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    int frame_size;
33} LibSpeexContext;
34
35
36static av_cold int libspeex_decode_init(AVCodecContext *avctx)
37{
38    LibSpeexContext *s = avctx->priv_data;
39    const SpeexMode *mode;
40
41    // defaults in the case of a missing header
42    if (avctx->sample_rate <= 8000)
43        mode = &speex_nb_mode;
44    else if (avctx->sample_rate <= 16000)
45        mode = &speex_wb_mode;
46    else
47        mode = &speex_uwb_mode;
48
49    if (avctx->extradata_size >= 80)
50        s->header = speex_packet_to_header(avctx->extradata, avctx->extradata_size);
51
52    avctx->sample_fmt = SAMPLE_FMT_S16;
53    if (s->header) {
54        avctx->sample_rate = s->header->rate;
55        avctx->channels    = s->header->nb_channels;
56        avctx->frame_size  = s->frame_size = s->header->frame_size;
57        if (s->header->frames_per_packet)
58            avctx->frame_size *= s->header->frames_per_packet;
59
60        mode = speex_lib_get_mode(s->header->mode);
61        if (!mode) {
62            av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", s->header->mode);
63            return -1;
64        }
65    } else
66        av_log(avctx, AV_LOG_INFO, "Missing Speex header, assuming defaults.\n");
67
68    if (avctx->channels > 2) {
69        av_log(avctx, AV_LOG_ERROR, "Only stereo and mono are supported.\n");
70        return -1;
71    }
72
73    speex_bits_init(&s->bits);
74    s->dec_state = speex_decoder_init(mode);
75    if (!s->dec_state) {
76        av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder.\n");
77        return -1;
78    }
79
80    if (!s->header) {
81        speex_decoder_ctl(s->dec_state, SPEEX_GET_FRAME_SIZE, &s->frame_size);
82    }
83
84    if (avctx->channels == 2) {
85        SpeexCallback callback;
86        callback.callback_id = SPEEX_INBAND_STEREO;
87        callback.func = speex_std_stereo_request_handler;
88        callback.data = &s->stereo;
89        s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
90        speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
91    }
92    return 0;
93}
94
95static int libspeex_decode_frame(AVCodecContext *avctx,
96                                 void *data, int *data_size,
97                                 AVPacket *avpkt)
98{
99    const uint8_t *buf = avpkt->data;
100    int buf_size = avpkt->size;
101    LibSpeexContext *s = avctx->priv_data;
102    int16_t *output = data, *end;
103    int i, num_samples;
104
105    num_samples = s->frame_size * avctx->channels;
106    end = output + *data_size / sizeof(*output);
107
108    speex_bits_read_from(&s->bits, buf, buf_size);
109
110    for (i = 0; speex_bits_remaining(&s->bits) && output + num_samples < end; i++) {
111        int ret = speex_decode_int(s->dec_state, &s->bits, output);
112        if (ret <= -2) {
113            av_log(avctx, AV_LOG_ERROR, "Error decoding Speex frame.\n");
114            return -1;
115        } else if (ret == -1)
116            // end of stream
117            break;
118
119        if (avctx->channels == 2)
120            speex_decode_stereo_int(output, s->frame_size, &s->stereo);
121
122        output += num_samples;
123    }
124
125    avctx->frame_size = s->frame_size * i;
126    *data_size = avctx->channels * avctx->frame_size * sizeof(*output);
127    return buf_size;
128}
129
130static av_cold int libspeex_decode_close(AVCodecContext *avctx)
131{
132    LibSpeexContext *s = avctx->priv_data;
133
134    speex_header_free(s->header);
135    speex_bits_destroy(&s->bits);
136    speex_decoder_destroy(s->dec_state);
137
138    return 0;
139}
140
141AVCodec libspeex_decoder = {
142    "libspeex",
143    AVMEDIA_TYPE_AUDIO,
144    CODEC_ID_SPEEX,
145    sizeof(LibSpeexContext),
146    libspeex_decode_init,
147    NULL,
148    libspeex_decode_close,
149    libspeex_decode_frame,
150    .long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"),
151};
152