@@ -46,6 +46,7 @@ version <next>:

 - RedSpark demuxer

 - ADPCM IMA Radical decoder

 - zmq filters

+- DCT denoiser filter (dctdnoiz)

 version 1.2:

@@ -2129,6 +2129,7 @@ blackframe_filter_deps="gpl"

 boxblur_filter_deps="gpl"

 colormatrix_filter_deps="gpl"

 cropdetect_filter_deps="gpl"

+dctdnoiz_filter_deps="avcodec"

 delogo_filter_deps="gpl"

 deshake_filter_deps="avcodec"

 deshake_filter_select="dsputil"

@@ -2655,6 +2655,59 @@ curves=psfile='MyCurvesPresets/purple.asv':green='0.45/0.53'

 @end example

 @end itemize

+@section dctdnoiz

+

+Denoise frames using 2D DCT (frequency domain filtering).

+

+This filter is not designed for real time and can be extremely slow.

+

+The filter accepts the following options:

+

+@table @option

+@item sigma, s

+Set the noise sigma constant.

+

+This @var{sigma} defines a hard threshold of @code{3 * sigma}; every DCT

+coefficient (absolute value) below this threshold with be dropped.

+

+If you need a more advanced filtering, see @option{expr}.

+

+Default is @code{0}.

+

+@item overlap

+Set number overlapping pixels for each block. Each block is of size

+@code{16x16}. Since the filter can be slow, you may want to reduce this value,

+at the cost of a less effective filter and the risk of various artefacts.

+

+If the overlapping value doesn't allow to process the whole input width or

+height, a warning will be displayed and according borders won't be denoised.

+

+Default value is @code{15}.

+

+@item expr, e

+Set the coefficient factor expression.

+

+For each coefficient of a DCT block, this expression will be evaluated as a

+multiplier value for the coefficient.

+

+If this is option is set, the @option{sigma} option will be ignored.

+

+The absolute value of the coefficient can be accessed through the @var{c}

+variable.

+@end table

+

+@subsection Examples

+

+Apply a denoise with a @option{sigma} of @code{4.5}:

+@example

+dctdnoiz=4.5

+@end example

+

+The same operation can be achieved using the expression system:

+@example

+dctdnoiz=e='gte(c, 4.5*3)'

+@end example

+

 @anchor{decimate}

 @section decimate

@@ -116,6 +116,7 @@ OBJS-$(CONFIG_COPY_FILTER)                   += vf_copy.o

 OBJS-$(CONFIG_CROP_FILTER)                   += vf_crop.o

 OBJS-$(CONFIG_CROPDETECT_FILTER)             += vf_cropdetect.o

 OBJS-$(CONFIG_CURVES_FILTER)                 += vf_curves.o

+OBJS-$(CONFIG_DCTDNOIZ_FILTER)               += vf_dctdnoiz.o

 OBJS-$(CONFIG_DECIMATE_FILTER)               += vf_decimate.o

 OBJS-$(CONFIG_DELOGO_FILTER)                 += vf_delogo.o

 OBJS-$(CONFIG_DESHAKE_FILTER)                += vf_deshake.o

@@ -114,6 +114,7 @@ void avfilter_register_all(void)

     REGISTER_FILTER(CROP,           crop,           vf);

     REGISTER_FILTER(CROPDETECT,     cropdetect,     vf);

     REGISTER_FILTER(CURVES,         curves,         vf);

+    REGISTER_FILTER(DCTDNOIZ,       dctdnoiz,       vf);

     REGISTER_FILTER(DECIMATE,       decimate,       vf);

     REGISTER_FILTER(DELOGO,         delogo,         vf);

     REGISTER_FILTER(DESHAKE,        deshake,        vf);

@@ -29,7 +29,7 @@

 #include "libavutil/avutil.h"

 #define LIBAVFILTER_VERSION_MAJOR  3

-#define LIBAVFILTER_VERSION_MINOR  66

+#define LIBAVFILTER_VERSION_MINOR  67

 #define LIBAVFILTER_VERSION_MICRO 100

 #define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

new file mode 100644

@@ -0,0 +1,431 @@

+/*

+ * Copyright (c) 2013 Clément Bœsch

+ *

+ * 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

+ */

+

+/**

+ * A simple, relatively efficient and extremely slow DCT image denoiser.

+ * @see http://www.ipol.im/pub/art/2011/ys-dct/

+ */

+

+#include "libavcodec/avfft.h"

+#include "libavutil/eval.h"

+#include "libavutil/opt.h"

+#include "drawutils.h"

+#include "internal.h"

+

+#define NBITS 4

+#define BSIZE (1<<(NBITS))

+

+static const char *const var_names[] = { "c", NULL };

+enum { VAR_C, VAR_VARS_NB };

+

+typedef struct {

+    const AVClass *class;

+

+    /* coefficient factor expression */

+    char *expr_str;

+    AVExpr *expr;

+    double var_values[VAR_VARS_NB];

+

+    int pr_width, pr_height;    // width and height to process

+    float sigma;                // used when no expression are st

+    float th;                   // threshold (3*sigma)

+    float color_dct[3][3];      // 3x3 DCT for color decorrelation

+    float *cbuf[2][3];          // two planar rgb color buffers

+    float *weights;             // dct coeff are cumulated with overlapping; these values are used for averaging

+    int p_linesize;             // line sizes for color and weights

+    int overlap;                // number of block overlapping pixels

+    int step;                   // block step increment (BSIZE - overlap)

+    DCTContext *dct, *idct;     // DCT and inverse DCT contexts

+    float *block, *tmp_block;   // two BSIZE x BSIZE block buffers

+} DCTdnoizContext;

+

+#define OFFSET(x) offsetof(DCTdnoizContext, x)

+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM

+static const AVOption dctdnoiz_options[] = {

+    { "sigma",   "set noise sigma constant",               OFFSET(sigma),    AV_OPT_TYPE_FLOAT,  {.dbl=0},            0, 999,          .flags = FLAGS },

+    { "s",       "set noise sigma constant",               OFFSET(sigma),    AV_OPT_TYPE_FLOAT,  {.dbl=0},            0, 999,          .flags = FLAGS },

+    { "overlap", "set number of block overlapping pixels", OFFSET(overlap),  AV_OPT_TYPE_INT,    {.i64=(1<<NBITS)-1}, 0, (1<<NBITS)-1, .flags = FLAGS },

+    { "expr",    "set coefficient factor expression",      OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str=NULL},                          .flags = FLAGS },

+    { "e",       "set coefficient factor expression",      OFFSET(expr_str), AV_OPT_TYPE_STRING, {.str=NULL},                          .flags = FLAGS },

+    { NULL }

+};

+

+AVFILTER_DEFINE_CLASS(dctdnoiz);

+

+static float *dct_block(DCTdnoizContext *ctx, const float *src, int src_linesize)

+{

+    int x, y;

+    float *column;

+

+    for (y = 0; y < BSIZE; y++) {

+        float *line = ctx->block;

+

+        memcpy(line, src, BSIZE * sizeof(*line));

+        src += src_linesize;

+        av_dct_calc(ctx->dct, line);

+

+        column = ctx->tmp_block + y;

+        for (x = 0; x < BSIZE; x++) {

+            *line *= x == 0 ? 1. / sqrt(BSIZE) : sqrt(2. / BSIZE);

+            *column = *line++;

+            column += BSIZE;

+        }

+    }

+

+    column = ctx->tmp_block;

+    for (x = 0; x < BSIZE; x++) {

+        av_dct_calc(ctx->dct, column);

+        for (y = 0; y < BSIZE; y++)

+            column[y] *= y == 0 ? 1. / sqrt(BSIZE) : sqrt(2. / BSIZE);

+        column += BSIZE;

+    }

+

+    for (y = 0; y < BSIZE; y++)

+        for (x = 0; x < BSIZE; x++)

+            ctx->block[y*BSIZE + x] = ctx->tmp_block[x*BSIZE + y];

+

+    return ctx->block;

+}

+

+static void idct_block(DCTdnoizContext *ctx, float *dst, int dst_linesize)

+{

+    int x, y;

+    float *block = ctx->block;

+    float *tmp = ctx->tmp_block;

+

+    for (y = 0; y < BSIZE; y++) {

+        for (x = 0; x < BSIZE; x++)

+            block[x] *= x == 0 ? sqrt(BSIZE) : 1./sqrt(2. / BSIZE);

+        av_dct_calc(ctx->idct, block);

+        block += BSIZE;

+    }

+

+    block = ctx->block;

+    for (y = 0; y < BSIZE; y++) {

+        for (x = 0; x < BSIZE; x++) {

+            tmp[x] = block[x*BSIZE + y];

+            tmp[x] *= x == 0 ? sqrt(BSIZE) : 1./sqrt(2. / BSIZE);

+        }

+        av_dct_calc(ctx->idct, tmp);

+        for (x = 0; x < BSIZE; x++)

+            dst[x*dst_linesize + y] += tmp[x];

+    }

+}

+

+static int config_input(AVFilterLink *inlink)

+{

+    AVFilterContext *ctx = inlink->dst;

+    DCTdnoizContext *s = ctx->priv;

+    int i, x, y, bx, by, linesize, *iweights;

+    const float dct_3x3[3][3] = {

+        { 1./sqrt(3),  1./sqrt(3),  1./sqrt(3) },

+        { 1./sqrt(2),           0, -1./sqrt(2) },

+        { 1./sqrt(6), -2./sqrt(6),  1./sqrt(6) },

+    };

+    uint8_t rgba_map[4];

+

+    ff_fill_rgba_map(rgba_map, inlink->format);

+    for (y = 0; y < 3; y++)

+        for (x = 0; x < 3; x++)

+            s->color_dct[y][x] = dct_3x3[rgba_map[y]][rgba_map[x]];

+

+    s->pr_width  = inlink->w - (inlink->w - BSIZE) % s->step;

+    s->pr_height = inlink->w - (inlink->h - BSIZE) % s->step;

+    if (s->pr_width != inlink->w)

+        av_log(ctx, AV_LOG_WARNING, "The last %d horizontal pixels won't be denoised\n",

+               inlink->w - s->pr_width);

+    if (s->pr_height != inlink->h)

+        av_log(ctx, AV_LOG_WARNING, "The last %d vertical pixels won't be denoised\n",

+               inlink->h - s->pr_height);

+

+    s->p_linesize = linesize = FFALIGN(s->pr_width, 32);

+    for (i = 0; i < 2; i++) {

+        s->cbuf[i][0] = av_malloc(linesize * s->pr_height * sizeof(*s->cbuf[i][0]));

+        s->cbuf[i][1] = av_malloc(linesize * s->pr_height * sizeof(*s->cbuf[i][1]));

+        s->cbuf[i][2] = av_malloc(linesize * s->pr_height * sizeof(*s->cbuf[i][2]));

+        if (!s->cbuf[i][0] || !s->cbuf[i][1] || !s->cbuf[i][2])

+            return AVERROR(ENOMEM);

+    }

+

+    s->weights = av_malloc(s->pr_height * linesize * sizeof(*s->weights));

+    if (!s->weights)

+        return AVERROR(ENOMEM);

+    iweights = av_calloc(s->pr_height, linesize * sizeof(*iweights));

+    if (!iweights)

+        return AVERROR(ENOMEM);

+    for (y = 0; y < s->pr_height - BSIZE + 1; y += s->step)

+        for (x = 0; x < s->pr_width - BSIZE + 1; x += s->step)

+            for (by = 0; by < BSIZE; by++)

+                for (bx = 0; bx < BSIZE; bx++)

+                    iweights[(y + by)*linesize + x + bx]++;

+    for (y = 0; y < s->pr_height; y++)

+        for (x = 0; x < s->pr_width; x++)

+            s->weights[y*linesize + x] = 1. / iweights[y*linesize + x];

+    av_free(iweights);

+

+    return 0;

+}

+

+static av_cold int init(AVFilterContext *ctx)

+{

+    DCTdnoizContext *s = ctx->priv;

+

+    if (s->expr_str) {

+        int ret = av_expr_parse(&s->expr, s->expr_str, var_names,

+                                NULL, NULL, NULL, NULL, 0, ctx);

+        if (ret < 0)

+            return ret;

+    }

+

+    s->th   = s->sigma * 3.;

+    s->step = BSIZE - s->overlap;

+    s->dct  = av_dct_init(NBITS, DCT_II);

+    s->idct = av_dct_init(NBITS, DCT_III);

+    s->block     = av_malloc(BSIZE * BSIZE * sizeof(*s->block));

+    s->tmp_block = av_malloc(BSIZE * BSIZE * sizeof(*s->tmp_block));

+

+    if (!s->dct || !s->idct || !s->tmp_block || !s->block)

+        return AVERROR(ENOMEM);

+

+    return 0;

+}

+

+static int query_formats(AVFilterContext *ctx)

+{

+    static const enum AVPixelFormat pix_fmts[] = {

+        AV_PIX_FMT_BGR24, AV_PIX_FMT_RGB24,

+        AV_PIX_FMT_NONE

+    };

+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));

+    return 0;

+}

+

+static void color_decorrelation(float dct3ch[3][3], float **dst, int dst_linesize,

+                                const uint8_t *src, int src_linesize, int w, int h)

+{

+    int x, y;

+    float *dstp_r = dst[0];

+    float *dstp_g = dst[1];

+    float *dstp_b = dst[2];

+

+    for (y = 0; y < h; y++) {

+        const uint8_t *srcp = src;

+

+        for (x = 0; x < w; x++) {

+            dstp_r[x] = srcp[0] * dct3ch[0][0] + srcp[1] * dct3ch[0][1] + srcp[2] * dct3ch[0][2];

+            dstp_g[x] = srcp[0] * dct3ch[1][0] + srcp[1] * dct3ch[1][1] + srcp[2] * dct3ch[1][2];

+            dstp_b[x] = srcp[0] * dct3ch[2][0] + srcp[1] * dct3ch[2][1] + srcp[2] * dct3ch[2][2];

+            srcp += 3;

+        }

+        src += src_linesize;

+        dstp_r += dst_linesize;

+        dstp_g += dst_linesize;

+        dstp_b += dst_linesize;

+    }

+}

+

+static void color_correlation(float dct3ch[3][3], uint8_t *dst, int dst_linesize,

+                              float **src, int src_linesize, int w, int h)

+{

+    int x, y;

+    const float *src_r = src[0];

+    const float *src_g = src[1];

+    const float *src_b = src[2];

+

+    for (y = 0; y < h; y++) {

+        uint8_t *dstp = dst;

+

+        for (x = 0; x < w; x++) {

+            dstp[0] = av_clip_uint8(src_r[x] * dct3ch[0][0] + src_g[x] * dct3ch[1][0] + src_b[x] * dct3ch[2][0]);

+            dstp[1] = av_clip_uint8(src_r[x] * dct3ch[0][1] + src_g[x] * dct3ch[1][1] + src_b[x] * dct3ch[2][1]);

+            dstp[2] = av_clip_uint8(src_r[x] * dct3ch[0][2] + src_g[x] * dct3ch[1][2] + src_b[x] * dct3ch[2][2]);

+            dstp += 3;

+        }

+        dst += dst_linesize;

+        src_r += src_linesize;

+        src_g += src_linesize;

+        src_b += src_linesize;

+    }

+}

+

+static void filter_plane(AVFilterContext *ctx,

+                         float *dst, int dst_linesize,

+                         const float *src, int src_linesize,

+                         int w, int h)

+{

+    int x, y, bx, by;

+    DCTdnoizContext *s = ctx->priv;

+    float *dst0 = dst;

+    const float *weights = s->weights;

+

+    // reset block sums

+    memset(dst, 0, h * dst_linesize * sizeof(*dst));

+

+    // block dct sums

+    for (y = 0; y < h - BSIZE + 1; y += s->step) {

+        for (x = 0; x < w - BSIZE + 1; x += s->step) {

+            float *ftb = dct_block(s, src + x, src_linesize);

+

+            if (s->expr) {

+                for (by = 0; by < BSIZE; by++) {

+                    for (bx = 0; bx < BSIZE; bx++) {

+                        s->var_values[VAR_C] = FFABS(*ftb);

+                        *ftb++ *= av_expr_eval(s->expr, s->var_values, s);

+                    }

+                }

+            } else {

+                for (by = 0; by < BSIZE; by++) {

+                    for (bx = 0; bx < BSIZE; bx++) {

+                        if (FFABS(*ftb) < s->th)

+                            *ftb = 0;

+                        ftb++;

+                    }

+                }

+            }

+            idct_block(s, dst + x, dst_linesize);

+        }

+        src += s->step * src_linesize;

+        dst += s->step * dst_linesize;

+    }

+

+    // average blocks

+    dst = dst0;

+    for (y = 0; y < h; y++) {

+        for (x = 0; x < w; x++)

+            dst[x] *= weights[x];

+        dst += dst_linesize;

+        weights += dst_linesize;

+    }

+}

+

+static int filter_frame(AVFilterLink *inlink, AVFrame *in)

+{

+    AVFilterContext *ctx = inlink->dst;

+    DCTdnoizContext *s = ctx->priv;

+    AVFilterLink *outlink = inlink->dst->outputs[0];

+    int direct, plane;

+    AVFrame *out;

+

+    if (av_frame_is_writable(in)) {

+        direct = 1;

+        out = in;

+    } else {

+        direct = 0;

+        out = ff_get_video_buffer(outlink, outlink->w, outlink->h);

+        if (!out) {

+            av_frame_free(&in);

+            return AVERROR(ENOMEM);

+        }

+        av_frame_copy_props(out, in);

+    }

+

+    color_decorrelation(s->color_dct, s->cbuf[0], s->p_linesize,

+                        in->data[0], in->linesize[0], s->pr_width, s->pr_height);

+    for (plane = 0; plane < 3; plane++)

+        filter_plane(ctx, s->cbuf[1][plane], s->p_linesize,

+                          s->cbuf[0][plane], s->p_linesize,

+                          s->pr_width, s->pr_height);

+    color_correlation(s->color_dct, out->data[0], out->linesize[0],

+                      s->cbuf[1], s->p_linesize, s->pr_width, s->pr_height);

+

+    if (!direct) {

+        int y;

+        uint8_t *dst = out->data[0];

+        const uint8_t *src = in->data[0];

+        const int dst_linesize = out->linesize[0];

+        const int src_linesize = in->linesize[0];

+        const int hpad = (inlink->w - s->pr_width) * 3;

+        const int vpad = (inlink->h - s->pr_height);

+

+        if (hpad) {

+            uint8_t       *dstp = dst + s->pr_width * 3;

+            const uint8_t *srcp = src + s->pr_width * 3;

+

+            for (y = 0; y < s->pr_height; y++) {

+                memcpy(dstp, srcp, hpad);

+                dstp += dst_linesize;

+                srcp += src_linesize;

+            }

+        }

+        if (vpad) {

+            uint8_t       *dstp = dst + s->pr_height * dst_linesize;

+            const uint8_t *srcp = src + s->pr_height * src_linesize;

+

+            for (y = 0; y < vpad; y++) {

+                memcpy(dstp, srcp, inlink->w * 3);

+                dstp += dst_linesize;

+                srcp += src_linesize;

+            }

+        }

+

+        av_frame_free(&in);

+    }

+

+    return ff_filter_frame(outlink, out);

+}

+

+static av_cold void uninit(AVFilterContext *ctx)

+{

+    int i;

+    DCTdnoizContext *s = ctx->priv;

+

+    av_dct_end(s->dct);

+    av_dct_end(s->idct);

+    av_free(s->block);

+    av_free(s->tmp_block);

+    av_free(s->weights);

+    for (i = 0; i < 2; i++) {

+        av_free(s->cbuf[i][0]);

+        av_free(s->cbuf[i][1]);

+        av_free(s->cbuf[i][2]);

+    }

+    av_expr_free(s->expr);

+}

+

+static const AVFilterPad dctdnoiz_inputs[] = {

+    {

+        .name         = "default",

+        .type         = AVMEDIA_TYPE_VIDEO,

+        .filter_frame = filter_frame,

+        .config_props = config_input,

+    },

+    { NULL }

+};

+

+static const AVFilterPad dctdnoiz_outputs[] = {

+    {

+        .name = "default",

+        .type = AVMEDIA_TYPE_VIDEO,

+    },

+    { NULL }

+};

+

+AVFilter avfilter_vf_dctdnoiz = {

+    .name          = "dctdnoiz",

+    .description   = NULL_IF_CONFIG_SMALL("Denoise frames using 2D DCT."),

+    .priv_size     = sizeof(DCTdnoizContext),

+    .init          = init,

+    .uninit        = uninit,

+    .query_formats = query_formats,

+    .inputs        = dctdnoiz_inputs,

+    .outputs       = dctdnoiz_outputs,

+    .priv_class    = &dctdnoiz_class,

+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,

+};