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/*
* Copyright (C) 2004 Michael Niedermayer <michaelni@gmx.at>
*
* 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
*/
#include <math.h>
#include "libavutil/eval.h"
#include "libavutil/opt.h"
#include "libavutil/video_enc_params.h"
#include "avfilter.h"
#include "filters.h"
#include "video.h"
typedef struct QPContext {
const AVClass *class;
char *qp_expr_str;
int8_t lut[257];
int h, qstride;
int evaluate_per_mb;
} QPContext;
static const char *const var_names[] = { "known", "qp", "x", "y", "w", "h", NULL };
#define OFFSET(x) offsetof(QPContext, x)
#define FLAGS AV_OPT_FLAG_FILTERING_PARAM|AV_OPT_FLAG_VIDEO_PARAM
static const AVOption qp_options[] = {
{ "qp", "set qp expression", OFFSET(qp_expr_str), AV_OPT_TYPE_STRING, {.str=NULL}, 0, 0, FLAGS },
{ NULL }
};
AVFILTER_DEFINE_CLASS(qp);
static int config_input(AVFilterLink *inlink)
{
AVFilterContext *ctx = inlink->dst;
QPContext *s = ctx->priv;
int i;
int ret;
AVExpr *e = NULL;
if (!s->qp_expr_str)
return 0;
ret = av_expr_parse(&e, s->qp_expr_str, var_names, NULL, NULL, NULL, NULL, 0, ctx);
if (ret < 0)
return ret;
s->h = (inlink->h + 15) >> 4;
s->qstride = (inlink->w + 15) >> 4;
for (i = -129; i < 128; i++) {
double var_values[] = { i != -129, i, NAN, NAN, s->qstride, s->h, 0};
double temp_val = av_expr_eval(e, var_values, NULL);
if (isnan(temp_val)) {
if(strchr(s->qp_expr_str, 'x') || strchr(s->qp_expr_str, 'y'))
s->evaluate_per_mb = 1;
else {
av_expr_free(e);
return AVERROR(EINVAL);
}
}
s->lut[i + 129] = lrintf(temp_val);
}
av_expr_free(e);
return 0;
}
static int filter_frame(AVFilterLink *inlink, AVFrame *in)
{
AVFilterContext *ctx = inlink->dst;
AVFilterLink *outlink = ctx->outputs[0];
QPContext *s = ctx->priv;
AVFrame *out = NULL;
int ret;
AVFrameSideData *sd_in;
AVVideoEncParams *par_in = NULL;
int8_t in_qp_global = 0;
AVVideoEncParams *par_out;
if (!s->qp_expr_str || ctx->is_disabled)
return ff_filter_frame(outlink, in);
sd_in = av_frame_get_side_data(in, AV_FRAME_DATA_VIDEO_ENC_PARAMS);
if (sd_in && sd_in->size >= sizeof(AVVideoEncParams)) {
par_in = (AVVideoEncParams*)sd_in->data;
// we accept the input QP table only if it is of the MPEG2 type
// and contains either no blocks at all or 16x16 macroblocks
if (par_in->type == AV_VIDEO_ENC_PARAMS_MPEG2 &&
(par_in->nb_blocks == s->h * s->qstride || !par_in->nb_blocks)) {
in_qp_global = par_in->qp;
if (!par_in->nb_blocks)
par_in = NULL;
} else
par_in = NULL;
}
out = av_frame_clone(in);
if (!out) {
ret = AVERROR(ENOMEM);
goto fail;
}
par_out = av_video_enc_params_create_side_data(out, AV_VIDEO_ENC_PARAMS_MPEG2,
(s->evaluate_per_mb || sd_in) ?
s->h * s->qstride : 0);
if (!par_out) {
ret = AVERROR(ENOMEM);
goto fail;
}
#define BLOCK_QP_DELTA(block_idx) \
(par_in ? av_video_enc_params_block(par_in, block_idx)->delta_qp : 0)
if (s->evaluate_per_mb) {
int y, x;
for (y = 0; y < s->h; y++)
for (x = 0; x < s->qstride; x++) {
unsigned int block_idx = y * s->qstride + x;
AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
double qp = sd_in ? in_qp_global + BLOCK_QP_DELTA(block_idx) : NAN;
double var_values[] = { !!sd_in, qp, x, y, s->qstride, s->h, 0};
double temp_val;
ret = av_expr_parse_and_eval(&temp_val, s->qp_expr_str,
var_names, var_values,
NULL, NULL, NULL, NULL, 0, 0, ctx);
if (ret < 0)
goto fail;
b->delta_qp = lrintf(temp_val);
}
} else if (sd_in) {
int y, x;
for (y = 0; y < s->h; y++)
for (x = 0; x < s->qstride; x++) {
unsigned int block_idx = y * s->qstride + x;
AVVideoBlockParams *b = av_video_enc_params_block(par_out, block_idx);
b->delta_qp = s->lut[129 + (int8_t)(in_qp_global + BLOCK_QP_DELTA(block_idx))];
}
} else {
par_out->qp = s->lut[0];
}
ret = ff_filter_frame(outlink, out);
out = NULL;
fail:
av_frame_free(&in);
av_frame_free(&out);
return ret;
}
static const AVFilterPad qp_inputs[] = {
{
.name = "default",
.type = AVMEDIA_TYPE_VIDEO,
.filter_frame = filter_frame,
.config_props = config_input,
},
};
const AVFilter ff_vf_qp = {
.name = "qp",
.description = NULL_IF_CONFIG_SMALL("Change video quantization parameters."),
.priv_size = sizeof(QPContext),
FILTER_INPUTS(qp_inputs),
FILTER_OUTPUTS(ff_video_default_filterpad),
.priv_class = &qp_class,
.flags = AVFILTER_FLAG_SUPPORT_TIMELINE_INTERNAL |
AVFILTER_FLAG_METADATA_ONLY,
};
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