aboutsummaryrefslogtreecommitdiffstats
path: root/libavformat/avio_internal.h
blob: bd58499b64a76f29a8f6722b1f91ec6cca0cc94a (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
/*
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */

#ifndef AVFORMAT_AVIO_INTERNAL_H
#define AVFORMAT_AVIO_INTERNAL_H

#include "avio.h"

#include "libavutil/log.h"

extern const AVClass ff_avio_class;

typedef struct FFIOContext {
    AVIOContext pub;
    /**
     * A callback that is used instead of short_seek_threshold.
     */
    int (*short_seek_get)(void *opaque);

    /**
     * Threshold to favor readahead over seek.
     */
    int short_seek_threshold;

    enum AVIODataMarkerType current_type;
    int64_t last_time;

    /**
     * max filesize, used to limit allocations
     */
    int64_t maxsize;

    /**
     * Bytes read statistic
     */
    int64_t bytes_read;

    /**
     * Bytes written statistic
     */
    int64_t bytes_written;

    /**
     * seek statistic
     */
    int seek_count;

    /**
     * writeout statistic
     */
    int writeout_count;

    /**
     * Original buffer size
     * used after probing to ensure seekback and to reset the buffer size
     */
    int orig_buffer_size;

    /**
     * Written output size
     * is updated each time a successful writeout ends up further position-wise
     */
    int64_t written_output_size;
} FFIOContext;

static av_always_inline FFIOContext *ffiocontext(AVIOContext *ctx)
{
    return (FFIOContext*)ctx;
}

void ffio_init_context(FFIOContext *s,
                  unsigned char *buffer,
                  int buffer_size,
                  int write_flag,
                  void *opaque,
                  int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
#if FF_API_AVIO_WRITE_NONCONST
                  int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
#else
                  int (*write_packet)(void *opaque, const uint8_t *buf, int buf_size),
#endif
                  int64_t (*seek)(void *opaque, int64_t offset, int whence));

/**
 * Wrap a buffer in an AVIOContext for reading.
 */
void ffio_init_read_context(FFIOContext *s, const uint8_t *buffer, int buffer_size);

/**
 * Wrap a buffer in an AVIOContext for writing.
 */
void ffio_init_write_context(FFIOContext *s, uint8_t *buffer, int buffer_size);

/**
 * Read size bytes from AVIOContext, returning a pointer.
 * Note that the data pointed at by the returned pointer is only
 * valid until the next call that references the same IO context.
 * @param s IO context
 * @param buf pointer to buffer into which to assemble the requested
 *    data if it is not available in contiguous addresses in the
 *    underlying buffer
 * @param size number of bytes requested
 * @param data address at which to store pointer: this will be a
 *    a direct pointer into the underlying buffer if the requested
 *    number of bytes are available at contiguous addresses, otherwise
 *    will be a copy of buf
 * @return number of bytes read or AVERROR
 */
int ffio_read_indirect(AVIOContext *s, unsigned char *buf, int size, const unsigned char **data);

void ffio_fill(AVIOContext *s, int b, int64_t count);

static av_always_inline void ffio_wfourcc(AVIOContext *pb, const uint8_t *s)
{
    avio_wl32(pb, MKTAG(s[0], s[1], s[2], s[3]));
}

/**
 * Rewind the AVIOContext using the specified buffer containing the first buf_size bytes of the file.
 * Used after probing to avoid seeking.
 * Joins buf and s->buffer, taking any overlap into consideration.
 * @note s->buffer must overlap with buf or they can't be joined and the function fails
 *
 * @param s The read-only AVIOContext to rewind
 * @param buf The probe buffer containing the first buf_size bytes of the file
 * @param buf_size The size of buf
 * @return >= 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 */
int ffio_rewind_with_probe_data(AVIOContext *s, unsigned char **buf, int buf_size);

uint64_t ffio_read_varlen(AVIOContext *bc);

/**
 * Read size bytes from AVIOContext into buf.
 * Check that exactly size bytes have been read.
 * @return number of bytes read or AVERROR
 */
int ffio_read_size(AVIOContext *s, unsigned char *buf, int size);

/**
 * Reallocate a given buffer for AVIOContext.
 *
 * @param s the AVIOContext to realloc.
 * @param buf_size required new buffer size.
 * @return 0 on success, a negative AVERROR on failure.
 */
int ffio_realloc_buf(AVIOContext *s, int buf_size);

/**
 * Ensures that the requested seekback buffer size will be available
 *
 * Will ensure that when reading sequentially up to buf_size, seeking
 * within the current pos and pos+buf_size is possible.
 * Once the stream position moves outside this window or another
 * ffio_ensure_seekback call requests a buffer outside this window this
 * guarantee is lost.
 */
int ffio_ensure_seekback(AVIOContext *s, int64_t buf_size);

int ffio_limit(AVIOContext *s, int size);

void ffio_init_checksum(AVIOContext *s,
                        unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
                        unsigned long checksum);
unsigned long ffio_get_checksum(AVIOContext *s);
unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
                                    unsigned int len);
unsigned long ff_crcEDB88320_update(unsigned long checksum, const uint8_t *buf,
                                    unsigned int len);
unsigned long ff_crcA001_update(unsigned long checksum, const uint8_t *buf,
                                unsigned int len);

/**
 * Open a write only packetized memory stream with a maximum packet
 * size of 'max_packet_size'.  The stream is stored in a memory buffer
 * with a big-endian 4 byte header giving the packet size in bytes.
 *
 * @param s new IO context
 * @param max_packet_size maximum packet size (must be > 0)
 * @return zero if no error.
 */
int ffio_open_dyn_packet_buf(AVIOContext **s, int max_packet_size);

/**
 * Return the URLContext associated with the AVIOContext
 *
 * @param s IO context
 * @return pointer to URLContext or NULL.
 */
struct URLContext *ffio_geturlcontext(AVIOContext *s);

/**
 * Create and initialize a AVIOContext for accessing the
 * resource referenced by the URLContext h.
 * @note When the URLContext h has been opened in read+write mode, the
 * AVIOContext can be used only for writing.
 *
 * @param s Used to return the pointer to the created AVIOContext.
 * In case of failure the pointed to value is set to NULL.
 * @return >= 0 in case of success, a negative value corresponding to an
 * AVERROR code in case of failure
 */
int ffio_fdopen(AVIOContext **s, struct URLContext *h);


/**
 * Read url related dictionary options from the AVIOContext and write to the given dictionary
 */
int ffio_copy_url_options(AVIOContext* pb, AVDictionary** avio_opts);

/**
 * Open a write-only fake memory stream. The written data is not stored
 * anywhere - this is only used for measuring the amount of data
 * written.
 *
 * @param s new IO context
 * @return zero if no error.
 */
int ffio_open_null_buf(AVIOContext **s);

int ffio_open_whitelist(AVIOContext **s, const char *url, int flags,
                         const AVIOInterruptCB *int_cb, AVDictionary **options,
                         const char *whitelist, const char *blacklist);

/**
 * Close a null buffer.
 *
 * @param s an IO context opened by ffio_open_null_buf
 * @return the number of bytes written to the null buffer
 */
int ffio_close_null_buf(AVIOContext *s);

/**
 * Reset a dynamic buffer.
 *
 * Resets everything, but keeps the allocated buffer for later use.
 */
void ffio_reset_dyn_buf(AVIOContext *s);

/**
 * Free a dynamic buffer.
 *
 * @param s a pointer to an IO context opened by avio_open_dyn_buf()
 */
void ffio_free_dyn_buf(AVIOContext **s);

struct AVBPrint;
/**
 * Read a whole line of text from AVIOContext to an AVBPrint buffer overwriting
 * its contents. Stop reading after reaching a \\r, a \\n, a \\r\\n, a \\0 or
 * EOF. The line ending characters are NOT included in the buffer, but they
 * are skipped on the input.
 *
 * @param s the read-only AVIOContext
 * @param bp the AVBPrint buffer
 * @return the length of the read line not including the line endings,
 *         negative on error, or if the buffer becomes truncated.
 */
int64_t ff_read_line_to_bprint_overwrite(AVIOContext *s, struct AVBPrint *bp);

/**
 * Read a whole null-terminated string of text from AVIOContext to an AVBPrint
 * buffer overwriting its contents. Stop reading after reaching the maximum
 * length, a \\0 or EOF.
 *
 * @param s the read-only AVIOContext
 * @param bp the AVBPrint buffer
 * @param max_len the maximum length to be read from the AVIOContext.
 *                Negative (< 0) values signal that there is no known maximum
 *                length applicable. A maximum length of zero means that the
 *                AVIOContext is not touched, and the function returns
 *                with a read length of zero. In all cases the AVBprint
 *                is cleared.
 * @return the length of the read string not including the terminating null,
 *         negative on error, or if the buffer becomes truncated.
 */
int64_t ff_read_string_to_bprint_overwrite(AVIOContext *s, struct AVBPrint *bp,
                                           int64_t max_len);

#endif /* AVFORMAT_AVIO_INTERNAL_H */