diff options
Diffstat (limited to 'libavfilter/vf_decimate.c')
| -rw-r--r-- | libavfilter/vf_decimate.c | 268 |
1 files changed, 268 insertions, 0 deletions
diff --git a/libavfilter/vf_decimate.c b/libavfilter/vf_decimate.c new file mode 100644 index 0000000..b4abfa3 --- /dev/null +++ b/libavfilter/vf_decimate.c @@ -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 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_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 } + }, +}; |
