1 /*
2 * RFC 3389 comfort noise generator
3 * Copyright (c) 2012 Martin Storsjo
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22 #include <math.h>
23
28
35
37 {
42 return 0;
43 }
44
46 {
48 int ret;
49
53 }
54
58 return ret;
64 }
65
66 return 0;
67 }
68
71 {
73 int ret, i;
74 double energy = 0;
75 int qdbov;
76 int16_t *samples = (int16_t*) frame->
data[0];
77
80 return ret;
81 }
82
85 energy += samples[i] * samples[i];
86 }
88 if (energy > 0) {
89 double dbov = 10 * log10(energy / 1081109975);
90 qdbov = av_clip_uintp2(-floor(dbov), 7);
91 } else {
92 qdbov = 127;
93 }
95 avpkt->
data[0] = qdbov;
96 for (i = 0; i < p->
order; i++)
98
99 *got_packet_ptr = 1;
101
102 return 0;
103 }
104
106 .
name =
"comfortnoise",
116 };
This structure describes decoded (raw) audio or video data.
static av_cold int init(AVCodecContext *avctx)
int ff_lpc_calc_ref_coefs(LPCContext *s, const int32_t *samples, int order, double *ref)
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
const char * name
Name of the codec implementation.
av_cold void ff_lpc_end(LPCContext *s)
Uninitialize LPCContext.
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
AVCodec ff_comfortnoise_encoder
static av_cold int cng_encode_close(AVCodecContext *avctx)
int frame_size
Number of samples per channel in an audio frame.
Libavcodec external API header.
AVSampleFormat
Audio sample formats.
main external API structure.
Levinson-Durbin recursion.
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
av_cold int ff_lpc_init(LPCContext *s, int blocksize, int max_order, enum FFLPCType lpc_type)
Initialize LPCContext.
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
static int cng_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)
common internal api header.
common internal and external API header
int channels
number of audio channels
static enum AVSampleFormat sample_fmts[]
static av_cold int cng_encode_init(AVCodecContext *avctx)
#define av_malloc_array(a, b)
This structure stores compressed data.
int nb_samples
number of audio samples (per channel) described by this frame