summaryrefslogtreecommitdiff
path: root/libavformat/flacdec.c
blob: a1bb51b074d6b39c67449f7f13bb7d79cbe6dfaf (plain)
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
/*
 * Raw FLAC demuxer
 * Copyright (c) 2001 Fabrice Bellard
 *
 * 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 "libavcodec/flac.h"
#include "avformat.h"
#include "raw.h"
#include "id3v2.h"
#include "oggdec.h"
#include "vorbiscomment.h"

static int flac_read_header(AVFormatContext *s,
                             AVFormatParameters *ap)
{
    uint8_t buf[ID3v2_HEADER_SIZE];
    int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
    uint8_t header[4];
    uint8_t *buffer=NULL;
    AVStream *st = av_new_stream(s, 0);
    if (!st)
        return AVERROR(ENOMEM);
    st->codec->codec_type = CODEC_TYPE_AUDIO;
    st->codec->codec_id = CODEC_ID_FLAC;
    st->need_parsing = AVSTREAM_PARSE_FULL;
    /* the parameters will be extracted from the compressed bitstream */

    /* skip ID3v2 header if found */
    ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
    if (ret == ID3v2_HEADER_SIZE && ff_id3v2_match(buf)) {
        int len = ff_id3v2_tag_len(buf);
        url_fseek(s->pb, len - ID3v2_HEADER_SIZE, SEEK_CUR);
    } else {
        url_fseek(s->pb, 0, SEEK_SET);
    }

    /* if fLaC marker is not found, assume there is no header */
    if (get_le32(s->pb) != MKTAG('f','L','a','C')) {
        url_fseek(s->pb, -4, SEEK_CUR);
        return 0;
    }

    /* process metadata blocks */
    while (!url_feof(s->pb) && !metadata_last) {
        get_buffer(s->pb, header, 4);
        ff_flac_parse_block_header(header, &metadata_last, &metadata_type,
                                   &metadata_size);
        switch (metadata_type) {
        /* allocate and read metadata block for supported types */
        case FLAC_METADATA_TYPE_STREAMINFO:
        case FLAC_METADATA_TYPE_VORBIS_COMMENT:
            buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
            if (!buffer) {
                return AVERROR_NOMEM;
            }
            if (get_buffer(s->pb, buffer, metadata_size) != metadata_size) {
                av_freep(&buffer);
                return AVERROR(EIO);
            }
            break;
        /* skip metadata block for unsupported types */
        default:
            ret = url_fseek(s->pb, metadata_size, SEEK_CUR);
            if (ret < 0)
                return ret;
        }

        if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
            FLACStreaminfo si;
            /* STREAMINFO can only occur once */
            if (found_streaminfo) {
                av_freep(&buffer);
                return AVERROR_INVALIDDATA;
            }
            if (metadata_size != FLAC_STREAMINFO_SIZE) {
                av_freep(&buffer);
                return AVERROR_INVALIDDATA;
            }
            found_streaminfo = 1;
            st->codec->extradata      = buffer;
            st->codec->extradata_size = metadata_size;
            buffer = NULL;

            /* get codec params from STREAMINFO header */
            ff_flac_parse_streaminfo(st->codec, &si, st->codec->extradata);

            /* set time base and duration */
            if (si.samplerate > 0) {
                av_set_pts_info(st, 64, 1, si.samplerate);
                if (si.samples > 0)
                    st->duration = si.samples;
            }
        } else {
            /* STREAMINFO must be the first block */
            if (!found_streaminfo) {
                av_freep(&buffer);
                return AVERROR_INVALIDDATA;
            }
            /* process supported blocks other than STREAMINFO */
            if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
                if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size)) {
                    av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
                }
            }
            av_freep(&buffer);
        }
    }

    return 0;
}

static int flac_probe(AVProbeData *p)
{
    uint8_t *bufptr = p->buf;
    uint8_t *end    = p->buf + p->buf_size;

    if(ff_id3v2_match(bufptr))
        bufptr += ff_id3v2_tag_len(bufptr);

    if(bufptr > end-4 || memcmp(bufptr, "fLaC", 4)) return 0;
    else                                            return AVPROBE_SCORE_MAX/2;
}

AVInputFormat flac_demuxer = {
    "flac",
    NULL_IF_CONFIG_SMALL("raw FLAC"),
    0,
    flac_probe,
    flac_read_header,
    ff_raw_read_partial_packet,
    .flags= AVFMT_GENERIC_INDEX,
    .extensions = "flac",
    .value = CODEC_ID_FLAC,
    .metadata_conv = ff_vorbiscomment_metadata_conv,
};