Speex decoding via libspeex
[libav.git] / libavcodec / libspeexdec.c
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ae14f311
DC
1/*
2 * Copyright (C) 2008 David Conrad
3 *
4 * This file is part of FFmpeg.
5 *
6 * FFmpeg is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
10 *
11 * FFmpeg is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
15 *
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with FFmpeg; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19 */
20
21#include "avcodec.h"
22#include <speex/speex.h>
23#include <speex/speex_header.h>
24#include <speex/speex_stereo.h>
25#include <speex/speex_callbacks.h>
26
27typedef struct {
28 SpeexBits bits;
29 SpeexStereoState stereo;
30 void *dec_state;
31 SpeexHeader *header;
32} LibSpeexContext;
33
34
35static av_cold int libspeex_decode_init(AVCodecContext *avctx)
36{
37 LibSpeexContext *s = avctx->priv_data;
38 const SpeexMode *mode;
39
40 // defaults in the case of a missing header
41 if (avctx->sample_rate <= 8000)
42 mode = &speex_nb_mode;
43 else if (avctx->sample_rate <= 16000)
44 mode = &speex_wb_mode;
45 else
46 mode = &speex_uwb_mode;
47
48 if (avctx->extradata_size >= 80)
49 s->header = speex_packet_to_header(avctx->extradata, avctx->extradata_size);
50
51 avctx->sample_fmt = SAMPLE_FMT_S16;
52 if (s->header) {
53 avctx->sample_rate = s->header->rate;
54 avctx->channels = s->header->nb_channels;
55 avctx->frame_size = s->header->frame_size;
56
57 mode = speex_lib_get_mode(s->header->mode);
58 if (!mode) {
59 av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", s->header->mode);
60 return -1;
61 }
62 } else
63 av_log(avctx, AV_LOG_INFO, "Missing speex header, assuming defaults\n");
64
65 if (avctx->channels > 2) {
66 av_log(avctx, AV_LOG_ERROR, "Only stereo and mono supported\n");
67 return -1;
68 }
69
70 speex_bits_init(&s->bits);
71 s->dec_state = speex_decoder_init(mode);
72 if (!s->dec_state) {
73 av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder\n");
74 return -1;
75 }
76
77 if (!s->header)
78 speex_decoder_ctl(s->dec_state, SPEEX_GET_FRAME_SIZE, &avctx->frame_size);
79
80 if (avctx->channels == 2) {
81 SpeexCallback callback;
82 callback.callback_id = SPEEX_INBAND_STEREO;
83 callback.func = speex_std_stereo_request_handler;
84 callback.data = &s->stereo;
85 s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
86 speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
87 }
88 return 0;
89}
90
91static int libspeex_decode_frame(AVCodecContext *avctx,
92 void *data, int *data_size,
93 const uint8_t *buf, int buf_size)
94{
95 LibSpeexContext *s = avctx->priv_data;
96 int16_t *output = data, *end;
97 int i, num_samples;
98
99 num_samples = avctx->frame_size * avctx->channels;
100 end = output + *data_size/2;
101
102 speex_bits_read_from(&s->bits, buf, buf_size);
103
104 for (i = 0; speex_bits_remaining(&s->bits) && output + num_samples < end; i++) {
105 int ret = speex_decode_int(s->dec_state, &s->bits, output);
106 if (ret <= -2) {
107 av_log(avctx, AV_LOG_ERROR, "Error decoding speex frame\n");
108 return -1;
109 } else if (ret == -1)
110 // end of stream
111 break;
112
113 if (avctx->channels == 2)
114 speex_decode_stereo_int(output, avctx->frame_size, &s->stereo);
115
116 output += num_samples;
117 }
118
119 *data_size = i * avctx->channels * avctx->frame_size * 2;
120 return buf_size;
121}
122
123static av_cold int libspeex_decode_close(AVCodecContext *avctx)
124{
125 LibSpeexContext *s = avctx->priv_data;
126
127 speex_header_free(s->header);
128 speex_bits_destroy(&s->bits);
129 speex_decoder_destroy(s->dec_state);
130
131 return 0;
132}
133
134AVCodec libspeex_decoder = {
135 "libspeex",
136 CODEC_TYPE_AUDIO,
137 CODEC_ID_SPEEX,
138 sizeof(LibSpeexContext),
139 libspeex_decode_init,
140 NULL,
141 libspeex_decode_close,
142 libspeex_decode_frame,
143 .long_name = NULL_IF_CONFIG_SMALL("libspeex"),
144};