blob: cd56995183bdddf92a54874f1b2f79af5163c2cb
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 "libavutil/channel_layout.h" |
28 | #include "avcodec.h" |
29 | #include "get_bits.h" |
30 | #include "internal.h" |
31 | #include "msgsmdec.h" |
32 | |
33 | #include "gsmdec_template.c" |
34 | |
35 | static av_cold int gsm_init(AVCodecContext *avctx) |
36 | { |
37 | avctx->channels = 1; |
38 | avctx->channel_layout = AV_CH_LAYOUT_MONO; |
39 | if (!avctx->sample_rate) |
40 | avctx->sample_rate = 8000; |
41 | avctx->sample_fmt = AV_SAMPLE_FMT_S16; |
42 | |
43 | switch (avctx->codec_id) { |
44 | case AV_CODEC_ID_GSM: |
45 | avctx->frame_size = GSM_FRAME_SIZE; |
46 | avctx->block_align = GSM_BLOCK_SIZE; |
47 | break; |
48 | case AV_CODEC_ID_GSM_MS: |
49 | avctx->frame_size = 2 * GSM_FRAME_SIZE; |
50 | if (!avctx->block_align) |
51 | avctx->block_align = GSM_MS_BLOCK_SIZE; |
52 | else |
53 | if (avctx->block_align < MSN_MIN_BLOCK_SIZE || |
54 | avctx->block_align > GSM_MS_BLOCK_SIZE || |
55 | (avctx->block_align - MSN_MIN_BLOCK_SIZE) % 3) { |
56 | av_log(avctx, AV_LOG_ERROR, "Invalid block alignment %d\n", |
57 | avctx->block_align); |
58 | return AVERROR_INVALIDDATA; |
59 | } |
60 | } |
61 | |
62 | return 0; |
63 | } |
64 | |
65 | static int gsm_decode_frame(AVCodecContext *avctx, void *data, |
66 | int *got_frame_ptr, AVPacket *avpkt) |
67 | { |
68 | AVFrame *frame = data; |
69 | int res; |
70 | GetBitContext gb; |
71 | const uint8_t *buf = avpkt->data; |
72 | int buf_size = avpkt->size; |
73 | int16_t *samples; |
74 | |
75 | if (buf_size < avctx->block_align) { |
76 | av_log(avctx, AV_LOG_ERROR, "Packet is too small\n"); |
77 | return AVERROR_INVALIDDATA; |
78 | } |
79 | |
80 | /* get output buffer */ |
81 | frame->nb_samples = avctx->frame_size; |
82 | if ((res = ff_get_buffer(avctx, frame, 0)) < 0) |
83 | return res; |
84 | samples = (int16_t *)frame->data[0]; |
85 | |
86 | switch (avctx->codec_id) { |
87 | case AV_CODEC_ID_GSM: |
88 | init_get_bits(&gb, buf, buf_size * 8); |
89 | if (get_bits(&gb, 4) != 0xd) |
90 | av_log(avctx, AV_LOG_WARNING, "Missing GSM magic!\n"); |
91 | res = gsm_decode_block(avctx, samples, &gb, GSM_13000); |
92 | if (res < 0) |
93 | return res; |
94 | break; |
95 | case AV_CODEC_ID_GSM_MS: |
96 | res = ff_msgsm_decode_block(avctx, samples, buf, |
97 | (GSM_MS_BLOCK_SIZE - avctx->block_align) / 3); |
98 | if (res < 0) |
99 | return res; |
100 | } |
101 | |
102 | *got_frame_ptr = 1; |
103 | |
104 | return avctx->block_align; |
105 | } |
106 | |
107 | static void gsm_flush(AVCodecContext *avctx) |
108 | { |
109 | GSMContext *s = avctx->priv_data; |
110 | memset(s, 0, sizeof(*s)); |
111 | } |
112 | |
113 | #if CONFIG_GSM_DECODER |
114 | AVCodec ff_gsm_decoder = { |
115 | .name = "gsm", |
116 | .long_name = NULL_IF_CONFIG_SMALL("GSM"), |
117 | .type = AVMEDIA_TYPE_AUDIO, |
118 | .id = AV_CODEC_ID_GSM, |
119 | .priv_data_size = sizeof(GSMContext), |
120 | .init = gsm_init, |
121 | .decode = gsm_decode_frame, |
122 | .flush = gsm_flush, |
123 | .capabilities = AV_CODEC_CAP_DR1, |
124 | }; |
125 | #endif |
126 | #if CONFIG_GSM_MS_DECODER |
127 | AVCodec ff_gsm_ms_decoder = { |
128 | .name = "gsm_ms", |
129 | .long_name = NULL_IF_CONFIG_SMALL("GSM Microsoft variant"), |
130 | .type = AVMEDIA_TYPE_AUDIO, |
131 | .id = AV_CODEC_ID_GSM_MS, |
132 | .priv_data_size = sizeof(GSMContext), |
133 | .init = gsm_init, |
134 | .decode = gsm_decode_frame, |
135 | .flush = gsm_flush, |
136 | .capabilities = AV_CODEC_CAP_DR1, |
137 | }; |
138 | #endif |
139 |