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