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 #include "config_components.h"
32 #if HAVE_GSM_H
33 #include <gsm.h>
34 #else
35 #include <gsm/gsm.h>
36 #endif
37
38 #include "libavutil/channel_layout.h"
39 #include "libavutil/common.h"
40
41 #include "avcodec.h"
42 #include "codec_internal.h"
43 #include "encode.h"
44 #include "gsm.h"
45
libgsm_encode_close(AVCodecContext *avctx)46 static av_cold int libgsm_encode_close(AVCodecContext *avctx) {
47 gsm_destroy(avctx->priv_data);
48 avctx->priv_data = NULL;
49 return 0;
50 }
51
libgsm_encode_init(AVCodecContext *avctx)52 static av_cold int libgsm_encode_init(AVCodecContext *avctx) {
53 if (avctx->sample_rate != 8000) {
54 av_log(avctx, AV_LOG_ERROR, "Sample rate 8000Hz required for GSM, got %dHz\n",
55 avctx->sample_rate);
56 if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
57 return -1;
58 }
59 if (avctx->bit_rate != 13000 /* Official */ &&
60 avctx->bit_rate != 13200 /* Very common */ &&
61 avctx->bit_rate != 0 /* Unknown; a.o. mov does not set bitrate when decoding */ ) {
62 av_log(avctx, AV_LOG_ERROR, "Bitrate 13000bps required for GSM, got %"PRId64"bps\n",
63 avctx->bit_rate);
64 if (avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL)
65 return -1;
66 }
67
68 avctx->priv_data = gsm_create();
69 if (!avctx->priv_data)
70 goto error;
71
72 switch(avctx->codec_id) {
73 case AV_CODEC_ID_GSM:
74 avctx->frame_size = GSM_FRAME_SIZE;
75 avctx->block_align = GSM_BLOCK_SIZE;
76 break;
77 case AV_CODEC_ID_GSM_MS: {
78 int one = 1;
79 gsm_option(avctx->priv_data, GSM_OPT_WAV49, &one);
80 avctx->frame_size = 2*GSM_FRAME_SIZE;
81 avctx->block_align = GSM_MS_BLOCK_SIZE;
82 }
83 }
84
85 return 0;
86 error:
87 libgsm_encode_close(avctx);
88 return -1;
89 }
90
libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)91 static int libgsm_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
92 const AVFrame *frame, int *got_packet_ptr)
93 {
94 int ret;
95 gsm_signal *samples = (gsm_signal *)frame->data[0];
96 struct gsm_state *state = avctx->priv_data;
97
98 if ((ret = ff_get_encode_buffer(avctx, avpkt, avctx->block_align, 0)) < 0)
99 return ret;
100
101 switch(avctx->codec_id) {
102 case AV_CODEC_ID_GSM:
103 gsm_encode(state, samples, avpkt->data);
104 break;
105 case AV_CODEC_ID_GSM_MS:
106 gsm_encode(state, samples, avpkt->data);
107 gsm_encode(state, samples + GSM_FRAME_SIZE, avpkt->data + 32);
108 }
109
110 *got_packet_ptr = 1;
111 return 0;
112 }
113
114 static const FFCodecDefault libgsm_defaults[] = {
115 { "b", "13000" },
116 { NULL },
117 };
118
119 #if CONFIG_LIBGSM_ENCODER
120 const FFCodec ff_libgsm_encoder = {
121 .p.name = "libgsm",
122 .p.long_name = NULL_IF_CONFIG_SMALL("libgsm GSM"),
123 .p.type = AVMEDIA_TYPE_AUDIO,
124 .p.id = AV_CODEC_ID_GSM,
125 .p.capabilities = AV_CODEC_CAP_DR1,
126 .init = libgsm_encode_init,
127 FF_CODEC_ENCODE_CB(libgsm_encode_frame),
128 .close = libgsm_encode_close,
129 .defaults = libgsm_defaults,
130 #if FF_API_OLD_CHANNEL_LAYOUT
131 .p.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
132 #endif
133 .p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_MONO, { 0 } },
134 .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
135 AV_SAMPLE_FMT_NONE },
136 .p.wrapper_name = "libgsm",
137 };
138 #endif
139 #if CONFIG_LIBGSM_MS_ENCODER
140 const FFCodec ff_libgsm_ms_encoder = {
141 .p.name = "libgsm_ms",
142 .p.long_name = NULL_IF_CONFIG_SMALL("libgsm GSM Microsoft variant"),
143 .p.type = AVMEDIA_TYPE_AUDIO,
144 .p.id = AV_CODEC_ID_GSM_MS,
145 .p.capabilities = AV_CODEC_CAP_DR1,
146 .init = libgsm_encode_init,
147 FF_CODEC_ENCODE_CB(libgsm_encode_frame),
148 .close = libgsm_encode_close,
149 .defaults = libgsm_defaults,
150 #if FF_API_OLD_CHANNEL_LAYOUT
151 .p.channel_layouts = (const uint64_t[]) { AV_CH_LAYOUT_MONO, 0 },
152 #endif
153 .p.ch_layouts = (const AVChannelLayout[]) { AV_CHANNEL_LAYOUT_MONO, { 0 } },
154 .p.sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
155 AV_SAMPLE_FMT_NONE },
156 .p.wrapper_name = "libgsm",
157 };
158 #endif
159