1 /*
2 ** Copyright (C) 2008-2011 Erik de Castro Lopo <erikd@mega-nerd.com>
3 ** Copyright (C) 2018 Arthur Taylor <art@ified.ca>
4 **
5 ** This program is free software ; you can redistribute it and/or modify
6 ** it under the terms of the GNU Lesser General Public License as published by
7 ** the Free Software Foundation ; either version 2.1 of the License, or
8 ** (at your option) any later version.
9 **
10 ** This program is distributed in the hope that it will be useful,
11 ** but WITHOUT ANY WARRANTY ; without even the implied warranty of
12 ** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
13 ** GNU Lesser General Public License for more details.
14 **
15 ** You should have received a copy of the GNU Lesser General Public License
16 ** along with this program ; if not, write to the Free Software
17 ** Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
18 */
19
20 #ifndef SF_SRC_OGG_H
21 #define SF_SRC_OGG_H
22
23 enum
24 { OGG_ANNODEX = 300,
25 OGG_ANXDATA,
26 OGG_FLAC,
27 OGG_FLAC0,
28 OGG_PCM,
29 OGG_SPEEX,
30 OGG_VORBIS,
31 OGG_OPUS,
32 } ;
33
34 typedef struct
35 { /* Sync and verify incoming physical bitstream */
36 ogg_sync_state osync ;
37 /* Take physical pages, weld into a logical stream of packets */
38 ogg_stream_state ostream ;
39 /* One Ogg bitstream page. Codec packets are inside */
40 ogg_page opage ;
41 /* One raw packet of data for decode */
42 ogg_packet opacket ;
43
44 /* Unpacked packets. 255 is max there can ever be in one page. */
45 ogg_packet pkt [255] ;
46 /* How many packets */
47 int pkt_len ;
48 /* Current packet */
49 int pkt_indx ;
50
51 int eos ;
52 int codec ;
53 } OGG_PRIVATE ;
54
55
56 #define readint(buf, base) (((buf [base + 3] << 24) & 0xff000000) | \
57 ((buf [base + 2] <<16) & 0xff0000) | \
58 ((buf [base + 1] << 8) & 0xff00) | \
59 (buf [base] & 0xff))
60 /*-----------------------------------------------------------------------------------------------
61 ** Inline functions.
62 */
63
64 /*
65 ** LibOgg documentation is noted as being bad by it's author.
66 ** Add some useful utility inline functions for introspecting Ogg pages.
67 */
68
69 /* ogg_page_segments returns how many segments are in this page. */
70 static inline int
ogg_page_segments(ogg_page * pg)71 ogg_page_segments (ogg_page *pg)
72 { return (int) (pg->header [26]) ; }
73
74 /* ogg_page_continues returns true if this page ends in a continued packet. */
75 static inline int
ogg_page_continues(ogg_page * pg)76 ogg_page_continues (ogg_page *pg)
77 { return pg->header [27 + pg->header [26] - 1] == 255 ;
78 }
79
80 /*-----------------------------------------------------------------------------------------------
81 ** Exported functions.
82 */
83
84 /*
85 ** ogg_read_first_page loads the first Ogg page found in the file, and sets the
86 ** OGG_PRIVATE serialno to match the logical stream of the page. Data is read
87 ** without seeking backwards, loading any data present from psf->header into
88 ** the ogg_sync state first, so that this function works with pipes.
89 */
90 int ogg_read_first_page (SF_PRIVATE *, OGG_PRIVATE *) ;
91
92 /*
93 ** Write the whole Ogg page out. Convenience function as the ogg_page struct
94 ** splits header and body data into separate buffers.
95 */
96 int ogg_write_page (SF_PRIVATE *, ogg_page *) ;
97
98 /*
99 ** Wrapper around psf_ftell() that returns the current offset in the file after
100 ** the most recent page that has been returned by ogg_sync_pageout().
101 */
102 sf_count_t ogg_sync_ftell (SF_PRIVATE *) ;
103
104 /*
105 ** Wrapper around psf_fseek() that on success resets the ogg_sync_state struct
106 ** so that it doesn't get corrupted.
107 */
108 sf_count_t ogg_sync_fseek (SF_PRIVATE *, sf_count_t offset, int whence) ;
109
110 /*
111 ** Get the next page from the physical bitstream, reading in data as necessary.
112 ** Pays no attention to Ogg BOS/EOS markers or stream serial numbers.
113 ** The page is buffered in the ogg_sync_state struct, (replacing any other
114 ** buffered there) and also returned in *og. readmax sets a boundary for how
115 ** many bytes more may be read from the file, use already buffered only, or
116 ** unlimited reading in the case of a positive, zero or negative argument
117 ** respectively. If a pointer to a sf_count_t is passed in offset, then it will
118 ** be incremented by how many bytes were skipped to find the next page header.
119 ** (Useful for seeking, normally zero.) Returns the page size in bytes on
120 ** success, 0 on out-of-data (be it end of file or readmax reached) and -1 on
121 ** error with psf->error set appropriately.
122 */
123 int ogg_sync_next_page (SF_PRIVATE * psf, ogg_page *og, sf_count_t readmax, sf_count_t *offset) ;
124
125 /*
126 ** Load the last page of a stream before the provided file offset. Searches the
127 ** physical bitstream, and selects a page of the passed serialno. The page
128 ** found is loaded in the sync buffer and exposed in odata->opage, and not
129 ** loaded into the ogg_stream_state. If found, the granulepos is returned in
130 ** *gp_out. Returns the file offset *before* the last page on success, or -1 on
131 ** error, setting psf->error as appropriate.
132 */
133 sf_count_t ogg_sync_last_page_before (SF_PRIVATE *psf, OGG_PRIVATE *odata, uint64_t *gp_out, sf_count_t offset, int32_t serialno) ;
134
135 /*
136 ** Load the next page from the virtual bitstream, reading data as necessary.
137 ** Reads in pages from the physical bitstream, skipping pages until one of the
138 ** virtual bitstream of interest is found, and then feeds it into the
139 ** ogg_stream_state of odata->ostream, where it is buffered. Heeds EOS markers.
140 ** Returns 1 on success, 0 on end of stream, and -1 on fatal error.
141 */
142 int ogg_stream_next_page (SF_PRIVATE * psf, OGG_PRIVATE *odata) ;
143
144 /*
145 ** Loads the next page using ogg_stream_next_page() and unpacks all packets
146 ** into the array odata->pkt, updating odata->pkt_len and setting
147 ** odata->pkt_indx to 0. Returns 1 if okay, 2 if okay but a hole was found
148 ** in the bitstream, 0 if on end of stream, and -1 on fatal error.
149 */
150 int ogg_stream_unpack_page (SF_PRIVATE *psf, OGG_PRIVATE *odata) ;
151
152 /*
153 ** Seek within the Ogg virtual bitstream for a page containing target_gp.
154 ** Preforms a bisection search. If not found exactly, the best result is
155 ** returned in *best_gp. Found page is loaded into the virtual bitstream,
156 ** ready for unpacking. Arguments pcm_start and pcm_end are the highest and
157 ** lowest granule positions of the file. begin and end are the file offset
158 ** range to search. gp_rate is an information hint so granule positions can
159 ** be correlated to playback time, so the search can figure out how close it
160 ** is, should be granule positions per second.
161 */
162 int ogg_stream_seek_page_search (SF_PRIVATE *psf, OGG_PRIVATE *odata,
163 uint64_t target_gp,
164 uint64_t pcm_start, uint64_t pcm_end,
165 uint64_t *best_gp,
166 sf_count_t begin, sf_count_t end,
167 uint64_t gp_rate) ;
168
169 #endif /* SF_SRC_OGG_H */
170