lavfi: add elbg filter

1 files changed, 212 insertions, 0 deletions

diff --git a/libavfilter/vf_elbg.c b/libavfilter/vf_elbg.c
new file mode 100644
index 0000000000..2781281f71
--- /dev/null
+++ b/libavfilter/vf_elbg.c
@@ -0,0 +1,212 @@
+/*
+ * Copyright (c) 2013 Stefano Sabatini
+ *
+ * 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
+ * video quantizer filter based on ELBG
+ */
+
+#include "libavcodec/elbg.h"
+#include "libavutil/opt.h"
+#include "libavutil/pixdesc.h"
+#include "libavutil/random_seed.h"
+
+#include "avfilter.h"
+#include "drawutils.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct {
+    const AVClass *class;
+    AVLFG lfg;
+    int lfg_seed;
+    int max_steps_nb;
+    int *codeword;
+    int codeword_length;
+    int *codeword_closest_codebook_idxs;
+    int *codebook;
+    int codebook_length;
+    const AVPixFmtDescriptor *pix_desc;
+    uint8_t rgba_map[4];
+} ELBGContext;
+
+#define OFFSET(x) offsetof(ELBGContext, x)
+#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
+
+static const AVOption elbg_options[] = {
+    { "codebook_length", "set codebook length", OFFSET(codebook_length), AV_OPT_TYPE_INT, { .i64 = 256 }, 1, INT_MAX, FLAGS },
+    { "l",               "set codebook length", OFFSET(codebook_length), AV_OPT_TYPE_INT, { .i64 = 256 }, 1, INT_MAX, FLAGS },
+    { "nb_steps", "set max number of steps used to compute the mapping", OFFSET(max_steps_nb), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, INT_MAX, FLAGS },
+    { "n",        "set max number of steps used to compute the mapping", OFFSET(max_steps_nb), AV_OPT_TYPE_INT, { .i64 = 1 }, 1, INT_MAX, FLAGS },
+    { "seed", "set the random seed", OFFSET(lfg_seed), AV_OPT_TYPE_INT, {.i64 = -1}, -1, UINT32_MAX, FLAGS },
+    { "s",    "set the random seed", OFFSET(lfg_seed), AV_OPT_TYPE_INT, { .i64 = -1 }, -1, INT_MAX, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(elbg);
+
+static av_cold int init(AVFilterContext *ctx)
+{
+    ELBGContext *elbg = ctx->priv;
+
+    if (elbg->lfg_seed == -1)
+        elbg->lfg_seed = av_get_random_seed();
+
+    av_lfg_init(&elbg->lfg, elbg->lfg_seed);
+    return 0;
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum PixelFormat pix_fmts[] = {
+        AV_PIX_FMT_ARGB, AV_PIX_FMT_RGBA, AV_PIX_FMT_ABGR, AV_PIX_FMT_BGRA,
+        AV_PIX_FMT_RGB24, AV_PIX_FMT_BGR24,
+        AV_PIX_FMT_NONE
+    };
+
+    ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+
+    return 0;
+}
+
+#define NB_COMPONENTS 3
+
+static int config_input(AVFilterLink *inlink)
+{
+    AVFilterContext *ctx = inlink->dst;
+    ELBGContext *elbg = ctx->priv;
+
+    elbg->pix_desc = av_pix_fmt_desc_get(inlink->format);
+    elbg->codeword_length = inlink->w * inlink->h;
+    elbg->codeword = av_realloc_f(elbg->codeword, elbg->codeword_length,
+                                  NB_COMPONENTS * sizeof(*elbg->codeword));
+    if (!elbg->codeword)
+        return AVERROR(ENOMEM);
+
+    elbg->codeword_closest_codebook_idxs =
+        av_realloc_f(elbg->codeword_closest_codebook_idxs, elbg->codeword_length,
+                     sizeof(*elbg->codeword_closest_codebook_idxs));
+    if (!elbg->codeword_closest_codebook_idxs)
+        return AVERROR(ENOMEM);
+
+    elbg->codebook = av_realloc_f(elbg->codebook, elbg->codebook_length,
+                                  NB_COMPONENTS * sizeof(*elbg->codebook));
+    if (!elbg->codebook)
+        return AVERROR(ENOMEM);
+
+    ff_fill_rgba_map(elbg->rgba_map, inlink->format);
+
+    return 0;
+}
+
+#define R 0
+#define G 1
+#define B 2
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *frame)
+{
+    ELBGContext *elbg = inlink->dst->priv;
+    int i, j, k;
+    uint8_t *p, *p0;
+
+    const uint8_t r_idx  = elbg->rgba_map[R];
+    const uint8_t g_idx  = elbg->rgba_map[G];
+    const uint8_t b_idx  = elbg->rgba_map[B];
+
+    /* build the codeword */
+    p0 = frame->data[0];
+    k = 0;
+    for (i = 0; i < inlink->h; i++) {
+        p = p0;
+        for (j = 0; j < inlink->w; j++) {
+            elbg->codeword[k++] = p[r_idx];
+            elbg->codeword[k++] = p[g_idx];
+            elbg->codeword[k++] = p[b_idx];
+            p += elbg->pix_desc->nb_components;
+        }
+        p0 += frame->linesize[0];
+    }
+
+    /* compute the codebook */
+    avpriv_init_elbg(elbg->codeword, NB_COMPONENTS, elbg->codeword_length,
+                     elbg->codebook, elbg->codebook_length, elbg->max_steps_nb,
+                     elbg->codeword_closest_codebook_idxs, &elbg->lfg);
+    avpriv_do_elbg(elbg->codeword, NB_COMPONENTS, elbg->codeword_length,
+                   elbg->codebook, elbg->codebook_length, elbg->max_steps_nb,
+                   elbg->codeword_closest_codebook_idxs, &elbg->lfg);
+
+    /* fill the output with the codebook values */
+    p0 = frame->data[0];
+
+    k = 0;
+    for (i = 0; i < inlink->h; i++) {
+        p = p0;
+        for (j = 0; j < inlink->w; j++) {
+            int cb_idx = NB_COMPONENTS * elbg->codeword_closest_codebook_idxs[k++];
+            p[r_idx] = elbg->codebook[cb_idx];
+            p[g_idx] = elbg->codebook[cb_idx+1];
+            p[b_idx] = elbg->codebook[cb_idx+2];
+            p += elbg->pix_desc->nb_components;
+        }
+        p0 += frame->linesize[0];
+    }
+
+    return ff_filter_frame(inlink->dst->outputs[0], frame);
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+    ELBGContext *elbg = ctx->priv;
+
+    av_freep(&elbg->codebook);
+    av_freep(&elbg->codeword);
+    av_freep(&elbg->codeword_closest_codebook_idxs);
+}
+
+static const AVFilterPad elbg_inputs[] = {
+    {
+        .name           = "default",
+        .type           = AVMEDIA_TYPE_VIDEO,
+        .config_props   = config_input,
+        .filter_frame   = filter_frame,
+        .needs_writable = 1,
+    },
+    { NULL }
+};
+
+static const AVFilterPad elbg_outputs[] = {
+    {
+        .name = "default",
+        .type = AVMEDIA_TYPE_VIDEO,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_elbg = {
+    .name          = "elbg",
+    .description   = NULL_IF_CONFIG_SMALL("Apply posterize effect, using the ELBG algorithm."),
+    .priv_size     = sizeof(ELBGContext),
+    .priv_class    = &elbg_class,
+    .query_formats = query_formats,
+    .init          = init,
+    .uninit        = uninit,
+    .inputs        = elbg_inputs,
+    .outputs       = elbg_outputs,
+};