aboutsummaryrefslogtreecommitdiffstats
path: root/libavcodec/libcelt_dec.c
blob: 496b95a0ed87f5f3751edb8a40af09974b1eb1f3 (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
/*
 * Xiph CELT decoder using libcelt
 * Copyright (c) 2011 Nicolas George
 *
 * 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 <celt/celt.h>
#include <celt/celt_header.h>
#include "avcodec.h"
#include "internal.h"
#include "libavutil/intreadwrite.h"

struct libcelt_context {
    CELTMode *mode;
    CELTDecoder *dec;
    int discard;
};

static int ff_celt_error_to_averror(int err)
{
    switch (err) {
        case CELT_BAD_ARG:          return AVERROR(EINVAL);
#ifdef CELT_BUFFER_TOO_SMALL
        case CELT_BUFFER_TOO_SMALL: return AVERROR(ENOBUFS);
#endif
        case CELT_INTERNAL_ERROR:   return AVERROR(EFAULT);
        case CELT_CORRUPTED_DATA:   return AVERROR_INVALIDDATA;
        case CELT_UNIMPLEMENTED:    return AVERROR(ENOSYS);
#ifdef ENOTRECOVERABLE
        case CELT_INVALID_STATE:    return AVERROR(ENOTRECOVERABLE);
#endif
        case CELT_ALLOC_FAIL:       return AVERROR(ENOMEM);
        default:                    return AVERROR(EINVAL);
    }
}

static int ff_celt_bitstream_version_hack(CELTMode *mode)
{
    CELTHeader header = { .version_id = 0 };
    celt_header_init(&header, mode, 960, 2);
    return header.version_id;
}

static av_cold int libcelt_dec_init(AVCodecContext *c)
{
    struct libcelt_context *celt = c->priv_data;
    int err;

    if (!c->channels || !c->frame_size ||
        c->frame_size > INT_MAX / sizeof(int16_t) / c->channels)
        return AVERROR(EINVAL);
    celt->mode = celt_mode_create(c->sample_rate, c->frame_size, &err);
    if (!celt->mode)
        return ff_celt_error_to_averror(err);
    celt->dec = celt_decoder_create_custom(celt->mode, c->channels, &err);
    if (!celt->dec) {
        celt_mode_destroy(celt->mode);
        return ff_celt_error_to_averror(err);
    }
    if (c->extradata_size >= 4) {
        celt->discard = AV_RL32(c->extradata);
        if (celt->discard < 0 || celt->discard >= c->frame_size) {
            av_log(c, AV_LOG_WARNING,
                   "Invalid overlap (%d), ignored.\n", celt->discard);
            celt->discard = 0;
        }
    }
    if (c->extradata_size >= 8) {
        unsigned version = AV_RL32(c->extradata + 4);
        unsigned lib_version = ff_celt_bitstream_version_hack(celt->mode);
        if (version != lib_version)
            av_log(c, AV_LOG_WARNING,
                   "CELT bitstream version 0x%x may be "
                   "improperly decoded by libcelt for version 0x%x.\n",
                   version, lib_version);
    }
    c->sample_fmt = AV_SAMPLE_FMT_S16;
    return 0;
}

static av_cold int libcelt_dec_close(AVCodecContext *c)
{
    struct libcelt_context *celt = c->priv_data;

    celt_decoder_destroy(celt->dec);
    celt_mode_destroy(celt->mode);
    return 0;
}

static int libcelt_dec_decode(AVCodecContext *c, void *data,
                              int *got_frame_ptr, AVPacket *pkt)
{
    struct libcelt_context *celt = c->priv_data;
    AVFrame *frame = data;
    int err;
    int16_t *pcm;

    frame->nb_samples = c->frame_size;
    err = ff_get_buffer(c, frame, 0);
    if (err < 0) {
        av_log(c, AV_LOG_ERROR, "get_buffer() failed\n");
        return err;
    }
    pcm = (int16_t *)frame->data[0];
    err = celt_decode(celt->dec, pkt->data, pkt->size, pcm, c->frame_size);
    if (err < 0)
        return ff_celt_error_to_averror(err);
    if (celt->discard) {
        frame->nb_samples -= celt->discard;
        memmove(pcm, pcm + celt->discard * c->channels,
                frame->nb_samples * c->channels * sizeof(int16_t));
        celt->discard = 0;
    }
    *got_frame_ptr = 1;
    return pkt->size;
}

AVCodec ff_libcelt_decoder = {
    .name           = "libcelt",
    .type           = AVMEDIA_TYPE_AUDIO,
    .id             = AV_CODEC_ID_CELT,
    .priv_data_size = sizeof(struct libcelt_context),
    .init           = libcelt_dec_init,
    .close          = libcelt_dec_close,
    .decode         = libcelt_dec_decode,
    .capabilities   = CODEC_CAP_DR1,
    .long_name      = NULL_IF_CONFIG_SMALL("Xiph CELT decoder using libcelt"),
};