mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-18 03:19:31 +02:00
ba87f0801d
Passing an explicit filename to this command is only necessary if the documentation in the @file block refers to a file different from the one the block resides in. Originally committed as revision 22921 to svn://svn.ffmpeg.org/ffmpeg/trunk
118 lines
3.9 KiB
C
118 lines
3.9 KiB
C
/*
|
|
* copyright (c) 2007 Bobby Bingham
|
|
*
|
|
* This file is part of FFmpeg.
|
|
*
|
|
* FFmpeg is free software; you can redistribute it and/or
|
|
* modify it under the terms of the GNU Lesser General Public
|
|
* License as published by the Free Software Foundation; either
|
|
* version 2.1 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
|
|
* Lesser General Public License for more details.
|
|
*
|
|
* You should have received a copy of the GNU Lesser 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
|
|
* video slicing filter
|
|
*/
|
|
|
|
#include "avfilter.h"
|
|
#include "libavutil/pixdesc.h"
|
|
|
|
typedef struct {
|
|
int h; ///< output slice height
|
|
int vshift; ///< vertical chroma subsampling shift
|
|
uint32_t lcg_state; ///< LCG state used to compute random slice height
|
|
int use_random_h; ///< enable the use of random slice height values
|
|
} SliceContext;
|
|
|
|
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
|
|
{
|
|
SliceContext *slice = ctx->priv;
|
|
|
|
slice->h = 16;
|
|
if (args) {
|
|
if (!strcmp(args, "random")) {
|
|
slice->use_random_h = 1;
|
|
} else {
|
|
sscanf(args, "%d", &slice->h);
|
|
}
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
static int config_props(AVFilterLink *link)
|
|
{
|
|
SliceContext *slice = link->dst->priv;
|
|
|
|
slice->vshift = av_pix_fmt_descriptors[link->format].log2_chroma_h;
|
|
|
|
return 0;
|
|
}
|
|
|
|
static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
|
|
{
|
|
SliceContext *slice = link->dst->priv;
|
|
|
|
if (slice->use_random_h) {
|
|
slice->lcg_state = slice->lcg_state * 1664525 + 1013904223;
|
|
slice->h = 8 + (uint64_t)slice->lcg_state * 25 / UINT32_MAX;
|
|
}
|
|
|
|
/* ensure that slices play nice with chroma subsampling, and enforce
|
|
* a reasonable minimum size for the slices */
|
|
slice->h = FFMAX(8, slice->h & (-1 << slice->vshift));
|
|
|
|
av_log(link->dst, AV_LOG_DEBUG, "h:%d\n", slice->h);
|
|
|
|
avfilter_start_frame(link->dst->outputs[0], picref);
|
|
}
|
|
|
|
static void draw_slice(AVFilterLink *link, int y, int h, int slice_dir)
|
|
{
|
|
SliceContext *slice = link->dst->priv;
|
|
int y2;
|
|
|
|
if (slice_dir == 1) {
|
|
for (y2 = y; y2 + slice->h <= y + h; y2 += slice->h)
|
|
avfilter_draw_slice(link->dst->outputs[0], y2, slice->h, slice_dir);
|
|
|
|
if (y2 < y + h)
|
|
avfilter_draw_slice(link->dst->outputs[0], y2, y + h - y2, slice_dir);
|
|
} else if (slice_dir == -1) {
|
|
for (y2 = y + h; y2 - slice->h >= y; y2 -= slice->h)
|
|
avfilter_draw_slice(link->dst->outputs[0], y2 - slice->h, slice->h, slice_dir);
|
|
|
|
if (y2 > y)
|
|
avfilter_draw_slice(link->dst->outputs[0], y, y2 - y, slice_dir);
|
|
}
|
|
}
|
|
|
|
AVFilter avfilter_vf_slicify = {
|
|
.name = "slicify",
|
|
.description = "Pass the images of input video on to next video filter as multiple slices.",
|
|
|
|
.init = init,
|
|
|
|
.priv_size = sizeof(SliceContext),
|
|
|
|
.inputs = (AVFilterPad[]) {{ .name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.get_video_buffer = avfilter_null_get_video_buffer,
|
|
.start_frame = start_frame,
|
|
.draw_slice = draw_slice,
|
|
.config_props = config_props,
|
|
.end_frame = avfilter_null_end_frame, },
|
|
{ .name = NULL}},
|
|
.outputs = (AVFilterPad[]) {{ .name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO, },
|
|
{ .name = NULL}},
|
|
};
|