1/*
2 * Raw FLAC demuxer
3 * Copyright (c) 2001 Fabrice Bellard
4 *
5 * This file is part of Libav.
6 *
7 * Libav is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
11 *
12 * Libav is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15 * Lesser General Public License for more details.
16 *
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with Libav; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 */
21
22#include "libavcodec/flac.h"
23#include "avformat.h"
24#include "internal.h"
25#include "rawdec.h"
26#include "oggdec.h"
27#include "vorbiscomment.h"
28#include "libavcodec/bytestream.h"
29
30static int flac_read_header(AVFormatContext *s,
31                             AVFormatParameters *ap)
32{
33    int ret, metadata_last=0, metadata_type, metadata_size, found_streaminfo=0;
34    uint8_t header[4];
35    uint8_t *buffer=NULL;
36    AVStream *st = avformat_new_stream(s, NULL);
37    if (!st)
38        return AVERROR(ENOMEM);
39    st->codec->codec_type = AVMEDIA_TYPE_AUDIO;
40    st->codec->codec_id = CODEC_ID_FLAC;
41    st->need_parsing = AVSTREAM_PARSE_FULL;
42    /* the parameters will be extracted from the compressed bitstream */
43
44    /* if fLaC marker is not found, assume there is no header */
45    if (avio_rl32(s->pb) != MKTAG('f','L','a','C')) {
46        avio_seek(s->pb, -4, SEEK_CUR);
47        return 0;
48    }
49
50    /* process metadata blocks */
51    while (!s->pb->eof_reached && !metadata_last) {
52        avio_read(s->pb, header, 4);
53        avpriv_flac_parse_block_header(header, &metadata_last, &metadata_type,
54                                   &metadata_size);
55        switch (metadata_type) {
56        /* allocate and read metadata block for supported types */
57        case FLAC_METADATA_TYPE_STREAMINFO:
58        case FLAC_METADATA_TYPE_CUESHEET:
59        case FLAC_METADATA_TYPE_VORBIS_COMMENT:
60            buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
61            if (!buffer) {
62                return AVERROR(ENOMEM);
63            }
64            if (avio_read(s->pb, buffer, metadata_size) != metadata_size) {
65                av_freep(&buffer);
66                return AVERROR(EIO);
67            }
68            break;
69        /* skip metadata block for unsupported types */
70        default:
71            ret = avio_skip(s->pb, metadata_size);
72            if (ret < 0)
73                return ret;
74        }
75
76        if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
77            FLACStreaminfo si;
78            /* STREAMINFO can only occur once */
79            if (found_streaminfo) {
80                av_freep(&buffer);
81                return AVERROR_INVALIDDATA;
82            }
83            if (metadata_size != FLAC_STREAMINFO_SIZE) {
84                av_freep(&buffer);
85                return AVERROR_INVALIDDATA;
86            }
87            found_streaminfo = 1;
88            st->codec->extradata      = buffer;
89            st->codec->extradata_size = metadata_size;
90            buffer = NULL;
91
92            /* get codec params from STREAMINFO header */
93            avpriv_flac_parse_streaminfo(st->codec, &si, st->codec->extradata);
94
95            /* set time base and duration */
96            if (si.samplerate > 0) {
97                avpriv_set_pts_info(st, 64, 1, si.samplerate);
98                if (si.samples > 0)
99                    st->duration = si.samples;
100            }
101        } else if (metadata_type == FLAC_METADATA_TYPE_CUESHEET) {
102            uint8_t isrc[13];
103            uint64_t start;
104            const uint8_t *offset;
105            int i, chapters, track, ti;
106            if (metadata_size < 431)
107                return AVERROR_INVALIDDATA;
108            offset = buffer + 395;
109            chapters = bytestream_get_byte(&offset) - 1;
110            if (chapters <= 0)
111                return AVERROR_INVALIDDATA;
112            for (i = 0; i < chapters; i++) {
113                if (offset + 36 - buffer > metadata_size)
114                    return AVERROR_INVALIDDATA;
115                start = bytestream_get_be64(&offset);
116                track = bytestream_get_byte(&offset);
117                bytestream_get_buffer(&offset, isrc, 12);
118                isrc[12] = 0;
119                offset += 14;
120                ti = bytestream_get_byte(&offset);
121                if (ti <= 0) return AVERROR_INVALIDDATA;
122                offset += ti * 12;
123                avpriv_new_chapter(s, track, st->time_base, start, AV_NOPTS_VALUE, isrc);
124            }
125        } else {
126            /* STREAMINFO must be the first block */
127            if (!found_streaminfo) {
128                av_freep(&buffer);
129                return AVERROR_INVALIDDATA;
130            }
131            /* process supported blocks other than STREAMINFO */
132            if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
133                if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size)) {
134                    av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
135                }
136            }
137            av_freep(&buffer);
138        }
139    }
140
141    return 0;
142}
143
144static int flac_probe(AVProbeData *p)
145{
146    if (p->buf_size < 4 || memcmp(p->buf, "fLaC", 4))
147        return 0;
148    return AVPROBE_SCORE_MAX/2;
149}
150
151AVInputFormat ff_flac_demuxer = {
152    .name           = "flac",
153    .long_name      = NULL_IF_CONFIG_SMALL("raw FLAC"),
154    .read_probe     = flac_probe,
155    .read_header    = flac_read_header,
156    .read_packet    = ff_raw_read_partial_packet,
157    .flags= AVFMT_GENERIC_INDEX,
158    .extensions = "flac",
159    .value = CODEC_ID_FLAC,
160};
161