Statistics
| Branch: | Revision:

ffmpeg / libavcodec / libspeexdec.c @ 72415b2a

History | View | Annotate | Download (4.55 KB)

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

    
27
typedef struct {
28
    SpeexBits bits;
29
    SpeexStereoState stereo;
30
    void *dec_state;
31
    SpeexHeader *header;
32
    int frame_size;
33
} LibSpeexContext;
34

    
35

    
36
static 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

    
95
static 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

    
130
static 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

    
141
AVCodec 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
};