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 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 */ 44typedef struct 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 URL */ 54} URLContext; 55 56typedef struct URLPollEntry { 57 URLContext *handle; 58 int events; 59 int revents; 60} URLPollEntry; 61 62#define URL_RDONLY 0 63#define URL_WRONLY 1 64#define URL_RDWR 2 65 66typedef int URLInterruptCB(void); 67 68/** 69 * Creates an URLContext for accessing to the resource indicated by 70 * url, and opens it using the URLProtocol up. 71 * 72 * @param puc pointer to the location where, in case of success, the 73 * function puts the pointer to the created URLContext 74 * @param flags flags which control how the resource indicated by url 75 * is to be opened 76 * @return 0 in case of success, a negative value corresponding to an 77 * AVERROR code in case of failure 78 */ 79int url_open_protocol (URLContext **puc, struct URLProtocol *up, 80 const char *url, int flags); 81 82/** 83 * Creates an URLContext for accessing to the resource indicated by 84 * url, and opens it. 85 * 86 * @param puc pointer to the location where, in case of success, the 87 * function puts the pointer to the created URLContext 88 * @param flags flags which control how the resource indicated by url 89 * is to be opened 90 * @return 0 in case of success, a negative value corresponding to an 91 * AVERROR code in case of failure 92 */ 93int url_open(URLContext **h, const char *url, int flags); 94 95/** 96 * Reads up to size bytes from the resource accessed by h, and stores 97 * the read bytes in buf. 98 * 99 * @return The number of bytes actually read, or a negative value 100 * corresponding to an AVERROR code in case of error. A value of zero 101 * indicates that it is not possible to read more from the accessed 102 * resource (except if the value of the size argument is also zero). 103 */ 104int url_read(URLContext *h, unsigned char *buf, int size); 105 106/** 107 * Read as many bytes as possible (up to size), calling the 108 * read function multiple times if necessary. 109 * Will also retry if the read function returns AVERROR(EAGAIN). 110 * This makes special short-read handling in applications 111 * unnecessary, if the return value is < size then it is 112 * certain there was either an error or the end of file was reached. 113 */ 114int url_read_complete(URLContext *h, unsigned char *buf, int size); 115int url_write(URLContext *h, unsigned char *buf, int size); 116 117/** 118 * Changes the position that will be used by the next read/write 119 * operation on the resource accessed by h. 120 * 121 * @param pos specifies the new position to set 122 * @param whence specifies how pos should be interpreted, it must be 123 * one of SEEK_SET (seek from the beginning), SEEK_CUR (seek from the 124 * current position), SEEK_END (seek from the end), or AVSEEK_SIZE 125 * (return the filesize of the requested resource, pos is ignored). 126 * @return a negative value corresponding to an AVERROR code in case 127 * of failure, or the resulting file position, measured in bytes from 128 * the beginning of the file. You can use this feature together with 129 * SEEK_CUR to read the current file position. 130 */ 131int64_t url_seek(URLContext *h, int64_t pos, int whence); 132 133/** 134 * Closes the resource accessed by the URLContext h, and frees the 135 * memory used by it. 136 * 137 * @return a negative value if an error condition occurred, 0 138 * otherwise 139 */ 140int url_close(URLContext *h); 141 142/** 143 * Returns a non-zero value if the resource indicated by url 144 * exists, 0 otherwise. 145 */ 146int url_exist(const char *url); 147 148int64_t url_filesize(URLContext *h); 149 150/** 151 * Return the file descriptor associated with this URL. For RTP, this 152 * will return only the RTP file descriptor, not the RTCP file descriptor. 153 * To get both, use rtp_get_file_handles(). 154 * 155 * @return the file descriptor associated with this URL, or <0 on error. 156 */ 157int url_get_file_handle(URLContext *h); 158 159/** 160 * Return the maximum packet size associated to packetized file 161 * handle. If the file is not packetized (stream like HTTP or file on 162 * disk), then 0 is returned. 163 * 164 * @param h file handle 165 * @return maximum packet size in bytes 166 */ 167int url_get_max_packet_size(URLContext *h); 168void url_get_filename(URLContext *h, char *buf, int buf_size); 169 170/** 171 * The callback is called in blocking functions to test regulary if 172 * asynchronous interruption is needed. AVERROR(EINTR) is returned 173 * in this case by the interrupted function. 'NULL' means no interrupt 174 * callback is given. 175 */ 176void url_set_interrupt_cb(URLInterruptCB *interrupt_cb); 177 178/* not implemented */ 179int url_poll(URLPollEntry *poll_table, int n, int timeout); 180 181/** 182 * Pause and resume playing - only meaningful if using a network streaming 183 * protocol (e.g. MMS). 184 * @param pause 1 for pause, 0 for resume 185 */ 186int av_url_read_pause(URLContext *h, int pause); 187 188/** 189 * Seek to a given timestamp relative to some component stream. 190 * Only meaningful if using a network streaming protocol (e.g. MMS.). 191 * @param stream_index The stream index that the timestamp is relative to. 192 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE 193 * units from the beginning of the presentation. 194 * If a stream_index >= 0 is used and the protocol does not support 195 * seeking based on component streams, the call will fail with ENOTSUP. 196 * @param timestamp timestamp in AVStream.time_base units 197 * or if there is no stream specified then in AV_TIME_BASE units. 198 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE 199 * and AVSEEK_FLAG_ANY. The protocol may silently ignore 200 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will 201 * fail with ENOTSUP if used and not supported. 202 * @return >= 0 on success 203 * @see AVInputFormat::read_seek 204 */ 205int64_t av_url_read_seek(URLContext *h, int stream_index, 206 int64_t timestamp, int flags); 207 208/** 209 * Passing this as the "whence" parameter to a seek function causes it to 210 * return the filesize without seeking anywhere. Supporting this is optional. 211 * If it is not supported then the seek function will return <0. 212 */ 213#define AVSEEK_SIZE 0x10000 214 215/** 216 * Oring this flag as into the "whence" parameter to a seek function causes it to 217 * seek by any means (like reopening and linear reading) or other normally unreasonble 218 * means that can be extreemly slow. 219 * This may be ignored by the seek code. 220 */ 221#define AVSEEK_FORCE 0x20000 222 223typedef struct URLProtocol { 224 const char *name; 225 int (*url_open)(URLContext *h, const char *url, int flags); 226 int (*url_read)(URLContext *h, unsigned char *buf, int size); 227 int (*url_write)(URLContext *h, unsigned char *buf, int size); 228 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence); 229 int (*url_close)(URLContext *h); 230 struct URLProtocol *next; 231 int (*url_read_pause)(URLContext *h, int pause); 232 int64_t (*url_read_seek)(URLContext *h, int stream_index, 233 int64_t timestamp, int flags); 234 int (*url_get_file_handle)(URLContext *h); 235} URLProtocol; 236 237#if LIBAVFORMAT_VERSION_MAJOR < 53 238extern URLProtocol *first_protocol; 239#endif 240 241extern URLInterruptCB *url_interrupt_cb; 242 243/** 244 * If protocol is NULL, returns the first registered protocol, 245 * if protocol is non-NULL, returns the next registered protocol after protocol, 246 * or NULL if protocol is the last one. 247 */ 248URLProtocol *av_protocol_next(URLProtocol *p); 249 250#if LIBAVFORMAT_VERSION_MAJOR < 53 251/** 252 * @deprecated Use av_register_protocol() instead. 253 */ 254attribute_deprecated int register_protocol(URLProtocol *protocol); 255#endif 256 257/** 258 * Registers the URLProtocol protocol. 259 */ 260int av_register_protocol(URLProtocol *protocol); 261 262/** 263 * Bytestream IO Context. 264 * New fields can be added to the end with minor version bumps. 265 * Removal, reordering and changes to existing fields require a major 266 * version bump. 267 * sizeof(ByteIOContext) must not be used outside libav*. 268 */ 269typedef struct { 270 unsigned char *buffer; 271 int buffer_size; 272 unsigned char *buf_ptr, *buf_end; 273 void *opaque; 274 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size); 275 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size); 276 int64_t (*seek)(void *opaque, int64_t offset, int whence); 277 int64_t pos; /**< position in the file of the current buffer */ 278 int must_flush; /**< true if the next seek should flush */ 279 int eof_reached; /**< true if eof reached */ 280 int write_flag; /**< true if open for writing */ 281 int is_streamed; 282 int max_packet_size; 283 unsigned long checksum; 284 unsigned char *checksum_ptr; 285 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size); 286 int error; ///< contains the error code or 0 if no error happened 287 int (*read_pause)(void *opaque, int pause); 288 int64_t (*read_seek)(void *opaque, int stream_index, 289 int64_t timestamp, int flags); 290} ByteIOContext; 291 292int init_put_byte(ByteIOContext *s, 293 unsigned char *buffer, 294 int buffer_size, 295 int write_flag, 296 void *opaque, 297 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), 298 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), 299 int64_t (*seek)(void *opaque, int64_t offset, int whence)); 300ByteIOContext *av_alloc_put_byte( 301 unsigned char *buffer, 302 int buffer_size, 303 int write_flag, 304 void *opaque, 305 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size), 306 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size), 307 int64_t (*seek)(void *opaque, int64_t offset, int whence)); 308 309void put_byte(ByteIOContext *s, int b); 310void put_buffer(ByteIOContext *s, const unsigned char *buf, int size); 311void put_le64(ByteIOContext *s, uint64_t val); 312void put_be64(ByteIOContext *s, uint64_t val); 313void put_le32(ByteIOContext *s, unsigned int val); 314void put_be32(ByteIOContext *s, unsigned int val); 315void put_le24(ByteIOContext *s, unsigned int val); 316void put_be24(ByteIOContext *s, unsigned int val); 317void put_le16(ByteIOContext *s, unsigned int val); 318void put_be16(ByteIOContext *s, unsigned int val); 319void put_tag(ByteIOContext *s, const char *tag); 320 321void put_strz(ByteIOContext *s, const char *buf); 322 323/** 324 * fseek() equivalent for ByteIOContext. 325 * @return new position or AVERROR. 326 */ 327int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence); 328 329/** 330 * Skip given number of bytes forward. 331 * @param offset number of bytes 332 */ 333void url_fskip(ByteIOContext *s, int64_t offset); 334 335/** 336 * ftell() equivalent for ByteIOContext. 337 * @return position or AVERROR. 338 */ 339int64_t url_ftell(ByteIOContext *s); 340 341/** 342 * Gets the filesize. 343 * @return filesize or AVERROR 344 */ 345int64_t url_fsize(ByteIOContext *s); 346 347/** 348 * feof() equivalent for ByteIOContext. 349 * @return non zero if and only if end of file 350 */ 351int url_feof(ByteIOContext *s); 352 353int url_ferror(ByteIOContext *s); 354 355int av_url_read_fpause(ByteIOContext *h, int pause); 356int64_t av_url_read_fseek(ByteIOContext *h, int stream_index, 357 int64_t timestamp, int flags); 358 359#define URL_EOF (-1) 360/** @note return URL_EOF (-1) if EOF */ 361int url_fgetc(ByteIOContext *s); 362 363/** @warning currently size is limited */ 364#ifdef __GNUC__ 365int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3))); 366#else 367int url_fprintf(ByteIOContext *s, const char *fmt, ...); 368#endif 369 370/** @note unlike fgets, the EOL character is not returned and a whole 371 line is parsed. return NULL if first char read was EOF */ 372char *url_fgets(ByteIOContext *s, char *buf, int buf_size); 373 374void put_flush_packet(ByteIOContext *s); 375 376 377/** 378 * Reads size bytes from ByteIOContext into buf. 379 * @return number of bytes read or AVERROR 380 */ 381int get_buffer(ByteIOContext *s, unsigned char *buf, int size); 382 383/** 384 * Reads size bytes from ByteIOContext into buf. 385 * This reads at most 1 packet. If that is not enough fewer bytes will be 386 * returned. 387 * @return number of bytes read or AVERROR 388 */ 389int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size); 390 391/** @note return 0 if EOF, so you cannot use it if EOF handling is 392 necessary */ 393int get_byte(ByteIOContext *s); 394unsigned int get_le24(ByteIOContext *s); 395unsigned int get_le32(ByteIOContext *s); 396uint64_t get_le64(ByteIOContext *s); 397unsigned int get_le16(ByteIOContext *s); 398 399char *get_strz(ByteIOContext *s, char *buf, int maxlen); 400unsigned int get_be16(ByteIOContext *s); 401unsigned int get_be24(ByteIOContext *s); 402unsigned int get_be32(ByteIOContext *s); 403uint64_t get_be64(ByteIOContext *s); 404 405uint64_t ff_get_v(ByteIOContext *bc); 406 407static inline int url_is_streamed(ByteIOContext *s) 408{ 409 return s->is_streamed; 410} 411 412/** 413 * Creates and initializes a ByteIOContext for accessing the 414 * resource referenced by the URLContext h. 415 * @note When the URLContext h has been opened in read+write mode, the 416 * ByteIOContext can be used only for writing. 417 * 418 * @param s Used to return the pointer to the created ByteIOContext. 419 * In case of failure the pointed to value is set to NULL. 420 * @return 0 in case of success, a negative value corresponding to an 421 * AVERROR code in case of failure 422 */ 423int url_fdopen(ByteIOContext **s, URLContext *h); 424 425/** @warning must be called before any I/O */ 426int url_setbufsize(ByteIOContext *s, int buf_size); 427#if LIBAVFORMAT_VERSION_MAJOR < 53 428/** Reset the buffer for reading or writing. 429 * @note Will drop any data currently in the buffer without transmitting it. 430 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY 431 * to set up the buffer for writing. */ 432int url_resetbuf(ByteIOContext *s, int flags); 433#endif 434 435/** 436 * Rewinds the ByteIOContext using the specified buffer containing the first buf_size bytes of the file. 437 * Used after probing to avoid seeking. 438 * Joins buf and s->buffer, taking any overlap into consideration. 439 * @note s->buffer must overlap with buf or they can't be joined and the function fails 440 * @note This function is NOT part of the public API 441 * 442 * @param s The read-only ByteIOContext to rewind 443 * @param buf The probe buffer containing the first buf_size bytes of the file 444 * @param buf_size The size of buf 445 * @return 0 in case of success, a negative value corresponding to an 446 * AVERROR code in case of failure 447 */ 448int ff_rewind_with_probe_data(ByteIOContext *s, unsigned char *buf, int buf_size); 449 450/** 451 * Creates and initializes a ByteIOContext for accessing the 452 * resource indicated by url. 453 * @note When the resource indicated by url has been opened in 454 * read+write mode, the ByteIOContext can be used only for writing. 455 * 456 * @param s Used to return the pointer to the created ByteIOContext. 457 * In case of failure the pointed to value is set to NULL. 458 * @param flags flags which control how the resource indicated by url 459 * is to be opened 460 * @return 0 in case of success, a negative value corresponding to an 461 * AVERROR code in case of failure 462 */ 463int url_fopen(ByteIOContext **s, const char *url, int flags); 464 465int url_fclose(ByteIOContext *s); 466URLContext *url_fileno(ByteIOContext *s); 467 468/** 469 * Return the maximum packet size associated to packetized buffered file 470 * handle. If the file is not packetized (stream like http or file on 471 * disk), then 0 is returned. 472 * 473 * @param s buffered file handle 474 * @return maximum packet size in bytes 475 */ 476int url_fget_max_packet_size(ByteIOContext *s); 477 478int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags); 479 480/** return the written or read size */ 481int url_close_buf(ByteIOContext *s); 482 483/** 484 * Open a write only memory stream. 485 * 486 * @param s new IO context 487 * @return zero if no error. 488 */ 489int url_open_dyn_buf(ByteIOContext **s); 490 491/** 492 * Open a write only packetized memory stream with a maximum packet 493 * size of 'max_packet_size'. The stream is stored in a memory buffer 494 * with a big endian 4 byte header giving the packet size in bytes. 495 * 496 * @param s new IO context 497 * @param max_packet_size maximum packet size (must be > 0) 498 * @return zero if no error. 499 */ 500int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size); 501 502/** 503 * Return the written size and a pointer to the buffer. The buffer 504 * must be freed with av_free(). 505 * @param s IO context 506 * @param pbuffer pointer to a byte buffer 507 * @return the length of the byte buffer 508 */ 509int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer); 510 511unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, 512 unsigned int len); 513unsigned long get_checksum(ByteIOContext *s); 514void init_checksum(ByteIOContext *s, 515 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), 516 unsigned long checksum); 517 518/* udp.c */ 519int udp_set_remote_url(URLContext *h, const char *uri); 520int udp_get_local_port(URLContext *h); 521#if (LIBAVFORMAT_VERSION_MAJOR <= 52) 522int udp_get_file_handle(URLContext *h); 523#endif 524 525#endif /* AVFORMAT_AVIO_H */ 526