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/*
* 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));
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;
avcodec_get_chroma_sub_sample(link->format, &scale->hsub, &scale->vsub);
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(link->dst, 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}},
};
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