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libilbc.c
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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 
25 #include "libavutil/common.h"
26 #include "libavutil/opt.h"
27 #include "avcodec.h"
28 #include "internal.h"
29 
30 static 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 
42 typedef struct ILBCDecContext {
43  const AVClass *class;
44  iLBC_Dec_Inst_t decoder;
45  int enhance;
47 
48 static 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 
53 static 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 
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;
74  avctx->sample_rate = 8000;
76 
77  return 0;
78 }
79 
80 static 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((WebRtc_Word16*) frame->data[0],
100  (const WebRtc_UWord16*) buf, &s->decoder, 1);
101 
102  *got_frame_ptr = 1;
103 
104  return s->decoder.no_of_bytes;
105 }
106 
108  .name = "libilbc",
109  .long_name = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),
110  .type = AVMEDIA_TYPE_AUDIO,
111  .id = AV_CODEC_ID_ILBC,
112  .priv_data_size = sizeof(ILBCDecContext),
115  .capabilities = CODEC_CAP_DR1,
116  .priv_class = &ilbc_dec_class,
117 };
118 
119 typedef struct ILBCEncContext {
120  const AVClass *class;
121  iLBC_Enc_Inst_t encoder;
122  int mode;
124 
125 static const AVOption ilbc_enc_options[] = {
126  { "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 },
127  { NULL }
128 };
129 
130 static const AVClass ilbc_enc_class = {
131  .class_name = "libilbc",
132  .item_name = av_default_item_name,
133  .option = ilbc_enc_options,
134  .version = LIBAVUTIL_VERSION_INT,
135 };
136 
138 {
139  ILBCEncContext *s = avctx->priv_data;
140  int mode;
141 
142  if (avctx->sample_rate != 8000) {
143  av_log(avctx, AV_LOG_ERROR, "Only 8000Hz sample rate supported\n");
144  return AVERROR(EINVAL);
145  }
146 
147  if (avctx->channels != 1) {
148  av_log(avctx, AV_LOG_ERROR, "Only mono supported\n");
149  return AVERROR(EINVAL);
150  }
151 
152  if ((mode = get_mode(avctx)) > 0)
153  s->mode = mode;
154  else
155  s->mode = s->mode != 30 ? 20 : 30;
156  WebRtcIlbcfix_InitEncode(&s->encoder, s->mode);
157 
158  avctx->block_align = s->encoder.no_of_bytes;
159  avctx->frame_size = s->encoder.blockl;
160 
161  return 0;
162 }
163 
164 static int ilbc_encode_frame(AVCodecContext *avctx, AVPacket *avpkt,
165  const AVFrame *frame, int *got_packet_ptr)
166 {
167  ILBCEncContext *s = avctx->priv_data;
168  int ret;
169 
170  if ((ret = ff_alloc_packet2(avctx, avpkt, 50)) < 0)
171  return ret;
172 
173  WebRtcIlbcfix_EncodeImpl((WebRtc_UWord16*) avpkt->data, (const WebRtc_Word16*) frame->data[0], &s->encoder);
174 
175  avpkt->size = s->encoder.no_of_bytes;
176  *got_packet_ptr = 1;
177  return 0;
178 }
179 
181  { "b", "0" },
182  { NULL }
183 };
184 
186  .name = "libilbc",
187  .long_name = NULL_IF_CONFIG_SMALL("iLBC (Internet Low Bitrate Codec)"),
188  .type = AVMEDIA_TYPE_AUDIO,
189  .id = AV_CODEC_ID_ILBC,
190  .priv_data_size = sizeof(ILBCEncContext),
192  .encode2 = ilbc_encode_frame,
193  .sample_fmts = (const enum AVSampleFormat[]){ AV_SAMPLE_FMT_S16,
195  .defaults = ilbc_encode_defaults,
196  .priv_class = &ilbc_enc_class,
197 };