libspeexdec.c
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1 /*
2  * Copyright (C) 2008 David Conrad
3  *
4  * This file is part of Libav.
5  *
6  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <speex/speex.h>
22 #include <speex/speex_header.h>
23 #include <speex/speex_stereo.h>
24 #include <speex/speex_callbacks.h>
25 #include "avcodec.h"
26 
27 typedef struct {
29  SpeexBits bits;
30  SpeexStereoState stereo;
31  void *dec_state;
32  SpeexHeader *header;
35 
36 
38 {
39  LibSpeexContext *s = avctx->priv_data;
40  const SpeexMode *mode;
41 
42  // defaults in the case of a missing header
43  if (avctx->sample_rate <= 8000)
44  mode = &speex_nb_mode;
45  else if (avctx->sample_rate <= 16000)
46  mode = &speex_wb_mode;
47  else
48  mode = &speex_uwb_mode;
49 
50  if (avctx->extradata_size >= 80)
51  s->header = speex_packet_to_header(avctx->extradata, avctx->extradata_size);
52 
54  if (s->header) {
55  avctx->sample_rate = s->header->rate;
56  avctx->channels = s->header->nb_channels;
57  avctx->frame_size = s->frame_size = s->header->frame_size;
58  if (s->header->frames_per_packet)
59  avctx->frame_size *= s->header->frames_per_packet;
60 
61  mode = speex_lib_get_mode(s->header->mode);
62  if (!mode) {
63  av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", s->header->mode);
64  return AVERROR_INVALIDDATA;
65  }
66  } else
67  av_log(avctx, AV_LOG_INFO, "Missing Speex header, assuming defaults.\n");
68 
69  if (avctx->channels > 2) {
70  av_log(avctx, AV_LOG_ERROR, "Only stereo and mono are supported.\n");
71  return AVERROR(EINVAL);
72  }
73 
74  speex_bits_init(&s->bits);
75  s->dec_state = speex_decoder_init(mode);
76  if (!s->dec_state) {
77  av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder.\n");
78  return -1;
79  }
80 
81  if (!s->header) {
82  speex_decoder_ctl(s->dec_state, SPEEX_GET_FRAME_SIZE, &s->frame_size);
83  }
84 
85  if (avctx->channels == 2) {
86  SpeexCallback callback;
87  callback.callback_id = SPEEX_INBAND_STEREO;
88  callback.func = speex_std_stereo_request_handler;
89  callback.data = &s->stereo;
90  s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
91  speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
92  }
93 
95  avctx->coded_frame = &s->frame;
96 
97  return 0;
98 }
99 
100 static int libspeex_decode_frame(AVCodecContext *avctx, void *data,
101  int *got_frame_ptr, AVPacket *avpkt)
102 {
103  uint8_t *buf = avpkt->data;
104  int buf_size = avpkt->size;
105  LibSpeexContext *s = avctx->priv_data;
106  int16_t *output;
107  int ret, consumed = 0;
108 
109  /* get output buffer */
110  s->frame.nb_samples = s->frame_size;
111  if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
112  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
113  return ret;
114  }
115  output = (int16_t *)s->frame.data[0];
116 
117  /* if there is not enough data left for the smallest possible frame,
118  reset the libspeex buffer using the current packet, otherwise ignore
119  the current packet and keep decoding frames from the libspeex buffer. */
120  if (speex_bits_remaining(&s->bits) < 43) {
121  /* check for flush packet */
122  if (!buf || !buf_size) {
123  *got_frame_ptr = 0;
124  return buf_size;
125  }
126  /* set new buffer */
127  speex_bits_read_from(&s->bits, buf, buf_size);
128  consumed = buf_size;
129  }
130 
131  /* decode a single frame */
132  ret = speex_decode_int(s->dec_state, &s->bits, output);
133  if (ret <= -2) {
134  av_log(avctx, AV_LOG_ERROR, "Error decoding Speex frame.\n");
135  return AVERROR_INVALIDDATA;
136  }
137  if (avctx->channels == 2)
138  speex_decode_stereo_int(output, s->frame_size, &s->stereo);
139 
140  *got_frame_ptr = 1;
141  *(AVFrame *)data = s->frame;
142 
143  return consumed;
144 }
145 
147 {
148  LibSpeexContext *s = avctx->priv_data;
149 
150  speex_header_free(s->header);
151  speex_bits_destroy(&s->bits);
152  speex_decoder_destroy(s->dec_state);
153 
154  return 0;
155 }
156 
158 {
159  LibSpeexContext *s = avctx->priv_data;
160  speex_bits_reset(&s->bits);
161 }
162 
164  .name = "libspeex",
165  .type = AVMEDIA_TYPE_AUDIO,
166  .id = CODEC_ID_SPEEX,
167  .priv_data_size = sizeof(LibSpeexContext),
173  .long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"),
174 };