blob: 69ce439ec1db88316288e27b7704b6360ce54158
1 | /* |
2 | * Interface to libgsm for GSM encoding |
3 | * Copyright (c) 2005 Alban Bedel <albeu@free.fr> |
4 | * Copyright (c) 2006, 2007 Michel Bardiaux <mbardiaux@mediaxim.be> |
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 | /** |
24 | * @file |
25 | * Interface to libgsm for GSM encoding |
26 | */ |
27 | |
28 | // The idiosyncrasies of GSM-in-WAV are explained at http://kbs.cs.tu-berlin.de/~jutta/toast.html |
29 | |
30 | #include "config.h" |
31 | #if HAVE_GSM_H |
32 | #include <gsm.h> |
33 | #else |
34 | #include <gsm/gsm.h> |
35 | #endif |
36 | |
37 | #include "libavutil/common.h" |
38 | |
39 | #include "avcodec.h" |
40 | #include "internal.h" |
41 | #include "gsm.h" |
42 | |
43 | static av_cold int libgsm_encode_close(AVCodecContext *avctx) { |
44 | gsm_destroy(avctx->priv_data); |
45 | avctx->priv_data = NULL; |
46 | return 0; |
47 | } |
48 | |
49 | static av_cold int libgsm_encode_init(AVCodecContext *avctx) { |
50 | if (avctx->channels > 1) { |
51 | av_log(avctx, AV_LOG_ERROR, "Mono required for GSM, got %d channels\n", |
52 | avctx->channels); |
53 | return -1; |
54 | } |
55 | |
56 | if (avctx->sample_rate != 8000) { |
57 | av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n", |
58 | avctx->sample_rate); |
59 | if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) |
60 | return -1; |
61 | } |
62 | if (avctx->bit_rate != 13000 /* Official */ && |
63 | avctx->bit_rate != 13200 /* Very common */ && |
64 | avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) { |
65 | av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %"PRId64"bps\n", |
66 | (int64_t)avctx->bit_rate); |
67 | if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) |
68 | return -1; |
69 | } |
70 | |
71 | avctx->priv_data = gsm_create(); |
72 | if (!avctx->priv_data) |
73 | goto error; |
74 | |
75 | switch(avctx->codec_id) { |
76 | case AV_CODEC_ID_GSM: |
77 | avctx->frame_size = GSM_FRAME_SIZE; |
78 | avctx->block_align = GSM_BLOCK_SIZE; |
79 | break; |
80 | case AV_CODEC_ID_GSM_MS: { |
81 | int one = 1; |
82 | gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one); |
83 | avctx->frame_size = 2*GSM_FRAME_SIZE; |
84 | avctx->block_align = GSM_MS_BLOCK_SIZE; |
85 | } |
86 | } |
87 | |
88 | return 0; |
89 | error: |
90 | libgsm_encode_close(avctx); |
91 | return -1; |
92 | } |
93 | |
94 | static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, |
95 | const AVFrame *frame, int *got_packet_ptr) |
96 | { |
97 | int ret; |
98 | gsm_signal *samples = (gsm_signal *)frame->data[0]; |
99 | struct gsm_state *state = avctx->priv_data; |
100 | |
101 | if ((ret = ff_alloc_packet2(avctx, avpkt, avctx->block_align, 0)) < 0) |
102 | return ret; |
103 | |
104 | switch(avctx->codec_id) { |
105 | case AV_CODEC_ID_GSM: |
106 | gsm_encode(state, samples, avpkt->data); |
107 | break; |
108 | case AV_CODEC_ID_GSM_MS: |
109 | gsm_encode(state, samples, avpkt->data); |
110 | gsm_encode(state, samples + GSM_FRAME_SIZE, avpkt->data + 32); |
111 | } |
112 | |
113 | *got_packet_ptr = 1; |
114 | return 0; |
115 | } |
116 | |
117 | |
118 | #if CONFIG_LIBGSM_ENCODER |
119 | AVCodec ff_libgsm_encoder = { |
120 | .name = "libgsm", |
121 | .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"), |
122 | .type = AVMEDIA_TYPE_AUDIO, |
123 | .id = AV_CODEC_ID_GSM, |
124 | .init = libgsm_encode_init, |
125 | .encode2 = libgsm_encode_frame, |
126 | .close = libgsm_encode_close, |
127 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
128 | AV_SAMPLE_FMT_NONE }, |
129 | }; |
130 | #endif |
131 | #if CONFIG_LIBGSM_MS_ENCODER |
132 | AVCodec ff_libgsm_ms_encoder = { |
133 | .name = "libgsm_ms", |
134 | .long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"), |
135 | .type = AVMEDIA_TYPE_AUDIO, |
136 | .id = AV_CODEC_ID_GSM_MS, |
137 | .init = libgsm_encode_init, |
138 | .encode2 = libgsm_encode_frame, |
139 | .close = libgsm_encode_close, |
140 | .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16, |
141 | AV_SAMPLE_FMT_NONE }, |
142 | }; |
143 | #endif |
144 |