(peak); + break; + case TONEMAP_REINHARD: + sig = sig / (sig + s->param) * (peak + s->param) / peak; + break; + case TONEMAP_MOBIUS: + sig = mobius(sig, s->param, peak); + break; + } + + /* apply the computed scale factor to the color, + * linearly to prevent discoloration */ + *r_out *= sig / sig_orig; + *g_out *= sig / sig_orig; + *b_out *= sig / sig_orig; +} + +static int filter_frame(AVFilterLink *link, AVFrame *in) +{ + TonemapContext *s = link->dst->priv; + AVFilterLink *outlink = link->dst->outputs[0]; + AVFrame *out; + const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format); + const AVPixFmtDescriptor *odesc = av_pix_fmt_desc_get(outlink->format); + int ret, x, y; + double peak = s->peak; + + if (!desc || !odesc) { + av_frame_free(&in); + return AVERROR_BUG; + } + + out = ff_get_video_buffer(outlink, outlink->w, outlink->h); + if (!out) { + av_frame_free(&in); + return AVERROR(ENOMEM); + } + + ret = av_frame_copy_props(out, in); + if (ret < 0) { + av_frame_free(&in); + av_frame_free(&out); + return ret; + } + + /* input and output transfer will be linear */ + if (in->color_trc == AVCOL_TRC_UNSPECIFIED) { + av_log(s, AV_LOG_WARNING, "Untagged transfer, assuming linear light\n"); + out->color_trc = AVCOL_TRC_LINEAR; + } else if (in->color_trc != AVCOL_TRC_LINEAR) + av_log(s, AV_LOG_WARNING, "Tonemapping works on linear light only\n"); + + /* read peak from side data if not passed in */ + if (!peak) { + peak = determine_signal_peak(in); + av_log(s, AV_LOG_DEBUG, "Computed signal peak: %f\n", peak); + } + + /* load original color space even if pixel format is RGB to compute overbrights */ + s->coeffs = &luma_coefficients[in->colorspace]; + if (s->desat > 0 && (in->colorspace == AVCOL_SPC_UNSPECIFIED || !s->coeffs)) { + if (in->colorspace == AVCOL_SPC_UNSPECIFIED) + av_log(s, AV_LOG_WARNING, "Missing color space information, "); + else if (!s->coeffs) + av_log(s, AV_LOG_WARNING, "Unsupported color space '%s', ", + av_color_space_name(in->colorspace)); + av_log(s, AV_LOG_WARNING, "desaturation is disabled\n"); + s->desat = 0; + } + + /* do the tone map */ + for (y = 0; y < out->height; y++) + for (x = 0; x < out->width; x++) + tonemap(s, out, in, desc, x, y, peak); + + /* copy/generate alpha if needed */ + if (desc->flags & AV_PIX_FMT_FLAG_ALPHA && odesc->flags & AV_PIX_FMT_FLAG_ALPHA) { + av_image_copy_plane(out->data[3], out->linesize[3], + in->data[3], in->linesize[3], + out->linesize[3], outlink->h); + } else if (odesc->flags & AV_PIX_FMT_FLAG_ALPHA) { + for (y = 0; y < out->height; y++) { + for (x = 0; x < out->width; x++) { + AV_WN32(out->data[3] + x * odesc->comp[3].step + y * out->linesize[3], + av_float2int(1.0f)); + } + } + } + + av_frame_free(&in); + + return ff_filter_frame(outlink, out); +} + +#define OFFSET(x) offsetof(TonemapContext, x) +#define FLAGS AV_OPT_FLAG_VIDEO_PARAM | AV_OPT_FLAG_FILTERING_PARAM +static const AVOption tonemap_options[] = { + { "tonemap", "tonemap algorithm selection", OFFSET(tonemap), AV_OPT_TYPE_INT, {.i64 = TONEMAP_NONE}, TONEMAP_NONE, TONEMAP_MAX - 1, FLAGS, "tonemap" }, + { "none", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_NONE}, 0, 0, FLAGS, "tonemap" }, + { "linear", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_LINEAR}, 0, 0, FLAGS, "tonemap" }, + { "gamma", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_GAMMA}, 0, 0, FLAGS, "tonemap" }, + { "clip", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_CLIP}, 0, 0, FLAGS, "tonemap" }, + { "reinhard", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_REINHARD}, 0, 0, FLAGS, "tonemap" }, + { "hable", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_HABLE}, 0, 0, FLAGS, "tonemap" }, + { "mobius", 0, 0, AV_OPT_TYPE_CONST, {.i64 = TONEMAP_MOBIUS}, 0, 0, FLAGS, "tonemap" }, + { "param", "tonemap parameter", OFFSET(param), AV_OPT_TYPE_DOUBLE, {.dbl = NAN}, DBL_MIN, DBL_MAX, FLAGS }, + { "desat", "desaturation strength", OFFSET(desat), AV_OPT_TYPE_DOUBLE, {.dbl = 2}, 0, DBL_MAX, FLAGS }, + { "peak", "signal peak override", OFFSET(peak), AV_OPT_TYPE_DOUBLE, {.dbl = 0}, 0, DBL_MAX, FLAGS }, + { NULL } +}; + +static const AVClass tonemap_class = { + .class_name = "tonemap", + .item_name = av_default_item_name, + .option = tonemap_options, + .version = LIBAVUTIL_VERSION_INT, + .category = AV_CLASS_CATEGORY_FILTER, +}; + +static const AVFilterPad tonemap_inputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .filter_frame = filter_frame, + }, + { NULL } +}; + +static const AVFilterPad tonemap_outputs[] = { + { + .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + }, + { NULL } +}; + +AVFilter ff_vf_tonemap = { + .name = "tonemap", + .description = NULL_IF_CONFIG_SMALL("Conversion to/from different dynamic ranges."), + .init = init, + .query_formats = query_formats, + .priv_size = sizeof(TonemapContext), + .priv_class = &tonemap_class, + .inputs = tonemap_inputs, + .outputs = tonemap_outputs, +};