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Add video crop filter. 

Originally committed as revision 20342 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Stefano Sabatini 2009-10-21 20:57:30 +00:00
parent 9abba21ad3
commit 190c166960
4 changed files with 266 additions and 0 deletions
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31
doc/libavfilter.texi
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@ -84,4 +84,35 @@ Below is a description of the currently available video filters.
Pass the source unchanged to the output.
@section crop
Crop the input video to x:y:width:height.
@example
./ffmpeg -i in.avi -vfilters "crop=0:0:0:240" out.avi
@end example
``x'' and ``y'' specify the position of the top-left corner of the
output (non-cropped) area.
The default value of ``x'' and ``y'' is 0.
The ``w'' and ``h'' parameters specify the width and height of the
output (non-cropped) area.
A value of 0 is interpreted as the maximum possible size contained in
the area delimited by the top-left corner at position x:y.
For example the parameters:
@example
"crop=100:100:0:0"
@end example
will delimit the rectangle with the top-left corner placed at position
100:100 and the right-bottom corner corresponding to the right-bottom
corner of the input image.
The default value of ``w'' and ``h'' is 0.
@bye

1
libavfilter/Makefile
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@ -11,6 +11,7 @@ OBJS = allfilters.o \
defaults.o \
formats.o \
OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_NULL_FILTER) += vf_null.o
include $(SUBDIR)../subdir.mak

1
libavfilter/allfilters.c
View File

@ -34,5 +34,6 @@ void avfilter_register_all(void)
return;
initialized = 1;
REGISTER_FILTER (CROP,crop,vf);
REGISTER_FILTER (NULL,null,vf);
}

233
libavfilter/vf_crop.c Normal file
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@ -0,0 +1,233 @@
/*
* 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 libavfilter/vf_crop.c
* video crop filter
*/
#include "avfilter.h"
typedef struct {
int x; ///< x offset of the non-cropped area with respect to the input area
int y; ///< y offset of the non-cropped area with respect to the input area
int w; ///< width of the cropped area
int h; ///< height of the cropped area
int bpp; ///< bits per pixel
int hsub, vsub; ///< chroma subsampling
} CropContext;
static int query_formats(AVFilterContext *ctx)
{
enum PixelFormat pix_fmts[] = {
PIX_FMT_RGB48BE, PIX_FMT_RGB48LE,
PIX_FMT_ARGB, PIX_FMT_RGBA,
PIX_FMT_ABGR, PIX_FMT_BGRA,
PIX_FMT_RGB24, PIX_FMT_BGR24,
PIX_FMT_RGB565BE, PIX_FMT_RGB565LE,
PIX_FMT_RGB555BE, PIX_FMT_RGB555LE,
PIX_FMT_BGR565BE, PIX_FMT_BGR565LE,
PIX_FMT_BGR555BE, PIX_FMT_BGR555LE,
PIX_FMT_GRAY16BE, PIX_FMT_GRAY16LE,
PIX_FMT_YUV420P16LE, PIX_FMT_YUV420P16BE,
PIX_FMT_YUV422P16LE, PIX_FMT_YUV422P16BE,
PIX_FMT_YUV444P16LE, PIX_FMT_YUV444P16BE,
PIX_FMT_YUV444P, PIX_FMT_YUV422P,
PIX_FMT_YUV420P, PIX_FMT_YUV411P,
PIX_FMT_YUV410P, PIX_FMT_YUV440P,
PIX_FMT_YUVJ444P, PIX_FMT_YUVJ422P,
PIX_FMT_YUVJ420P, PIX_FMT_YUVJ440P,
PIX_FMT_YUVA420P,
PIX_FMT_NV12, PIX_FMT_NV21,
PIX_FMT_YUYV422, PIX_FMT_UYVY422,
PIX_FMT_UYYVYY411,
PIX_FMT_RGB8, PIX_FMT_BGR8,
PIX_FMT_RGB4_BYTE, PIX_FMT_BGR4_BYTE,
PIX_FMT_PAL8, PIX_FMT_GRAY8,
PIX_FMT_NONE
};
avfilter_set_common_formats(ctx, avfilter_make_format_list(pix_fmts));
return 0;
}
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
CropContext *crop = ctx->priv;
if (args)
sscanf(args, "%d:%d:%d:%d", &crop->x, &crop->y, &crop->w, &crop->h);
return 0;
}
static int config_input(AVFilterLink *link)
{
AVFilterContext *ctx = link->dst;
CropContext *crop = ctx->priv;
switch (link->format) {
case PIX_FMT_RGB48BE:
case PIX_FMT_RGB48LE:
crop->bpp = 48;
break;
case PIX_FMT_ARGB:
case PIX_FMT_RGBA:
case PIX_FMT_ABGR:
case PIX_FMT_BGRA:
crop->bpp = 32;
break;
case PIX_FMT_RGB24:
case PIX_FMT_BGR24:
crop->bpp = 24;
break;
case PIX_FMT_RGB565BE:
case PIX_FMT_RGB565LE:
case PIX_FMT_RGB555BE:
case PIX_FMT_RGB555LE:
case PIX_FMT_BGR565BE:
case PIX_FMT_BGR565LE:
case PIX_FMT_BGR555BE:
case PIX_FMT_BGR555LE:
case PIX_FMT_GRAY16BE:
case PIX_FMT_GRAY16LE:
case PIX_FMT_YUV420P16LE:
case PIX_FMT_YUV420P16BE:
case PIX_FMT_YUV422P16LE:
case PIX_FMT_YUV422P16BE:
case PIX_FMT_YUV444P16LE:
case PIX_FMT_YUV444P16BE:
crop->bpp = 16;
break;
default:
crop->bpp = 8;
}
avcodec_get_chroma_sub_sample(link->format, &crop->hsub, &crop->vsub);
if (crop->w == 0)
crop->w = link->w - crop->x;
if (crop->h == 0)
crop->h = link->h - crop->y;
crop->x &= ~((1 << crop->hsub) - 1);
crop->y &= ~((1 << crop->vsub) - 1);
av_log(link->dst, AV_LOG_INFO, "x:%d y:%d w:%d h:%d\n",
crop->x, crop->y, crop->w, crop->h);
if (crop->x < 0 || crop->y < 0 ||
crop->w <= 0 || crop->h <= 0 ||
(unsigned)crop->x + (unsigned)crop->w > link->w ||
(unsigned)crop->y + (unsigned)crop->h > link->h) {
av_log(ctx, AV_LOG_ERROR,
"Output area %d:%d:%d:%d not within the input area 0:0:%d:%d or zero-sized\n",
crop->x, crop->y, crop->w, crop->h, link->w, link->h);
return -1;
}
return 0;
}
static int config_output(AVFilterLink *link)
{
CropContext *crop = link->src->priv;
link->w = crop->w;
link->h = crop->h;
return 0;
}
static AVFilterPicRef *get_video_buffer(AVFilterLink *link, int perms,
int w, int h)
{
return avfilter_get_video_buffer(link->dst->outputs[0], perms, w, h);
}
static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
{
CropContext *crop = link->dst->priv;
AVFilterPicRef *ref2 = avfilter_ref_pic(picref, ~0);
int i;
ref2->w = crop->w;
ref2->h = crop->h;
ref2->data[0] += crop->y * ref2->linesize[0];
ref2->data[0] += (crop->x * crop->bpp) >> 3;
if (link->format != PIX_FMT_PAL8) {
for (i = 1; i < 3; i ++) {
if (ref2->data[i]) {
ref2->data[i] += (crop->y >> crop->vsub) * ref2->linesize[i];
ref2->data[i] += crop->x >> crop->hsub;
}
}
}
/* alpha plane */
if (ref2->data[3]) {
ref2->data[3] += crop->y * ref2->linesize[3];
ref2->data[3] += (crop->x * crop->bpp) >> 3;
}
avfilter_start_frame(link->dst->outputs[0], ref2);
}
static void draw_slice(AVFilterLink *link, int y, int h)
{
AVFilterContext *ctx = link->dst;
CropContext *crop = ctx->priv;
if (y >= crop->y + crop->h || y + h <= crop->y)
return;
if (y < crop->y) {
h -= crop->y - y;
y = crop->y;
}
if (y + h > crop->y + crop->h)
h = crop->y + crop->h - y;
avfilter_draw_slice(ctx->outputs[0], y - crop->y, h);
}
AVFilter avfilter_vf_crop = {
.name = "crop",
.priv_size = sizeof(CropContext),
.query_formats = query_formats,
.init = init,
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = CODEC_TYPE_VIDEO,
.start_frame = start_frame,
.draw_slice = draw_slice,
.get_video_buffer = get_video_buffer,
.config_props = config_input, },
{ .name = NULL}},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = CODEC_TYPE_VIDEO,
.config_props = config_output, },
{ .name = NULL}},
};