/*
 * Copyright (c) 2016 Ronald S. Bultje <rsbultje@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
 */

/*
 * @file
 * Convert between colorspaces.
 */

#include "libavutil/avassert.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libavutil/pixfmt.h"

#include "avfilter.h"
#include "colorspacedsp.h"
#include "formats.h"
#include "internal.h"
#include "video.h"

enum DitherMode {
    DITHER_NONE,
    DITHER_FSB,
    DITHER_NB,
};

enum Colorspace {
    CS_UNSPECIFIED,
    CS_BT470M,
    CS_BT470BG,
    CS_BT601_6_525,
    CS_BT601_6_625,
    CS_BT709,
    CS_SMPTE170M,
    CS_SMPTE240M,
    CS_BT2020,
    CS_NB,
};

enum Whitepoint {
    WP_D65,
    WP_C,
    WP_DCI,
    WP_NB,
};

enum WhitepointAdaptation {
    WP_ADAPT_BRADFORD,
    WP_ADAPT_VON_KRIES,
    NB_WP_ADAPT_NON_IDENTITY,
    WP_ADAPT_IDENTITY = NB_WP_ADAPT_NON_IDENTITY,
    NB_WP_ADAPT,
};

static const enum AVColorTransferCharacteristic default_trc[CS_NB + 1] = {
    [CS_UNSPECIFIED] = AVCOL_TRC_UNSPECIFIED,
    [CS_BT470M]      = AVCOL_TRC_GAMMA22,
    [CS_BT470BG]     = AVCOL_TRC_GAMMA28,
    [CS_BT601_6_525] = AVCOL_TRC_SMPTE170M,
    [CS_BT601_6_625] = AVCOL_TRC_SMPTE170M,
    [CS_BT709]       = AVCOL_TRC_BT709,
    [CS_SMPTE170M]   = AVCOL_TRC_SMPTE170M,
    [CS_SMPTE240M]   = AVCOL_TRC_SMPTE240M,
    [CS_BT2020]      = AVCOL_TRC_BT2020_10,
    [CS_NB]          = AVCOL_TRC_UNSPECIFIED,
};

static const enum AVColorPrimaries default_prm[CS_NB + 1] = {
    [CS_UNSPECIFIED] = AVCOL_PRI_UNSPECIFIED,
    [CS_BT470M]      = AVCOL_PRI_BT470M,
    [CS_BT470BG]     = AVCOL_PRI_BT470BG,
    [CS_BT601_6_525] = AVCOL_PRI_SMPTE170M,
    [CS_BT601_6_625] = AVCOL_PRI_BT470BG,
    [CS_BT709]       = AVCOL_PRI_BT709,
    [CS_SMPTE170M]   = AVCOL_PRI_SMPTE170M,
    [CS_SMPTE240M]   = AVCOL_PRI_SMPTE240M,
    [CS_BT2020]      = AVCOL_PRI_BT2020,
    [CS_NB]          = AVCOL_PRI_UNSPECIFIED,
};

static const enum AVColorSpace default_csp[CS_NB + 1] = {
    [CS_UNSPECIFIED] = AVCOL_SPC_UNSPECIFIED,
    [CS_BT470M]      = AVCOL_SPC_SMPTE170M,
    [CS_BT470BG]     = AVCOL_SPC_BT470BG,
    [CS_BT601_6_525] = AVCOL_SPC_SMPTE170M,
    [CS_BT601_6_625] = AVCOL_SPC_BT470BG,
    [CS_BT709]       = AVCOL_SPC_BT709,
    [CS_SMPTE170M]   = AVCOL_SPC_SMPTE170M,
    [CS_SMPTE240M]   = AVCOL_SPC_SMPTE240M,
    [CS_BT2020]      = AVCOL_SPC_BT2020_NCL,
    [CS_NB]          = AVCOL_SPC_UNSPECIFIED,
};

struct ColorPrimaries {
    enum Whitepoint wp;
    double xr, yr, xg, yg, xb, yb;
};

struct TransferCharacteristics {
    double alpha, beta, gamma, delta;
};

struct LumaCoefficients {
    double cr, cg, cb;
};

struct WhitepointCoefficients {
    double xw, yw;
};

typedef struct ColorSpaceContext {
    const AVClass *class;

    ColorSpaceDSPContext dsp;

    enum Colorspace user_all, user_iall;
    enum AVColorSpace in_csp, out_csp, user_csp, user_icsp;
    enum AVColorRange in_rng, out_rng, user_rng, user_irng;
    enum AVColorTransferCharacteristic in_trc, out_trc, user_trc, user_itrc;
    enum AVColorPrimaries in_prm, out_prm, user_prm, user_iprm;
    enum AVPixelFormat in_format, user_format;
    int fast_mode;
    enum DitherMode dither;
    enum WhitepointAdaptation wp_adapt;

    int16_t *rgb[3];
    ptrdiff_t rgb_stride;
    unsigned rgb_sz;
    int *dither_scratch[3][2], *dither_scratch_base[3][2];

    const struct ColorPrimaries *in_primaries, *out_primaries;
    int lrgb2lrgb_passthrough;
    DECLARE_ALIGNED(16, int16_t, lrgb2lrgb_coeffs)[3][3][8];

    const struct TransferCharacteristics *in_txchr, *out_txchr;
    int rgb2rgb_passthrough;
    int16_t *lin_lut, *delin_lut;

    const struct LumaCoefficients *in_lumacoef, *out_lumacoef;
    int yuv2yuv_passthrough, yuv2yuv_fastmode;
    DECLARE_ALIGNED(16, int16_t, yuv2rgb_coeffs)[3][3][8];
    DECLARE_ALIGNED(16, int16_t, rgb2yuv_coeffs)[3][3][8];
    DECLARE_ALIGNED(16, int16_t, yuv2yuv_coeffs)[3][3][8];
    DECLARE_ALIGNED(16, int16_t, yuv_offset)[2 /* in, out */][8];
    yuv2rgb_fn yuv2rgb;
    rgb2yuv_fn rgb2yuv;
    rgb2yuv_fsb_fn rgb2yuv_fsb;
    yuv2yuv_fn yuv2yuv;
    double yuv2rgb_dbl_coeffs[3][3], rgb2yuv_dbl_coeffs[3][3];
    int in_y_rng, in_uv_rng, out_y_rng, out_uv_rng;

    int did_warn_range;
} ColorSpaceContext;

// FIXME deal with odd width/heights
// FIXME faster linearize/delinearize implementation (integer pow)
// FIXME bt2020cl support (linearization between yuv/rgb step instead of between rgb/xyz)
// FIXME test that the values in (de)lin_lut don't exceed their container storage
// type size (only useful if we keep the LUT and don't move to fast integer pow)
// FIXME dithering if bitdepth goes down?
// FIXME bitexact for fate integration?

static const double ycgco_matrix[3][3] =
{
    {  0.25, 0.5,  0.25 },
    { -0.25, 0.5, -0.25 },
    {  0.5,  0,   -0.5  },
};

static const double gbr_matrix[3][3] =
{
    { 0,    1,   0   },
    { 0,   -0.5, 0.5 },
    { 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 },
};

static const struct LumaCoefficients *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;
}

static void fill_rgb2yuv_table(const struct LumaCoefficients *coeffs,
                               double rgb2yuv[3][3])
{
    double bscale, rscale;

    // special ycgco matrix
    if (coeffs->cr == 0.25 && coeffs->cg == 0.5 && coeffs->cb == 0.25) {
        memcpy(rgb2yuv, ycgco_matrix, sizeof(double) * 9);
        return;
    } else if (coeffs->cr == 1 && coeffs->cg == 1 && coeffs->cb == 1) {
        memcpy(rgb2yuv, gbr_matrix, sizeof(double) * 9);
        return;
    }

    rgb2yuv[0][0] = coeffs->cr;
    rgb2yuv[0][1] = coeffs->cg;
    rgb2yuv[0][2] = coeffs->cb;
    bscale = 0.5 / (coeffs->cb - 1.0);
    rscale = 0.5 / (coeffs->cr - 1.0);
    rgb2yuv[1][0] = bscale * coeffs->cr;
    rgb2yuv[1][1] = bscale * coeffs->cg;
    rgb2yuv[1][2] = 0.5;
    rgb2yuv[2][0] = 0.5;
    rgb2yuv[2][1] = rscale * coeffs->cg;
    rgb2yuv[2][2] = rscale * coeffs->cb;
}

// FIXME I'm pretty sure gamma22/28 also have a linear toe slope, but I can't
// find any actual tables that document their real values...
// See http://www.13thmonkey.org/~boris/gammacorrection/ first graph why it matters
static const struct TransferCharacteristics transfer_characteristics[AVCOL_TRC_NB] = {
    [AVCOL_TRC_BT709]     = { 1.099,  0.018,  0.45, 4.5 },
    [AVCOL_TRC_GAMMA22]   = { 1.0,    0.0,    1.0 / 2.2, 0.0 },
    [AVCOL_TRC_GAMMA28]   = { 1.0,    0.0,    1.0 / 2.8, 0.0 },
    [AVCOL_TRC_SMPTE170M] = { 1.099,  0.018,  0.45, 4.5 },
    [AVCOL_TRC_SMPTE240M] = { 1.1115, 0.0228, 0.45, 4.0 },
    [AVCOL_TRC_IEC61966_2_1] = { 1.055, 0.0031308, 1.0 / 2.4, 12.92 },
    [AVCOL_TRC_IEC61966_2_4] = { 1.099, 0.018, 0.45, 4.5 },
    [AVCOL_TRC_BT2020_10] = { 1.099,  0.018,  0.45, 4.5 },
    [AVCOL_TRC_BT2020_12] = { 1.0993, 0.0181, 0.45, 4.5 },
};

static const struct TransferCharacteristics *
    get_transfer_characteristics(enum AVColorTransferCharacteristic trc)
{
    const struct TransferCharacteristics *coeffs;

    if (trc >= AVCOL_TRC_NB)
        return NULL;
    coeffs = &transfer_characteristics[trc];
    if (!coeffs->alpha)
        return NULL;

    return coeffs;
}

static const struct WhitepointCoefficients whitepoint_coefficients[WP_NB] = {
    [WP_D65] = { 0.3127, 0.3290 },
    [WP_C]   = { 0.3100, 0.3160 },
    [WP_DCI] = { 0.3140, 0.3510 },
};

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_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 },
};

static const struct ColorPrimaries *get_color_primaries(enum AVColorPrimaries prm)
{
    const struct ColorPrimaries *coeffs;

    if (prm >= AVCOL_PRI_NB)
        return NULL;
    coeffs = &color_primaries[prm];
    if (!coeffs->xr)
        return NULL;

    return coeffs;
}

static void invert_matrix3x3(const double in[3][3], double out[3][3])
{
    double m00 = in[0][0], m01 = in[0][1], m02 = in[0][2],
           m10 = in[1][0], m11 = in[1][1], m12 = in[1][2],
           m20 = in[2][0], m21 = in[2][1], m22 = in[2][2];
    int i, j;
    double det;

    out[0][0] =  (m11 * m22 - m21 * m12);
    out[0][1] = -(m01 * m22 - m21 * m02);
    out[0][2] =  (m01 * m12 - m11 * m02);
    out[1][0] = -(m10 * m22 - m20 * m12);
    out[1][1] =  (m00 * m22 - m20 * m02);
    out[1][2] = -(m00 * m12 - m10 * m02);
    out[2][0] =  (m10 * m21 - m20 * m11);
    out[2][1] = -(m00 * m21 - m20 * m01);
    out[2][2] =  (m00 * m11 - m10 * m01);

    det = m00 * out[0][0] + m10 * out[0][1] + m20 * out[0][2];
    det = 1.0 / det;

    for (i = 0; i < 3; i++) {
        for (j = 0; j < 3; j++)
            out[i][j] *= det;
    }
}

static int fill_gamma_table(ColorSpaceContext *s)
{
    int n;
    double in_alpha = s->in_txchr->alpha, in_beta = s->in_txchr->beta;
    double in_gamma = s->in_txchr->gamma, in_delta = s->in_txchr->delta;
    double in_ialpha = 1.0 / in_alpha, in_igamma = 1.0 / in_gamma, in_idelta = 1.0 / in_delta;
    double out_alpha = s->out_txchr->alpha, out_beta = s->out_txchr->beta;
    double out_gamma = s->out_txchr->gamma, out_delta = s->out_txchr->delta;

    s->lin_lut = av_malloc(sizeof(*s->lin_lut) * 32768 * 2);
    if (!s->lin_lut)
        return AVERROR(ENOMEM);
    s->delin_lut = &s->lin_lut[32768];
    for (n = 0; n < 32768; n++) {
        double v = (n - 2048.0) / 28672.0, d, l;

        // delinearize
        if (v <= -out_beta) {
            d = -out_alpha * pow(-v, out_gamma) + (out_alpha - 1.0);
        } else if (v < out_beta) {
            d = out_delta * v;
        } else {
            d = out_alpha * pow(v, out_gamma) - (out_alpha - 1.0);
        }
        s->delin_lut[n] = av_clip_int16(lrint(d * 28672.0));

        // linearize
        if (v <= -in_beta) {
            l = -pow((1.0 - in_alpha - v) * in_ialpha, in_igamma);
        } else if (v < in_beta) {
            l = v * in_idelta;
        } else {
            l = pow((v + in_alpha - 1.0) * in_ialpha, in_igamma);
        }
        s->lin_lut[n] = av_clip_int16(lrint(l * 28672.0));
    }

    return 0;
}

/*
 * see e.g. http://www.brucelindbloom.com/index.html?Eqn_RGB_XYZ_Matrix.html
 */
static void fill_rgb2xyz_table(const struct ColorPrimaries *coeffs,
                               double rgb2xyz[3][3])
{
    const struct WhitepointCoefficients *wp = &whitepoint_coefficients[coeffs->wp];
    double i[3][3], sr, sg, sb, zw;

    rgb2xyz[0][0] = coeffs->xr / coeffs->yr;
    rgb2xyz[0][1] = coeffs->xg / coeffs->yg;
    rgb2xyz[0][2] = coeffs->xb / coeffs->yb;
    rgb2xyz[1][0] = rgb2xyz[1][1] = rgb2xyz[1][2] = 1.0;
    rgb2xyz[2][0] = (1.0 - coeffs->xr - coeffs->yr) / coeffs->yr;
    rgb2xyz[2][1] = (1.0 - coeffs->xg - coeffs->yg) / coeffs->yg;
    rgb2xyz[2][2] = (1.0 - coeffs->xb - coeffs->yb) / coeffs->yb;
    invert_matrix3x3(rgb2xyz, i);
    zw = 1.0 - wp->xw - wp->yw;
    sr = i[0][0] * wp->xw + i[0][1] * wp->yw + i[0][2] * zw;
    sg = i[1][0] * wp->xw + i[1][1] * wp->yw + i[1][2] * zw;
    sb = i[2][0] * wp->xw + i[2][1] * wp->yw + i[2][2] * zw;
    rgb2xyz[0][0] *= sr;
    rgb2xyz[0][1] *= sg;
    rgb2xyz[0][2] *= sb;
    rgb2xyz[1][0] *= sr;
    rgb2xyz[1][1] *= sg;
    rgb2xyz[1][2] *= sb;
    rgb2xyz[2][0] *= sr;
    rgb2xyz[2][1] *= sg;
    rgb2xyz[2][2] *= sb;
}

static void mul3x3(double dst[3][3], const double src1[3][3], const double src2[3][3])
{
    int m, n;

    for (m = 0; m < 3; m++)
        for (n = 0; n < 3; n++)
            dst[m][n] = src2[m][0] * src1[0][n] +
                        src2[m][1] * src1[1][n] +
                        src2[m][2] * src1[2][n];
}

/*
 * See http://www.brucelindbloom.com/index.html?Eqn_ChromAdapt.html
 * This function uses the Bradford mechanism.
 */
static void fill_whitepoint_conv_table(double out[3][3], enum WhitepointAdaptation wp_adapt,
                                       enum Whitepoint src, enum Whitepoint dst)
{
    static const double ma_tbl[NB_WP_ADAPT_NON_IDENTITY][3][3] = {
        [WP_ADAPT_BRADFORD] = {
            {  0.8951,  0.2664, -0.1614 },
            { -0.7502,  1.7135,  0.0367 },
            {  0.0389, -0.0685,  1.0296 },
        }, [WP_ADAPT_VON_KRIES] = {
            {  0.40024,  0.70760, -0.08081 },
            { -0.22630,  1.16532,  0.04570 },
            {  0.00000,  0.00000,  0.91822 },
        },
    };
    const double (*ma)[3] = ma_tbl[wp_adapt];
    const struct WhitepointCoefficients *wp_src = &whitepoint_coefficients[src];
    double zw_src = 1.0 - wp_src->xw - wp_src->yw;
    const struct WhitepointCoefficients *wp_dst = &whitepoint_coefficients[dst];
    double zw_dst = 1.0 - wp_dst->xw - wp_dst->yw;
    double mai[3][3], fac[3][3], tmp[3][3];
    double rs, gs, bs, rd, gd, bd;

    invert_matrix3x3(ma, mai);
    rs = ma[0][0] * wp_src->xw + ma[0][1] * wp_src->yw + ma[0][2] * zw_src;
    gs = ma[1][0] * wp_src->xw + ma[1][1] * wp_src->yw + ma[1][2] * zw_src;
    bs = ma[2][0] * wp_src->xw + ma[2][1] * wp_src->yw + ma[2][2] * zw_src;
    rd = ma[0][0] * wp_dst->xw + ma[0][1] * wp_dst->yw + ma[0][2] * zw_dst;
    gd = ma[1][0] * wp_dst->xw + ma[1][1] * wp_dst->yw + ma[1][2] * zw_dst;
    bd = ma[2][0] * wp_dst->xw + ma[2][1] * wp_dst->yw + ma[2][2] * zw_dst;
    fac[0][0] = rd / rs;
    fac[1][1] = gd / gs;
    fac[2][2] = bd / bs;
    fac[0][1] = fac[0][2] = fac[1][0] = fac[1][2] = fac[2][0] = fac[2][1] = 0.0;
    mul3x3(tmp, ma, fac);
    mul3x3(out, tmp, mai);
}

static void apply_lut(int16_t *buf[3], ptrdiff_t stride,
                      int w, int h, const int16_t *lut)
{
    int y, x, n;

    for (n = 0; n < 3; n++) {
        int16_t *data = buf[n];

        for (y = 0; y < h; y++) {
            for (x = 0; x < w; x++)
                data[x] = lut[av_clip_uintp2(2048 + data[x], 15)];

            data += stride;
        }
    }
}

struct ThreadData {
    AVFrame *in, *out;
    ptrdiff_t in_linesize[3], out_linesize[3];
    int in_ss_h, out_ss_h;
};

static int convert(AVFilterContext *ctx, void *data, int job_nr, int n_jobs)
{
    struct ThreadData *td = data;
    ColorSpaceContext *s = ctx->priv;
    uint8_t *in_data[3], *out_data[3];
    int16_t *rgb[3];
    int h_in = (td->in->height + 1) >> 1;
    int h1 = 2 * (job_nr * h_in / n_jobs), h2 = 2 * ((job_nr + 1) * h_in / n_jobs);
    int w = td->in->width, h = h2 - h1;

    in_data[0]  = td->in->data[0]  + td->in_linesize[0]  *  h1;
    in_data[1]  = td->in->data[1]  + td->in_linesize[1]  * (h1 >> td->in_ss_h);
    in_data[2]  = td->in->data[2]  + td->in_linesize[2]  * (h1 >> td->in_ss_h);
    out_data[0] = td->out->data[0] + td->out_linesize[0] *  h1;
    out_data[1] = td->out->data[1] + td->out_linesize[1] * (h1 >> td->out_ss_h);
    out_data[2] = td->out->data[2] + td->out_linesize[2] * (h1 >> td->out_ss_h);
    rgb[0]      = s->rgb[0]        + s->rgb_stride       *  h1;
    rgb[1]      = s->rgb[1]        + s->rgb_stride       *  h1;
    rgb[2]      = s->rgb[2]        + s->rgb_stride       *  h1;

    // FIXME for simd, also make sure we do pictures with negative stride
    // top-down so we don't overwrite lines with padding of data before it
    // in the same buffer (same as swscale)

    if (s->yuv2yuv_fastmode) {
        // FIXME possibly use a fast mode in case only the y range changes?
        // since in that case, only the diagonal entries in yuv2yuv_coeffs[]
        // are non-zero
        s->yuv2yuv(out_data, td->out_linesize, in_data, td->in_linesize, w, h,
                   s->yuv2yuv_coeffs, s->yuv_offset);
    } else {
        // FIXME maybe (for caching effciency) do pipeline per-line instead of
        // full buffer per function? (Or, since yuv2rgb requires 2 lines: per
        // 2 lines, for yuv420.)
        /*
         * General design:
         * - yuv2rgb converts from whatever range the input was ([16-235/240] or
         *   [0,255] or the 10/12bpp equivalents thereof) to an integer version
         *   of RGB in psuedo-restricted 15+sign bits. That means that the float
         *   range [0.0,1.0] is in [0,28762], and the remainder of the int16_t
         *   range is used for overflow/underflow outside the representable
         *   range of this RGB type. rgb2yuv is the exact opposite.
         * - gamma correction is done using a LUT since that appears to work
         *   fairly fast.
         * - If the input is chroma-subsampled (420/422), the yuv2rgb conversion
         *   (or rgb2yuv conversion) uses nearest-neighbour sampling to read
         *   read chroma pixels at luma resolution. If you want some more fancy
         *   filter, you can use swscale to convert to yuv444p.
         * - all coefficients are 14bit (so in the [-2.0,2.0] range).
         */
        s->yuv2rgb(rgb, s->rgb_stride, in_data, td->in_linesize, w, h,
                   s->yuv2rgb_coeffs, s->yuv_offset[0]);
        if (!s->rgb2rgb_passthrough) {
            apply_lut(rgb, s->rgb_stride, w, h, s->lin_lut);
            if (!s->lrgb2lrgb_passthrough)
                s->dsp.multiply3x3(rgb, s->rgb_stride, w, h, s->lrgb2lrgb_coeffs);
            apply_lut(rgb, s->rgb_stride, w, h, s->delin_lut);
        }
        if (s->dither == DITHER_FSB) {
            s->rgb2yuv_fsb(out_data, td->out_linesize, rgb, s->rgb_stride, w, h,
                           s->rgb2yuv_coeffs, s->yuv_offset[1], s->dither_scratch);
        } else {
            s->rgb2yuv(out_data, td->out_linesize, rgb, s->rgb_stride, w, h,
                       s->rgb2yuv_coeffs, s->yuv_offset[1]);
        }
    }

    return 0;
}

static int get_range_off(AVFilterContext *ctx, int *off,
                         int *y_rng, int *uv_rng,
                         enum AVColorRange rng, int depth)
{
    switch (rng) {
    case AVCOL_RANGE_UNSPECIFIED: {
        ColorSpaceContext *s = ctx->priv;

        if (!s->did_warn_range) {
            av_log(ctx, AV_LOG_WARNING, "Input range not set, assuming tv/mpeg\n");
            s->did_warn_range = 1;
        }
    }
        // fall-through
    case AVCOL_RANGE_MPEG:
        *off = 16 << (depth - 8);
        *y_rng = 219 << (depth - 8);
        *uv_rng = 224 << (depth - 8);
        break;
    case AVCOL_RANGE_JPEG:
        *off = 0;
        *y_rng = *uv_rng = (256 << (depth - 8)) - 1;
        break;
    default:
        return AVERROR(EINVAL);
    }

    return 0;
}

static int create_filtergraph(AVFilterContext *ctx,
                              const AVFrame *in, const AVFrame *out)
{
    ColorSpaceContext *s = ctx->priv;
    const AVPixFmtDescriptor *in_desc  = av_pix_fmt_desc_get(in->format);
    const AVPixFmtDescriptor *out_desc = av_pix_fmt_desc_get(out->format);
    int emms = 0, m, n, o, res, fmt_identical, redo_yuv2rgb = 0, redo_rgb2yuv = 0;

#define supported_depth(d) ((d) == 8 || (d) == 10 || (d) == 12)
#define supported_subsampling(lcw, lch) \
    (((lcw) == 0 && (lch) == 0) || ((lcw) == 1 && (lch) == 0) || ((lcw) == 1 && (lch) == 1))
#define supported_format(d) \
    ((d) != NULL && (d)->nb_components == 3 && \
     !((d)->flags & AV_PIX_FMT_FLAG_RGB) && \
     supported_depth((d)->comp[0].depth) && \
     supported_subsampling((d)->log2_chroma_w, (d)->log2_chroma_h))

    if (!supported_format(in_desc)) {
        av_log(ctx, AV_LOG_ERROR,
               "Unsupported input format %d (%s) or bitdepth (%d)\n",
               in->format, av_get_pix_fmt_name(in->format),
               in_desc ? in_desc->comp[0].depth : -1);
        return AVERROR(EINVAL);
    }
    if (!supported_format(out_desc)) {
        av_log(ctx, AV_LOG_ERROR,
               "Unsupported output format %d (%s) or bitdepth (%d)\n",
               out->format, av_get_pix_fmt_name(out->format),
               out_desc ? out_desc->comp[0].depth : -1);
        return AVERROR(EINVAL);
    }

    if (in->color_primaries  != s->in_prm)  s->in_primaries  = NULL;
    if (out->color_primaries != s->out_prm) s->out_primaries = NULL;
    if (in->color_trc        != s->in_trc)  s->in_txchr      = NULL;
    if (out->color_trc       != s->out_trc) s->out_txchr     = NULL;
    if (in->colorspace       != s->in_csp ||
        in->color_range      != s->in_rng)  s->in_lumacoef   = NULL;
    if (out->colorspace      != s->out_csp ||
        out->color_range     != s->out_rng) s->out_lumacoef  = NULL;

    if (!s->out_primaries || !s->in_primaries) {
        s->in_prm = in->color_primaries;
        if (s->user_iall != CS_UNSPECIFIED)
            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 = get_color_primaries(s->in_prm);
        if (!s->in_primaries) {
            av_log(ctx, AV_LOG_ERROR,
                   "Unsupported input primaries %d (%s)\n",
                   s->in_prm, av_color_primaries_name(s->in_prm));
            return AVERROR(EINVAL);
        }
        s->out_prm = out->color_primaries;
        s->out_primaries = get_color_primaries(s->out_prm);
        if (!s->out_primaries) {
            if (s->out_prm == AVCOL_PRI_UNSPECIFIED) {
                if (s->user_all == CS_UNSPECIFIED) {
                    av_log(ctx, AV_LOG_ERROR, "Please specify output primaries\n");
                } else {
                    av_log(ctx, AV_LOG_ERROR,
                           "Unsupported output color property %d\n", s->user_all);
                }
            } else {
                av_log(ctx, AV_LOG_ERROR,
                       "Unsupported output primaries %d (%s)\n",
                       s->out_prm, av_color_primaries_name(s->out_prm));
            }
            return AVERROR(EINVAL);
        }
        s->lrgb2lrgb_passthrough = !memcmp(s->in_primaries, s->out_primaries,
                                           sizeof(*s->in_primaries));
        if (!s->lrgb2lrgb_passthrough) {
            double rgb2xyz[3][3], xyz2rgb[3][3], rgb2rgb[3][3];

            fill_rgb2xyz_table(s->out_primaries, rgb2xyz);
            invert_matrix3x3(rgb2xyz, xyz2rgb);
            fill_rgb2xyz_table(s->in_primaries, rgb2xyz);
            if (s->out_primaries->wp != s->in_primaries->wp &&
                s->wp_adapt != WP_ADAPT_IDENTITY) {
                double wpconv[3][3], tmp[3][3];

                fill_whitepoint_conv_table(wpconv, s->wp_adapt, s->in_primaries->wp,
                                           s->out_primaries->wp);
                mul3x3(tmp, rgb2xyz, wpconv);
                mul3x3(rgb2rgb, tmp, xyz2rgb);
            } else {
                mul3x3(rgb2rgb, rgb2xyz, xyz2rgb);
            }
            for (m = 0; m < 3; m++)
                for (n = 0; n < 3; n++) {
                    s->lrgb2lrgb_coeffs[m][n][0] = lrint(16384.0 * rgb2rgb[m][n]);
                    for (o = 1; o < 8; o++)
                        s->lrgb2lrgb_coeffs[m][n][o] = s->lrgb2lrgb_coeffs[m][n][0];
                }

            emms = 1;
        }
    }

    if (!s->in_txchr) {
        av_freep(&s->lin_lut);
        s->in_trc = in->color_trc;
        if (s->user_iall != CS_UNSPECIFIED)
            s->in_trc = default_trc[FFMIN(s->user_iall, CS_NB)];
        if (s->user_itrc != AVCOL_TRC_UNSPECIFIED)
            s->in_trc = s->user_itrc;
        s->in_txchr = get_transfer_characteristics(s->in_trc);
        if (!s->in_txchr) {
            av_log(ctx, AV_LOG_ERROR,
                   "Unsupported input transfer characteristics %d (%s)\n",
                   s->in_trc, av_color_transfer_name(s->in_trc));
            return AVERROR(EINVAL);
        }
    }

    if (!s->out_txchr) {
        av_freep(&s->lin_lut);
        s->out_trc = out->color_trc;
        s->out_txchr = get_transfer_characteristics(s->out_trc);
        if (!s->out_txchr) {
            if (s->out_trc == AVCOL_TRC_UNSPECIFIED) {
                if (s->user_all == CS_UNSPECIFIED) {
                    av_log(ctx, AV_LOG_ERROR,
                           "Please specify output transfer characteristics\n");
                } else {
                    av_log(ctx, AV_LOG_ERROR,
                           "Unsupported output color property %d\n", s->user_all);
                }
            } else {
                av_log(ctx, AV_LOG_ERROR,
                       "Unsupported output transfer characteristics %d (%s)\n",
                       s->out_trc, av_color_transfer_name(s->out_trc));
            }
            return AVERROR(EINVAL);
        }
    }

    s->rgb2rgb_passthrough = s->fast_mode || (s->lrgb2lrgb_passthrough &&
                             !memcmp(s->in_txchr, s->out_txchr, sizeof(*s->in_txchr)));
    if (!s->rgb2rgb_passthrough && !s->lin_lut) {
        res = fill_gamma_table(s);
        if (res < 0)
            return res;
        emms = 1;
    }

    if (!s->in_lumacoef) {
        s->in_csp = in->colorspace;
        if (s->user_iall != CS_UNSPECIFIED)
            s->in_csp = default_csp[FFMIN(s->user_iall, CS_NB)];
        if (s->user_icsp != AVCOL_SPC_UNSPECIFIED)
            s->in_csp = s->user_icsp;
        s->in_rng = in->color_range;
        if (s->user_irng != AVCOL_RANGE_UNSPECIFIED)
            s->in_rng = s->user_irng;
        s->in_lumacoef = get_luma_coefficients(s->in_csp);
        if (!s->in_lumacoef) {
            av_log(ctx, AV_LOG_ERROR,
                   "Unsupported input colorspace %d (%s)\n",
                   s->in_csp, av_color_space_name(s->in_csp));
            return AVERROR(EINVAL);
        }
        redo_yuv2rgb = 1;
    }

    if (!s->out_lumacoef) {
        s->out_csp = out->colorspace;
        s->out_rng = out->color_range;
        s->out_lumacoef = get_luma_coefficients(s->out_csp);
        if (!s->out_lumacoef) {
            if (s->out_csp == AVCOL_SPC_UNSPECIFIED) {
                if (s->user_all == CS_UNSPECIFIED) {
                    av_log(ctx, AV_LOG_ERROR,
                           "Please specify output transfer characteristics\n");
                } else {
                    av_log(ctx, AV_LOG_ERROR,
                           "Unsupported output color property %d\n", s->user_all);
                }
            } else {
                av_log(ctx, AV_LOG_ERROR,
                       "Unsupported output transfer characteristics %d (%s)\n",
                       s->out_csp, av_color_space_name(s->out_csp));
            }
            return AVERROR(EINVAL);
        }
        redo_rgb2yuv = 1;
    }

    fmt_identical = in_desc->log2_chroma_h == out_desc->log2_chroma_h &&
                    in_desc->log2_chroma_w == out_desc->log2_chroma_w;
    s->yuv2yuv_fastmode = s->rgb2rgb_passthrough && fmt_identical;
    s->yuv2yuv_passthrough = s->yuv2yuv_fastmode && s->in_rng == s->out_rng &&
                             !memcmp(s->in_lumacoef, s->out_lumacoef,
                                     sizeof(*s->in_lumacoef)) &&
                             in_desc->comp[0].depth == out_desc->comp[0].depth;
    if (!s->yuv2yuv_passthrough) {
        if (redo_yuv2rgb) {
            double rgb2yuv[3][3], (*yuv2rgb)[3] = s->yuv2rgb_dbl_coeffs;
            int off, bits, in_rng;

            res = get_range_off(ctx, &off, &s->in_y_rng, &s->in_uv_rng,
                                s->in_rng, in_desc->comp[0].depth);
            if (res < 0) {
                av_log(ctx, AV_LOG_ERROR,
                       "Unsupported input color range %d (%s)\n",
                       s->in_rng, av_color_range_name(s->in_rng));
                return res;
            }
            for (n = 0; n < 8; n++)
                s->yuv_offset[0][n] = off;
            fill_rgb2yuv_table(s->in_lumacoef, rgb2yuv);
            invert_matrix3x3(rgb2yuv, yuv2rgb);
            bits = 1 << (in_desc->comp[0].depth - 1);
            for (n = 0; n < 3; n++) {
                for (in_rng = s->in_y_rng, m = 0; m < 3; m++, in_rng = s->in_uv_rng) {
                    s->yuv2rgb_coeffs[n][m][0] = lrint(28672 * bits * yuv2rgb[n][m] / in_rng);
                    for (o = 1; o < 8; o++)
                        s->yuv2rgb_coeffs[n][m][o] = s->yuv2rgb_coeffs[n][m][0];
                }
            }
            av_assert2(s->yuv2rgb_coeffs[0][1][0] == 0);
            av_assert2(s->yuv2rgb_coeffs[2][2][0] == 0);
            av_assert2(s->yuv2rgb_coeffs[0][0][0] == s->yuv2rgb_coeffs[1][0][0]);
            av_assert2(s->yuv2rgb_coeffs[0][0][0] == s->yuv2rgb_coeffs[2][0][0]);
            s->yuv2rgb = s->dsp.yuv2rgb[(in_desc->comp[0].depth - 8) >> 1]
                                       [in_desc->log2_chroma_h + in_desc->log2_chroma_w];
            emms = 1;
        }

        if (redo_rgb2yuv) {
            double (*rgb2yuv)[3] = s->rgb2yuv_dbl_coeffs;
            int off, out_rng, bits;

            res = get_range_off(ctx, &off, &s->out_y_rng, &s->out_uv_rng,
                                s->out_rng, out_desc->comp[0].depth);
            if (res < 0) {
                av_log(ctx, AV_LOG_ERROR,
                       "Unsupported output color range %d (%s)\n",
                       s->out_rng, av_color_range_name(s->out_rng));
                return res;
            }
            for (n = 0; n < 8; n++)
                s->yuv_offset[1][n] = off;
            fill_rgb2yuv_table(s->out_lumacoef, rgb2yuv);
            bits = 1 << (29 - out_desc->comp[0].depth);
            for (out_rng = s->out_y_rng, n = 0; n < 3; n++, out_rng = s->out_uv_rng) {
                for (m = 0; m < 3; m++) {
                    s->rgb2yuv_coeffs[n][m][0] = lrint(bits * out_rng * rgb2yuv[n][m] / 28672);
                    for (o = 1; o < 8; o++)
                        s->rgb2yuv_coeffs[n][m][o] = s->rgb2yuv_coeffs[n][m][0];
                }
            }
            av_assert2(s->rgb2yuv_coeffs[1][2][0] == s->rgb2yuv_coeffs[2][0][0]);
            s->rgb2yuv = s->dsp.rgb2yuv[(out_desc->comp[0].depth - 8) >> 1]
                                       [out_desc->log2_chroma_h + out_desc->log2_chroma_w];
            s->rgb2yuv_fsb = s->dsp.rgb2yuv_fsb[(out_desc->comp[0].depth - 8) >> 1]
                                       [out_desc->log2_chroma_h + out_desc->log2_chroma_w];
            emms = 1;
        }

        if (s->yuv2yuv_fastmode && (redo_yuv2rgb || redo_rgb2yuv)) {
            int idepth = in_desc->comp[0].depth, odepth = out_desc->comp[0].depth;
            double (*rgb2yuv)[3] = s->rgb2yuv_dbl_coeffs;
            double (*yuv2rgb)[3] = s->yuv2rgb_dbl_coeffs;
            double yuv2yuv[3][3];
            int in_rng, out_rng;

            mul3x3(yuv2yuv, yuv2rgb, rgb2yuv);
            for (out_rng = s->out_y_rng, m = 0; m < 3; m++, out_rng = s->out_uv_rng) {
                for (in_rng = s->in_y_rng, n = 0; n < 3; n++, in_rng = s->in_uv_rng) {
                    s->yuv2yuv_coeffs[m][n][0] =
                        lrint(16384 * yuv2yuv[m][n] * out_rng * (1 << idepth) /
                              (in_rng * (1 << odepth)));
                    for (o = 1; o < 8; o++)
                        s->yuv2yuv_coeffs[m][n][o] = s->yuv2yuv_coeffs[m][n][0];
                }
            }
            av_assert2(s->yuv2yuv_coeffs[1][0][0] == 0);
            av_assert2(s->yuv2yuv_coeffs[2][0][0] == 0);
            s->yuv2yuv = s->dsp.yuv2yuv[(idepth - 8) >> 1][(odepth - 8) >> 1]
                                       [in_desc->log2_chroma_h + in_desc->log2_chroma_w];
        }
    }

    if (emms)
        emms_c();

    return 0;
}

static int init(AVFilterContext *ctx)
{
    ColorSpaceContext *s = ctx->priv;

    ff_colorspacedsp_init(&s->dsp);

    return 0;
}

static void uninit(AVFilterContext *ctx)
{
    ColorSpaceContext *s = ctx->priv;

    av_freep(&s->rgb[0]);
    av_freep(&s->rgb[1]);
    av_freep(&s->rgb[2]);
    s->rgb_sz = 0;
    av_freep(&s->dither_scratch_base[0][0]);
    av_freep(&s->dither_scratch_base[0][1]);
    av_freep(&s->dither_scratch_base[1][0]);
    av_freep(&s->dither_scratch_base[1][1]);
    av_freep(&s->dither_scratch_base[2][0]);
    av_freep(&s->dither_scratch_base[2][1]);

    av_freep(&s->lin_lut);
}

static int filter_frame(AVFilterLink *link, AVFrame *in)
{
    AVFilterContext *ctx = link->dst;
    AVFilterLink *outlink = ctx->outputs[0];
    ColorSpaceContext *s = ctx->priv;
    // FIXME if yuv2yuv_passthrough, don't get a new buffer but use the
    // input one if it is writable *OR* the actual literal values of in_*
    // and out_* are identical (not just their respective properties)
    AVFrame *out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
    int res;
    ptrdiff_t rgb_stride = FFALIGN(in->width * sizeof(int16_t), 32);
    unsigned rgb_sz = rgb_stride * in->height;
    struct ThreadData td;

    if (!out) {
        av_frame_free(&in);
        return AVERROR(ENOMEM);
    }
    res = av_frame_copy_props(out, in);
    if (res < 0) {
        av_frame_free(&in);
        return res;
    }

    out->color_primaries = s->user_prm == AVCOL_PRI_UNSPECIFIED ?
                           default_prm[FFMIN(s->user_all, CS_NB)] : s->user_prm;
    if (s->user_trc == AVCOL_TRC_UNSPECIFIED) {
        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(out->format);

        out->color_trc   = default_trc[FFMIN(s->user_all, CS_NB)];
        if (out->color_trc == AVCOL_TRC_BT2020_10 && desc && desc->comp[0].depth >= 12)
            out->color_trc = AVCOL_TRC_BT2020_12;
    } else {
        out->color_trc   = s->user_trc;
    }
    out->colorspace      = s->user_csp == AVCOL_SPC_UNSPECIFIED ?
                           default_csp[FFMIN(s->user_all, CS_NB)] : s->user_csp;
    out->color_range     = s->user_rng == AVCOL_RANGE_UNSPECIFIED ?
                           in->color_range : s->user_rng;
    if (rgb_sz != s->rgb_sz) {
        const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(out->format);
        int uvw = in->width >> desc->log2_chroma_w;

        av_freep(&s->rgb[0]);
        av_freep(&s->rgb[1]);
        av_freep(&s->rgb[2]);
        s->rgb_sz = 0;
        av_freep(&s->dither_scratch_base[0][0]);
        av_freep(&s->dither_scratch_base[0][1]);
        av_freep(&s->dither_scratch_base[1][0]);
        av_freep(&s->dither_scratch_base[1][1]);
        av_freep(&s->dither_scratch_base[2][0]);
        av_freep(&s->dither_scratch_base[2][1]);

        s->rgb[0] = av_malloc(rgb_sz);
        s->rgb[1] = av_malloc(rgb_sz);
        s->rgb[2] = av_malloc(rgb_sz);
        s->dither_scratch_base[0][0] =
            av_malloc(sizeof(*s->dither_scratch_base[0][0]) * (in->width + 4));
        s->dither_scratch_base[0][1] =
            av_malloc(sizeof(*s->dither_scratch_base[0][1]) * (in->width + 4));
        s->dither_scratch_base[1][0] =
            av_malloc(sizeof(*s->dither_scratch_base[1][0]) * (uvw + 4));
        s->dither_scratch_base[1][1] =
            av_malloc(sizeof(*s->dither_scratch_base[1][1]) * (uvw + 4));
        s->dither_scratch_base[2][0] =
            av_malloc(sizeof(*s->dither_scratch_base[2][0]) * (uvw + 4));
        s->dither_scratch_base[2][1] =
            av_malloc(sizeof(*s->dither_scratch_base[2][1]) * (uvw + 4));
        s->dither_scratch[0][0] = &s->dither_scratch_base[0][0][1];
        s->dither_scratch[0][1] = &s->dither_scratch_base[0][1][1];
        s->dither_scratch[1][0] = &s->dither_scratch_base[1][0][1];
        s->dither_scratch[1][1] = &s->dither_scratch_base[1][1][1];
        s->dither_scratch[2][0] = &s->dither_scratch_base[2][0][1];
        s->dither_scratch[2][1] = &s->dither_scratch_base[2][1][1];
        if (!s->rgb[0] || !s->rgb[1] || !s->rgb[2] ||
            !s->dither_scratch_base[0][0] || !s->dither_scratch_base[0][1] ||
            !s->dither_scratch_base[1][0] || !s->dither_scratch_base[1][1] ||
            !s->dither_scratch_base[2][0] || !s->dither_scratch_base[2][1]) {
            uninit(ctx);
            return AVERROR(ENOMEM);
        }
        s->rgb_sz = rgb_sz;
    }
    res = create_filtergraph(ctx, in, out);
    if (res < 0)
        return res;
    s->rgb_stride = rgb_stride / sizeof(int16_t);
    td.in = in;
    td.out = out;
    td.in_linesize[0] = in->linesize[0];
    td.in_linesize[1] = in->linesize[1];
    td.in_linesize[2] = in->linesize[2];
    td.out_linesize[0] = out->linesize[0];
    td.out_linesize[1] = out->linesize[1];
    td.out_linesize[2] = out->linesize[2];
    td.in_ss_h = av_pix_fmt_desc_get(in->format)->log2_chroma_h;
    td.out_ss_h = av_pix_fmt_desc_get(out->format)->log2_chroma_h;
    if (s->yuv2yuv_passthrough) {
        res = av_frame_copy(out, in);
        if (res < 0)
            return res;
    } else {
        ctx->internal->execute(ctx, convert, &td, NULL,
                               FFMIN((in->height + 1) >> 1, ff_filter_get_nb_threads(ctx)));
    }
    av_frame_free(&in);

    return ff_filter_frame(outlink, out);
}

static int query_formats(AVFilterContext *ctx)
{
    static const enum AVPixelFormat pix_fmts[] = {
        AV_PIX_FMT_YUV420P,   AV_PIX_FMT_YUV422P,   AV_PIX_FMT_YUV444P,
        AV_PIX_FMT_YUV420P10, AV_PIX_FMT_YUV422P10, AV_PIX_FMT_YUV444P10,
        AV_PIX_FMT_YUV420P12, AV_PIX_FMT_YUV422P12, AV_PIX_FMT_YUV444P12,
        AV_PIX_FMT_YUVJ420P,  AV_PIX_FMT_YUVJ422P,  AV_PIX_FMT_YUVJ444P,
        AV_PIX_FMT_NONE
    };
    int res;
    ColorSpaceContext *s = ctx->priv;
    AVFilterFormats *formats = ff_make_format_list(pix_fmts);

    if (!formats)
        return AVERROR(ENOMEM);
    if (s->user_format == AV_PIX_FMT_NONE)
        return ff_set_common_formats(ctx, formats);
    res = ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
    if (res < 0)
        return res;
    formats = NULL;
    res = ff_add_format(&formats, s->user_format);
    if (res < 0)
        return res;

    return ff_formats_ref(formats, &ctx->outputs[0]->in_formats);
}

static int config_props(AVFilterLink *outlink)
{
    AVFilterContext *ctx = outlink->dst;
    AVFilterLink *inlink = outlink->src->inputs[0];

    if (inlink->w % 2 || inlink->h % 2) {
        av_log(ctx, AV_LOG_ERROR, "Invalid odd size (%dx%d)\n",
               inlink->w, inlink->h);
        return AVERROR_PATCHWELCOME;
    }

    outlink->w = inlink->w;
    outlink->h = inlink->h;
    outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
    outlink->time_base = inlink->time_base;

    return 0;
}

#define OFFSET(x) offsetof(ColorSpaceContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM | AV_OPT_FLAG_VIDEO_PARAM
#define ENUM(x, y, z) { x, "", 0, AV_OPT_TYPE_CONST, { .i64 = y }, INT_MIN, INT_MAX, FLAGS, z }

static const AVOption colorspace_options[] = {
    { "all",        "Set all color properties together",
      OFFSET(user_all),   AV_OPT_TYPE_INT, { .i64 = CS_UNSPECIFIED },
      CS_UNSPECIFIED, CS_NB - 1, FLAGS, "all" },
    ENUM("bt470m",      CS_BT470M,             "all"),
    ENUM("bt470bg",     CS_BT470BG,            "all"),
    ENUM("bt601-6-525", CS_BT601_6_525,        "all"),
    ENUM("bt601-6-625", CS_BT601_6_625,        "all"),
    ENUM("bt709",       CS_BT709,              "all"),
    ENUM("smpte170m",   CS_SMPTE170M,          "all"),
    ENUM("smpte240m",   CS_SMPTE240M,          "all"),
    ENUM("bt2020",      CS_BT2020,             "all"),

    { "space",      "Output colorspace",
      OFFSET(user_csp),   AV_OPT_TYPE_INT, { .i64 = AVCOL_SPC_UNSPECIFIED },
      AVCOL_SPC_RGB, AVCOL_SPC_NB - 1, FLAGS,  "csp"},
    ENUM("bt709",       AVCOL_SPC_BT709,       "csp"),
    ENUM("fcc",         AVCOL_SPC_FCC,         "csp"),
    ENUM("bt470bg",     AVCOL_SPC_BT470BG,     "csp"),
    ENUM("smpte170m",   AVCOL_SPC_SMPTE170M,   "csp"),
    ENUM("smpte240m",   AVCOL_SPC_SMPTE240M,   "csp"),
    ENUM("ycgco",       AVCOL_SPC_YCGCO,       "csp"),
    ENUM("gbr",         AVCOL_SPC_RGB,         "csp"),
    ENUM("bt2020ncl",   AVCOL_SPC_BT2020_NCL,  "csp"),

    { "range",      "Output color range",
      OFFSET(user_rng),   AV_OPT_TYPE_INT, { .i64 = AVCOL_RANGE_UNSPECIFIED },
      AVCOL_RANGE_UNSPECIFIED, AVCOL_RANGE_NB - 1, FLAGS, "rng" },
    ENUM("tv",          AVCOL_RANGE_MPEG,      "rng"),
    ENUM("mpeg",        AVCOL_RANGE_MPEG,      "rng"),
    ENUM("pc",          AVCOL_RANGE_JPEG,      "rng"),
    ENUM("jpeg",        AVCOL_RANGE_JPEG,      "rng"),

    { "primaries",  "Output color primaries",
      OFFSET(user_prm),   AV_OPT_TYPE_INT, { .i64 = AVCOL_PRI_UNSPECIFIED },
      AVCOL_PRI_RESERVED0, AVCOL_PRI_NB - 1, FLAGS, "prm" },
    ENUM("bt709",        AVCOL_PRI_BT709,      "prm"),
    ENUM("bt470m",       AVCOL_PRI_BT470M,     "prm"),
    ENUM("bt470bg",      AVCOL_PRI_BT470BG,    "prm"),
    ENUM("smpte170m",    AVCOL_PRI_SMPTE170M,  "prm"),
    ENUM("smpte240m",    AVCOL_PRI_SMPTE240M,  "prm"),
    ENUM("film",         AVCOL_PRI_FILM,       "prm"),
    ENUM("smpte431",     AVCOL_PRI_SMPTE431,   "prm"),
    ENUM("smpte432",     AVCOL_PRI_SMPTE432,   "prm"),
    ENUM("bt2020",       AVCOL_PRI_BT2020,     "prm"),

    { "trc",        "Output transfer characteristics",
      OFFSET(user_trc),   AV_OPT_TYPE_INT, { .i64 = AVCOL_TRC_UNSPECIFIED },
      AVCOL_TRC_RESERVED0, AVCOL_TRC_NB - 1, FLAGS, "trc" },
    ENUM("bt709",        AVCOL_TRC_BT709,        "trc"),
    ENUM("bt470m",       AVCOL_TRC_GAMMA22,      "trc"),
    ENUM("gamma22",      AVCOL_TRC_GAMMA22,      "trc"),
    ENUM("bt470bg",      AVCOL_TRC_GAMMA28,      "trc"),
    ENUM("gamma28",      AVCOL_TRC_GAMMA28,      "trc"),
    ENUM("smpte170m",    AVCOL_TRC_SMPTE170M,    "trc"),
    ENUM("smpte240m",    AVCOL_TRC_SMPTE240M,    "trc"),
    ENUM("srgb",         AVCOL_TRC_IEC61966_2_1, "trc"),
    ENUM("iec61966-2-1", AVCOL_TRC_IEC61966_2_1, "trc"),
    ENUM("xvycc",        AVCOL_TRC_IEC61966_2_4, "trc"),
    ENUM("iec61966-2-4", AVCOL_TRC_IEC61966_2_4, "trc"),
    ENUM("bt2020-10",    AVCOL_TRC_BT2020_10,    "trc"),
    ENUM("bt2020-12",    AVCOL_TRC_BT2020_12,    "trc"),

    { "format",   "Output pixel format",
      OFFSET(user_format), AV_OPT_TYPE_INT,  { .i64 = AV_PIX_FMT_NONE },
      AV_PIX_FMT_NONE, AV_PIX_FMT_GBRAP12LE, FLAGS, "fmt" },
    ENUM("yuv420p",   AV_PIX_FMT_YUV420P,   "fmt"),
    ENUM("yuv420p10", AV_PIX_FMT_YUV420P10, "fmt"),
    ENUM("yuv420p12", AV_PIX_FMT_YUV420P12, "fmt"),
    ENUM("yuv422p",   AV_PIX_FMT_YUV422P,   "fmt"),
    ENUM("yuv422p10", AV_PIX_FMT_YUV422P10, "fmt"),
    ENUM("yuv422p12", AV_PIX_FMT_YUV422P12, "fmt"),
    ENUM("yuv444p",   AV_PIX_FMT_YUV444P,   "fmt"),
    ENUM("yuv444p10", AV_PIX_FMT_YUV444P10, "fmt"),
    ENUM("yuv444p12", AV_PIX_FMT_YUV444P12, "fmt"),

    { "fast",     "Ignore primary chromaticity and gamma correction",
      OFFSET(fast_mode), AV_OPT_TYPE_BOOL,  { .i64 = 0    },
      0, 1, FLAGS },

    { "dither",   "Dithering mode",
      OFFSET(dither), AV_OPT_TYPE_INT, { .i64 = DITHER_NONE },
      DITHER_NONE, DITHER_NB - 1, FLAGS, "dither" },
    ENUM("none", DITHER_NONE, "dither"),
    ENUM("fsb",  DITHER_FSB,  "dither"),

    { "wpadapt", "Whitepoint adaptation method",
      OFFSET(wp_adapt), AV_OPT_TYPE_INT, { .i64 = WP_ADAPT_BRADFORD },
      WP_ADAPT_BRADFORD, NB_WP_ADAPT - 1, FLAGS, "wpadapt" },
    ENUM("bradford", WP_ADAPT_BRADFORD, "wpadapt"),
    ENUM("vonkries", WP_ADAPT_VON_KRIES, "wpadapt"),
    ENUM("identity", WP_ADAPT_IDENTITY, "wpadapt"),

    { "iall",       "Set all input color properties together",
      OFFSET(user_iall),   AV_OPT_TYPE_INT, { .i64 = CS_UNSPECIFIED },
      CS_UNSPECIFIED, CS_NB - 1, FLAGS, "all" },
    { "ispace",     "Input colorspace",
      OFFSET(user_icsp),  AV_OPT_TYPE_INT, { .i64 = AVCOL_SPC_UNSPECIFIED },
      AVCOL_PRI_RESERVED0, AVCOL_PRI_NB - 1, FLAGS, "csp" },
    { "irange",     "Input color range",
      OFFSET(user_irng),  AV_OPT_TYPE_INT, { .i64 = AVCOL_RANGE_UNSPECIFIED },
      AVCOL_RANGE_UNSPECIFIED, AVCOL_RANGE_NB - 1, FLAGS, "rng" },
    { "iprimaries", "Input color primaries",
      OFFSET(user_iprm),  AV_OPT_TYPE_INT, { .i64 = AVCOL_PRI_UNSPECIFIED },
      AVCOL_PRI_RESERVED0, AVCOL_PRI_NB - 1, FLAGS, "prm" },
    { "itrc",       "Input transfer characteristics",
      OFFSET(user_itrc),  AV_OPT_TYPE_INT, { .i64 = AVCOL_TRC_UNSPECIFIED },
      AVCOL_TRC_RESERVED0, AVCOL_TRC_NB - 1, FLAGS, "trc" },

    { NULL }
};

AVFILTER_DEFINE_CLASS(colorspace);

static const AVFilterPad inputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .filter_frame = filter_frame,
    },
    { NULL }
};

static const AVFilterPad outputs[] = {
    {
        .name         = "default",
        .type         = AVMEDIA_TYPE_VIDEO,
        .config_props = config_props,
    },
    { NULL }
};

AVFilter ff_vf_colorspace = {
    .name            = "colorspace",
    .description     = NULL_IF_CONFIG_SMALL("Convert between colorspaces."),
    .init            = init,
    .uninit          = uninit,
    .query_formats   = query_formats,
    .priv_size       = sizeof(ColorSpaceContext),
    .priv_class      = &colorspace_class,
    .inputs          = inputs,
    .outputs         = outputs,
    .flags           = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
};
