1/*
2 *
3 * This file is part of Libav.
4 *
5 * Libav is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU Lesser General Public
7 * License as published by the Free Software Foundation; either
8 * version 2.1 of the License, or (at your option) any later version.
9 *
10 * Libav 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 GNU
13 * Lesser General Public License for more details.
14 *
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with Libav; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
18 */
19
20#ifndef AVFORMAT_AVIO_INTERNAL_H
21#define AVFORMAT_AVIO_INTERNAL_H
22
23#include "avio.h"
24#include "url.h"
25
26#include "libavutil/log.h"
27
28extern const AVClass ffio_url_class;
29
30int ffio_init_context(AVIOContext *s,
31                  unsigned char *buffer,
32                  int buffer_size,
33                  int write_flag,
34                  void *opaque,
35                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
36                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
37                  int64_t (*seek)(void *opaque, int64_t offset, int whence));
38
39
40/**
41 * Read size bytes from AVIOContext into buf.
42 * This reads at most 1 packet. If that is not enough fewer bytes will be
43 * returned.
44 * @return number of bytes read or AVERROR
45 */
46int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size);
47
48void ffio_fill(AVIOContext *s, int b, int count);
49
50static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
51{
52    avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
53}
54
55/**
56 * Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
57 * Used after probing to avoid seeking.
58 * Joins buf and s->buffer, taking any overlap into consideration.
59 * @note s->buffer must overlap with buf or they can't be joined and the function fails
60 *
61 * @param s The read-only AVIOContext to rewind
62 * @param buf The probe buffer containing the first buf_size bytes of the file
63 * @param buf_size The size of buf
64 * @return 0 in case of success, a negative value corresponding to an
65 * AVERROR code in case of failure
66 */
67int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char *buf, int buf_size);
68
69uint64_t ffio_read_varlen(AVIOContext *bc);
70
71/** @warning must be called before any I/O */
72int ffio_set_buf_size(AVIOContext *s, int buf_size);
73
74void ffio_init_checksum(AVIOContext *s,
75                        unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
76                        unsigned long checksum);
77unsigned long ffio_get_checksum(AVIOContext *s);
78unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
79                                    unsigned int len);
80
81/**
82 * Open a write only packetized memory stream with a maximum packet
83 * size of 'max_packet_size'.  The stream is stored in a memory buffer
84 * with a big endian 4 byte header giving the packet size in bytes.
85 *
86 * @param s new IO context
87 * @param max_packet_size maximum packet size (must be > 0)
88 * @return zero if no error.
89 */
90int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
91
92/**
93 * Create and initialize a AVIOContext for accessing the
94 * resource referenced by the URLContext h.
95 * @note When the URLContext h has been opened in read+write mode, the
96 * AVIOContext can be used only for writing.
97 *
98 * @param s Used to return the pointer to the created AVIOContext.
99 * In case of failure the pointed to value is set to NULL.
100 * @return 0 in case of success, a negative value corresponding to an
101 * AVERROR code in case of failure
102 */
103int ffio_fdopen(AVIOContext **s, URLContext *h);
104
105#endif /* AVFORMAT_AVIO_INTERNAL_H */
106