yading@10: /*
yading@10:  * Copyright (c) 2003 Rich Felker
yading@10:  * Copyright (c) 2012 Stefano Sabatini
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or modify
yading@10:  * it under the terms of the GNU General Public License as published by
yading@10:  * the Free Software Foundation; either version 2 of the License, or
yading@10:  * (at your option) any later version.
yading@10:  *
yading@10:  * FFmpeg is distributed in the hope that it will be useful,
yading@10:  * but WITHOUT ANY WARRANTY; without even the implied warranty of
yading@10:  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
yading@10:  * GNU General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU General Public License along
yading@10:  * with FFmpeg; if not, write to the Free Software Foundation, Inc.,
yading@10:  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
yading@10:  */
yading@10: 
yading@10: /**
yading@10:  * @file mpdecimate filter, ported from libmpcodecs/vf_decimate.c by
yading@10:  * Rich Felker.
yading@10:  */
yading@10: 
yading@10: #include "libavutil/opt.h"
yading@10: #include "libavutil/pixdesc.h"
yading@10: #include "libavutil/timestamp.h"
yading@10: #include "libavcodec/dsputil.h"
yading@10: #include "avfilter.h"
yading@10: #include "internal.h"
yading@10: #include "formats.h"
yading@10: #include "video.h"
yading@10: 
yading@10: typedef struct {
yading@10:     const AVClass *class;
yading@10:     int lo, hi;                    ///< lower and higher threshold number of differences
yading@10:                                    ///< values for 8x8 blocks
yading@10: 
yading@10:     float frac;                    ///< threshold of changed pixels over the total fraction
yading@10: 
yading@10:     int max_drop_count;            ///< if positive: maximum number of sequential frames to drop
yading@10:                                    ///< if negative: minimum number of frames between two drops
yading@10: 
yading@10:     int drop_count;                ///< if positive: number of frames sequentially dropped
yading@10:                                    ///< if negative: number of sequential frames which were not dropped
yading@10: 
yading@10:     int hsub, vsub;                ///< chroma subsampling values
yading@10:     AVFrame *ref;                  ///< reference picture
yading@10:     DSPContext dspctx;             ///< context providing optimized diff routines
yading@10:     AVCodecContext *avctx;         ///< codec context required for the DSPContext
yading@10: } DecimateContext;
yading@10: 
yading@10: #define OFFSET(x) offsetof(DecimateContext, x)
yading@10: #define FLAGS AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_FILTERING_PARAM
yading@10: 
yading@10: static const AVOption mpdecimate_options[] = {
yading@10:     { "max",  "set the maximum number of consecutive dropped frames (positive), or the minimum interval between dropped frames (negative)",
yading@10:       OFFSET(max_drop_count), AV_OPT_TYPE_INT, {.i64=0}, INT_MIN, INT_MAX, FLAGS },
yading@10:     { "hi",   "set high dropping threshold", OFFSET(hi), AV_OPT_TYPE_INT, {.i64=64*12}, INT_MIN, INT_MAX, FLAGS },
yading@10:     { "lo",   "set low dropping threshold", OFFSET(lo), AV_OPT_TYPE_INT, {.i64=64*5}, INT_MIN, INT_MAX, FLAGS },
yading@10:     { "frac", "set fraction dropping threshold",  OFFSET(frac), AV_OPT_TYPE_FLOAT, {.dbl=0.33}, 0, 1, FLAGS },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(mpdecimate);
yading@10: 
yading@10: /**
yading@10:  * Return 1 if the two planes are different, 0 otherwise.
yading@10:  */
yading@10: static int diff_planes(AVFilterContext *ctx,
yading@10:                        uint8_t *cur, uint8_t *ref, int linesize,
yading@10:                        int w, int h)
yading@10: {
yading@10:     DecimateContext *decimate = ctx->priv;
yading@10:     DSPContext *dspctx = &decimate->dspctx;
yading@10: 
yading@10:     int x, y;
yading@10:     int d, c = 0;
yading@10:     int t = (w/16)*(h/16)*decimate->frac;
yading@10:     int16_t block[8*8];
yading@10: 
yading@10:     /* compute difference for blocks of 8x8 bytes */
yading@10:     for (y = 0; y < h-7; y += 4) {
yading@10:         for (x = 8; x < w-7; x += 4) {
yading@10:             dspctx->diff_pixels(block,
yading@10:                                 cur+x+y*linesize,
yading@10:                                 ref+x+y*linesize, linesize);
yading@10:             d = dspctx->sum_abs_dctelem(block);
yading@10:             if (d > decimate->hi)
yading@10:                 return 1;
yading@10:             if (d > decimate->lo) {
yading@10:                 c++;
yading@10:                 if (c > t)
yading@10:                     return 1;
yading@10:             }
yading@10:         }
yading@10:     }
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: /**
yading@10:  * Tell if the frame should be decimated, for example if it is no much
yading@10:  * different with respect to the reference frame ref.
yading@10:  */
yading@10: static int decimate_frame(AVFilterContext *ctx,
yading@10:                           AVFrame *cur, AVFrame *ref)
yading@10: {
yading@10:     DecimateContext *decimate = ctx->priv;
yading@10:     int plane;
yading@10: 
yading@10:     if (decimate->max_drop_count > 0 &&
yading@10:         decimate->drop_count >= decimate->max_drop_count)
yading@10:         return 0;
yading@10:     if (decimate->max_drop_count < 0 &&
yading@10:         (decimate->drop_count-1) > decimate->max_drop_count)
yading@10:         return 0;
yading@10: 
yading@10:     for (plane = 0; ref->data[plane] && ref->linesize[plane]; plane++) {
yading@10:         int vsub = plane == 1 || plane == 2 ? decimate->vsub : 0;
yading@10:         int hsub = plane == 1 || plane == 2 ? decimate->hsub : 0;
yading@10:         if (diff_planes(ctx,
yading@10:                         cur->data[plane], ref->data[plane], ref->linesize[plane],
yading@10:                         ref->width>>hsub, ref->height>>vsub))
yading@10:             return 0;
yading@10:     }
yading@10: 
yading@10:     return 1;
yading@10: }
yading@10: 
yading@10: static av_cold int init(AVFilterContext *ctx)
yading@10: {
yading@10:     DecimateContext *decimate = ctx->priv;
yading@10: 
yading@10:     av_log(ctx, AV_LOG_VERBOSE, "max_drop_count:%d hi:%d lo:%d frac:%f\n",
yading@10:            decimate->max_drop_count, decimate->hi, decimate->lo, decimate->frac);
yading@10: 
yading@10:     decimate->avctx = avcodec_alloc_context3(NULL);
yading@10:     if (!decimate->avctx)
yading@10:         return AVERROR(ENOMEM);
yading@10:     avpriv_dsputil_init(&decimate->dspctx, decimate->avctx);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold void uninit(AVFilterContext *ctx)
yading@10: {
yading@10:     DecimateContext *decimate = ctx->priv;
yading@10:     av_frame_free(&decimate->ref);
yading@10:     if (decimate->avctx) {
yading@10:         avcodec_close(decimate->avctx);
yading@10:         av_freep(&decimate->avctx);
yading@10:     }
yading@10: }
yading@10: 
yading@10: static int query_formats(AVFilterContext *ctx)
yading@10: {
yading@10:     static const enum AVPixelFormat pix_fmts[] = {
yading@10:         AV_PIX_FMT_YUV444P,      AV_PIX_FMT_YUV422P,
yading@10:         AV_PIX_FMT_YUV420P,      AV_PIX_FMT_YUV411P,
yading@10:         AV_PIX_FMT_YUV410P,      AV_PIX_FMT_YUV440P,
yading@10:         AV_PIX_FMT_YUVJ444P,     AV_PIX_FMT_YUVJ422P,
yading@10:         AV_PIX_FMT_YUVJ420P,     AV_PIX_FMT_YUVJ440P,
yading@10:         AV_PIX_FMT_YUVA420P,
yading@10:         AV_PIX_FMT_NONE
yading@10:     };
yading@10: 
yading@10:     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int config_input(AVFilterLink *inlink)
yading@10: {
yading@10:     AVFilterContext *ctx = inlink->dst;
yading@10:     DecimateContext *decimate = ctx->priv;
yading@10:     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
yading@10:     decimate->hsub = pix_desc->log2_chroma_w;
yading@10:     decimate->vsub = pix_desc->log2_chroma_h;
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *cur)
yading@10: {
yading@10:     DecimateContext *decimate = inlink->dst->priv;
yading@10:     AVFilterLink *outlink = inlink->dst->outputs[0];
yading@10:     int ret;
yading@10: 
yading@10:     if (decimate->ref && decimate_frame(inlink->dst, cur, decimate->ref)) {
yading@10:         decimate->drop_count = FFMAX(1, decimate->drop_count+1);
yading@10:     } else {
yading@10:         av_frame_free(&decimate->ref);
yading@10:         decimate->ref = cur;
yading@10:         decimate->drop_count = FFMIN(-1, decimate->drop_count-1);
yading@10: 
yading@10:         if (ret = ff_filter_frame(outlink, av_frame_clone(cur)) < 0)
yading@10:             return ret;
yading@10:     }
yading@10: 
yading@10:     av_log(inlink->dst, AV_LOG_DEBUG,
yading@10:            "%s pts:%s pts_time:%s drop_count:%d\n",
yading@10:            decimate->drop_count > 0 ? "drop" : "keep",
yading@10:            av_ts2str(cur->pts), av_ts2timestr(cur->pts, &inlink->time_base),
yading@10:            decimate->drop_count);
yading@10: 
yading@10:     if (decimate->drop_count > 0)
yading@10:         av_frame_free(&cur);
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int request_frame(AVFilterLink *outlink)
yading@10: {
yading@10:     DecimateContext *decimate = outlink->src->priv;
yading@10:     AVFilterLink *inlink = outlink->src->inputs[0];
yading@10:     int ret;
yading@10: 
yading@10:     do {
yading@10:         ret = ff_request_frame(inlink);
yading@10:     } while (decimate->drop_count > 0 && ret >= 0);
yading@10: 
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static const AVFilterPad mpdecimate_inputs[] = {
yading@10:     {
yading@10:         .name             = "default",
yading@10:         .type             = AVMEDIA_TYPE_VIDEO,
yading@10:         .get_video_buffer = ff_null_get_video_buffer,
yading@10:         .config_props     = config_input,
yading@10:         .filter_frame     = filter_frame,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: static const AVFilterPad mpdecimate_outputs[] = {
yading@10:     {
yading@10:         .name          = "default",
yading@10:         .type          = AVMEDIA_TYPE_VIDEO,
yading@10:         .request_frame = request_frame,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_vf_mpdecimate = {
yading@10:     .name        = "mpdecimate",
yading@10:     .description = NULL_IF_CONFIG_SMALL("Remove near-duplicate frames."),
yading@10:     .init        = init,
yading@10:     .uninit      = uninit,
yading@10: 
yading@10:     .priv_size = sizeof(DecimateContext),
yading@10:     .query_formats = query_formats,
yading@10:     .inputs        = mpdecimate_inputs,
yading@10:     .outputs       = mpdecimate_outputs,
yading@10:     .priv_class    = &mpdecimate_class,
yading@10: };