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 #include "internal.h"
27 
28 typedef struct {
30  SpeexBits bits;
31  SpeexStereoState stereo;
32  void *dec_state;
33  SpeexHeader *header;
36 
37 
39 {
40  LibSpeexContext *s = avctx->priv_data;
41  const SpeexMode *mode;
42 
43  // defaults in the case of a missing header
44  if (avctx->sample_rate <= 8000)
45  mode = &speex_nb_mode;
46  else if (avctx->sample_rate <= 16000)
47  mode = &speex_wb_mode;
48  else
49  mode = &speex_uwb_mode;
50 
51  if (avctx->extradata_size >= 80)
52  s->header = speex_packet_to_header(avctx->extradata, avctx->extradata_size);
53 
55  if (s->header) {
56  avctx->sample_rate = s->header->rate;
57  avctx->channels = s->header->nb_channels;
58  avctx->frame_size = s->frame_size = s->header->frame_size;
59  if (s->header->frames_per_packet)
60  avctx->frame_size *= s->header->frames_per_packet;
61 
62  mode = speex_lib_get_mode(s->header->mode);
63  if (!mode) {
64  av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", s->header->mode);
65  return AVERROR_INVALIDDATA;
66  }
67  } else
68  av_log(avctx, AV_LOG_INFO, "Missing Speex header, assuming defaults.\n");
69 
70  if (avctx->channels > 2) {
71  av_log(avctx, AV_LOG_ERROR, "Only stereo and mono are supported.\n");
72  return AVERROR(EINVAL);
73  }
74 
75  speex_bits_init(&s->bits);
76  s->dec_state = speex_decoder_init(mode);
77  if (!s->dec_state) {
78  av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder.\n");
79  return -1;
80  }
81 
82  if (!s->header) {
83  speex_decoder_ctl(s->dec_state, SPEEX_GET_FRAME_SIZE, &s->frame_size);
84  }
85 
86  if (avctx->channels == 2) {
87  SpeexCallback callback;
88  callback.callback_id = SPEEX_INBAND_STEREO;
89  callback.func = speex_std_stereo_request_handler;
90  callback.data = &s->stereo;
91  s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
92  speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
93  }
94 
96  avctx->coded_frame = &s->frame;
97 
98  return 0;
99 }
100 
101 static int libspeex_decode_frame(AVCodecContext *avctx, void *data,
102  int *got_frame_ptr, AVPacket *avpkt)
103 {
104  uint8_t *buf = avpkt->data;
105  int buf_size = avpkt->size;
106  LibSpeexContext *s = avctx->priv_data;
107  int16_t *output;
108  int ret, consumed = 0;
109 
110  /* get output buffer */
111  s->frame.nb_samples = s->frame_size;
112  if ((ret = ff_get_buffer(avctx, &s->frame)) < 0) {
113  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
114  return ret;
115  }
116  output = (int16_t *)s->frame.data[0];
117 
118  /* if there is not enough data left for the smallest possible frame,
119  reset the libspeex buffer using the current packet, otherwise ignore
120  the current packet and keep decoding frames from the libspeex buffer. */
121  if (speex_bits_remaining(&s->bits) < 43) {
122  /* check for flush packet */
123  if (!buf || !buf_size) {
124  *got_frame_ptr = 0;
125  return buf_size;
126  }
127  /* set new buffer */
128  speex_bits_read_from(&s->bits, buf, buf_size);
129  consumed = buf_size;
130  }
131 
132  /* decode a single frame */
133  ret = speex_decode_int(s->dec_state, &s->bits, output);
134  if (ret <= -2) {
135  av_log(avctx, AV_LOG_ERROR, "Error decoding Speex frame.\n");
136  return AVERROR_INVALIDDATA;
137  }
138  if (avctx->channels == 2)
139  speex_decode_stereo_int(output, s->frame_size, &s->stereo);
140 
141  *got_frame_ptr = 1;
142  *(AVFrame *)data = s->frame;
143 
144  return consumed;
145 }
146 
148 {
149  LibSpeexContext *s = avctx->priv_data;
150 
151  speex_header_free(s->header);
152  speex_bits_destroy(&s->bits);
153  speex_decoder_destroy(s->dec_state);
154 
155  return 0;
156 }
157 
159 {
160  LibSpeexContext *s = avctx->priv_data;
161  speex_bits_reset(&s->bits);
162 }
163 
165  .name = "libspeex",
166  .type = AVMEDIA_TYPE_AUDIO,
167  .id = CODEC_ID_SPEEX,
168  .priv_data_size = sizeof(LibSpeexContext),
174  .long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"),
175 };