aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/libspeexdec.c
blob: 7c36208bf1d034d151235368801a35204cdf61c4 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
/*
 * Copyright (C) 2008 David Conrad
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#include <speex/speex.h>
#include <speex/speex_header.h>
#include <speex/speex_stereo.h>
#include <speex/speex_callbacks.h>
#include "avcodec.h"

typedef struct {
    AVFrame frame;
    SpeexBits bits;
    SpeexStereoState stereo;
    void *dec_state;
    SpeexHeader *header;
    int frame_size;
} LibSpeexContext;


static av_cold int libspeex_decode_init(AVCodecContext *avctx)
{
    LibSpeexContext *s = avctx->priv_data;
    const SpeexMode *mode;

    // defaults in the case of a missing header
    if (avctx->sample_rate <= 8000)
        mode = &speex_nb_mode;
    else if (avctx->sample_rate <= 16000)
        mode = &speex_wb_mode;
    else
        mode = &speex_uwb_mode;

    if (avctx->extradata_size >= 80)
        s->header = speex_packet_to_header(avctx->extradata, avctx->extradata_size);

    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
    if (s->header) {
        avctx->sample_rate = s->header->rate;
        avctx->channels    = s->header->nb_channels;

        mode = speex_lib_get_mode(s->header->mode);
        if (!mode) {
            av_log(avctx, AV_LOG_ERROR, "Unknown Speex mode %d", s->header->mode);
            return AVERROR_INVALIDDATA;
        }
    } else
        av_log(avctx, AV_LOG_INFO, "Missing Speex header, assuming defaults.\n");

    if (avctx->channels > 2) {
        av_log(avctx, AV_LOG_ERROR, "Only stereo and mono are supported.\n");
        return AVERROR(EINVAL);
    }

    speex_bits_init(&s->bits);
    s->dec_state = speex_decoder_init(mode);
    if (!s->dec_state) {
        av_log(avctx, AV_LOG_ERROR, "Error initializing libspeex decoder.\n");
        return -1;
    }

    if (!s->header) {
        speex_decoder_ctl(s->dec_state, SPEEX_GET_FRAME_SIZE, &s->frame_size);
    }

    if (avctx->channels == 2) {
        SpeexCallback callback;
        callback.callback_id = SPEEX_INBAND_STEREO;
        callback.func = speex_std_stereo_request_handler;
        callback.data = &s->stereo;
        s->stereo = (SpeexStereoState)SPEEX_STEREO_STATE_INIT;
        speex_decoder_ctl(s->dec_state, SPEEX_SET_HANDLER, &callback);
    }

    avcodec_get_frame_defaults(&s->frame);
    avctx->coded_frame = &s->frame;

    return 0;
}

static int libspeex_decode_frame(AVCodecContext *avctx, void *data,
                                 int *got_frame_ptr, AVPacket *avpkt)
{
    uint8_t *buf = avpkt->data;
    int buf_size = avpkt->size;
    LibSpeexContext *s = avctx->priv_data;
    int16_t *output;
    int ret, consumed = 0;

    /* get output buffer */
    s->frame.nb_samples = s->frame_size;
    if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {
        av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
        return ret;
    }
    output = (int16_t *)s->frame.data[0];

    /* if there is not enough data left for the smallest possible frame,
       reset the libspeex buffer using the current packet, otherwise ignore
       the current packet and keep decoding frames from the libspeex buffer. */
    if (speex_bits_remaining(&s->bits) < 43) {
        /* check for flush packet */
        if (!buf || !buf_size) {
            *got_frame_ptr = 0;
            return buf_size;
        }
        /* set new buffer */
        speex_bits_read_from(&s->bits, buf, buf_size);
        consumed = buf_size;
    }

    /* decode a single frame */
    ret = speex_decode_int(s->dec_state, &s->bits, output);
    if (ret <= -2) {
        av_log(avctx, AV_LOG_ERROR, "Error decoding Speex frame.\n");
        return AVERROR_INVALIDDATA;
    }
    if (avctx->channels == 2)
        speex_decode_stereo_int(output, s->frame_size, &s->stereo);

    *got_frame_ptr   = 1;
    *(AVFrame *)data = s->frame;

    return consumed;
}

static av_cold int libspeex_decode_close(AVCodecContext *avctx)
{
    LibSpeexContext *s = avctx->priv_data;

    speex_header_free(s->header);
    speex_bits_destroy(&s->bits);
    speex_decoder_destroy(s->dec_state);

    return 0;
}

static av_cold void libspeex_decode_flush(AVCodecContext *avctx)
{
    LibSpeexContext *s = avctx->priv_data;
    speex_bits_reset(&s->bits);
}

AVCodec ff_libspeex_decoder = {
    .name           = "libspeex",
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = CODEC_ID_SPEEX,
    .priv_data_size = sizeof(LibSpeexContext),
    .init           = libspeex_decode_init,
    .close          = libspeex_decode_close,
    .decode         = libspeex_decode_frame,
    .flush          = libspeex_decode_flush,
    .capabilities   = CODEC_CAP_SUBFRAMES | CODEC_CAP_DELAY | CODEC_CAP_DR1,
    .long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"),
};