1/*
2 * Raw FLAC demuxer
3 * Copyright (c) 2001 Fabrice Bellard
4 *
5 * This file is part of FFmpeg.
6 *
7 * FFmpeg 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 * FFmpeg 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 FFmpeg; 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 "raw.h"
25#include "id3v2.h"
26#include "oggdec.h"
27#include "vorbiscomment.h"
28
29static int flac_read_header(AVFormatContext *s,
30                             AVFormatParameters *ap)
31{
32    uint8_t buf[ID3v2_HEADER_SIZE];
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 = av_new_stream(s, 0);
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    /* skip ID3v2 header if found */
45    ret = get_buffer(s->pb, buf, ID3v2_HEADER_SIZE);
46    if (ret == ID3v2_HEADER_SIZE && ff_id3v2_match(buf)) {
47        int len = ff_id3v2_tag_len(buf);
48        url_fseek(s->pb, len - ID3v2_HEADER_SIZE, SEEK_CUR);
49    } else {
50        url_fseek(s->pb, 0, SEEK_SET);
51    }
52
53    /* if fLaC marker is not found, assume there is no header */
54    if (get_le32(s->pb) != MKTAG('f','L','a','C')) {
55        url_fseek(s->pb, -4, SEEK_CUR);
56        return 0;
57    }
58
59    /* process metadata blocks */
60    while (!url_feof(s->pb) && !metadata_last) {
61        get_buffer(s->pb, header, 4);
62        ff_flac_parse_block_header(header, &metadata_last, &metadata_type,
63                                   &metadata_size);
64        switch (metadata_type) {
65        /* allocate and read metadata block for supported types */
66        case FLAC_METADATA_TYPE_STREAMINFO:
67        case FLAC_METADATA_TYPE_VORBIS_COMMENT:
68            buffer = av_mallocz(metadata_size + FF_INPUT_BUFFER_PADDING_SIZE);
69            if (!buffer) {
70                return AVERROR(ENOMEM);
71            }
72            if (get_buffer(s->pb, buffer, metadata_size) != metadata_size) {
73                av_freep(&buffer);
74                return AVERROR(EIO);
75            }
76            break;
77        /* skip metadata block for unsupported types */
78        default:
79            ret = url_fseek(s->pb, metadata_size, SEEK_CUR);
80            if (ret < 0)
81                return ret;
82        }
83
84        if (metadata_type == FLAC_METADATA_TYPE_STREAMINFO) {
85            FLACStreaminfo si;
86            /* STREAMINFO can only occur once */
87            if (found_streaminfo) {
88                av_freep(&buffer);
89                return AVERROR_INVALIDDATA;
90            }
91            if (metadata_size != FLAC_STREAMINFO_SIZE) {
92                av_freep(&buffer);
93                return AVERROR_INVALIDDATA;
94            }
95            found_streaminfo = 1;
96            st->codec->extradata      = buffer;
97            st->codec->extradata_size = metadata_size;
98            buffer = NULL;
99
100            /* get codec params from STREAMINFO header */
101            ff_flac_parse_streaminfo(st->codec, &si, st->codec->extradata);
102
103            /* set time base and duration */
104            if (si.samplerate > 0) {
105                av_set_pts_info(st, 64, 1, si.samplerate);
106                if (si.samples > 0)
107                    st->duration = si.samples;
108            }
109        } else {
110            /* STREAMINFO must be the first block */
111            if (!found_streaminfo) {
112                av_freep(&buffer);
113                return AVERROR_INVALIDDATA;
114            }
115            /* process supported blocks other than STREAMINFO */
116            if (metadata_type == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
117                if (ff_vorbis_comment(s, &s->metadata, buffer, metadata_size)) {
118                    av_log(s, AV_LOG_WARNING, "error parsing VorbisComment metadata\n");
119                }
120            }
121            av_freep(&buffer);
122        }
123    }
124
125    return 0;
126}
127
128static int flac_probe(AVProbeData *p)
129{
130    uint8_t *bufptr = p->buf;
131    uint8_t *end    = p->buf + p->buf_size;
132
133    if(ff_id3v2_match(bufptr))
134        bufptr += ff_id3v2_tag_len(bufptr);
135
136    if(bufptr > end-4 || memcmp(bufptr, "fLaC", 4)) return 0;
137    else                                            return AVPROBE_SCORE_MAX/2;
138}
139
140AVInputFormat flac_demuxer = {
141    "flac",
142    NULL_IF_CONFIG_SMALL("raw FLAC"),
143    0,
144    flac_probe,
145    flac_read_header,
146    ff_raw_read_partial_packet,
147    .flags= AVFMT_GENERIC_INDEX,
148    .extensions = "flac",
149    .value = CODEC_ID_FLAC,
150    .metadata_conv = ff_vorbiscomment_metadata_conv,
151};
152