1/* 2 * copyright (c) 2001 Fabrice Bellard 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#ifndef AVFORMAT_AVIO_H 21#define AVFORMAT_AVIO_H 22 23/** 24 * @file libavformat/avio.h 25 * unbuffered I/O operations 26 * 27 * @warning This file has to be considered an internal but installed 28 * header, so it should not be directly included in your projects. 29 */ 30 31#include <stdint.h> 32 33#include "libavutil/common.h" 34 35/* unbuffered I/O */ 36 37/** 38 * URL Context. 39 * New fields can be added to the end with minor version bumps. 40 * Removal, reordering and changes to existing fields require a major 41 * version bump. 42 * sizeof(URLContext) must not be used outside libav*. 43 */ 44struct URLContext { 45#if LIBAVFORMAT_VERSION_MAJOR >= 53 46 const AVClass *av_class; ///< information for av_log(). Set by url_open(). 47#endif 48 struct URLProtocol *prot; 49 int flags; 50 int is_streamed; /**< true if streamed (no seek possible), default = false */ 51 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */ 52 void *priv_data; 53 char *filename; /**< specified filename */ 54}; 55 56typedef struct URLContext URLContext; 57 58typedef struct URLPollEntry { 59 URLContext *handle; 60 int events; 61 int revents; 62} URLPollEntry; 63 64#define URL_RDONLY 0 65#define URL_WRONLY 1 66#define URL_RDWR 2 67 68typedef int URLInterruptCB(void); 69 70int url_open_protocol (URLContext **puc, struct URLProtocol *up, 71 const char *filename, int flags); 72int url_open(URLContext **h, const char *filename, int flags); 73int url_read(URLContext *h, unsigned char *buf, int size); 74int url_write(URLContext *h, unsigned char *buf, int size); 75int64_t url_seek(URLContext *h, int64_t pos, int whence); 76int url_close(URLContext *h); 77int url_exist(const char *filename); 78int64_t url_filesize(URLContext *h); 79 80/** 81 * Return the maximum packet size associated to packetized file 82 * handle. If the file is not packetized (stream like HTTP or file on 83 * disk), then 0 is returned. 84 * 85 * @param h file handle 86 * @return maximum packet size in bytes 87 */ 88int url_get_max_packet_size(URLContext *h); 89void url_get_filename(URLContext *h, char *buf, int buf_size); 90 91/** 92 * The callback is called in blocking functions to test regulary if 93 * asynchronous interruption is needed. AVERROR(EINTR) is returned 94 * in this case by the interrupted function. 'NULL' means no interrupt 95 * callback is given. 96 */ 97void url_set_interrupt_cb(URLInterruptCB *interrupt_cb); 98 99/* not implemented */ 100int url_poll(URLPollEntry *poll_table, int n, int timeout); 101 102/** 103 * Pause and resume playing - only meaningful if using a network streaming 104 * protocol (e.g. MMS). 105 * @param pause 1 for pause, 0 for resume 106 */ 107int av_url_read_pause(URLContext *h, int pause); 108 109/** 110 * Seek to a given timestamp relative to some component stream. 111 * Only meaningful if using a network streaming protocol (e.g. MMS.). 112 * @param stream_index The stream index that the timestamp is relative to. 113 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE 114 * units from the beginning of the presentation. 115 * If a stream_index >= 0 is used and the protocol does not support 116 * seeking based on component streams, the call will fail with ENOTSUP. 117 * @param timestamp timestamp in AVStream.time_base units 118 * or if there is no stream specified then in AV_TIME_BASE units. 119 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE 120 * and AVSEEK_FLAG_ANY. The protocol may silently ignore 121 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will 122 * fail with ENOTSUP if used and not supported. 123 * @return >= 0 on success 124 * @see AVInputFormat::read_seek 125 */ 126int64_t av_url_read_seek(URLContext *h, int stream_index, 127 int64_t timestamp, int flags); 128 129/** 130 * Passing this as the "whence" parameter to a seek function causes it to 131 * return the filesize without seeking anywhere. Supporting this is optional. 132 * If it is not supported then the seek function will return <0. 133 */ 134#define AVSEEK_SIZE 0x10000 135 136typedef struct URLProtocol { 137 const char *name; 138 int (*url_open)(URLContext *h, const char *filename, int flags); 139 int (*url_read)(URLContext *h, unsigned char *buf, int size); 140 int (*url_write)(URLContext *h, unsigned char *buf, int size); 141 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence); 142 int (*url_close)(URLContext *h); 143 struct URLProtocol *next; 144 int (*url_read_pause)(URLContext *h, int pause); 145 int64_t (*url_read_seek)(URLContext *h, int stream_index, 146 int64_t timestamp, int flags); 147} URLProtocol; 148 149#if LIBAVFORMAT_VERSION_MAJOR < 53 150extern URLProtocol *first_protocol; 151#endif 152 153extern URLInterruptCB *url_interrupt_cb; 154 155/** 156 * If protocol is NULL, returns the first registered protocol, 157 * if protocol is non-NULL, returns the next registered protocol after protocol, 158 * or NULL if protocol is the last one. 159 */ 160URLProtocol *av_protocol_next(URLProtocol *p); 161 162#if LIBAVFORMAT_VERSION_MAJOR < 53 163/** 164 * @deprecated Use av_register_protocol() instead. 165 */ 166attribute_deprecated int register_protocol(URLProtocol *protocol); 167#endif 168 169int av_register_protocol(URLProtocol *protocol); 170 171/** 172 * Bytestream IO Context. 173 * New fields can be added to the end with minor version bumps. 174 * Removal, reordering and changes to existing fields require a major 175 * version bump. 176 * sizeof(ByteIOContext) must not be used outside libav*. 177 */ 178typedef struct { 179 unsigned char *buffer; 180 int buffer_size; 181 unsigned char *buf_ptr, *buf_end; 182 void *opaque; 183 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size); 184 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size); 185 int64_t (*seek)(void *opaque, int64_t offset, int whence); 186 int64_t pos; /**< position in the file of the current buffer */ 187 int must_flush; /**< true if the next seek should flush */ 188 int eof_reached; /**< true if eof reached */ 189 int write_flag; /**< true if open for writing */ 190 int is_streamed; 191 int max_packet_size; 192 unsigned long checksum; 193 unsigned char *checksum_ptr; 194 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size); 195 int error; ///< contains the error code or 0 if no error happened 196 int (*read_pause)(void *opaque, int pause); 197 int64_t (*read_seek)(void *opaque, int stream_index, 198 int64_t timestamp, int flags); 199} ByteIOContext; 200 201int init_put_byte(ByteIOContext *s, 202 unsigned char *buffer, 203 int buffer_size, 204 int write_flag, 205 void *opaque, 206 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), 207 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), 208 int64_t (*seek)(void *opaque, int64_t offset, int whence)); 209ByteIOContext *av_alloc_put_byte( 210 unsigned char *buffer, 211 int buffer_size, 212 int write_flag, 213 void *opaque, 214 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), 215 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), 216 int64_t (*seek)(void *opaque, int64_t offset, int whence)); 217 218void put_byte(ByteIOContext *s, int b); 219void put_buffer(ByteIOContext *s, const unsigned char *buf, int size); 220void put_le64(ByteIOContext *s, uint64_t val); 221void put_be64(ByteIOContext *s, uint64_t val); 222void put_le32(ByteIOContext *s, unsigned int val); 223void put_be32(ByteIOContext *s, unsigned int val); 224void put_le24(ByteIOContext *s, unsigned int val); 225void put_be24(ByteIOContext *s, unsigned int val); 226void put_le16(ByteIOContext *s, unsigned int val); 227void put_be16(ByteIOContext *s, unsigned int val); 228void put_tag(ByteIOContext *s, const char *tag); 229 230void put_strz(ByteIOContext *s, const char *buf); 231 232/** 233 * fseek() equivalent for ByteIOContext. 234 * @return new position or AVERROR. 235 */ 236int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence); 237 238/** 239 * Skip given number of bytes forward. 240 * @param offset number of bytes 241 */ 242void url_fskip(ByteIOContext *s, int64_t offset); 243 244/** 245 * ftell() equivalent for ByteIOContext. 246 * @return position or AVERROR. 247 */ 248int64_t url_ftell(ByteIOContext *s); 249 250/** 251 * Gets the filesize. 252 * @return filesize or AVERROR 253 */ 254int64_t url_fsize(ByteIOContext *s); 255 256/** 257 * feof() equivalent for ByteIOContext. 258 * @return non zero if and only if end of file 259 */ 260int url_feof(ByteIOContext *s); 261 262int url_ferror(ByteIOContext *s); 263 264int av_url_read_fpause(ByteIOContext *h, int pause); 265int64_t av_url_read_fseek(ByteIOContext *h, int stream_index, 266 int64_t timestamp, int flags); 267 268#define URL_EOF (-1) 269/** @note return URL_EOF (-1) if EOF */ 270int url_fgetc(ByteIOContext *s); 271 272/** @warning currently size is limited */ 273#ifdef __GNUC__ 274int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3))); 275#else 276int url_fprintf(ByteIOContext *s, const char *fmt, ...); 277#endif 278 279/** @note unlike fgets, the EOL character is not returned and a whole 280 line is parsed. return NULL if first char read was EOF */ 281char *url_fgets(ByteIOContext *s, char *buf, int buf_size); 282 283void put_flush_packet(ByteIOContext *s); 284 285 286/** 287 * Reads size bytes from ByteIOContext into buf. 288 * @returns number of bytes read or AVERROR 289 */ 290int get_buffer(ByteIOContext *s, unsigned char *buf, int size); 291 292/** 293 * Reads size bytes from ByteIOContext into buf. 294 * This reads at most 1 packet. If that is not enough fewer bytes will be 295 * returned. 296 * @returns number of bytes read or AVERROR 297 */ 298int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size); 299 300/** @note return 0 if EOF, so you cannot use it if EOF handling is 301 necessary */ 302int get_byte(ByteIOContext *s); 303unsigned int get_le24(ByteIOContext *s); 304unsigned int get_le32(ByteIOContext *s); 305uint64_t get_le64(ByteIOContext *s); 306unsigned int get_le16(ByteIOContext *s); 307 308char *get_strz(ByteIOContext *s, char *buf, int maxlen); 309unsigned int get_be16(ByteIOContext *s); 310unsigned int get_be24(ByteIOContext *s); 311unsigned int get_be32(ByteIOContext *s); 312uint64_t get_be64(ByteIOContext *s); 313 314uint64_t ff_get_v(ByteIOContext *bc); 315 316static inline int url_is_streamed(ByteIOContext *s) 317{ 318 return s->is_streamed; 319} 320 321/** @note when opened as read/write, the buffers are only used for 322 writing */ 323int url_fdopen(ByteIOContext **s, URLContext *h); 324 325/** @warning must be called before any I/O */ 326int url_setbufsize(ByteIOContext *s, int buf_size); 327/** Reset the buffer for reading or writing. 328 * @note Will drop any data currently in the buffer without transmitting it. 329 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY 330 * to set up the buffer for writing. */ 331int url_resetbuf(ByteIOContext *s, int flags); 332 333/** @note when opened as read/write, the buffers are only used for 334 writing */ 335int url_fopen(ByteIOContext **s, const char *filename, int flags); 336int url_fclose(ByteIOContext *s); 337URLContext *url_fileno(ByteIOContext *s); 338 339/** 340 * Return the maximum packet size associated to packetized buffered file 341 * handle. If the file is not packetized (stream like http or file on 342 * disk), then 0 is returned. 343 * 344 * @param s buffered file handle 345 * @return maximum packet size in bytes 346 */ 347int url_fget_max_packet_size(ByteIOContext *s); 348 349int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags); 350 351/** return the written or read size */ 352int url_close_buf(ByteIOContext *s); 353 354/** 355 * Open a write only memory stream. 356 * 357 * @param s new IO context 358 * @return zero if no error. 359 */ 360int url_open_dyn_buf(ByteIOContext **s); 361 362/** 363 * Open a write only packetized memory stream with a maximum packet 364 * size of 'max_packet_size'. The stream is stored in a memory buffer 365 * with a big endian 4 byte header giving the packet size in bytes. 366 * 367 * @param s new IO context 368 * @param max_packet_size maximum packet size (must be > 0) 369 * @return zero if no error. 370 */ 371int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size); 372 373/** 374 * Return the written size and a pointer to the buffer. The buffer 375 * must be freed with av_free(). 376 * @param s IO context 377 * @param pbuffer pointer to a byte buffer 378 * @return the length of the byte buffer 379 */ 380int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer); 381 382unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, 383 unsigned int len); 384unsigned long get_checksum(ByteIOContext *s); 385void init_checksum(ByteIOContext *s, 386 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), 387 unsigned long checksum); 388 389/* udp.c */ 390int udp_set_remote_url(URLContext *h, const char *uri); 391int udp_get_local_port(URLContext *h); 392int udp_get_file_handle(URLContext *h); 393 394#endif /* AVFORMAT_AVIO_H */ 395