1/* 2 * Copyright (c) 2003 Rich Felker 3 * Copyright (c) 2012 Stefano Sabatini 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License along 18 * with FFmpeg; if not, write to the Free Software Foundation, Inc., 19 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA. 20 */ 21 22/** 23 * @file mpdecimate filter, ported from libmpcodecs/vf_decimate.c by 24 * Rich Felker. 25 */ 26 27#include "libavutil/opt.h" 28#include "libavutil/pixdesc.h" 29#include "libavutil/timestamp.h" 30#include "libavcodec/dsputil.h" 31#include "libavcodec/pixblockdsp.h" 32#include "avfilter.h" 33#include "internal.h" 34#include "formats.h" 35#include "video.h" 36 37typedef struct { 38 const AVClass *class; 39 int lo, hi; ///< lower and higher threshold number of differences 40 ///< values for 8x8 blocks 41 42 float frac; ///< threshold of changed pixels over the total fraction 43 44 int max_drop_count; ///< if positive: maximum number of sequential frames to drop 45 ///< if negative: minimum number of frames between two drops 46 47 int drop_count; ///< if positive: number of frames sequentially dropped 48 ///< if negative: number of sequential frames which were not dropped 49 50 int hsub, vsub; ///< chroma subsampling values 51 AVFrame *ref; ///< reference picture 52 DSPContext dspctx; ///< context providing optimized diff routines 53 PixblockDSPContext pdsp; 54 AVCodecContext *avctx; ///< codec context required for the DSPContext 55} DecimateContext; 56 57#define OFFSET(x) offsetof(DecimateContext, x) 58#define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM 59 60static const AVOption mpdecimate_options[] = { 61 { "max", "set the maximum number of consecutive dropped frames (positive), or the minimum interval between dropped frames (negative)", 62 OFFSET(max_drop_count), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS }, 63 { "hi", "set high dropping threshold", OFFSET(hi), AV_OPT_TYPE_INT, {.i64=64*12}, INT_MIN, INT_MAX, FLAGS }, 64 { "lo", "set low dropping threshold", OFFSET(lo), AV_OPT_TYPE_INT, {.i64=64*5}, INT_MIN, INT_MAX, FLAGS }, 65 { "frac", "set fraction dropping threshold", OFFSET(frac), AV_OPT_TYPE_FLOAT, {.dbl=0.33}, 0, 1, FLAGS }, 66 { NULL } 67}; 68 69AVFILTER_DEFINE_CLASS(mpdecimate); 70 71/** 72 * Return 1 if the two planes are different, 0 otherwise. 73 */ 74static int diff_planes(AVFilterContext *ctx, 75 uint8_t *cur, uint8_t *ref, int linesize, 76 int w, int h) 77{ 78 DecimateContext *decimate = ctx->priv; 79 DSPContext *dspctx = &decimate->dspctx; 80 PixblockDSPContext *pdsp = &decimate->pdsp; 81 82 int x, y; 83 int d, c = 0; 84 int t = (w/16)*(h/16)*decimate->frac; 85 int16_t block[8*8]; 86 87 /* compute difference for blocks of 8x8 bytes */ 88 for (y = 0; y < h-7; y += 4) { 89 for (x = 8; x < w-7; x += 4) { 90 pdsp->diff_pixels(block, 91 cur+x+y*linesize, 92 ref+x+y*linesize, linesize); 93 d = dspctx->sum_abs_dctelem(block); 94 if (d > decimate->hi) 95 return 1; 96 if (d > decimate->lo) { 97 c++; 98 if (c > t) 99 return 1; 100 } 101 } 102 } 103 return 0; 104} 105 106/** 107 * Tell if the frame should be decimated, for example if it is no much 108 * different with respect to the reference frame ref. 109 */ 110static int decimate_frame(AVFilterContext *ctx, 111 AVFrame *cur, AVFrame *ref) 112{ 113 DecimateContext *decimate = ctx->priv; 114 int plane; 115 116 if (decimate->max_drop_count > 0 && 117 decimate->drop_count >= decimate->max_drop_count) 118 return 0; 119 if (decimate->max_drop_count < 0 && 120 (decimate->drop_count-1) > decimate->max_drop_count) 121 return 0; 122 123 for (plane = 0; ref->data[plane] && ref->linesize[plane]; plane++) { 124 int vsub = plane == 1 || plane == 2 ? decimate->vsub : 0; 125 int hsub = plane == 1 || plane == 2 ? decimate->hsub : 0; 126 if (diff_planes(ctx, 127 cur->data[plane], ref->data[plane], ref->linesize[plane], 128 FF_CEIL_RSHIFT(ref->width, hsub), 129 FF_CEIL_RSHIFT(ref->height, vsub))) 130 return 0; 131 } 132 133 return 1; 134} 135 136static av_cold int init(AVFilterContext *ctx) 137{ 138 DecimateContext *decimate = ctx->priv; 139 140 av_log(ctx, AV_LOG_VERBOSE, "max_drop_count:%d hi:%d lo:%d frac:%f\n", 141 decimate->max_drop_count, decimate->hi, decimate->lo, decimate->frac); 142 143 decimate->avctx = avcodec_alloc_context3(NULL); 144 if (!decimate->avctx) 145 return AVERROR(ENOMEM); 146 avpriv_dsputil_init(&decimate->dspctx, decimate->avctx); 147 ff_pixblockdsp_init(&decimate->pdsp, decimate->avctx); 148 149 return 0; 150} 151 152static av_cold void uninit(AVFilterContext *ctx) 153{ 154 DecimateContext *decimate = ctx->priv; 155 av_frame_free(&decimate->ref); 156 if (decimate->avctx) { 157 avcodec_close(decimate->avctx); 158 av_freep(&decimate->avctx); 159 } 160} 161 162static int query_formats(AVFilterContext *ctx) 163{ 164 static const enum AVPixelFormat pix_fmts[] = { 165 AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P, 166 AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV411P, 167 AV_PIX_FMT_YUV410P, AV_PIX_FMT_YUV440P, 168 AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P, 169 AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ440P, 170 AV_PIX_FMT_YUVA420P, 171 AV_PIX_FMT_NONE 172 }; 173 174 ff_set_common_formats(ctx, ff_make_format_list(pix_fmts)); 175 176 return 0; 177} 178 179static int config_input(AVFilterLink *inlink) 180{ 181 AVFilterContext *ctx = inlink->dst; 182 DecimateContext *decimate = ctx->priv; 183 const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format); 184 decimate->hsub = pix_desc->log2_chroma_w; 185 decimate->vsub = pix_desc->log2_chroma_h; 186 187 return 0; 188} 189 190static int filter_frame(AVFilterLink *inlink, AVFrame *cur) 191{ 192 DecimateContext *decimate = inlink->dst->priv; 193 AVFilterLink *outlink = inlink->dst->outputs[0]; 194 int ret; 195 196 if (decimate->ref && decimate_frame(inlink->dst, cur, decimate->ref)) { 197 decimate->drop_count = FFMAX(1, decimate->drop_count+1); 198 } else { 199 av_frame_free(&decimate->ref); 200 decimate->ref = cur; 201 decimate->drop_count = FFMIN(-1, decimate->drop_count-1); 202 203 if (ret = ff_filter_frame(outlink, av_frame_clone(cur)) < 0) 204 return ret; 205 } 206 207 av_log(inlink->dst, AV_LOG_DEBUG, 208 "%s pts:%s pts_time:%s drop_count:%d\n", 209 decimate->drop_count > 0 ? "drop" : "keep", 210 av_ts2str(cur->pts), av_ts2timestr(cur->pts, &inlink->time_base), 211 decimate->drop_count); 212 213 if (decimate->drop_count > 0) 214 av_frame_free(&cur); 215 216 return 0; 217} 218 219static int request_frame(AVFilterLink *outlink) 220{ 221 DecimateContext *decimate = outlink->src->priv; 222 AVFilterLink *inlink = outlink->src->inputs[0]; 223 int ret; 224 225 do { 226 ret = ff_request_frame(inlink); 227 } while (decimate->drop_count > 0 && ret >= 0); 228 229 return ret; 230} 231 232static const AVFilterPad mpdecimate_inputs[] = { 233 { 234 .name = "default", 235 .type = AVMEDIA_TYPE_VIDEO, 236 .config_props = config_input, 237 .filter_frame = filter_frame, 238 }, 239 { NULL } 240}; 241 242static const AVFilterPad mpdecimate_outputs[] = { 243 { 244 .name = "default", 245 .type = AVMEDIA_TYPE_VIDEO, 246 .request_frame = request_frame, 247 }, 248 { NULL } 249}; 250 251AVFilter ff_vf_mpdecimate = { 252 .name = "mpdecimate", 253 .description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."), 254 .init = init, 255 .uninit = uninit, 256 .priv_size = sizeof(DecimateContext), 257 .priv_class = &mpdecimate_class, 258 .query_formats = query_formats, 259 .inputs = mpdecimate_inputs, 260 .outputs = mpdecimate_outputs, 261}; 262