Add slicify video filter.

Originally committed as revision 20445 to svn://svn.ffmpeg.org/ffmpeg/trunk

1 files changed, 107 insertions, 0 deletions

diff --git a/libavfilter/vf_slicify.c b/libavfilter/vf_slicify.c
new file mode 100644
index 0000000000..40824cefdc
--- /dev/null
+++ b/libavfilter/vf_slicify.c
@@ -0,0 +1,107 @@
+/*
+ * copyright (c) 2007 Bobby Bingham
+ *
+ * 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 libavfilter/vf_slicify.c
+ * video slicing filter
+ */
+
+#include "avfilter.h"
+
+typedef struct {
+    int h;          ///< output slice height
+    int vshift;     ///< vertical chroma subsampling shift
+} SliceContext;
+
+static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
+{
+    SliceContext *slice = ctx->priv;
+
+    slice->h = 16;
+    if (args)
+        sscanf(args, "%d", &slice->h);
+
+    return 0;
+}
+
+static int config_props(AVFilterLink *link)
+{
+    SliceContext *slice = link->dst->priv;
+    int tmp;
+
+    avcodec_get_chroma_sub_sample(link->format, &tmp, &slice->vshift);
+
+    /* ensure that slices play nice with chroma subsampling, and enforce
+     * a reasonable minimum size for the slices */
+    slice->h = FFMAX(8, slice->h & (-1 << slice->vshift));
+
+    av_log(link->dst, AV_LOG_INFO, "h:%d\n", slice->h);
+
+    return 0;
+}
+
+static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
+                                        int w, int h)
+{
+    return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
+}
+
+static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
+{
+    avfilter_start_frame(link->dst->outputs[0], picref);
+}
+
+static void end_frame(AVFilterLink *link)
+{
+    avfilter_end_frame(link->dst->outputs[0]);
+}
+
+static void draw_slice(AVFilterLink *link, int y, int h)
+{
+    SliceContext *slice = link->dst->priv;
+    int y2;
+
+    for (y2 = y; y2 + slice->h <= y + h; y2 += slice->h)
+        avfilter_draw_slice(link->dst->outputs[0], y2, slice->h);
+
+    if (y2 < y + h)
+        avfilter_draw_slice(link->dst->outputs[0], y2, y + h - y2);
+}
+
+AVFilter avfilter_vf_slicify = {
+    .name      = "slicify",
+    .description = "Pass the images of input video on to next video filter as multiple slices.",
+
+    .init      = init,
+
+    .priv_size = sizeof(SliceContext),
+
+    .inputs    = (AVFilterPad[]) {{ .name             = "default",
+                                    .type             = CODEC_TYPE_VIDEO,
+                                    .get_video_buffer = get_video_buffer,
+                                    .start_frame      = start_frame,
+                                    .draw_slice       = draw_slice,
+                                    .config_props     = config_props,
+                                    .end_frame        = end_frame, },
+                                  { .name = NULL}},
+    .outputs   = (AVFilterPad[]) {{ .name            = "default",
+                                    .type            = CODEC_TYPE_VIDEO, },
+                                  { .name = NULL}},
+};