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
27typedef struct {
28    AVFrame frame;
29    SpeexBits bits;
30    SpeexStereoState stereo;
31    void *dec_state;
32    SpeexHeader *header;
33    int frame_size;
34} LibSpeexContext;
35
36
37static av_cold int libspeex_decode_init(AVCodecContext *avctx)
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
53    avctx->sample_fmt = AV_SAMPLE_FMT_S16;
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
94    avcodec_get_frame_defaults(&s->frame);
95    avctx->coded_frame = &s->frame;
96
97    return 0;
98}
99
100static 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
146static av_cold int libspeex_decode_close(AVCodecContext *avctx)
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
157static av_cold void libspeex_decode_flush(AVCodecContext *avctx)
158{
159    LibSpeexContext *s = avctx->priv_data;
160    speex_bits_reset(&s->bits);
161}
162
163AVCodec ff_libspeex_decoder = {
164    .name           = "libspeex",
165    .type           = AVMEDIA_TYPE_AUDIO,
166    .id             = CODEC_ID_SPEEX,
167    .priv_data_size = sizeof(LibSpeexContext),
168    .init           = libspeex_decode_init,
169    .close          = libspeex_decode_close,
170    .decode         = libspeex_decode_frame,
171    .flush          = libspeex_decode_flush,
172    .capabilities   = CODEC_CAP_SUBFRAMES | CODEC_CAP_DELAY | CODEC_CAP_DR1,
173    .long_name = NULL_IF_CONFIG_SMALL("libspeex Speex"),
174};
175