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/*
* copyright (c) 2006 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 <stdlib.h>
#include "bsf.h"
#include "bsf_internal.h"
#include "libavutil/log.h"
#include "libavutil/opt.h"
#include "libavutil/eval.h"
static const char *const var_names[] = {
"n", ///< packet index, starting from zero
"tb", ///< timebase
"pts", ///< packet presentation timestamp
"dts", ///< packet decoding timestamp
"nopts", ///< AV_NOPTS_VALUE
"startpts", ///< first seen non-AV_NOPTS_VALUE packet timestamp
"startdts", ///< first seen non-AV_NOPTS_VALUE packet timestamp
"duration", "d", ///< packet duration
"pos", ///< original position of packet in its source
"size", ///< packet size
"key" , ///< packet keyframe flag
"state", ///< random-ish state
NULL
};
enum var_name {
VAR_N,
VAR_TB,
VAR_PTS,
VAR_DTS,
VAR_NOPTS,
VAR_STARTPTS,
VAR_STARTDTS,
VAR_DURATION, VAR_D,
VAR_POS,
VAR_SIZE,
VAR_KEY,
VAR_STATE,
VAR_VARS_NB
};
typedef struct NoiseContext {
const AVClass *class;
char *amount_str;
char *drop_str;
int dropamount;
AVExpr *amount_pexpr;
AVExpr *drop_pexpr;
double var_values[VAR_VARS_NB];
unsigned int state;
unsigned int pkt_idx;
} NoiseContext;
static int noise_init(AVBSFContext *ctx)
{
NoiseContext *s = ctx->priv_data;
int ret;
if (!s->amount_str) {
s->amount_str = (!s->drop_str && !s->dropamount) ? av_strdup("-1") : av_strdup("0");
if (!s->amount_str)
return AVERROR(ENOMEM);
}
if (ctx->par_in->codec_id == AV_CODEC_ID_WRAPPED_AVFRAME &&
strcmp(s->amount_str, "0")) {
av_log(ctx, AV_LOG_ERROR, "Wrapped AVFrame noising is unsupported\n");
return AVERROR_PATCHWELCOME;
}
ret = av_expr_parse(&s->amount_pexpr, s->amount_str,
var_names, NULL, NULL, NULL, NULL, 0, ctx);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Error in parsing expr for amount: %s\n", s->amount_str);
return ret;
}
if (s->drop_str && s->dropamount) {
av_log(ctx, AV_LOG_WARNING, "Both drop '%s' and dropamount=%d set. Ignoring dropamount.\n",
s->drop_str, s->dropamount);
s->dropamount = 0;
}
if (s->drop_str) {
ret = av_expr_parse(&s->drop_pexpr, s->drop_str,
var_names, NULL, NULL, NULL, NULL, 0, ctx);
if (ret < 0) {
av_log(ctx, AV_LOG_ERROR, "Error in parsing expr for drop: %s\n", s->drop_str);
return ret;
}
}
s->var_values[VAR_TB] = ctx->time_base_out.den ? av_q2d(ctx->time_base_out) : 0;
s->var_values[VAR_NOPTS] = AV_NOPTS_VALUE;
s->var_values[VAR_STARTPTS] = AV_NOPTS_VALUE;
s->var_values[VAR_STARTDTS] = AV_NOPTS_VALUE;
s->var_values[VAR_STATE] = 0;
return 0;
}
static int noise(AVBSFContext *ctx, AVPacket *pkt)
{
NoiseContext *s = ctx->priv_data;
int i, ret, amount, drop = 0;
double res;
ret = ff_bsf_get_packet_ref(ctx, pkt);
if (ret < 0)
return ret;
s->var_values[VAR_N] = s->pkt_idx++;
s->var_values[VAR_PTS] = pkt->pts;
s->var_values[VAR_DTS] = pkt->dts;
s->var_values[VAR_DURATION] =
s->var_values[VAR_D] = pkt->duration;
s->var_values[VAR_SIZE] = pkt->size;
s->var_values[VAR_KEY] = !!(pkt->flags & AV_PKT_FLAG_KEY);
s->var_values[VAR_POS] = pkt->pos;
if (s->var_values[VAR_STARTPTS] == AV_NOPTS_VALUE)
s->var_values[VAR_STARTPTS] = pkt->pts;
if (s->var_values[VAR_STARTDTS] == AV_NOPTS_VALUE)
s->var_values[VAR_STARTDTS] = pkt->dts;
res = av_expr_eval(s->amount_pexpr, s->var_values, NULL);
if (isnan(res))
amount = 0;
else if (res < 0)
amount = (s->state % 10001 + 1);
else
amount = (int)res;
if (s->drop_str) {
res = av_expr_eval(s->drop_pexpr, s->var_values, NULL);
if (isnan(res))
drop = 0;
else if (res < 0)
drop = !(s->state % FFABS((int)res));
else
drop = !!res;
}
if(s->dropamount) {
drop = !(s->state % s->dropamount);
}
av_log(ctx, AV_LOG_VERBOSE, "Stream #%d packet %d pts %"PRId64" - amount %d drop %d\n",
pkt->stream_index, (unsigned int)s->var_values[VAR_N], pkt->pts, amount, drop);
if (drop) {
s->var_values[VAR_STATE] = ++s->state;
av_packet_unref(pkt);
return AVERROR(EAGAIN);
}
if (amount) {
ret = av_packet_make_writable(pkt);
if (ret < 0) {
av_packet_unref(pkt);
return ret;
}
}
for (i = 0; i < pkt->size; i++) {
s->state += pkt->data[i] + 1;
if (amount && s->state % amount == 0)
pkt->data[i] = s->state;
}
s->var_values[VAR_STATE] = s->state;
return 0;
}
static void noise_close(AVBSFContext *bsf)
{
NoiseContext *s = bsf->priv_data;
av_expr_free(s->amount_pexpr);
av_expr_free(s->drop_pexpr);
s->amount_pexpr = s->drop_pexpr = NULL;
}
#define OFFSET(x) offsetof(NoiseContext, x)
#define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_BSF_PARAM)
static const AVOption options[] = {
{ "amount", NULL, OFFSET(amount_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, FLAGS },
{ "drop", NULL, OFFSET(drop_str), AV_OPT_TYPE_STRING, { .str = NULL }, 0, 0, FLAGS },
{ "dropamount", NULL, OFFSET(dropamount), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
{ NULL },
};
static const AVClass noise_class = {
.class_name = "noise",
.item_name = av_default_item_name,
.option = options,
.version = LIBAVUTIL_VERSION_INT,
};
const FFBitStreamFilter ff_noise_bsf = {
.p.name = "noise",
.p.priv_class = &noise_class,
.priv_data_size = sizeof(NoiseContext),
.init = noise_init,
.close = noise_close,
.filter = noise,
};
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