/* * 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/opt.h" #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 { const AVClass *class; 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; #define OFFSET(x) offsetof(DecimateContext, x) #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM static const AVOption decimate_options[] = { { "max", "set the maximum number of consecutive dropped frames (positive), or the minimum interval between dropped frames (negative)", OFFSET(max_drop_count), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS }, { "hi", "set high dropping threshold", OFFSET(hi), AV_OPT_TYPE_INT, {.i64=64*12}, INT_MIN, INT_MAX, FLAGS }, { "lo", "set low dropping threshold", OFFSET(lo), AV_OPT_TYPE_INT, {.i64=64*5}, INT_MIN, INT_MAX, FLAGS }, { "frac", "set fraction dropping threshold", OFFSET(frac), AV_OPT_TYPE_FLOAT, {.dbl=0.33}, 0, 1, FLAGS }, { NULL } }; AVFILTER_DEFINE_CLASS(decimate); /** * 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; int16_t 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; static const char *shorthand[] = { "max", "hi", "lo", "frac", NULL }; int ret; decimate->class = &decimate_class; av_opt_set_defaults(decimate); if ((ret = av_opt_set_from_string(decimate, args, shorthand, "=", ":")) < 0) return ret; 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_opt_free(decimate); av_freep(&decimate->avctx); } static int query_formats(AVFilterContext *ctx) { static const enum AVPixelFormat pix_fmts[] = { AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ440P, AV_PIX_FMT_YUVA420P, AV_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_desc_get(inlink->format); decimate->hsub = pix_desc->log2_chroma_w; decimate->vsub = pix_desc->log2_chroma_h; return 0; } static int filter_frame(AVFilterLink *inlink, AVFilterBufferRef *cur) { DecimateContext *decimate = inlink->dst->priv; 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; decimate->drop_count = FFMIN(-1, decimate->drop_count-1); if (ret = ff_filter_frame(outlink, avfilter_ref_buffer(cur, ~AV_PERM_WRITE)) < 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); if (decimate->drop_count > 0) avfilter_unref_buffer(cur); 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; } static const AVFilterPad decimate_inputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .get_video_buffer = ff_null_get_video_buffer, .config_props = config_input, .filter_frame = filter_frame, .min_perms = AV_PERM_READ | AV_PERM_PRESERVE, }, { NULL } }; static const AVFilterPad decimate_outputs[] = { { .name = "default", .type = AVMEDIA_TYPE_VIDEO, .request_frame = request_frame, }, { NULL } }; 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 = decimate_inputs, .outputs = decimate_outputs, .priv_class = &decimate_class, };