b316810c4d665a6f15f7198e92acc980f75f7fe5
[libav.git] / libavcodec / gsmdec.c
1 /*
2 * gsm 06.10 decoder
3 * Copyright (c) 2010 Reimar Döffinger <Reimar.Doeffinger@gmx.de>
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 /**
23 * @file
24 * GSM decoder
25 */
26
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "msgsmdec.h"
30
31 #include "gsmdec_template.c"
32
33 static av_cold int gsm_init(AVCodecContext *avctx)
34 {
35 avctx->channels = 1;
36 if (!avctx->sample_rate)
37 avctx->sample_rate = 8000;
38 avctx->sample_fmt = AV_SAMPLE_FMT_S16;
39
40 switch (avctx->codec_id) {
41 case CODEC_ID_GSM:
42 avctx->frame_size = GSM_FRAME_SIZE;
43 avctx->block_align = GSM_BLOCK_SIZE;
44 break;
45 case CODEC_ID_GSM_MS:
46 avctx->frame_size = 2 * GSM_FRAME_SIZE;
47 avctx->block_align = GSM_MS_BLOCK_SIZE;
48 }
49
50 return 0;
51 }
52
53 static int gsm_decode_frame(AVCodecContext *avctx, void *data,
54 int *data_size, AVPacket *avpkt)
55 {
56 int res;
57 GetBitContext gb;
58 const uint8_t *buf = avpkt->data;
59 int buf_size = avpkt->size;
60 int16_t *samples = data;
61 int frame_bytes = 2 * avctx->frame_size;
62
63 if (*data_size < frame_bytes)
64 return -1;
65 *data_size = 0;
66 if(buf_size < avctx->block_align)
67 return AVERROR_INVALIDDATA;
68
69 switch (avctx->codec_id) {
70 case CODEC_ID_GSM:
71 init_get_bits(&gb, buf, buf_size * 8);
72 if (get_bits(&gb, 4) != 0xd)
73 av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n");
74 res = gsm_decode_block(avctx, samples, &gb);
75 if (res < 0)
76 return res;
77 break;
78 case CODEC_ID_GSM_MS:
79 res = ff_msgsm_decode_block(avctx, samples, buf);
80 if (res < 0)
81 return res;
82 }
83 *data_size = frame_bytes;
84 return avctx->block_align;
85 }
86
87 AVCodec gsm_decoder = {
88 "gsm",
89 AVMEDIA_TYPE_AUDIO,
90 CODEC_ID_GSM,
91 sizeof(GSMContext),
92 gsm_init,
93 NULL,
94 NULL,
95 gsm_decode_frame,
96 .long_name = NULL_IF_CONFIG_SMALL("GSM"),
97 };
98
99 AVCodec gsm_ms_decoder = {
100 "gsm_ms",
101 AVMEDIA_TYPE_AUDIO,
102 CODEC_ID_GSM_MS,
103 sizeof(GSMContext),
104 gsm_init,
105 NULL,
106 NULL,
107 gsm_decode_frame,
108 .long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"),
109 };