https://github.com/libav/libav
Tip revision: 210881110d3e22cca36edeaca118b5e22c998266 authored by Reinhard Tartler on 18 January 2014, 15:27:27 UTC
Prepare for 10_alpha2 Release
Prepare for 10_alpha2 Release
Tip revision: 2108811
vf_scale.c
/*
* Copyright (c) 2007 Bobby Bingham
*
* This file is part of Libav.
*
* Libav 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.
*
* Libav 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 Libav; if not, write to the Free Software
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
* @file
* scale video filter
*/
#include <stdio.h>
#include <string.h>
#include "avfilter.h"
#include "formats.h"
#include "internal.h"
#include "video.h"
#include "libavutil/avstring.h"
#include "libavutil/eval.h"
#include "libavutil/internal.h"
#include "libavutil/mathematics.h"
#include "libavutil/opt.h"
#include "libavutil/pixdesc.h"
#include "libswscale/swscale.h"
static const char *const var_names[] = {
"PI",
"PHI",
"E",
"in_w", "iw",
"in_h", "ih",
"out_w", "ow",
"out_h", "oh",
"a", "dar",
"sar",
"hsub",
"vsub",
NULL
};
enum var_name {
VAR_PI,
VAR_PHI,
VAR_E,
VAR_IN_W, VAR_IW,
VAR_IN_H, VAR_IH,
VAR_OUT_W, VAR_OW,
VAR_OUT_H, VAR_OH,
VAR_A, VAR_DAR,
VAR_SAR,
VAR_HSUB,
VAR_VSUB,
VARS_NB
};
typedef struct {
const AVClass *class;
struct SwsContext *sws; ///< software scaler context
/**
* New dimensions. Special values are:
* 0 = original width/height
* -1 = keep original aspect
*/
int w, h;
unsigned int flags; ///sws flags
int hsub, vsub; ///< chroma subsampling
int slice_y; ///< top of current output slice
int input_is_pal; ///< set to 1 if the input format is paletted
char *w_expr; ///< width expression string
char *h_expr; ///< height expression string
char *flags_str;
} ScaleContext;
static av_cold int init(AVFilterContext *ctx)
{
ScaleContext *scale = ctx->priv;
if (scale->flags_str) {
const AVClass *class = sws_get_class();
const AVOption *o = av_opt_find(&class, "sws_flags", NULL, 0,
AV_OPT_SEARCH_FAKE_OBJ);
int ret = av_opt_eval_flags(&class, o, scale->flags_str, &scale->flags);
if (ret < 0)
return ret;
}
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;
enum AVPixelFormat pix_fmt;
int ret;
if (ctx->inputs[0]) {
formats = NULL;
for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
if ((sws_isSupportedInput(pix_fmt) ||
sws_isSupportedEndiannessConversion(pix_fmt))
&& (ret = ff_add_format(&formats, pix_fmt)) < 0) {
ff_formats_unref(&formats);
return ret;
}
ff_formats_ref(formats, &ctx->inputs[0]->out_formats);
}
if (ctx->outputs[0]) {
formats = NULL;
for (pix_fmt = 0; pix_fmt < AV_PIX_FMT_NB; pix_fmt++)
if ((sws_isSupportedOutput(pix_fmt) ||
sws_isSupportedEndiannessConversion(pix_fmt))
&& (ret = ff_add_format(&formats, pix_fmt)) < 0) {
ff_formats_unref(&formats);
return ret;
}
ff_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;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(inlink->format);
int64_t w, h;
double var_values[VARS_NB], res;
char *expr;
int ret;
var_values[VAR_PI] = M_PI;
var_values[VAR_PHI] = M_PHI;
var_values[VAR_E] = M_E;
var_values[VAR_IN_W] = var_values[VAR_IW] = inlink->w;
var_values[VAR_IN_H] = var_values[VAR_IH] = inlink->h;
var_values[VAR_OUT_W] = var_values[VAR_OW] = NAN;
var_values[VAR_OUT_H] = var_values[VAR_OH] = NAN;
var_values[VAR_A] = (double) inlink->w / inlink->h;
var_values[VAR_SAR] = inlink->sample_aspect_ratio.num ?
(double) inlink->sample_aspect_ratio.num / inlink->sample_aspect_ratio.den : 1;
var_values[VAR_DAR] = var_values[VAR_A] * var_values[VAR_SAR];
var_values[VAR_HSUB] = 1 << desc->log2_chroma_w;
var_values[VAR_VSUB] = 1 << desc->log2_chroma_h;
/* evaluate width and height */
av_expr_parse_and_eval(&res, (expr = scale->w_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx);
scale->w = var_values[VAR_OUT_W] = var_values[VAR_OW] = res;
if ((ret = av_expr_parse_and_eval(&res, (expr = scale->h_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
scale->h = var_values[VAR_OUT_H] = var_values[VAR_OH] = res;
/* evaluate again the width, as it may depend on the output height */
if ((ret = av_expr_parse_and_eval(&res, (expr = scale->w_expr),
var_names, var_values,
NULL, NULL, NULL, NULL, NULL, 0, ctx)) < 0)
goto fail;
scale->w = res;
w = scale->w;
h = scale->h;
/* sanity check params */
if (w < -1 || h < -1) {
av_log(ctx, AV_LOG_ERROR, "Size values less than -1 are not acceptable.\n");
return AVERROR(EINVAL);
}
if (w == -1 && h == -1)
scale->w = scale->h = 0;
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 */
av_log(ctx, AV_LOG_VERBOSE, "w:%d h:%d fmt:%s -> w:%d h:%d fmt:%s flags:0x%0x\n",
inlink ->w, inlink ->h, av_get_pix_fmt_name(inlink->format),
outlink->w, outlink->h, av_get_pix_fmt_name(outlink->format),
scale->flags);
scale->input_is_pal = desc->flags & AV_PIX_FMT_FLAG_PAL ||
desc->flags & AV_PIX_FMT_FLAG_PSEUDOPAL;
if (scale->sws)
sws_freeContext(scale->sws);
if (inlink->w == outlink->w && inlink->h == outlink->h &&
inlink->format == outlink->format)
scale->sws = NULL;
else {
scale->sws = sws_getContext(inlink ->w, inlink ->h, inlink ->format,
outlink->w, outlink->h, outlink->format,
scale->flags, NULL, NULL, NULL);
if (!scale->sws)
return AVERROR(EINVAL);
}
if (inlink->sample_aspect_ratio.num)
outlink->sample_aspect_ratio = av_mul_q((AVRational){outlink->h*inlink->w,
outlink->w*inlink->h},
inlink->sample_aspect_ratio);
else
outlink->sample_aspect_ratio = inlink->sample_aspect_ratio;
return 0;
fail:
av_log(NULL, AV_LOG_ERROR,
"Error when evaluating the expression '%s'\n", expr);
return ret;
}
static int filter_frame(AVFilterLink *link, AVFrame *in)
{
ScaleContext *scale = link->dst->priv;
AVFilterLink *outlink = link->dst->outputs[0];
AVFrame *out;
const AVPixFmtDescriptor *desc = av_pix_fmt_desc_get(link->format);
if (!scale->sws)
return ff_filter_frame(outlink, in);
scale->hsub = desc->log2_chroma_w;
scale->vsub = desc->log2_chroma_h;
out = ff_get_video_buffer(outlink, outlink->w, outlink->h);
if (!out) {
av_frame_free(&in);
return AVERROR(ENOMEM);
}
av_frame_copy_props(out, in);
out->width = outlink->w;
out->height = outlink->h;
av_reduce(&out->sample_aspect_ratio.num, &out->sample_aspect_ratio.den,
(int64_t)in->sample_aspect_ratio.num * outlink->h * link->w,
(int64_t)in->sample_aspect_ratio.den * outlink->w * link->h,
INT_MAX);
sws_scale(scale->sws, in->data, in->linesize, 0, in->height,
out->data, out->linesize);
av_frame_free(&in);
return ff_filter_frame(outlink, out);
}
#define OFFSET(x) offsetof(ScaleContext, x)
#define FLAGS AV_OPT_FLAG_VIDEO_PARAM
static const AVOption options[] = {
{ "w", "Output video width", OFFSET(w_expr), AV_OPT_TYPE_STRING, { .str = "iw" }, .flags = FLAGS },
{ "h", "Output video height", OFFSET(h_expr), AV_OPT_TYPE_STRING, { .str = "ih" }, .flags = FLAGS },
{ "flags", "Flags to pass to libswscale", OFFSET(flags_str), AV_OPT_TYPE_STRING, { .str = "bilinear" }, .flags = FLAGS },
{ NULL },
};
static const AVClass scale_class = {
.class_name = "scale",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
static const AVFilterPad avfilter_vf_scale_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
},
{ NULL }
};
static const AVFilterPad avfilter_vf_scale_outputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.config_props = config_props,
},
{ NULL }
};
AVFilter ff_vf_scale = {
.name = "scale",
.description = NULL_IF_CONFIG_SMALL("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),
.priv_class = &scale_class,
.inputs = avfilter_vf_scale_inputs,
.outputs = avfilter_vf_scale_outputs,
};