[FFmpeg-devel] [PATCH] avutil/csp: create public API for colorspace structs

Andreas Rheinhardt andreas.rheinhardt at outlook.com
Sun May 15 19:32:36 EEST 2022


Leo Izen:
> This commit moves some of the functionality from avfilter/colorspace
> into avutil/csp and exposes it as a public API so it can be used by
> libavcodec and/or libavformat.
> ---
>  libavfilter/colorspace.c    |  88 ----------------------------
>  libavfilter/colorspace.h    |  25 +-------
>  libavfilter/fflcms2.c       |   3 +-
>  libavfilter/fflcms2.h       |   2 +-
>  libavfilter/vf_colorspace.c |   9 +--
>  libavfilter/vf_iccdetect.c  |   3 +-
>  libavutil/Makefile          |   2 +
>  libavutil/csp.c             | 111 ++++++++++++++++++++++++++++++++++++
>  libavutil/csp.h             |  49 ++++++++++++++++
>  9 files changed, 173 insertions(+), 119 deletions(-)
>  create mode 100644 libavutil/csp.c
>  create mode 100644 libavutil/csp.h
> 
> diff --git a/libavfilter/colorspace.c b/libavfilter/colorspace.c
> index 8d7b882375..f22e7002e1 100644
> --- a/libavfilter/colorspace.c
> +++ b/libavfilter/colorspace.c
> @@ -107,94 +107,6 @@ static const double gbr_matrix[3][3] =
>      { 0.5, -0.5, 0   },
>  };
>  
> -/*
> - * All constants explained in e.g. https://linuxtv.org/downloads/v4l-dvb-apis/ch02s06.html
> - * The older ones (bt470bg/m) are also explained in their respective ITU docs
> - * (e.g. https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.470-5-199802-S!!PDF-E.pdf)
> - * whereas the newer ones can typically be copied directly from wikipedia :)
> - */
> -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_YCOCG]      = { 0.25,   0.5,    0.25   },
> -    [AVCOL_SPC_RGB]        = { 1,      1,      1      },
> -    [AVCOL_SPC_BT2020_NCL] = { 0.2627, 0.6780, 0.0593 },
> -    [AVCOL_SPC_BT2020_CL]  = { 0.2627, 0.6780, 0.0593 },
> -};
> -
> -const struct LumaCoefficients *ff_get_luma_coefficients(enum AVColorSpace csp)
> -{
> -    const struct LumaCoefficients *coeffs;
> -
> -    if (csp >= AVCOL_SPC_NB)
> -        return NULL;
> -    coeffs = &luma_coefficients[csp];
> -    if (!coeffs->cr)
> -        return NULL;
> -
> -    return coeffs;
> -}
> -
> -#define WP_D65 { 0.3127, 0.3290 }
> -#define WP_C   { 0.3100, 0.3160 }
> -#define WP_DCI { 0.3140, 0.3510 }
> -#define WP_E   { 1/3.0f, 1/3.0f }
> -
> -static const struct ColorPrimaries color_primaries[AVCOL_PRI_NB] = {
> -    [AVCOL_PRI_BT709]     = { WP_D65, { 0.640, 0.330, 0.300, 0.600, 0.150, 0.060 } },
> -    [AVCOL_PRI_BT470M]    = { WP_C,   { 0.670, 0.330, 0.210, 0.710, 0.140, 0.080 } },
> -    [AVCOL_PRI_BT470BG]   = { WP_D65, { 0.640, 0.330, 0.290, 0.600, 0.150, 0.060 } },
> -    [AVCOL_PRI_SMPTE170M] = { WP_D65, { 0.630, 0.340, 0.310, 0.595, 0.155, 0.070 } },
> -    [AVCOL_PRI_SMPTE240M] = { WP_D65, { 0.630, 0.340, 0.310, 0.595, 0.155, 0.070 } },
> -    [AVCOL_PRI_SMPTE428]  = { WP_E,   { 0.735, 0.265, 0.274, 0.718, 0.167, 0.009 } },
> -    [AVCOL_PRI_SMPTE431]  = { WP_DCI, { 0.680, 0.320, 0.265, 0.690, 0.150, 0.060 } },
> -    [AVCOL_PRI_SMPTE432]  = { WP_D65, { 0.680, 0.320, 0.265, 0.690, 0.150, 0.060 } },
> -    [AVCOL_PRI_FILM]      = { WP_C,   { 0.681, 0.319, 0.243, 0.692, 0.145, 0.049 } },
> -    [AVCOL_PRI_BT2020]    = { WP_D65, { 0.708, 0.292, 0.170, 0.797, 0.131, 0.046 } },
> -    [AVCOL_PRI_JEDEC_P22] = { WP_D65, { 0.630, 0.340, 0.295, 0.605, 0.155, 0.077 } },
> -};
> -
> -const struct ColorPrimaries *ff_get_color_primaries(enum AVColorPrimaries prm)
> -{
> -    const struct ColorPrimaries *p;
> -
> -    if (prm >= AVCOL_PRI_NB)
> -        return NULL;
> -    p = &color_primaries[prm];
> -    if (!p->prim.xr)
> -        return NULL;
> -
> -    return p;
> -}
> -
> -enum AVColorPrimaries ff_detect_color_primaries(const struct ColorPrimaries *prm)
> -{
> -    double delta;
> -
> -    for (enum AVColorPrimaries p = 0; p < AVCOL_PRI_NB; p++) {
> -        const struct ColorPrimaries *ref = &color_primaries[p];
> -        if (!ref->prim.xr)
> -            continue;
> -
> -        delta = fabs(prm->prim.xr - ref->prim.xr) +
> -                fabs(prm->prim.yr - ref->prim.yr) +
> -                fabs(prm->prim.yg - ref->prim.yg) +
> -                fabs(prm->prim.yg - ref->prim.yg) +
> -                fabs(prm->prim.yb - ref->prim.yb) +
> -                fabs(prm->prim.yb - ref->prim.yb) +
> -                fabs(prm->wp.xw - ref->wp.xw) +
> -                fabs(prm->wp.yw - ref->wp.yw);
> -
> -        if (delta < 0.001)
> -            return p;
> -    }
> -
> -    return AVCOL_PRI_UNSPECIFIED;
> -}
> -
>  void ff_fill_rgb2yuv_table(const struct LumaCoefficients *coeffs,
>                             double rgb2yuv[3][3])
>  {
> diff --git a/libavfilter/colorspace.h b/libavfilter/colorspace.h
> index 6959133a49..c5f39baca8 100644
> --- a/libavfilter/colorspace.h
> +++ b/libavfilter/colorspace.h
> @@ -20,43 +20,20 @@
>  #ifndef AVFILTER_COLORSPACE_H
>  #define AVFILTER_COLORSPACE_H
>  
> +#include "libavutil/csp.h"
>  #include "libavutil/frame.h"
>  #include "libavutil/pixfmt.h"
>  
>  #define REFERENCE_WHITE 100.0f
>  
> -struct LumaCoefficients {
> -    double cr, cg, cb;
> -};
> -
> -struct PrimaryCoefficients {
> -    double xr, yr, xg, yg, xb, yb;
> -};
> -
> -struct WhitepointCoefficients {
> -    double xw, yw;
> -};
> -
> -struct ColorPrimaries {
> -    struct WhitepointCoefficients wp;
> -    struct PrimaryCoefficients prim;
> -};
> -
>  void ff_matrix_invert_3x3(const double in[3][3], double out[3][3]);
>  void ff_matrix_mul_3x3(double dst[3][3],
>                 const double src1[3][3], const double src2[3][3]);
>  void ff_fill_rgb2xyz_table(const struct PrimaryCoefficients *coeffs,
>                             const struct WhitepointCoefficients *wp,
>                             double rgb2xyz[3][3]);
> -
> -/* Returns AVCOL_PRI_UNSPECIFIED if no clear match can be identified */
> -enum AVColorPrimaries ff_detect_color_primaries(const struct ColorPrimaries *prm);
> -
> -const struct ColorPrimaries *ff_get_color_primaries(enum AVColorPrimaries prm);
> -const struct LumaCoefficients *ff_get_luma_coefficients(enum AVColorSpace csp);
>  void ff_fill_rgb2yuv_table(const struct LumaCoefficients *coeffs,
>                             double rgb2yuv[3][3]);
> -
>  double ff_determine_signal_peak(AVFrame *in);
>  void ff_update_hdr_metadata(AVFrame *in, double peak);
>  
> diff --git a/libavfilter/fflcms2.c b/libavfilter/fflcms2.c
> index efc7cb5189..b1a0429010 100644
> --- a/libavfilter/fflcms2.c
> +++ b/libavfilter/fflcms2.c
> @@ -18,6 +18,7 @@
>   */
>  
>  #include "libavutil/color_utils.h"
> +#include "libavutil/csp.h"
>  
>  #include "fflcms2.h"
>  
> @@ -151,7 +152,7 @@ int ff_icc_profile_generate(FFIccContext *s,
>      const struct ColorPrimaries *prim;
>      int ret;
>  
> -    if (!(prim = ff_get_color_primaries(color_prim)))
> +    if (!(prim = av_get_color_primaries(color_prim)))
>          return AVERROR_INVALIDDATA;
>      if ((ret = get_curve(s, color_trc, &tonecurve)) < 0)
>          return ret;
> diff --git a/libavfilter/fflcms2.h b/libavfilter/fflcms2.h
> index ad6c8c47cf..628598a41c 100644
> --- a/libavfilter/fflcms2.h
> +++ b/libavfilter/fflcms2.h
> @@ -25,9 +25,9 @@
>  #ifndef AVFILTER_FFLCMS2_H
>  #define AVFILTER_FFLCMS2_H
>  
> +#include "libavutil/csp.h"
>  #include "libavutil/frame.h"
>  #include "libavutil/pixfmt.h"
> -#include "colorspace.h"
>  
>  #include <lcms2.h>
>  
> diff --git a/libavfilter/vf_colorspace.c b/libavfilter/vf_colorspace.c
> index 3c8b3b20eb..e5b1a06c54 100644
> --- a/libavfilter/vf_colorspace.c
> +++ b/libavfilter/vf_colorspace.c
> @@ -24,6 +24,7 @@
>   */
>  
>  #include "libavutil/avassert.h"
> +#include "libavutil/csp.h"
>  #include "libavutil/mem_internal.h"
>  #include "libavutil/opt.h"
>  #include "libavutil/pixdesc.h"
> @@ -438,7 +439,7 @@ static int create_filtergraph(AVFilterContext *ctx,
>              s->in_prm = default_prm[FFMIN(s->user_iall, CS_NB)];
>          if (s->user_iprm != AVCOL_PRI_UNSPECIFIED)
>              s->in_prm = s->user_iprm;
> -        s->in_primaries = ff_get_color_primaries(s->in_prm);
> +        s->in_primaries = av_get_color_primaries(s->in_prm);
>          if (!s->in_primaries) {
>              av_log(ctx, AV_LOG_ERROR,
>                     "Unsupported input primaries %d (%s)\n",
> @@ -446,7 +447,7 @@ static int create_filtergraph(AVFilterContext *ctx,
>              return AVERROR(EINVAL);
>          }
>          s->out_prm = out->color_primaries;
> -        s->out_primaries = ff_get_color_primaries(s->out_prm);
> +        s->out_primaries = av_get_color_primaries(s->out_prm);
>          if (!s->out_primaries) {
>              if (s->out_prm == AVCOL_PRI_UNSPECIFIED) {
>                  if (s->user_all == CS_UNSPECIFIED) {
> @@ -551,7 +552,7 @@ static int create_filtergraph(AVFilterContext *ctx,
>          s->in_rng = in->color_range;
>          if (s->user_irng != AVCOL_RANGE_UNSPECIFIED)
>              s->in_rng = s->user_irng;
> -        s->in_lumacoef = ff_get_luma_coefficients(s->in_csp);
> +        s->in_lumacoef = av_get_luma_coefficients(s->in_csp);
>          if (!s->in_lumacoef) {
>              av_log(ctx, AV_LOG_ERROR,
>                     "Unsupported input colorspace %d (%s)\n",
> @@ -564,7 +565,7 @@ static int create_filtergraph(AVFilterContext *ctx,
>      if (!s->out_lumacoef) {
>          s->out_csp = out->colorspace;
>          s->out_rng = out->color_range;
> -        s->out_lumacoef = ff_get_luma_coefficients(s->out_csp);
> +        s->out_lumacoef = av_get_luma_coefficients(s->out_csp);
>          if (!s->out_lumacoef) {
>              if (s->out_csp == AVCOL_SPC_UNSPECIFIED) {
>                  if (s->user_all == CS_UNSPECIFIED) {
> diff --git a/libavfilter/vf_iccdetect.c b/libavfilter/vf_iccdetect.c
> index fb7871f035..d2b0e5569f 100644
> --- a/libavfilter/vf_iccdetect.c
> +++ b/libavfilter/vf_iccdetect.c
> @@ -24,6 +24,7 @@
>  
>  #include <lcms2.h>
>  
> +#include "libavutil/csp.h"
>  #include "libavutil/opt.h"
>  #include "libavutil/pixdesc.h"
>  
> @@ -98,7 +99,7 @@ static int iccdetect_filter_frame(AVFilterLink *inlink, AVFrame *frame)
>      if (ret < 0)
>          return ret;
>  
> -    s->profile_prim = ff_detect_color_primaries(&coeffs);
> +    s->profile_prim = av_detect_color_primaries(&coeffs);
>  
>  done:
>      if (s->profile_prim != AVCOL_PRI_UNSPECIFIED) {
> diff --git a/libavutil/Makefile b/libavutil/Makefile
> index 234de62a4b..74d21a8103 100644
> --- a/libavutil/Makefile
> +++ b/libavutil/Makefile
> @@ -20,6 +20,7 @@ HEADERS = adler32.h                                                     \
>            common.h                                                      \
>            cpu.h                                                         \
>            crc.h                                                         \
> +          csp.h                                                         \
>            des.h                                                         \
>            detection_bbox.h                                              \
>            dict.h                                                        \
> @@ -113,6 +114,7 @@ OBJS = adler32.o                                                        \
>         color_utils.o                                                    \
>         cpu.o                                                            \
>         crc.o                                                            \
> +       csp.o                                                            \
>         des.o                                                            \
>         detection_bbox.o                                                 \
>         dict.o                                                           \
> diff --git a/libavutil/csp.c b/libavutil/csp.c
> new file mode 100644
> index 0000000000..cd755c1795
> --- /dev/null
> +++ b/libavutil/csp.c
> @@ -0,0 +1,111 @@
> +/*
> + * Copyright (c) 2016 Ronald S. Bultje <rsbultje at gmail.com>
> + * 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
> + */
> +
> +#include "csp.h"
> +#include "frame.h"
> +#include "mastering_display_metadata.h"
> +#include "pixfmt.h"
> +
> +/*
> + * All constants explained in e.g. https://linuxtv.org/downloads/v4l-dvb-apis/ch02s06.html
> + * The older ones (bt470bg/m) are also explained in their respective ITU docs
> + * (e.g. https://www.itu.int/dms_pubrec/itu-r/rec/bt/R-REC-BT.470-5-199802-S!!PDF-E.pdf)
> + * whereas the newer ones can typically be copied directly from wikipedia :)
> + */
> +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_YCOCG]      = { 0.25,   0.5,    0.25   },
> +    [AVCOL_SPC_RGB]        = { 1,      1,      1      },
> +    [AVCOL_SPC_BT2020_NCL] = { 0.2627, 0.6780, 0.0593 },
> +    [AVCOL_SPC_BT2020_CL]  = { 0.2627, 0.6780, 0.0593 },
> +};
> +
> +const struct LumaCoefficients *av_get_luma_coefficients(enum AVColorSpace csp)
> +{
> +    const struct LumaCoefficients *coeffs;
> +
> +    if (csp >= AVCOL_SPC_NB)
> +        return NULL;
> +    coeffs = &luma_coefficients[csp];
> +    if (!coeffs->cr)
> +        return NULL;
> +
> +    return coeffs;
> +}
> +
> +#define WP_D65 { 0.3127, 0.3290 }
> +#define WP_C   { 0.3100, 0.3160 }
> +#define WP_DCI { 0.3140, 0.3510 }
> +#define WP_E   { 1/3.0f, 1/3.0f }
> +
> +static const struct ColorPrimaries color_primaries[AVCOL_PRI_NB] = {
> +    [AVCOL_PRI_BT709]     = { WP_D65, { 0.640, 0.330, 0.300, 0.600, 0.150, 0.060 } },
> +    [AVCOL_PRI_BT470M]    = { WP_C,   { 0.670, 0.330, 0.210, 0.710, 0.140, 0.080 } },
> +    [AVCOL_PRI_BT470BG]   = { WP_D65, { 0.640, 0.330, 0.290, 0.600, 0.150, 0.060 } },
> +    [AVCOL_PRI_SMPTE170M] = { WP_D65, { 0.630, 0.340, 0.310, 0.595, 0.155, 0.070 } },
> +    [AVCOL_PRI_SMPTE240M] = { WP_D65, { 0.630, 0.340, 0.310, 0.595, 0.155, 0.070 } },
> +    [AVCOL_PRI_SMPTE428]  = { WP_E,   { 0.735, 0.265, 0.274, 0.718, 0.167, 0.009 } },
> +    [AVCOL_PRI_SMPTE431]  = { WP_DCI, { 0.680, 0.320, 0.265, 0.690, 0.150, 0.060 } },
> +    [AVCOL_PRI_SMPTE432]  = { WP_D65, { 0.680, 0.320, 0.265, 0.690, 0.150, 0.060 } },
> +    [AVCOL_PRI_FILM]      = { WP_C,   { 0.681, 0.319, 0.243, 0.692, 0.145, 0.049 } },
> +    [AVCOL_PRI_BT2020]    = { WP_D65, { 0.708, 0.292, 0.170, 0.797, 0.131, 0.046 } },
> +    [AVCOL_PRI_JEDEC_P22] = { WP_D65, { 0.630, 0.340, 0.295, 0.605, 0.155, 0.077 } },
> +};
> +
> +const struct ColorPrimaries *av_get_color_primaries(enum AVColorPrimaries prm)
> +{
> +    const struct ColorPrimaries *p;
> +
> +    if (prm >= AVCOL_PRI_NB)
> +        return NULL;
> +    p = &color_primaries[prm];
> +    if (!p->prim.xr)
> +        return NULL;
> +
> +    return p;
> +}
> +
> +enum AVColorPrimaries av_detect_color_primaries(const struct ColorPrimaries *prm)
> +{
> +    double delta;
> +
> +    for (enum AVColorPrimaries p = 0; p < AVCOL_PRI_NB; p++) {
> +        const struct ColorPrimaries *ref = &color_primaries[p];
> +        if (!ref->prim.xr)
> +            continue;
> +
> +        delta = fabs(prm->prim.xr - ref->prim.xr) +
> +                fabs(prm->prim.yr - ref->prim.yr) +
> +                fabs(prm->prim.yg - ref->prim.yg) +
> +                fabs(prm->prim.yg - ref->prim.yg) +
> +                fabs(prm->prim.yb - ref->prim.yb) +
> +                fabs(prm->prim.yb - ref->prim.yb) +
> +                fabs(prm->wp.xw - ref->wp.xw) +
> +                fabs(prm->wp.yw - ref->wp.yw);
> +
> +        if (delta < 0.001)
> +            return p;
> +    }
> +
> +    return AVCOL_PRI_UNSPECIFIED;
> +}
> diff --git a/libavutil/csp.h b/libavutil/csp.h
> new file mode 100644
> index 0000000000..1bcde7ddd3
> --- /dev/null
> +++ b/libavutil/csp.h
> @@ -0,0 +1,49 @@
> +/*
> + * Copyright (c) 2016 Ronald S. Bultje <rsbultje at gmail.com>
> + * 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
> + */
> +
> +#ifndef AVUTIL_CSP_H
> +#define AVUTIL_CSP_H
> +
> +#include "libavutil/frame.h"

?

> +#include "libavutil/pixfmt.h"
> +
> +struct LumaCoefficients {
> +    double cr, cg, cb;
> +};
> +
> +struct PrimaryCoefficients {
> +    double xr, yr, xg, yg, xb, yb;
> +};
> +
> +struct WhitepointCoefficients {
> +    double xw, yw;
> +};
> +
> +struct ColorPrimaries {
> +    struct WhitepointCoefficients wp;
> +    struct PrimaryCoefficients prim;
> +};
> +
> +/* Returns AVCOL_PRI_UNSPECIFIED if no clear match can be identified */
> +enum AVColorPrimaries av_detect_color_primaries(const struct ColorPrimaries *prm);
> +
> +const struct ColorPrimaries *av_get_color_primaries(enum AVColorPrimaries prm);
> +const struct LumaCoefficients *av_get_luma_coefficients(enum AVColorSpace csp);
> +
> +#endif /* AVUTIL_CSP_H */

Is there any scenario in which these structs might need to be extended?
This is something that we could no longer easily do if these structs
were public.

- Andreas


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