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a5e8c41c28
It is not used in any filters currently and is inherently evil. If passing binary data to filters is required in the future, it should be done with some AVOptions-based system.
120 lines
3.9 KiB
C
120 lines
3.9 KiB
C
/*
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* Copyright (c) 2007 Bobby Bingham
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*
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* This file is part of Libav.
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*
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* Libav is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2.1 of the License, or (at your option) any later version.
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*
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* Libav is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public
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* License along with Libav; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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*/
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/**
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* @file
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* video slicing filter
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*/
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#include "avfilter.h"
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#include "internal.h"
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#include "video.h"
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#include "libavutil/pixdesc.h"
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typedef struct {
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int h; ///< output slice height
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int vshift; ///< vertical chroma subsampling shift
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uint32_t lcg_state; ///< LCG state used to compute random slice height
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int use_random_h; ///< enable the use of random slice height values
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} SliceContext;
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static av_cold int init(AVFilterContext *ctx, const char *args)
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{
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SliceContext *slice = ctx->priv;
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slice->h = 16;
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if (args) {
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if (!strcmp(args, "random")) {
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slice->use_random_h = 1;
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} else {
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sscanf(args, "%d", &slice->h);
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}
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}
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return 0;
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}
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static int config_props(AVFilterLink *link)
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{
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SliceContext *slice = link->dst->priv;
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slice->vshift = av_pix_fmt_descriptors[link->format].log2_chroma_h;
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return 0;
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}
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static void start_frame(AVFilterLink *link, AVFilterBufferRef *picref)
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{
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SliceContext *slice = link->dst->priv;
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if (slice->use_random_h) {
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slice->lcg_state = slice->lcg_state * 1664525 + 1013904223;
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slice->h = 8 + (uint64_t)slice->lcg_state * 25 / UINT32_MAX;
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}
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/* ensure that slices play nice with chroma subsampling, and enforce
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* a reasonable minimum size for the slices */
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slice->h = FFMAX(8, slice->h & (-1 << slice->vshift));
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av_log(link->dst, AV_LOG_DEBUG, "h:%d\n", slice->h);
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ff_start_frame(link->dst->outputs[0], picref);
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}
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static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
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{
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SliceContext *slice = link->dst->priv;
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int y2;
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if (slice_dir == 1) {
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for (y2 = y; y2 + slice->h <= y + h; y2 += slice->h)
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ff_draw_slice(link->dst->outputs[0], y2, slice->h, slice_dir);
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if (y2 < y + h)
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ff_draw_slice(link->dst->outputs[0], y2, y + h - y2, slice_dir);
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} else if (slice_dir == -1) {
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for (y2 = y + h; y2 - slice->h >= y; y2 -= slice->h)
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ff_draw_slice(link->dst->outputs[0], y2 - slice->h, slice->h, slice_dir);
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if (y2 > y)
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ff_draw_slice(link->dst->outputs[0], y, y2 - y, slice_dir);
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}
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}
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AVFilter avfilter_vf_slicify = {
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.name = "slicify",
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.description = NULL_IF_CONFIG_SMALL("Pass the images of input video on to next video filter as multiple slices."),
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.init = init,
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.priv_size = sizeof(SliceContext),
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.inputs = (AVFilterPad[]) {{ .name = "default",
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.type = AVMEDIA_TYPE_VIDEO,
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.get_video_buffer = ff_null_get_video_buffer,
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.start_frame = start_frame,
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.draw_slice = draw_slice,
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.config_props = config_props,
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.end_frame = ff_null_end_frame, },
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{ .name = NULL}},
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.outputs = (AVFilterPad[]) {{ .name = "default",
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.type = AVMEDIA_TYPE_VIDEO, },
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{ .name = NULL}},
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};
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