FFmpeg  4.4
noise_bsf.c
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1 /*
2  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg is free software; you can redistribute it and/or
7  * modify it under the terms of the GNU Lesser General Public
8  * License as published by the Free Software Foundation; either
9  * version 2.1 of the License, or (at your option) any later version.
10  *
11  * FFmpeg is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14  * Lesser General Public License for more details.
15  *
16  * You should have received a copy of the GNU Lesser General Public
17  * License along with FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <stdlib.h>
22 
23 #include "bsf.h"
24 #include "bsf_internal.h"
25 
26 #include "libavutil/log.h"
27 #include "libavutil/opt.h"
28 
29 typedef struct NoiseContext {
30  const AVClass *class;
31  int amount;
33  unsigned int state;
34 } NoiseContext;
35 
37 {
39  int amount = s->amount > 0 ? s->amount : (s->state % 10001 + 1);
40  int i, ret;
41 
42  if (amount <= 0)
43  return AVERROR(EINVAL);
44 
46  if (ret < 0)
47  return ret;
48 
49  if (s->dropamount > 0 && s->state % s->dropamount == 0) {
50  s->state++;
52  return AVERROR(EAGAIN);
53  }
54 
56  if (ret < 0) {
58  return ret;
59  }
60 
61  for (i = 0; i < pkt->size; i++) {
62  s->state += pkt->data[i] + 1;
63  if (s->state % amount == 0)
64  pkt->data[i] = s->state;
65  }
66 
67  return 0;
68 }
69 
70 #define OFFSET(x) offsetof(NoiseContext, x)
71 #define FLAGS (AV_OPT_FLAG_VIDEO_PARAM|AV_OPT_FLAG_AUDIO_PARAM|AV_OPT_FLAG_BSF_PARAM)
72 static const AVOption options[] = {
73  { "amount", NULL, OFFSET(amount), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
74  { "dropamount", NULL, OFFSET(dropamount), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, INT_MAX, FLAGS },
75  { NULL },
76 };
77 
78 static const AVClass noise_class = {
79  .class_name = "noise",
80  .item_name = av_default_item_name,
81  .option = options,
82  .version = LIBAVUTIL_VERSION_INT,
83 };
84 
86  .name = "noise",
87  .priv_data_size = sizeof(NoiseContext),
88  .priv_class = &noise_class,
89  .filter = noise,
90 };
int ff_bsf_get_packet_ref(AVBSFContext *ctx, AVPacket *pkt)
Called by bitstream filters to get packet for filtering.
Definition: bsf.c:253
#define s(width, name)
Definition: cbs_vp9.c:257
static av_always_inline void filter(int16_t *output, ptrdiff_t out_stride, const int16_t *low, ptrdiff_t low_stride, const int16_t *high, ptrdiff_t high_stride, int len, int clip)
Definition: cfhddsp.c:27
#define NULL
Definition: coverity.c:32
@ AV_OPT_TYPE_INT
Definition: opt.h:225
void av_packet_unref(AVPacket *pkt)
Wipe the packet.
Definition: avpacket.c:634
int av_packet_make_writable(AVPacket *pkt)
Create a writable reference for the data described by a given packet, avoiding data copy if possible.
Definition: avpacket.c:715
#define AVERROR(e)
Definition: error.h:43
const char * av_default_item_name(void *ptr)
Return the context name.
Definition: log.c:235
#define LIBAVUTIL_VERSION_INT
Definition: version.h:85
int i
Definition: input.c:407
const AVBitStreamFilter ff_noise_bsf
Definition: noise_bsf.c:85
static const AVOption options[]
Definition: noise_bsf.c:72
static int noise(AVBSFContext *ctx, AVPacket *pkt)
Definition: noise_bsf.c:36
static const AVClass noise_class
Definition: noise_bsf.c:78
#define FLAGS
Definition: noise_bsf.c:71
#define OFFSET(x)
Definition: noise_bsf.c:70
AVOptions.
The bitstream filter state.
Definition: bsf.h:49
const char * name
Definition: bsf.h:99
Describe the class of an AVClass context structure.
Definition: log.h:67
const char * class_name
The name of the class; usually it is the same name as the context structure type to which the AVClass...
Definition: log.h:72
void * priv_data
Format private data.
Definition: avformat.h:1260
AVOption.
Definition: opt.h:248
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
unsigned int state
Definition: noise_bsf.c:33
int dropamount
Definition: noise_bsf.c:32
AVPacket * pkt
Definition: movenc.c:59
AVFormatContext * ctx
Definition: movenc.c:48