avfilter: add showpalette filter

1 files changed, 127 insertions, 0 deletions

diff --git a/libavfilter/vf_showpalette.c b/libavfilter/vf_showpalette.c
new file mode 100644
index 0000000000..adcfeb4f10
--- /dev/null
+++ b/libavfilter/vf_showpalette.c
@@ -0,0 +1,127 @@
+/*
+ * 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
+ * Display frame palette (AV_PIX_FMT_PAL8)
+ */
+
+#include "libavutil/avassert.h"
+#include "libavutil/opt.h"
+#include "avfilter.h"
+#include "formats.h"
+#include "internal.h"
+#include "video.h"
+
+typedef struct {
+    const AVClass *class;
+    int size;
+} ShowPaletteContext;
+
+#define OFFSET(x) offsetof(ShowPaletteContext, x)
+#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
+static const AVOption showpalette_options[] = {
+    { "s", "set pixel box size", OFFSET(size), AV_OPT_TYPE_INT, {.i64=30}, 1, 100, FLAGS },
+    { NULL }
+};
+
+AVFILTER_DEFINE_CLASS(showpalette);
+
+static int query_formats(AVFilterContext *ctx)
+{
+    static const enum AVPixelFormat in_fmts[]  = {AV_PIX_FMT_PAL8,  AV_PIX_FMT_NONE};
+    static const enum AVPixelFormat out_fmts[] = {AV_PIX_FMT_RGB32, AV_PIX_FMT_NONE};
+    AVFilterFormats *in  = ff_make_format_list(in_fmts);
+    AVFilterFormats *out = ff_make_format_list(out_fmts);
+    if (!in || !out)
+        return AVERROR(ENOMEM);
+    ff_formats_ref(in,  &ctx->inputs[0]->out_formats);
+    ff_formats_ref(out, &ctx->outputs[0]->in_formats);
+    return 0;
+}
+
+static int config_output(AVFilterLink *outlink)
+{
+    AVFilterContext *ctx = outlink->src;
+    const ShowPaletteContext *s = ctx->priv;
+    outlink->w = outlink->h = 16 * s->size;
+    return 0;
+}
+
+static int disp_palette(AVFrame *out, const AVFrame *in, int size)
+{
+    int x, y, i, j;
+    uint32_t *dst = (uint32_t *)out->data[0];
+    const int dst_linesize = out->linesize[0] >> 2;
+    const uint32_t *pal = (uint32_t *)in->data[1];
+
+    for (y = 0; y < 16; y++)
+        for (x = 0; x < 16; x++)
+            for (j = 0; j < size; j++)
+                for (i = 0; i < size; i++)
+                    dst[(y*dst_linesize + x) * size + j*dst_linesize + i] = pal[y*16 + x];
+    return 0;
+}
+
+static int filter_frame(AVFilterLink *inlink, AVFrame *in)
+{
+    int ret;
+    AVFrame *out;
+    AVFilterContext *ctx = inlink->dst;
+    const ShowPaletteContext *s= ctx->priv;
+    AVFilterLink *outlink = ctx->outputs[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);
+    ret = disp_palette(out, in, s->size);
+    av_frame_free(&in);
+    return ret < 0 ? ret : ff_filter_frame(outlink, out);
+}
+
+static const AVFilterPad showpalette_inputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .filter_frame = filter_frame,
+    },
+    { NULL }
+};
+
+static const AVFilterPad showpalette_outputs[] = {
+    {
+        .name         = "default",
+        .type         = AVMEDIA_TYPE_VIDEO,
+        .config_props = config_output,
+    },
+    { NULL }
+};
+
+AVFilter ff_vf_showpalette = {
+    .name          = "showpalette",
+    .description   = NULL_IF_CONFIG_SMALL("Display frame palette"),
+    .priv_size     = sizeof(ShowPaletteContext),
+    .query_formats = query_formats,
+    .inputs        = showpalette_inputs,
+    .outputs       = showpalette_outputs,
+    .priv_class    = &showpalette_class,
+    .flags         = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
+};