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1 /*
2  *    Copyright (C) 2005  Matthieu CASTET
3  *
4  * This file is part of FFmpeg.
5  *
6  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
19  */
20 
21 #include <stdlib.h>
22 #include "libavcodec/get_bits.h"
23 #include "libavcodec/flac.h"
24 #include "avformat.h"
25 #include "internal.h"
26 #include "oggdec.h"
27 
28 #define OGG_FLAC_METADATA_TYPE_STREAMINFO 0x7F
29 
30 static int
flac_header(AVFormatContext * s,int idx)31 flac_header (AVFormatContext * s, int idx)
32 {
33     struct ogg *ogg = s->priv_data;
34     struct ogg_stream *os = ogg->streams + idx;
35     AVStream *st = s->streams[idx];
36     GetBitContext gb;
37     int mdt, ret;
38 
39     if (os->buf[os->pstart] == 0xff)
40         return 0;
41 
42     init_get_bits(&gb, os->buf + os->pstart, os->psize*8);
43     skip_bits1(&gb); /* metadata_last */
44     mdt = get_bits(&gb, 7);
45 
46     if (mdt == OGG_FLAC_METADATA_TYPE_STREAMINFO) {
47         uint8_t *streaminfo_start = os->buf + os->pstart + 5 + 4 + 4 + 4;
48         uint32_t samplerate;
49 
50         skip_bits_long(&gb, 4*8); /* "FLAC" */
51         if(get_bits(&gb, 8) != 1) /* unsupported major version */
52             return -1;
53         skip_bits(&gb, 8 + 16);   /* minor version + header count */
54         skip_bits_long(&gb, 4*8); /* "fLaC" */
55 
56         /* METADATA_BLOCK_HEADER */
57         if (get_bits_long(&gb, 32) != FLAC_STREAMINFO_SIZE)
58             return -1;
59 
60         st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
61         st->codecpar->codec_id = AV_CODEC_ID_FLAC;
62         ffstream(st)->need_parsing = AVSTREAM_PARSE_HEADERS;
63 
64         if ((ret = ff_alloc_extradata(st->codecpar, FLAC_STREAMINFO_SIZE)) < 0)
65             return ret;
66         memcpy(st->codecpar->extradata, streaminfo_start, st->codecpar->extradata_size);
67 
68         samplerate = AV_RB24(st->codecpar->extradata + 10) >> 4;
69         if (!samplerate)
70             return AVERROR_INVALIDDATA;
71 
72         avpriv_set_pts_info(st, 64, 1, samplerate);
73     } else if (mdt == FLAC_METADATA_TYPE_VORBIS_COMMENT) {
74         ff_vorbis_stream_comment(s, st, os->buf + os->pstart + 4, os->psize - 4);
75     }
76 
77     return 1;
78 }
79 
80 static int
old_flac_header(AVFormatContext * s,int idx)81 old_flac_header (AVFormatContext * s, int idx)
82 {
83     struct ogg *ogg = s->priv_data;
84     AVStream *st = s->streams[idx];
85     struct ogg_stream *os = ogg->streams + idx;
86     AVCodecParserContext *parser = av_parser_init(AV_CODEC_ID_FLAC);
87     AVCodecContext *avctx;
88     int size, ret;
89     uint8_t *data;
90 
91     if (!parser)
92         return -1;
93 
94     st->codecpar->codec_type = AVMEDIA_TYPE_AUDIO;
95     st->codecpar->codec_id = AV_CODEC_ID_FLAC;
96 
97     avctx = avcodec_alloc_context3(NULL);
98     if (!avctx) {
99         ret = AVERROR(ENOMEM);
100         goto fail;
101     }
102 
103     ret = avcodec_parameters_to_context(avctx, st->codecpar);
104     if (ret < 0)
105         goto fail;
106 
107     parser->flags = PARSER_FLAG_COMPLETE_FRAMES;
108     av_parser_parse2(parser, avctx,
109                      &data, &size, os->buf + os->pstart, os->psize,
110                      AV_NOPTS_VALUE, AV_NOPTS_VALUE, -1);
111 
112     av_parser_close(parser);
113 
114     if (avctx->sample_rate) {
115         avpriv_set_pts_info(st, 64, 1, avctx->sample_rate);
116         avcodec_free_context(&avctx);
117         return 0;
118     }
119 
120     avcodec_free_context(&avctx);
121     return 1;
122 fail:
123     av_parser_close(parser);
124     avcodec_free_context(&avctx);
125     return ret;
126 }
127 
128 const struct ogg_codec ff_flac_codec = {
129     .magic = "\177FLAC",
130     .magicsize = 5,
131     .header = flac_header,
132     .nb_header = 2,
133 };
134 
135 const struct ogg_codec ff_old_flac_codec = {
136     .magic = "fLaC",
137     .magicsize = 4,
138     .header = old_flac_header,
139     .nb_header = 0,
140 };
141