1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
|
/*
* gsm 06.10 decoder
* Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
*
* 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
*/
/**
* @file
* GSM decoder
*/
#include "config_components.h"
#include "libavutil/channel_layout.h"
#include "avcodec.h"
#include "codec_internal.h"
#include "decode.h"
#include "get_bits.h"
#include "msgsmdec.h"
#include "gsmdec_template.c"
static av_cold int gsm_init(AVCodecContext *avctx)
{
av_channel_layout_uninit(&avctx->ch_layout);
avctx->ch_layout = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
if (!avctx->sample_rate)
avctx->sample_rate = 8000;
avctx->sample_fmt = AV_SAMPLE_FMT_S16;
switch (avctx->codec_id) {
case AV_CODEC_ID_GSM:
avctx->frame_size = GSM_FRAME_SIZE;
avctx->block_align = GSM_BLOCK_SIZE;
break;
case AV_CODEC_ID_GSM_MS:
avctx->frame_size = 2 * GSM_FRAME_SIZE;
if (!avctx->block_align)
avctx->block_align = GSM_MS_BLOCK_SIZE;
else
if (avctx->block_align < MSN_MIN_BLOCK_SIZE ||
avctx->block_align > GSM_MS_BLOCK_SIZE ||
(avctx->block_align - MSN_MIN_BLOCK_SIZE) % 3) {
av_log(avctx, AV_LOG_ERROR, "Invalid block alignment %d\n",
avctx->block_align);
return AVERROR_INVALIDDATA;
}
}
return 0;
}
static int gsm_decode_frame(AVCodecContext *avctx, AVFrame *frame,
int *got_frame_ptr, AVPacket *avpkt)
{
int res;
GetBitContext gb;
const uint8_t *buf = avpkt->data;
int buf_size = avpkt->size;
int16_t *samples;
if (buf_size < avctx->block_align) {
av_log(avctx, AV_LOG_ERROR, "Packet is too small\n");
return AVERROR_INVALIDDATA;
}
/* get output buffer */
frame->nb_samples = avctx->frame_size;
if ((res = ff_get_buffer(avctx, frame, 0)) < 0)
return res;
samples = (int16_t *)frame->data[0];
switch (avctx->codec_id) {
case AV_CODEC_ID_GSM:
init_get_bits(&gb, buf, buf_size * 8);
if (get_bits(&gb, 4) != 0xd)
av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n");
res = gsm_decode_block(avctx, samples, &gb, GSM_13000);
if (res < 0)
return res;
break;
case AV_CODEC_ID_GSM_MS:
res = ff_msgsm_decode_block(avctx, samples, buf,
(GSM_MS_BLOCK_SIZE - avctx->block_align) / 3);
if (res < 0)
return res;
}
*got_frame_ptr = 1;
return avctx->block_align;
}
static void gsm_flush(AVCodecContext *avctx)
{
GSMContext *s = avctx->priv_data;
memset(s, 0, sizeof(*s));
}
#if CONFIG_GSM_DECODER
const FFCodec ff_gsm_decoder = {
.p.name = "gsm",
CODEC_LONG_NAME("GSM"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_GSM,
.priv_data_size = sizeof(GSMContext),
.init = gsm_init,
FF_CODEC_DECODE_CB(gsm_decode_frame),
.flush = gsm_flush,
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
};
#endif
#if CONFIG_GSM_MS_DECODER
const FFCodec ff_gsm_ms_decoder = {
.p.name = "gsm_ms",
CODEC_LONG_NAME("GSM Microsoft variant"),
.p.type = AVMEDIA_TYPE_AUDIO,
.p.id = AV_CODEC_ID_GSM_MS,
.priv_data_size = sizeof(GSMContext),
.init = gsm_init,
FF_CODEC_DECODE_CB(gsm_decode_frame),
.flush = gsm_flush,
.p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
};
#endif
|
