From 68b79bfc482fe09faf259153920718261950a637 Mon Sep 17 00:00:00 2001 From: Stefano Sabatini Date: Tue, 12 Oct 2010 09:22:32 +0000 Subject: Implement cropdetect filter. Originally committed as revision 25447 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavfilter/vf_cropdetect.c | 214 ++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 214 insertions(+) create mode 100644 libavfilter/vf_cropdetect.c (limited to 'libavfilter/vf_cropdetect.c') diff --git a/libavfilter/vf_cropdetect.c b/libavfilter/vf_cropdetect.c new file mode 100644 index 0000000000..d651519eee --- /dev/null +++ b/libavfilter/vf_cropdetect.c @@ -0,0 +1,214 @@ +/* + * Copyright (C) 2002 A'rpi + * 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 + * border detection filter + * Ported from MPlayer libmpcodecs/vf_cropdetect.c. + */ + +#include "libavcore/imgutils.h" +#include "avfilter.h" + +typedef struct { + int x1, y1, x2, y2; + int limit; + int round; + int reset_count; + int frame_nb; + int max_pixsteps[4]; +} CropDetectContext; + +static int query_formats(AVFilterContext *ctx) +{ + static const enum PixelFormat pix_fmts[] = { + PIX_FMT_YUV420P, PIX_FMT_YUVJ420P, + PIX_FMT_YUV422P, PIX_FMT_YUVJ422P, + PIX_FMT_YUV444P, PIX_FMT_YUVJ444P, + PIX_FMT_YUV411P, PIX_FMT_GRAY8, + PIX_FMT_NV12, PIX_FMT_NV21, + PIX_FMT_NONE + }; + + avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts)); + return 0; +} + +static int checkline(void *ctx, const unsigned char *src, int stride, int len, int bpp) +{ + int total = 0; + int div = len; + + switch (bpp) { + case 1: + while (--len >= 0) { + total += src[0]; + src += stride; + } + break; + case 3: + case 4: + while (--len >= 0) { + total += src[0] + src[1] + src[2]; + src += stride; + } + div *= 3; + break; + } + total /= div; + + av_log(ctx, AV_LOG_DEBUG, "total:%d\n", total); + return total; +} + +static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque) +{ + CropDetectContext *cd = ctx->priv; + + cd->limit = 24; + cd->round = 0; + cd->reset_count = 0; + cd->frame_nb = -2; + + if (args) + sscanf(args, "%d:%d:%d", &cd->limit, &cd->round, &cd->reset_count); + + av_log(ctx, AV_LOG_INFO, "limit:%d round:%d reset_count:%d\n", + cd->limit, cd->round, cd->reset_count); + + return 0; +} + +static int config_input(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + CropDetectContext *cd = ctx->priv; + + av_image_fill_max_pixsteps(cd->max_pixsteps, NULL, + &av_pix_fmt_descriptors[inlink->format]); + + cd->x1 = inlink->w - 1; + cd->y1 = inlink->h - 1; + cd->x2 = 0; + cd->y2 = 0; + + return 0; +} + +static void end_frame(AVFilterLink *inlink) +{ + AVFilterContext *ctx = inlink->dst; + CropDetectContext *cd = ctx->priv; + AVFilterBufferRef *picref = inlink->cur_buf; + int bpp = cd->max_pixsteps[0]; + int w, h, x, y, shrink_by; + + // ignore first 2 frames - they may be empty + if (++cd->frame_nb > 0) { + // Reset the crop area every reset_count frames, if reset_count is > 0 + if (cd->reset_count > 0 && cd->frame_nb > cd->reset_count) { + cd->x1 = picref->video->w-1; + cd->y1 = picref->video->h-1; + cd->x2 = 0; + cd->y2 = 0; + cd->frame_nb = 1; + } + + for (y = 0; y < cd->y1; y++) { + if (checkline(ctx, picref->data[0] + picref->linesize[0] * y, bpp, picref->video->w, bpp) > cd->limit) { + cd->y1 = y; + break; + } + } + + for (y = picref->video->h-1; y > cd->y2; y--) { + if (checkline(ctx, picref->data[0] + picref->linesize[0] * y, bpp, picref->video->w, bpp) > cd->limit) { + cd->y2 = y; + break; + } + } + + for (y = 0; y < cd->x1; y++) { + if (checkline(ctx, picref->data[0] + bpp*y, picref->linesize[0], picref->video->h, bpp) > cd->limit) { + cd->x1 = y; + break; + } + } + + for (y = picref->video->w-1; y > cd->x2; y--) { + if (checkline(ctx, picref->data[0] + bpp*y, picref->linesize[0], picref->video->h, bpp) > cd->limit) { + cd->x2 = y; + break; + } + } + + // round x and y (up), important for yuv colorspaces + // make sure they stay rounded! + x = (cd->x1+1) & ~1; + y = (cd->y1+1) & ~1; + + w = cd->x2 - x + 1; + h = cd->y2 - y + 1; + + // w and h must be divisible by 2 as well because of yuv + // colorspace problems. + if (cd->round <= 1) + cd->round = 16; + if (cd->round % 2) + cd->round *= 2; + + shrink_by = w % cd->round; + w -= shrink_by; + x += (shrink_by/2 + 1) & ~1; + + shrink_by = h % cd->round; + h -= shrink_by; + y += (shrink_by/2 + 1) & ~1; + + av_log(ctx, AV_LOG_INFO, + "x1:%d x2:%d y1:%d y2:%d w:%d h:%d x:%d y:%d pos:%"PRId64" pts:%f crop=%d:%d:%d:%d\n", + cd->x1, cd->x2, cd->y1, cd->y2, w, h, x, y, picref->pos, + picref->pts == AV_NOPTS_VALUE ? -1 : (double)picref->pts / AV_TIME_BASE, + w, h, x, y); + } + + avfilter_end_frame(inlink->dst->outputs[0]); +} + +AVFilter avfilter_vf_cropdetect = { + .name = "cropdetect", + .description = NULL_IF_CONFIG_SMALL("Auto-detect crop size."), + + .priv_size = sizeof(CropDetectContext), + .init = init, + + .query_formats = query_formats, + + .inputs = (AVFilterPad[]) {{ .name = "default", + .type = AVMEDIA_TYPE_VIDEO, + .config_props = config_input, + .get_video_buffer = avfilter_null_get_video_buffer, + .start_frame = avfilter_null_start_frame, + .end_frame = end_frame, }, + { .name = NULL}}, + + .outputs = (AVFilterPad[]) {{ .name = "default", + .type = AVMEDIA_TYPE_VIDEO }, + { .name = NULL}}, +}; -- cgit v1.2.3