FFmpeg: libavcodec/sbc_parser.c Source File

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sbc_parser.c
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1/*
2 * SBC parser
3 *
4 * Copyright (C) 2017 Aurelien Jacobs <aurel@gnuage.org>
5 *
6 * This file is part of FFmpeg.
7 *
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
12 *
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
17 *
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23#include "sbc.h"
24#include "parser.h"
25#include "parser_internal.h"
26
33
35 const uint8_t *data, size_t len)
36{
37 static const int sample_rates[4] = { 16000, 32000, 44100, 48000 };
38 int sr, blocks, mode, subbands, bitpool, channels, joint;
39 int length;
40
41 if (len < 3)
42 return -1;
43
44 if (data[0] == MSBC_SYNCWORD && data[1] == 0 && data[2] == 0) {
47 avctx->ch_layout.nb_channels = 1;
48 avctx->sample_rate = 16000;
49 avctx->frame_size = 120;
50 s->duration = avctx->frame_size;
51 return 57;
52 }
53
54 if (data[0] != SBC_SYNCWORD)
55 return -2;
56
57 sr = (data[1] >> 6) & 0x03;
58 blocks = (((data[1] >> 4) & 0x03) + 1) << 2;
59 mode = (data[1] >> 2) & 0x03;
60 subbands = (((data[1] >> 0) & 0x01) + 1) << 2;
61 bitpool = data[2];
62
63 channels = mode == SBC_MODE_MONO ? 1 : 2;
64 joint = mode == SBC_MODE_JOINT_STEREO;
65
66 length = 4 + (subbands * channels) / 2
67 + ((((mode == SBC_MODE_DUAL_CHANNEL) + 1) * blocks * bitpool
68 + (joint * subbands)) + 7) / 8;
69
73 avctx->sample_rate = sample_rates[sr];
74 avctx->frame_size = subbands * blocks;
75 s->duration = avctx->frame_size;
76 return length;
77}
78
80 const uint8_t **poutbuf, int *poutbuf_size,
81 const uint8_t *buf, int buf_size)
82{
83 SBCParseContext *pc = s->priv_data;
84 int next;
85
86 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
87 next = buf_size;
88 } else {
89 if (pc->header_size) {
90 memcpy(pc->header + pc->header_size, buf,
91 sizeof(pc->header) - pc->header_size);
92 next = sbc_parse_header(s, avctx, pc->header, sizeof(pc->header))
93 - pc->buffered_size;
94 pc->header_size = 0;
95 } else {
96 next = sbc_parse_header(s, avctx, buf, buf_size);
97 if (next >= buf_size)
98 next = -1;
99 }
100
101 if (next < 0) {
102 pc->header_size = FFMIN(sizeof(pc->header), buf_size);
103 memcpy(pc->header, buf, pc->header_size);
104 pc->buffered_size = buf_size;
105 next = END_NOT_FOUND;
106 }
107
108 if (ff_combine_frame(&pc->pc, next, &buf, &buf_size) < 0) {
109 *poutbuf = NULL;
110 *poutbuf_size = 0;
111 return buf_size;
112 }
113 }
114
115 *poutbuf = buf;
116 *poutbuf_size = buf_size;
117 return next;
118}
119
122 .priv_data_size = sizeof(SBCParseContext),
123 .parse = sbc_parse,
125};
channels
Definition aptx.h:31
subbands
Definition aptx.h:37
static int parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition apv_parser.c:92
static av_cold void close(AVCodecParserContext *s)
Definition apv_parser.c:197
#define PARSER_FLAG_COMPLETE_FRAMES
Definition avcodec.h:2662
s
#define s(width, name)
Definition cbs_vp9.c:198
#define NULL
Definition coverity.c:32
static const int sample_rates[]
Definition dcaenc.h:34
@ AV_CODEC_ID_SBC
Definition codec_id.h:540
void av_channel_layout_uninit(AVChannelLayout *channel_layout)
Free any allocated data in the channel layout and reset the channel count to 0.
@ AV_CHANNEL_ORDER_UNSPEC
Only the channel count is specified, without any further information about the channel order.
#define FFMIN(a, b)
Definition macros.h:49
const char data[16]
Definition mxf.c:149
av_cold void ff_parse_close(AVCodecParserContext *s)
Definition parser.c:300
int ff_combine_frame(ParseContext *pc, int next, const uint8_t **buf, int *buf_size)
Combine the (truncated) bitstream to a complete frame.
Definition parser.c:213
#define END_NOT_FOUND
Definition parser.h:40
#define PARSER_CODEC_LIST(...)
const FFCodecParser ff_sbc_parser
Definition sbc_parser.c:120
SBC common definitions for the encoder and decoder.
#define SBC_MODE_JOINT_STEREO
Definition sbc.h:59
#define SBC_SYNCWORD
Definition sbc.h:70
#define MSBC_SYNCWORD
Definition sbc.h:71
#define SBC_MODE_DUAL_CHANNEL
Definition sbc.h:57
#define SBC_MODE_MONO
Definition sbc.h:56
static int sbc_parse(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t **poutbuf, int *poutbuf_size, const uint8_t *buf, int buf_size)
Definition sbc_parser.c:79
static int sbc_parse_header(AVCodecParserContext *s, AVCodecContext *avctx, const uint8_t *data, size_t len)
Definition sbc_parser.c:34
enum AVChannelOrder order
Channel order used in this layout.
int nb_channels
Number of channels in this layout.
main external API structure.
Definition avcodec.h:443
AVChannelLayout ch_layout
Audio channel layout.
Definition avcodec.h:1055
int sample_rate
samples per second
Definition avcodec.h:1040
int frame_size
Number of samples per channel in an audio frame.
Definition avcodec.h:1068
ParseContext pc
Definition sbc_parser.c:28
int buffered_size
Definition sbc_parser.c:31
uint8_t header[3]
Definition sbc_parser.c:29
Definition swscale.c:71
int len
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