3 * This file is part of FFmpeg.
5 * FFmpeg 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.
10 * FFmpeg 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.
15 * You should have received a copy of the GNU Lesser General Public
16 * License along with FFmpeg; if not, write to the Free Software
17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20 #ifndef AVFORMAT_AVIO_INTERNAL_H
21 #define AVFORMAT_AVIO_INTERNAL_H
26 #include "libavutil/log.h"
28 extern const AVClass ffio_url_class;
30 int ffio_init_context(AVIOContext *s,
31 unsigned char *buffer,
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));
41 * Read size bytes from AVIOContext into buf.
42 * This reads at most 1 packet. If that is not enough fewer bytes will be
44 * @return number of bytes read or AVERROR
46 int ffio_read_partial(AVIOContext *s, unsigned char *buf, int size);
48 void ffio_fill(AVIOContext *s, int b, int count);
50 static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
52 avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
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
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
67 int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **buf, int buf_size);
69 uint64_t ffio_read_varlen(AVIOContext *bc);
71 /** @warning must be called before any I/O */
72 int ffio_set_buf_size(AVIOContext *s, int buf_size);
75 * Ensures that the requested seekback buffer size will be available
77 * Will ensure that when reading sequentially up to buf_size, seeking
78 * within the current pos and pos+buf_size is possible.
79 * Once the stream position moves outside this window this gurantee is lost.
81 int ffio_ensure_seekback(AVIOContext *s, int buf_size);
83 int ffio_limit(AVIOContext *s, int size);
85 void ffio_init_checksum(AVIOContext *s,
86 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
87 unsigned long checksum);
88 unsigned long ffio_get_checksum(AVIOContext *s);
89 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
93 * Open a write only packetized memory stream with a maximum packet
94 * size of 'max_packet_size'. The stream is stored in a memory buffer
95 * with a big-endian 4 byte header giving the packet size in bytes.
97 * @param s new IO context
98 * @param max_packet_size maximum packet size (must be > 0)
99 * @return zero if no error.
101 int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);
104 * Create and initialize a AVIOContext for accessing the
105 * resource referenced by the URLContext h.
106 * @note When the URLContext h has been opened in read+write mode, the
107 * AVIOContext can be used only for writing.
109 * @param s Used to return the pointer to the created AVIOContext.
110 * In case of failure the pointed to value is set to NULL.
111 * @return 0 in case of success, a negative value corresponding to an
112 * AVERROR code in case of failure
114 int ffio_fdopen(AVIOContext **s, URLContext *h);
116 #endif /* AVFORMAT_AVIO_INTERNAL_H */