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 "internal.h"
29
30static int get_mode(AVCodecContext *avctx)
31{
32    if (avctx->block_align == 38)
33        return 20;
34    else if (avctx->block_align == 50)
35        return 30;
36    else if (avctx->bit_rate > 0)
37        return avctx->bit_rate <= 14000 ? 30 : 20;
38    else
39        return -1;
40}
41
42typedef struct ILBCDecContext {
43    const AVClass *class;
44    iLBC_Dec_Inst_t decoder;
45    int enhance;
46} ILBCDecContext;
47
48static const AVOption ilbc_dec_options[] = {
49    { "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 },
50    { NULL }
51};
52
53static const AVClass ilbc_dec_class = {
54    .class_name = "libilbc",
55    .item_name  = av_default_item_name,
56    .option     = ilbc_dec_options,
57    .version    = LIBAVUTIL_VERSION_INT,
58};
59
60static av_cold int ilbc_decode_init(AVCodecContext *avctx)
61{
62    ILBCDecContext *s  = avctx->priv_data;
63    int mode;
64
65    if ((mode = get_mode(avctx)) < 0) {
66        av_log(avctx, AV_LOG_ERROR, "iLBC frame mode not indicated\n");
67        return AVERROR(EINVAL);
68    }
69
70    WebRtcIlbcfix_InitDecode(&s->decoder, mode, s->enhance);
71
72    avctx->channels       = 1;
73    avctx->channel_layout = AV_CH_LAYOUT_MONO;
74    avctx->sample_rate    = 8000;
75    avctx->sample_fmt     = AV_SAMPLE_FMT_S16;
76
77    return 0;
78}
79
80static int ilbc_decode_frame(AVCodecContext *avctx, void *data,
81                             int *got_frame_ptr, AVPacket *avpkt)
82{
83    const uint8_t *buf = avpkt->data;
84    int buf_size       = avpkt->size;
85    ILBCDecContext *s  = avctx->priv_data;
86    AVFrame *frame     = data;
87    int ret;
88
89    if (s->decoder.no_of_bytes > buf_size) {
90        av_log(avctx, AV_LOG_ERROR, "iLBC frame too short (%u, should be %u)\n",
91               buf_size, s->decoder.no_of_bytes);
92        return AVERROR_INVALIDDATA;
93    }
94
95    frame->nb_samples = s->decoder.blockl;
96    if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
97        return ret;
98
99    WebRtcIlbcfix_DecodeImpl((int16_t *) frame->data[0], (const uint16_t *) buf, &s->decoder, 1);
100
101    *got_frame_ptr = 1;
102
103    return s->decoder.no_of_bytes;
104}
105
106AVCodec ff_libilbc_decoder = {
107    .name           = "libilbc",
108    .long_name      = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),
109    .type           = AVMEDIA_TYPE_AUDIO,
110    .id             = AV_CODEC_ID_ILBC,
111    .priv_data_size = sizeof(ILBCDecContext),
112    .init           = ilbc_decode_init,
113    .decode         = ilbc_decode_frame,
114    .capabilities   = CODEC_CAP_DR1,
115    .priv_class     = &ilbc_dec_class,
116};
117
118typedef struct ILBCEncContext {
119    const AVClass *class;
120    iLBC_Enc_Inst_t encoder;
121    int mode;
122} ILBCEncContext;
123
124static const AVOption ilbc_enc_options[] = {
125    { "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 },
126    { NULL }
127};
128
129static const AVClass ilbc_enc_class = {
130    .class_name = "libilbc",
131    .item_name  = av_default_item_name,
132    .option     = ilbc_enc_options,
133    .version    = LIBAVUTIL_VERSION_INT,
134};
135
136static av_cold int ilbc_encode_init(AVCodecContext *avctx)
137{
138    ILBCEncContext *s = avctx->priv_data;
139    int mode;
140
141    if (avctx->sample_rate != 8000) {
142        av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");
143        return AVERROR(EINVAL);
144    }
145
146    if (avctx->channels != 1) {
147        av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
148        return AVERROR(EINVAL);
149    }
150
151    if ((mode = get_mode(avctx)) > 0)
152        s->mode = mode;
153    else
154        s->mode = s->mode != 30 ? 20 : 30;
155    WebRtcIlbcfix_InitEncode(&s->encoder, s->mode);
156
157    avctx->block_align = s->encoder.no_of_bytes;
158    avctx->frame_size  = s->encoder.blockl;
159
160    return 0;
161}
162
163static int ilbc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
164                             const AVFrame *frame, int *got_packet_ptr)
165{
166    ILBCEncContext *s = avctx->priv_data;
167    int ret;
168
169    if ((ret = ff_alloc_packet2(avctx, avpkt, 50)) < 0)
170        return ret;
171
172    WebRtcIlbcfix_EncodeImpl((uint16_t *) avpkt->data, (const int16_t *) frame->data[0], &s->encoder);
173
174    avpkt->size     = s->encoder.no_of_bytes;
175    *got_packet_ptr = 1;
176    return 0;
177}
178
179static const AVCodecDefault ilbc_encode_defaults[] = {
180    { "b", "0" },
181    { NULL }
182};
183
184AVCodec ff_libilbc_encoder = {
185    .name           = "libilbc",
186    .long_name      = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),
187    .type           = AVMEDIA_TYPE_AUDIO,
188    .id             = AV_CODEC_ID_ILBC,
189    .priv_data_size = sizeof(ILBCEncContext),
190    .init           = ilbc_encode_init,
191    .encode2        = ilbc_encode_frame,
192    .sample_fmts    = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
193                                                     AV_SAMPLE_FMT_NONE },
194    .defaults       = ilbc_encode_defaults,
195    .priv_class     = &ilbc_enc_class,
196};
197