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lavfi: port decimate libmpcodecs filter

This filter is based on the MPlayer decimate filter by Rich Felker.
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1 parent 6c01078 commit 9dd3d6c72a2eca41e24d8c7bb8983abcb6310bf8 @saste saste committed Mar 17, 2012
Showing with 312 additions and 2 deletions.
  1. +1 −0 Changelog
  2. +1 −0 configure
  3. +37 −0 doc/filters.texi
  4. +2 −0 libavfilter/Makefile
  5. +1 −0 libavfilter/allfilters.c
  6. +2 −2 libavfilter/version.h
  7. +268 −0 libavfilter/vf_decimate.c
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@@ -58,6 +58,7 @@ version next:
instead of AV_CODEC_ID_TEXT
- smartblur filter ported from MPlayer
- CPiA decoder
+- decimate filter ported from MPlayer
version 0.11:
View
@@ -1889,6 +1889,7 @@ blackframe_filter_deps="gpl"
boxblur_filter_deps="gpl"
colormatrix_filter_deps="gpl"
cropdetect_filter_deps="gpl"
+decimate_filter_deps="gpl"
delogo_filter_deps="gpl"
deshake_filter_deps="avcodec"
drawtext_filter_deps="libfreetype"
View
@@ -1539,6 +1539,43 @@ indicates never reset and return the largest area encountered during
playback.
@end table
+@section decimate
+
+This filter drops frames that do not differ greatly from the previous
+frame in order to reduce framerate. The main use of this filter is
+for very-low-bitrate encoding (e.g. streaming over dialup modem), but
+it could in theory be used for fixing movies that were
+inverse-telecined incorrectly.
+
+It accepts the following parameters:
+@var{max}:@var{hi}:@var{lo}:@var{frac}.
+
+@table @option
+
+@item max
+Set the maximum number of consecutive frames which can be dropped (if
+positive), or the minimum interval between dropped frames (if
+negative). If the value is 0, the frame is dropped unregarding the
+number of previous sequentially dropped frames.
+
+Default value is 0.
+
+@item hi, lo, frac
+Set the dropping threshold values.
+
+Values for @var{hi} and @var{lo} are for 8x8 pixel blocks and
+represent actual pixel value differences, so a threshold of 64
+corresponds to 1 unit of difference for each pixel, or the same spread
+out differently over the block.
+
+A frame is a candidate for dropping if no 8x8 blocks differ by more
+than a threshold of @var{hi}, and if no more than @var{frac} blocks (1
+meaning the whole image) differ by more than a threshold of @var{lo}.
+
+Default value for @var{hi} is 64*12, default value for @var{lo} is
+64*5, and default value for @var{frac} is 0.33.
+@end table
+
@section delogo
Suppress a TV station logo by a simple interpolation of the surrounding
View
@@ -10,6 +10,7 @@ FFLIBS-$(CONFIG_ACONVERT_FILTER) += swresample
FFLIBS-$(CONFIG_AMOVIE_FILTER) += avformat avcodec
FFLIBS-$(CONFIG_ARESAMPLE_FILTER) += swresample
FFLIBS-$(CONFIG_ATEMPO_FILTER) += avcodec
+FFLIBS-$(CONFIG_DECIMATE_FILTER) += avcodec
FFLIBS-$(CONFIG_MOVIE_FILTER) += avformat avcodec
FFLIBS-$(CONFIG_PAN_FILTER) += swresample
FFLIBS-$(CONFIG_REMOVELOGO_FILTER) += avformat avcodec
@@ -88,6 +89,7 @@ OBJS-$(CONFIG_COLORMATRIX_FILTER) += vf_colormatrix.o
OBJS-$(CONFIG_COPY_FILTER) += vf_copy.o
OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_CROPDETECT_FILTER) += vf_cropdetect.o
+OBJS-$(CONFIG_DECIMATE_FILTER) += vf_decimate.o
OBJS-$(CONFIG_DELOGO_FILTER) += vf_delogo.o
OBJS-$(CONFIG_DESHAKE_FILTER) += vf_deshake.o
OBJS-$(CONFIG_DRAWBOX_FILTER) += vf_drawbox.o
View
@@ -78,6 +78,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (COPY, copy, vf);
REGISTER_FILTER (CROP, crop, vf);
REGISTER_FILTER (CROPDETECT, cropdetect, vf);
+ REGISTER_FILTER (DECIMATE, decimate, vf);
REGISTER_FILTER (DELOGO, delogo, vf);
REGISTER_FILTER (DESHAKE, deshake, vf);
REGISTER_FILTER (DRAWBOX, drawbox, vf);
View
@@ -29,8 +29,8 @@
#include "libavutil/avutil.h"
#define LIBAVFILTER_VERSION_MAJOR 3
-#define LIBAVFILTER_VERSION_MINOR 14
-#define LIBAVFILTER_VERSION_MICRO 101
+#define LIBAVFILTER_VERSION_MINOR 15
+#define LIBAVFILTER_VERSION_MICRO 100
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \
LIBAVFILTER_VERSION_MINOR, \
View
@@ -0,0 +1,268 @@
+/*
+ * Copyright (c) 2003 Rich Felker
+ * Copyright (c) 2012 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 General Public License as published by
+ * the Free Software Foundation; either version 2 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU 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 decimate filter, ported from libmpcodecs/vf_decimate.c by
+ * Rich Felker.
+ */
+
+#include "libavutil/pixdesc.h"
+#include "libavutil/timestamp.h"
+#include "libavcodec/dsputil.h"
+#include "avfilter.h"
+#include "internal.h"
+#include "formats.h"
+#include "video.h"
+
+typedef struct {
+ int lo, hi; ///< lower and higher threshold number of differences
+ ///< values for 8x8 blocks
+
+ float frac; ///< threshold of changed pixels over the total fraction
+
+ int max_drop_count; ///< if positive: maximum number of sequential frames to drop
+ ///< if negative: minimum number of frames between two drops
+
+ int drop_count; ///< if positive: number of frames sequentially dropped
+ ///< if negative: number of sequential frames which were not dropped
+
+ int hsub, vsub; ///< chroma subsampling values
+ AVFilterBufferRef *ref; ///< reference picture
+ DSPContext dspctx; ///< context providing optimized diff routines
+ AVCodecContext *avctx; ///< codec context required for the DSPContext
+} DecimateContext;
+
+/**
+ * Return 1 if the two planes are different, 0 otherwise.
+ */
+static int diff_planes(AVFilterContext *ctx,
+ uint8_t *cur, uint8_t *ref, int linesize,
+ int w, int h)
+{
+ DecimateContext *decimate = ctx->priv;
+ DSPContext *dspctx = &decimate->dspctx;
+
+ int x, y;
+ int d, c = 0;
+ int t = (w/16)*(h/16)*decimate->frac;
+ DCTELEM block[8*8];
+
+ /* compute difference for blocks of 8x8 bytes */
+ for (y = 0; y < h-7; y += 4) {
+ for (x = 8; x < w-7; x += 4) {
+ dspctx->diff_pixels(block,
+ cur+x+y*linesize,
+ ref+x+y*linesize, linesize);
+ d = dspctx->sum_abs_dctelem(block);
+ if (d > decimate->hi)
+ return 1;
+ if (d > decimate->lo) {
+ c++;
+ if (c > t)
+ return 1;
+ }
+ }
+ }
+ return 0;
+}
+
+/**
+ * Tell if the frame should be decimated, for example if it is no much
+ * different with respect to the reference frame ref.
+ */
+static int decimate_frame(AVFilterContext *ctx,
+ AVFilterBufferRef *cur, AVFilterBufferRef *ref)
+{
+ DecimateContext *decimate = ctx->priv;
+ int plane;
+
+ if (decimate->max_drop_count > 0 &&
+ decimate->drop_count >= decimate->max_drop_count)
+ return 0;
+ if (decimate->max_drop_count < 0 &&
+ (decimate->drop_count-1) > decimate->max_drop_count)
+ return 0;
+
+ for (plane = 0; ref->data[plane] && ref->linesize[plane]; plane++) {
+ int vsub = plane == 1 || plane == 2 ? decimate->vsub : 0;
+ int hsub = plane == 1 || plane == 2 ? decimate->hsub : 0;
+ if (diff_planes(ctx,
+ cur->data[plane], ref->data[plane], ref->linesize[plane],
+ ref->video->w>>hsub, ref->video->h>>vsub))
+ return 0;
+ }
+
+ return 1;
+}
+
+static av_cold int init(AVFilterContext *ctx, const char *args)
+{
+ DecimateContext *decimate = ctx->priv;
+
+ /* set default values */
+ decimate->drop_count = decimate->max_drop_count = 0;
+ decimate->lo = 64*5;
+ decimate->hi = 64*12;
+ decimate->frac = 0.33;
+
+ if (args) {
+ char c1, c2, c3, c4;
+ int n = sscanf(args, "%d%c%d%c%d%c%f%c",
+ &decimate->max_drop_count, &c1,
+ &decimate->hi, &c2, &decimate->lo, &c3,
+ &decimate->frac, &c4);
+ if (n != 1 &&
+ (n != 3 || c1 != ':') &&
+ (n != 5 || c1 != ':' || c2 != ':') &&
+ (n != 7 || c1 != ':' || c2 != ':' || c3 != ':')) {
+ av_log(ctx, AV_LOG_ERROR,
+ "Invalid syntax for argument '%s': "
+ "must be in the form 'max:hi:lo:frac'\n", args);
+ return AVERROR(EINVAL);
+ }
+ }
+
+ av_log(ctx, AV_LOG_VERBOSE, "max_drop_count:%d hi:%d lo:%d frac:%f\n",
+ decimate->max_drop_count, decimate->hi, decimate->lo, decimate->frac);
+
+ decimate->avctx = avcodec_alloc_context3(NULL);
+ if (!decimate->avctx)
+ return AVERROR(ENOMEM);
+ dsputil_init(&decimate->dspctx, decimate->avctx);
+
+ return 0;
+}
+
+static av_cold void uninit(AVFilterContext *ctx)
+{
+ DecimateContext *decimate = ctx->priv;
+ avfilter_unref_bufferp(&decimate->ref);
+ avcodec_close(decimate->avctx);
+ av_freep(&decimate->avctx);
+}
+
+static int query_formats(AVFilterContext *ctx)
+{
+ static const enum PixelFormat pix_fmts[] = {
+ PIX_FMT_YUV444P, PIX_FMT_YUV422P,
+ PIX_FMT_YUV420P, PIX_FMT_YUV411P,
+ PIX_FMT_YUV410P, PIX_FMT_YUV440P,
+ PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P,
+ PIX_FMT_YUVJ420P, PIX_FMT_YUVJ440P,
+ PIX_FMT_YUVA420P,
+ PIX_FMT_NONE
+ };
+
+ ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
+
+ return 0;
+}
+
+static int config_input(AVFilterLink *inlink)
+{
+ AVFilterContext *ctx = inlink->dst;
+ DecimateContext *decimate = ctx->priv;
+ const AVPixFmtDescriptor *pix_desc = &av_pix_fmt_descriptors[inlink->format];
+ decimate->hsub = pix_desc->log2_chroma_w;
+ decimate->vsub = pix_desc->log2_chroma_h;
+
+ return 0;
+}
+
+static int start_frame(AVFilterLink *inlink, AVFilterBufferRef *picref) { return 0; }
+
+static int draw_slice(AVFilterLink *inlink, int y, int h, int slice_dir) { return 0; }
+
+static int end_frame(AVFilterLink *inlink)
+{
+ DecimateContext *decimate = inlink->dst->priv;
+ AVFilterBufferRef *cur = inlink->cur_buf;
+ AVFilterLink *outlink = inlink->dst->outputs[0];
+ int ret;
+
+ if (decimate->ref && decimate_frame(inlink->dst, cur, decimate->ref)) {
+ decimate->drop_count = FFMAX(1, decimate->drop_count+1);
+ } else {
+ avfilter_unref_buffer(decimate->ref);
+ decimate->ref = cur;
+ inlink->cur_buf = NULL;
+ decimate->drop_count = FFMIN(-1, decimate->drop_count-1);
+
+ if ((ret = ff_start_frame(outlink,
+ avfilter_ref_buffer(cur, ~AV_PERM_WRITE)) < 0) ||
+ (ret = ff_draw_slice(outlink, 0, inlink->h, 1)) < 0 ||
+ (ret = ff_end_frame(outlink)) < 0)
+ return ret;
+ }
+
+ av_log(inlink->dst, AV_LOG_DEBUG,
+ "%s pts:%s pts_time:%s drop_count:%d\n",
+ decimate->drop_count > 0 ? "drop" : "keep",
+ av_ts2str(cur->pts), av_ts2timestr(cur->pts, &inlink->time_base),
+ decimate->drop_count);
+
+ return 0;
+}
+
+static int request_frame(AVFilterLink *outlink)
+{
+ DecimateContext *decimate = outlink->src->priv;
+ AVFilterLink *inlink = outlink->src->inputs[0];
+ int ret;
+
+ do {
+ ret = ff_request_frame(inlink);
+ } while (decimate->drop_count > 0 && ret >= 0);
+
+ return ret;
+}
+
+AVFilter avfilter_vf_decimate = {
+ .name = "decimate",
+ .description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."),
+ .init = init,
+ .uninit = uninit,
+
+ .priv_size = sizeof(DecimateContext),
+ .query_formats = query_formats,
+
+ .inputs = (const AVFilterPad[]) {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .get_video_buffer = ff_null_get_video_buffer,
+ .config_props = config_input,
+ .start_frame = start_frame,
+ .draw_slice = draw_slice,
+ .end_frame = end_frame,
+ .min_perms = AV_PERM_READ | AV_PERM_PRESERVE,
+ },
+ { .name = NULL }
+ },
+ .outputs = (const AVFilterPad[]) {
+ {
+ .name = "default",
+ .type = AVMEDIA_TYPE_VIDEO,
+ .request_frame = request_frame,
+ },
+ { .name = NULL }
+ },
+};

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