1 /*
2  * iLBC decoder/encoder stub
3  * Copyright (c) 2012 Martin Storsjo
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 #include <ilbc.h>
23 
24 #include "libavutil/channel_layout.h"
25 #include "libavutil/common.h"
26 #include "libavutil/opt.h"
27 #include "avcodec.h"
28 #include "codec_internal.h"
29 #include "encode.h"
30 #include "internal.h"
31 
32 #ifndef LIBILBC_VERSION_MAJOR
33 #define LIBILBC_VERSION_MAJOR 2
34 #endif
35 
get_mode(AVCodecContext *avctx)36 static int get_mode(AVCodecContext *avctx)
37 {
38     if (avctx->block_align == 38)
39         return 20;
40     else if (avctx->block_align == 50)
41         return 30;
42     else if (avctx->bit_rate > 0)
43         return avctx->bit_rate <= 14000 ? 30 : 20;
44     else
45         return -1;
46 }
47 
48 typedef struct ILBCDecContext {
49     const AVClass *class;
50 #if LIBILBC_VERSION_MAJOR < 3
51     iLBC_Dec_Inst_t decoder;
52 #else
53     IlbcDecoder decoder;
54 #endif
55     int enhance;
56 } ILBCDecContext;
57 
58 static const AVOption ilbc_dec_options[] = {
59     { "enhance", "Enhance the decoded audio (adds delay)", offsetof(ILBCDecContext, enhance), AV_OPT_TYPE_INT, { .i64 = 0 }, 0, 1, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_DECODING_PARAM },
60     { NULL }
61 };
62 
63 static const AVClass ilbc_dec_class = {
64     .class_name = "libilbc",
65     .item_name  = av_default_item_name,
66     .option     = ilbc_dec_options,
67     .version    = LIBAVUTIL_VERSION_INT,
68 };
69 
ilbc_decode_init(AVCodecContext *avctx)70 static av_cold int ilbc_decode_init(AVCodecContext *avctx)
71 {
72     ILBCDecContext *s  = avctx->priv_data;
73     int mode;
74 
75     if ((mode = get_mode(avctx)) < 0) {
76         av_log(avctx, AV_LOG_ERROR, "iLBC frame mode not indicated\n");
77         return AVERROR(EINVAL);
78     }
79 
80     WebRtcIlbcfix_InitDecode(&s->decoder, mode, s->enhance);
81 
82     av_channel_layout_uninit(&avctx->ch_layout);
83     avctx->ch_layout      = (AVChannelLayout)AV_CHANNEL_LAYOUT_MONO;
84     avctx->sample_rate    = 8000;
85     avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
86 
87     return 0;
88 }
89 
ilbc_decode_frame(AVCodecContext *avctx, AVFrame *frame, int *got_frame_ptr, AVPacket *avpkt)90 static int ilbc_decode_frame(AVCodecContext *avctx, AVFrame *frame,
91                              int *got_frame_ptr, AVPacket *avpkt)
92 {
93     const uint8_t *buf = avpkt->data;
94     int buf_size       = avpkt->size;
95     ILBCDecContext *s  = avctx->priv_data;
96     int ret;
97 
98     if (s->decoder.no_of_bytes > buf_size) {
99 #if LIBILBC_VERSION_MAJOR < 3
100         av_log(avctx, AV_LOG_ERROR, "iLBC frame too short (%u, should be %u)\n",
101 #else
102         av_log(avctx, AV_LOG_ERROR, "iLBC frame too short (%u, should be "
103                                     "%"SIZE_SPECIFIER")\n",
104 #endif
105                buf_size, s->decoder.no_of_bytes);
106         return AVERROR_INVALIDDATA;
107     }
108 
109     frame->nb_samples = s->decoder.blockl;
110     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
111         return ret;
112 
113     WebRtcIlbcfix_DecodeImpl((int16_t *) frame->data[0], (const uint16_t *) buf, &s->decoder, 1);
114 
115     *got_frame_ptr = 1;
116 
117     return s->decoder.no_of_bytes;
118 }
119 
120 const FFCodec ff_libilbc_decoder = {
121     .p.name         = "libilbc",
122     .p.long_name    = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),
123     .p.type         = AVMEDIA_TYPE_AUDIO,
124     .p.id           = AV_CODEC_ID_ILBC,
125     .priv_data_size = sizeof(ILBCDecContext),
126     .init           = ilbc_decode_init,
127     FF_CODEC_DECODE_CB(ilbc_decode_frame),
128     .p.capabilities = AV_CODEC_CAP_DR1 | AV_CODEC_CAP_CHANNEL_CONF,
129     .p.priv_class   = &ilbc_dec_class,
130 };
131 
132 typedef struct ILBCEncContext {
133     const AVClass *class;
134 #if LIBILBC_VERSION_MAJOR < 3
135     iLBC_Enc_Inst_t encoder;
136 #else
137     IlbcEncoder encoder;
138 #endif
139     int mode;
140 } ILBCEncContext;
141 
142 static const AVOption ilbc_enc_options[] = {
143     { "mode", "iLBC mode (20 or 30 ms frames)", offsetof(ILBCEncContext, mode), AV_OPT_TYPE_INT, { .i64 = 20 }, 20, 30, AV_OPT_FLAG_AUDIO_PARAM | AV_OPT_FLAG_ENCODING_PARAM },
144     { NULL }
145 };
146 
147 static const AVClass ilbc_enc_class = {
148     .class_name = "libilbc",
149     .item_name  = av_default_item_name,
150     .option     = ilbc_enc_options,
151     .version    = LIBAVUTIL_VERSION_INT,
152 };
153 
ilbc_encode_init(AVCodecContext *avctx)154 static av_cold int ilbc_encode_init(AVCodecContext *avctx)
155 {
156     ILBCEncContext *s = avctx->priv_data;
157     int mode;
158 
159     if (avctx->sample_rate != 8000) {
160         av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");
161         return AVERROR(EINVAL);
162     }
163 
164     if (avctx->ch_layout.nb_channels != 1) {
165         av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
166         return AVERROR(EINVAL);
167     }
168 
169     if ((mode = get_mode(avctx)) > 0)
170         s->mode = mode;
171     else
172         s->mode = s->mode != 30 ? 20 : 30;
173     WebRtcIlbcfix_InitEncode(&s->encoder, s->mode);
174 
175     avctx->block_align = s->encoder.no_of_bytes;
176     avctx->frame_size  = s->encoder.blockl;
177 
178     return 0;
179 }
180 
ilbc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt, const AVFrame *frame, int *got_packet_ptr)181 static int ilbc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
182                              const AVFrame *frame, int *got_packet_ptr)
183 {
184     ILBCEncContext *s = avctx->priv_data;
185     int ret;
186 
187     if ((ret = ff_alloc_packet(avctx, avpkt, 50)) < 0)
188         return ret;
189 
190     WebRtcIlbcfix_EncodeImpl((uint16_t *) avpkt->data, (const int16_t *) frame->data[0], &s->encoder);
191 
192     avpkt->size     = s->encoder.no_of_bytes;
193     *got_packet_ptr = 1;
194     return 0;
195 }
196 
197 static const FFCodecDefault ilbc_encode_defaults[] = {
198     { "b", "0" },
199     { NULL }
200 };
201 
202 const FFCodec ff_libilbc_encoder = {
203     .p.name         = "libilbc",
204     .p.long_name    = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),
205     .p.type         = AVMEDIA_TYPE_AUDIO,
206     .p.id           = AV_CODEC_ID_ILBC,
207     .priv_data_size = sizeof(ILBCEncContext),
208     .init           = ilbc_encode_init,
209     FF_CODEC_ENCODE_CB(ilbc_encode_frame),
210     .p.sample_fmts  = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
211                                                      AV_SAMPLE_FMT_NONE },
212     .defaults       = ilbc_encode_defaults,
213     .p.priv_class   = &ilbc_enc_class,
214     .p.wrapper_name = "libbilbc",
215 };
216