yading@10: /*
yading@10:  * Copyright (c) 2012 Fredrik Mellbin
yading@10:  * Copyright (c) 2013 Clément Bœsch
yading@10:  *
yading@10:  * This file is part of FFmpeg.
yading@10:  *
yading@10:  * FFmpeg is free software; you can redistribute it and/or
yading@10:  * modify it under the terms of the GNU Lesser General Public
yading@10:  * License as published by the Free Software Foundation; either
yading@10:  * version 2.1 of the License, or (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 GNU
yading@10:  * Lesser General Public License for more details.
yading@10:  *
yading@10:  * You should have received a copy of the GNU Lesser General Public
yading@10:  * License along with FFmpeg; if not, write to the Free Software
yading@10:  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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 "avfilter.h"
yading@10: #include "internal.h"
yading@10: 
yading@10: #define INPUT_MAIN     0
yading@10: #define INPUT_CLEANSRC 1
yading@10: 
yading@10: struct qitem {
yading@10:     AVFrame *frame;
yading@10:     int64_t maxbdiff;
yading@10:     int64_t totdiff;
yading@10: };
yading@10: 
yading@10: typedef struct {
yading@10:     const AVClass *class;
yading@10:     struct qitem *queue;    ///< window of cycle frames and the associated data diff
yading@10:     int fid;                ///< current frame id in the queue
yading@10:     int filled;             ///< 1 if the queue is filled, 0 otherwise
yading@10:     AVFrame *last;          ///< last frame from the previous queue
yading@10:     int64_t frame_count;    ///< output frame counter
yading@10:     AVFrame **clean_src;    ///< frame queue for the clean source
yading@10:     int got_frame[2];       ///< frame request flag for each input stream
yading@10:     double ts_unit;         ///< timestamp units for the output frames
yading@10:     uint32_t eof;           ///< bitmask for end of stream
yading@10:     int hsub, vsub;         ///< chroma subsampling values
yading@10:     int depth;
yading@10:     int nxblocks, nyblocks;
yading@10:     int bdiffsize;
yading@10:     int64_t *bdiffs;
yading@10: 
yading@10:     /* options */
yading@10:     int cycle;
yading@10:     double dupthresh_flt;
yading@10:     double scthresh_flt;
yading@10:     int64_t dupthresh;
yading@10:     int64_t scthresh;
yading@10:     int blockx, blocky;
yading@10:     int ppsrc;
yading@10:     int chroma;
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 decimate_options[] = {
yading@10:     { "cycle",     "set the number of frame from which one will be dropped", OFFSET(cycle), AV_OPT_TYPE_INT, {.i64 = 5}, 2, 25, FLAGS },
yading@10:     { "dupthresh", "set duplicate threshold",    OFFSET(dupthresh_flt), AV_OPT_TYPE_DOUBLE, {.dbl =  1.1}, 0, 100, FLAGS },
yading@10:     { "scthresh",  "set scene change threshold", OFFSET(scthresh_flt),  AV_OPT_TYPE_DOUBLE, {.dbl = 15.0}, 0, 100, FLAGS },
yading@10:     { "blockx",    "set the size of the x-axis blocks used during metric calculations", OFFSET(blockx), AV_OPT_TYPE_INT, {.i64 = 32}, 4, 1<<9, FLAGS },
yading@10:     { "blocky",    "set the size of the y-axis blocks used during metric calculations", OFFSET(blocky), AV_OPT_TYPE_INT, {.i64 = 32}, 4, 1<<9, FLAGS },
yading@10:     { "ppsrc",     "mark main input as a pre-processed input and activate clean source input stream", OFFSET(ppsrc), AV_OPT_TYPE_INT, {.i64=0}, 0, 1, FLAGS },
yading@10:     { "chroma",    "set whether or not chroma is considered in the metric calculations", OFFSET(chroma), AV_OPT_TYPE_INT, {.i64=1}, 0, 1, FLAGS },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFILTER_DEFINE_CLASS(decimate);
yading@10: 
yading@10: static void calc_diffs(const DecimateContext *dm, struct qitem *q,
yading@10:                        const AVFrame *f1, const AVFrame *f2)
yading@10: {
yading@10:     int64_t maxdiff = -1;
yading@10:     int64_t *bdiffs = dm->bdiffs;
yading@10:     int plane, i, j;
yading@10: 
yading@10:     memset(bdiffs, 0, dm->bdiffsize * sizeof(*bdiffs));
yading@10: 
yading@10:     for (plane = 0; plane < (dm->chroma ? 3 : 1); plane++) {
yading@10:         int x, y, xl;
yading@10:         const int linesize1 = f1->linesize[plane];
yading@10:         const int linesize2 = f2->linesize[plane];
yading@10:         const uint8_t *f1p = f1->data[plane];
yading@10:         const uint8_t *f2p = f2->data[plane];
yading@10:         int width    = plane ? f1->width  >> dm->hsub : f1->width;
yading@10:         int height   = plane ? f1->height >> dm->vsub : f1->height;
yading@10:         int hblockx  = dm->blockx / 2;
yading@10:         int hblocky  = dm->blocky / 2;
yading@10: 
yading@10:         if (plane) {
yading@10:             hblockx >>= dm->hsub;
yading@10:             hblocky >>= dm->vsub;
yading@10:         }
yading@10: 
yading@10:         for (y = 0; y < height; y++) {
yading@10:             int ydest = y / hblocky;
yading@10:             int xdest = 0;
yading@10: 
yading@10: #define CALC_DIFF(nbits) do {                               \
yading@10:     for (x = 0; x < width; x += hblockx) {                  \
yading@10:         int64_t acc = 0;                                    \
yading@10:         int m = FFMIN(width, x + hblockx);                  \
yading@10:         for (xl = x; xl < m; xl++)                          \
yading@10:             acc += abs(((const uint##nbits##_t *)f1p)[xl] - \
yading@10:                        ((const uint##nbits##_t *)f2p)[xl]); \
yading@10:         bdiffs[ydest * dm->nxblocks + xdest] += acc;        \
yading@10:         xdest++;                                            \
yading@10:     }                                                       \
yading@10: } while (0)
yading@10:             if (dm->depth == 8) CALC_DIFF(8);
yading@10:             else                CALC_DIFF(16);
yading@10: 
yading@10:             f1p += linesize1;
yading@10:             f2p += linesize2;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     for (i = 0; i < dm->nyblocks - 1; i++) {
yading@10:         for (j = 0; j < dm->nxblocks - 1; j++) {
yading@10:             int64_t tmp = bdiffs[      i * dm->nxblocks + j    ]
yading@10:                         + bdiffs[      i * dm->nxblocks + j + 1]
yading@10:                         + bdiffs[(i + 1) * dm->nxblocks + j    ]
yading@10:                         + bdiffs[(i + 1) * dm->nxblocks + j + 1];
yading@10:             if (tmp > maxdiff)
yading@10:                 maxdiff = tmp;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     q->totdiff = 0;
yading@10:     for (i = 0; i < dm->bdiffsize; i++)
yading@10:         q->totdiff += bdiffs[i];
yading@10:     q->maxbdiff = maxdiff;
yading@10: }
yading@10: 
yading@10: static int filter_frame(AVFilterLink *inlink, AVFrame *in)
yading@10: {
yading@10:     int scpos = -1, duppos = -1;
yading@10:     int drop = INT_MIN, i, lowest = 0, ret;
yading@10:     AVFilterContext *ctx  = inlink->dst;
yading@10:     AVFilterLink *outlink = ctx->outputs[0];
yading@10:     DecimateContext *dm   = ctx->priv;
yading@10:     AVFrame *prv;
yading@10: 
yading@10:     /* update frames queue(s) */
yading@10:     if (FF_INLINK_IDX(inlink) == INPUT_MAIN) {
yading@10:         dm->queue[dm->fid].frame = in;
yading@10:         dm->got_frame[INPUT_MAIN] = 1;
yading@10:     } else {
yading@10:         dm->clean_src[dm->fid] = in;
yading@10:         dm->got_frame[INPUT_CLEANSRC] = 1;
yading@10:     }
yading@10:     if (!dm->got_frame[INPUT_MAIN] || (dm->ppsrc && !dm->got_frame[INPUT_CLEANSRC]))
yading@10:         return 0;
yading@10:     dm->got_frame[INPUT_MAIN] = dm->got_frame[INPUT_CLEANSRC] = 0;
yading@10: 
yading@10:     if (in) {
yading@10:         /* update frame metrics */
yading@10:         prv = dm->fid ? dm->queue[dm->fid - 1].frame : dm->last;
yading@10:         if (!prv)
yading@10:             prv = in;
yading@10:         calc_diffs(dm, &dm->queue[dm->fid], prv, in);
yading@10:         if (++dm->fid != dm->cycle)
yading@10:             return 0;
yading@10:         av_frame_free(&dm->last);
yading@10:         dm->last = av_frame_clone(in);
yading@10:         dm->fid = 0;
yading@10: 
yading@10:         /* we have a complete cycle, select the frame to drop */
yading@10:         lowest = 0;
yading@10:         for (i = 0; i < dm->cycle; i++) {
yading@10:             if (dm->queue[i].totdiff > dm->scthresh)
yading@10:                 scpos = i;
yading@10:             if (dm->queue[i].maxbdiff < dm->queue[lowest].maxbdiff)
yading@10:                 lowest = i;
yading@10:         }
yading@10:         if (dm->queue[lowest].maxbdiff < dm->dupthresh)
yading@10:             duppos = lowest;
yading@10:         drop = scpos >= 0 && duppos < 0 ? scpos : lowest;
yading@10:     }
yading@10: 
yading@10:     /* metrics debug */
yading@10:     if (av_log_get_level() >= AV_LOG_DEBUG) {
yading@10:         av_log(ctx, AV_LOG_DEBUG, "1/%d frame drop:\n", dm->cycle);
yading@10:         for (i = 0; i < dm->cycle && dm->queue[i].frame; i++) {
yading@10:             av_log(ctx, AV_LOG_DEBUG,"  #%d: totdiff=%08"PRIx64" maxbdiff=%08"PRIx64"%s%s%s%s\n",
yading@10:                    i + 1, dm->queue[i].totdiff, dm->queue[i].maxbdiff,
yading@10:                    i == scpos  ? " sc"     : "",
yading@10:                    i == duppos ? " dup"    : "",
yading@10:                    i == lowest ? " lowest" : "",
yading@10:                    i == drop   ? " [DROP]" : "");
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     /* push all frames except the drop */
yading@10:     ret = 0;
yading@10:     for (i = 0; i < dm->cycle && dm->queue[i].frame; i++) {
yading@10:         if (i == drop) {
yading@10:             if (dm->ppsrc)
yading@10:                 av_frame_free(&dm->clean_src[i]);
yading@10:             av_frame_free(&dm->queue[i].frame);
yading@10:         } else {
yading@10:             AVFrame *frame = dm->queue[i].frame;
yading@10:             if (dm->ppsrc) {
yading@10:                 av_frame_free(&frame);
yading@10:                 frame = dm->clean_src[i];
yading@10:             }
yading@10:             frame->pts = dm->frame_count++ * dm->ts_unit;
yading@10:             ret = ff_filter_frame(outlink, frame);
yading@10:             if (ret < 0)
yading@10:                 break;
yading@10:         }
yading@10:     }
yading@10: 
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static int config_input(AVFilterLink *inlink)
yading@10: {
yading@10:     int max_value;
yading@10:     AVFilterContext *ctx = inlink->dst;
yading@10:     DecimateContext *dm = ctx->priv;
yading@10:     const AVPixFmtDescriptor *pix_desc = av_pix_fmt_desc_get(inlink->format);
yading@10:     const int w = inlink->w;
yading@10:     const int h = inlink->h;
yading@10: 
yading@10:     dm->hsub      = pix_desc->log2_chroma_w;
yading@10:     dm->vsub      = pix_desc->log2_chroma_h;
yading@10:     dm->depth     = pix_desc->comp[0].depth_minus1 + 1;
yading@10:     max_value     = (1 << dm->depth) - 1;
yading@10:     dm->scthresh  = (int64_t)(((int64_t)max_value *          w * h          * dm->scthresh_flt)  / 100);
yading@10:     dm->dupthresh = (int64_t)(((int64_t)max_value * dm->blockx * dm->blocky * dm->dupthresh_flt) / 100);
yading@10:     dm->nxblocks  = (w + dm->blockx/2 - 1) / (dm->blockx/2);
yading@10:     dm->nyblocks  = (h + dm->blocky/2 - 1) / (dm->blocky/2);
yading@10:     dm->bdiffsize = dm->nxblocks * dm->nyblocks;
yading@10:     dm->bdiffs    = av_malloc(dm->bdiffsize * sizeof(*dm->bdiffs));
yading@10:     dm->queue     = av_calloc(dm->cycle, sizeof(*dm->queue));
yading@10: 
yading@10:     if (!dm->bdiffs || !dm->queue)
yading@10:         return AVERROR(ENOMEM);
yading@10: 
yading@10:     if (dm->ppsrc) {
yading@10:         dm->clean_src = av_calloc(dm->cycle, sizeof(*dm->clean_src));
yading@10:         if (!dm->clean_src)
yading@10:             return AVERROR(ENOMEM);
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold int decimate_init(AVFilterContext *ctx)
yading@10: {
yading@10:     const DecimateContext *dm = ctx->priv;
yading@10:     AVFilterPad pad = {
yading@10:         .name         = av_strdup("main"),
yading@10:         .type         = AVMEDIA_TYPE_VIDEO,
yading@10:         .filter_frame = filter_frame,
yading@10:         .config_props = config_input,
yading@10:     };
yading@10: 
yading@10:     if (!pad.name)
yading@10:         return AVERROR(ENOMEM);
yading@10:     ff_insert_inpad(ctx, INPUT_MAIN, &pad);
yading@10: 
yading@10:     if (dm->ppsrc) {
yading@10:         pad.name = av_strdup("clean_src");
yading@10:         pad.config_props = NULL;
yading@10:         if (!pad.name)
yading@10:             return AVERROR(ENOMEM);
yading@10:         ff_insert_inpad(ctx, INPUT_CLEANSRC, &pad);
yading@10:     }
yading@10: 
yading@10:     if ((dm->blockx & (dm->blockx - 1)) ||
yading@10:         (dm->blocky & (dm->blocky - 1))) {
yading@10:         av_log(ctx, AV_LOG_ERROR, "blockx and blocky settings must be power of two\n");
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10: 
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static av_cold void decimate_uninit(AVFilterContext *ctx)
yading@10: {
yading@10:     int i;
yading@10:     DecimateContext *dm = ctx->priv;
yading@10: 
yading@10:     av_frame_free(&dm->last);
yading@10:     av_freep(&dm->bdiffs);
yading@10:     av_freep(&dm->queue);
yading@10:     av_freep(&dm->clean_src);
yading@10:     for (i = 0; i < ctx->nb_inputs; i++)
yading@10:         av_freep(&ctx->input_pads[i].name);
yading@10: }
yading@10: 
yading@10: static int request_inlink(AVFilterContext *ctx, int lid)
yading@10: {
yading@10:     int ret = 0;
yading@10:     DecimateContext *dm = ctx->priv;
yading@10: 
yading@10:     if (!dm->got_frame[lid]) {
yading@10:         AVFilterLink *inlink = ctx->inputs[lid];
yading@10:         ret = ff_request_frame(inlink);
yading@10:         if (ret == AVERROR_EOF) { // flushing
yading@10:             dm->eof |= 1 << lid;
yading@10:             ret = filter_frame(inlink, NULL);
yading@10:         }
yading@10:     }
yading@10:     return ret;
yading@10: }
yading@10: 
yading@10: static int request_frame(AVFilterLink *outlink)
yading@10: {
yading@10:     int ret;
yading@10:     AVFilterContext *ctx = outlink->src;
yading@10:     DecimateContext *dm = ctx->priv;
yading@10:     const uint32_t eof_mask = 1<<INPUT_MAIN | dm->ppsrc<<INPUT_CLEANSRC;
yading@10: 
yading@10:     if ((dm->eof & eof_mask) == eof_mask) // flush done?
yading@10:         return AVERROR_EOF;
yading@10:     if ((ret = request_inlink(ctx, INPUT_MAIN)) < 0)
yading@10:         return ret;
yading@10:     if (dm->ppsrc && (ret = request_inlink(ctx, INPUT_CLEANSRC)) < 0)
yading@10:         return ret;
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int query_formats(AVFilterContext *ctx)
yading@10: {
yading@10:     static const enum AVPixelFormat pix_fmts[] = {
yading@10: #define PF_NOALPHA(suf) AV_PIX_FMT_YUV420##suf,  AV_PIX_FMT_YUV422##suf,  AV_PIX_FMT_YUV444##suf
yading@10: #define PF_ALPHA(suf)   AV_PIX_FMT_YUVA420##suf, AV_PIX_FMT_YUVA422##suf, AV_PIX_FMT_YUVA444##suf
yading@10: #define PF(suf)         PF_NOALPHA(suf), PF_ALPHA(suf)
yading@10:         PF(P), PF(P9), PF(P10), PF_NOALPHA(P12), PF_NOALPHA(P14), PF(P16),
yading@10:         AV_PIX_FMT_YUV411P, AV_PIX_FMT_YUV410P,
yading@10:         AV_PIX_FMT_GRAY8,
yading@10:         AV_PIX_FMT_NONE
yading@10:     };
yading@10:     ff_set_common_formats(ctx, ff_make_format_list(pix_fmts));
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static int config_output(AVFilterLink *outlink)
yading@10: {
yading@10:     AVFilterContext *ctx = outlink->src;
yading@10:     DecimateContext *dm = ctx->priv;
yading@10:     const AVFilterLink *inlink =
yading@10:         ctx->inputs[dm->ppsrc ? INPUT_CLEANSRC : INPUT_MAIN];
yading@10:     AVRational fps = inlink->frame_rate;
yading@10: 
yading@10:     if (!fps.num || !fps.den) {
yading@10:         av_log(ctx, AV_LOG_ERROR, "The input needs a constant frame rate; "
yading@10:                "current rate of %d/%d is invalid\n", fps.num, fps.den);
yading@10:         return AVERROR(EINVAL);
yading@10:     }
yading@10:     fps = av_mul_q(fps, (AVRational){dm->cycle - 1, dm->cycle});
yading@10:     av_log(ctx, AV_LOG_VERBOSE, "FPS: %d/%d -> %d/%d\n",
yading@10:            inlink->frame_rate.num, inlink->frame_rate.den, fps.num, fps.den);
yading@10:     outlink->flags |= FF_LINK_FLAG_REQUEST_LOOP;
yading@10:     outlink->time_base  = inlink->time_base;
yading@10:     outlink->frame_rate = fps;
yading@10:     outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
yading@10:     outlink->w = inlink->w;
yading@10:     outlink->h = inlink->h;
yading@10:     dm->ts_unit = av_q2d(av_inv_q(av_mul_q(fps, outlink->time_base)));
yading@10:     return 0;
yading@10: }
yading@10: 
yading@10: static const AVFilterPad decimate_outputs[] = {
yading@10:     {
yading@10:         .name          = "default",
yading@10:         .type          = AVMEDIA_TYPE_VIDEO,
yading@10:         .request_frame = request_frame,
yading@10:         .config_props  = config_output,
yading@10:     },
yading@10:     { NULL }
yading@10: };
yading@10: 
yading@10: AVFilter avfilter_vf_decimate = {
yading@10:     .name          = "decimate",
yading@10:     .description   = NULL_IF_CONFIG_SMALL("Decimate frames (post field matching filter)."),
yading@10:     .init          = decimate_init,
yading@10:     .uninit        = decimate_uninit,
yading@10:     .priv_size     = sizeof(DecimateContext),
yading@10:     .query_formats = query_formats,
yading@10:     .outputs       = decimate_outputs,
yading@10:     .priv_class    = &decimate_class,
yading@10:     .flags         = AVFILTER_FLAG_DYNAMIC_INPUTS,
yading@10: };