mirror of
https://github.com/FFmpeg/FFmpeg.git
synced 2024-12-28 20:53:54 +02:00
125 lines
3.9 KiB
C
125 lines
3.9 KiB
C
/*
|
|
* Copyright (c) 2012 Steven Robertson
|
|
*
|
|
* 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
|
|
* simple channel-swapping filter to get at the alpha component
|
|
*/
|
|
|
|
#include <string.h>
|
|
|
|
#include "libavutil/pixfmt.h"
|
|
#include "avfilter.h"
|
|
#include "drawutils.h"
|
|
#include "formats.h"
|
|
#include "video.h"
|
|
|
|
enum { Y, U, V, A };
|
|
|
|
typedef struct {
|
|
int is_packed_rgb;
|
|
uint8_t rgba_map[4];
|
|
} AlphaExtractContext;
|
|
|
|
static int query_formats(AVFilterContext *ctx)
|
|
{
|
|
enum AVPixelFormat in_fmts[] = {
|
|
AV_PIX_FMT_YUVA444P, AV_PIX_FMT_YUVA422P, AV_PIX_FMT_YUVA420P,
|
|
AV_PIX_FMT_RGBA, AV_PIX_FMT_BGRA, AV_PIX_FMT_ARGB, AV_PIX_FMT_ABGR,
|
|
AV_PIX_FMT_NONE
|
|
};
|
|
enum AVPixelFormat out_fmts[] = { AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE };
|
|
ff_formats_ref(ff_make_format_list(in_fmts), &ctx->inputs[0]->out_formats);
|
|
ff_formats_ref(ff_make_format_list(out_fmts), &ctx->outputs[0]->in_formats);
|
|
return 0;
|
|
}
|
|
|
|
static int config_input(AVFilterLink *inlink)
|
|
{
|
|
AlphaExtractContext *extract = inlink->dst->priv;
|
|
extract->is_packed_rgb =
|
|
ff_fill_rgba_map(extract->rgba_map, inlink->format) >= 0;
|
|
return 0;
|
|
}
|
|
|
|
static int draw_slice(AVFilterLink *inlink, int y0, int h, int slice_dir)
|
|
{
|
|
AlphaExtractContext *extract = inlink->dst->priv;
|
|
AVFilterBufferRef *cur_buf = inlink->cur_buf;
|
|
AVFilterBufferRef *out_buf = inlink->dst->outputs[0]->out_buf;
|
|
|
|
if (extract->is_packed_rgb) {
|
|
int x, y;
|
|
uint8_t *pin, *pout;
|
|
for (y = y0; y < (y0 + h); y++) {
|
|
pin = cur_buf->data[0] + y * cur_buf->linesize[0] + extract->rgba_map[A];
|
|
pout = out_buf->data[0] + y * out_buf->linesize[0];
|
|
for (x = 0; x < out_buf->video->w; x++) {
|
|
*pout = *pin;
|
|
pout += 1;
|
|
pin += 4;
|
|
}
|
|
}
|
|
} else if (cur_buf->linesize[A] == out_buf->linesize[Y]) {
|
|
const int linesize = cur_buf->linesize[A];
|
|
memcpy(out_buf->data[Y] + y0 * linesize,
|
|
cur_buf->data[A] + y0 * linesize,
|
|
linesize * h);
|
|
} else {
|
|
const int linesize = FFMIN(out_buf->linesize[Y], cur_buf->linesize[A]);
|
|
int y;
|
|
for (y = y0; y < (y0 + h); y++) {
|
|
memcpy(out_buf->data[Y] + y * out_buf->linesize[Y],
|
|
cur_buf->data[A] + y * cur_buf->linesize[A],
|
|
linesize);
|
|
}
|
|
}
|
|
return ff_draw_slice(inlink->dst->outputs[0], y0, h, slice_dir);
|
|
}
|
|
|
|
static const AVFilterPad alphaextract_inputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
.config_props = config_input,
|
|
.draw_slice = draw_slice,
|
|
.min_perms = AV_PERM_READ,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
static const AVFilterPad alphaextract_outputs[] = {
|
|
{
|
|
.name = "default",
|
|
.type = AVMEDIA_TYPE_VIDEO,
|
|
},
|
|
{ NULL }
|
|
};
|
|
|
|
AVFilter avfilter_vf_alphaextract = {
|
|
.name = "alphaextract",
|
|
.description = NULL_IF_CONFIG_SMALL("Extract an alpha channel as a "
|
|
"grayscale image component."),
|
|
.priv_size = sizeof(AlphaExtractContext),
|
|
.query_formats = query_formats,
|
|
.inputs = alphaextract_inputs,
|
|
.outputs = alphaextract_outputs,
|
|
};
|