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Add scale filter.

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Originally committed as revision 20519 to svn://svn.ffmpeg.org/ffmpeg/trunk
This commit is contained in:
Stefano Sabatini 2009-11-11 23:50:21 +00:00
parent ba11257e48
commit c3eabb7d2f
5 changed files with 231 additions and 1 deletions
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25
doc/libavfilter.texi
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@ -164,6 +164,31 @@ not specified it will use the default value of 16.
Adding this in the beginning of filter chains should make filtering
faster due to better use of the memory cache.
@section scale
Scale the input video to width:height and/or convert the image format.
For example the command:
@example
./ffmpeg -i in.avi -vfilters "scale=200:100" out.avi
@end example
will scale the input video to a size of 200x100.
If the input image format is different from the format requested by
the next filter, the scale filter will convert the input to the
requested format.
If the value for ``width'' or ``height'' is 0, the respective input
size is used for the output.
If the value for ``width'' or ``height'' is -1, the scale filter will
use, for the respective output size, a value that maintains the aspect
ratio of the input image.
The default value of ``width'' and ``height'' is 0.
@section vflip
Flip the input video vertically.

1
libavfilter/Makefile
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@ -16,6 +16,7 @@ OBJS-$(CONFIG_CROP_FILTER) += vf_crop.o
OBJS-$(CONFIG_FORMAT_FILTER) += vf_format.o
OBJS-$(CONFIG_NOFORMAT_FILTER) += vf_format.o
OBJS-$(CONFIG_NULL_FILTER) += vf_null.o
OBJS-$(CONFIG_SCALE_FILTER) += vf_scale.o
OBJS-$(CONFIG_SLICIFY_FILTER) += vf_slicify.o
OBJS-$(CONFIG_VFLIP_FILTER) += vf_vflip.o

1
libavfilter/allfilters.c
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@ -38,6 +38,7 @@ void avfilter_register_all(void)
REGISTER_FILTER (FORMAT, format, vf);
REGISTER_FILTER (NOFORMAT, noformat, vf);
REGISTER_FILTER (NULL, null, vf);
REGISTER_FILTER (SCALE, scale, vf);
REGISTER_FILTER (SLICIFY, slicify, vf);
REGISTER_FILTER (VFLIP, vflip, vf);
}

2
libavfilter/avfilter.h
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@ -23,7 +23,7 @@
#define AVFILTER_AVFILTER_H
#define LIBAVFILTER_VERSION_MAJOR 1
#define LIBAVFILTER_VERSION_MINOR 7
#define LIBAVFILTER_VERSION_MINOR 8
#define LIBAVFILTER_VERSION_MICRO 0
#define LIBAVFILTER_VERSION_INT AV_VERSION_INT(LIBAVFILTER_VERSION_MAJOR, \

203
libavfilter/vf_scale.c Normal file
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@ -0,0 +1,203 @@
/*
* 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_scale.c
* scale video filter
*/
#include "avfilter.h"
#include "libswscale/swscale.h"
typedef struct {
struct SwsContext *sws; ///< software scaler context
/**
* New dimensions. Special values are:
* 0 = original width/height
* -1 = keep original aspect
*/
int w, h;
int hsub, vsub; ///< chroma subsampling
int slice_y; ///< top of current output slice
int slice_dir; ///< detected slice direction order for the current frame
int input_is_pal; ///< set to 1 if the input format is paletted
} ScaleContext;
static av_cold int init(AVFilterContext *ctx, const char *args, void *opaque)
{
ScaleContext *scale = ctx->priv;
if (args)
sscanf(args, "%d:%d", &scale->w, &scale->h);
/* sanity check params */
if (scale->w < -1 || scale->h < -1) {
av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
return -1;
}
if (scale->w == -1 && scale->h == -1)
scale->w = scale->h = 0;
return 0;
}
static av_cold void uninit(AVFilterContext *ctx)
{
ScaleContext *scale = ctx->priv;
sws_freeContext(scale->sws);
scale->sws = NULL;
}
static int query_formats(AVFilterContext *ctx)
{
AVFilterFormats *formats;
if (ctx->inputs[0]) {
formats = avfilter_all_colorspaces();
avfilter_formats_ref(formats, &ctx->inputs[0]->out_formats);
}
if (ctx->outputs[0]) {
formats = avfilter_all_colorspaces();
avfilter_formats_ref(formats, &ctx->outputs[0]->in_formats);
}
return 0;
}
static int config_props(AVFilterLink *outlink)
{
AVFilterContext *ctx = outlink->src;
AVFilterLink *inlink = outlink->src->inputs[0];
ScaleContext *scale = ctx->priv;
int64_t w, h;
if (!(w = scale->w))
w = inlink->w;
if (!(h = scale->h))
h = inlink->h;
if (w == -1)
w = av_rescale(h, inlink->w, inlink->h);
if (h == -1)
h = av_rescale(w, inlink->h, inlink->w);
if (w > INT_MAX || h > INT_MAX ||
(h * inlink->w) > INT_MAX ||
(w * inlink->h) > INT_MAX)
av_log(ctx, AV_LOG_ERROR, "Rescaled value for width or height is too big.\n");
outlink->w = w;
outlink->h = h;
/* TODO: make algorithm configurable */
scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
outlink->w, outlink->h, outlink->format,
SWS_BILINEAR, NULL, NULL, NULL);
av_log(ctx, AV_LOG_INFO, "w:%d h:%d fmt:%s\n",
outlink->w, outlink->h, avcodec_get_pix_fmt_name(outlink->format));
avcodec_get_chroma_sub_sample(outlink->format, &scale->hsub, &scale->vsub);
scale->input_is_pal = inlink->format == PIX_FMT_PAL8 ||
inlink->format == PIX_FMT_BGR4_BYTE ||
inlink->format == PIX_FMT_RGB4_BYTE ||
inlink->format == PIX_FMT_BGR8 ||
inlink->format == PIX_FMT_RGB8;
return !scale->sws;
}
static void start_frame(AVFilterLink *link, AVFilterPicRef *picref)
{
ScaleContext *scale = link->dst->priv;
AVFilterLink *outlink = link->dst->outputs[0];
AVFilterPicRef *outpicref;
outpicref = avfilter_get_video_buffer(outlink, AV_PERM_WRITE, outlink->w, outlink->h);
outpicref->pts = picref->pts;
outlink->outpic = outpicref;
av_reduce(&outpicref->pixel_aspect.num, &outpicref->pixel_aspect.den,
(int64_t)picref->pixel_aspect.num * outlink->h * link->w,
(int64_t)picref->pixel_aspect.den * outlink->w * link->h,
INT_MAX);
scale->slice_dir = 0;
avfilter_start_frame(outlink, avfilter_ref_pic(outpicref, ~0));
}
static void draw_slice(AVFilterLink *link, int y, int h)
{
ScaleContext *scale = link->dst->priv;
int out_h;
AVFilterPicRef *cur_pic = link->cur_pic;
uint8_t *data[4];
if (!scale->slice_dir) {
if (y != 0 && y + h != link->h) {
av_log(scale, AV_LOG_ERROR, "Slices start in the middle!\n");
return;
}
scale->slice_dir = y ? -1 : 1;
scale->slice_y = y ? link->dst->outputs[0]->h : y;
}
data[0] = cur_pic->data[0] + y * cur_pic->linesize[0];
data[1] = scale->input_is_pal ?
cur_pic->data[1] :
cur_pic->data[1] + (y>>scale->vsub) * cur_pic->linesize[1];
data[2] = cur_pic->data[2] + (y>>scale->vsub) * cur_pic->linesize[2];
data[3] = cur_pic->data[3] + y * cur_pic->linesize[3];
out_h = sws_scale(scale->sws, data, cur_pic->linesize, y, h,
link->dst->outputs[0]->outpic->data,
link->dst->outputs[0]->outpic->linesize);
if (scale->slice_dir == -1)
scale->slice_y -= out_h;
avfilter_draw_slice(link->dst->outputs[0], scale->slice_y, out_h);
if (scale->slice_dir == 1)
scale->slice_y += out_h;
}
AVFilter avfilter_vf_scale = {
.name = "scale",
.description = "Scale the input video to width:height size and/or convert the image format.",
.init = init,
.uninit = uninit,
.query_formats = query_formats,
.priv_size = sizeof(ScaleContext),
.inputs = (AVFilterPad[]) {{ .name = "default",
.type = CODEC_TYPE_VIDEO,
.start_frame = start_frame,
.draw_slice = draw_slice,
.min_perms = AV_PERM_READ, },
{ .name = NULL}},
.outputs = (AVFilterPad[]) {{ .name = "default",
.type = CODEC_TYPE_VIDEO,
.config_props = config_props, },
{ .name = NULL}},
};