2 * unbuffered io for ffmpeg system
3 * copyright (c) 2001 Fabrice Bellard
5 * This file is part of FFmpeg.
7 * FFmpeg is free software; you can redistribute it and/or
8 * modify it under the terms of the GNU Lesser General Public
9 * License as published by the Free Software Foundation; either
10 * version 2.1 of the License, or (at your option) any later version.
12 * FFmpeg is distributed in the hope that it will be useful,
13 * but WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * Lesser General Public License for more details.
17 * You should have received a copy of the GNU Lesser General Public
18 * License along with FFmpeg; if not, write to the Free Software
19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 #ifndef AVFORMAT_AVIO_H
22 #define AVFORMAT_AVIO_H
26 #include "libavutil/common.h"
32 * New fields can be added to the end with minor version bumps.
33 * Removal, reordering and changes to existing fields require a major
35 * sizeof(URLContext) must not be used outside libav*.
38 #if LIBAVFORMAT_VERSION_MAJOR >= 53
39 const AVClass *av_class; ///< information for av_log(). Set by url_open().
41 struct URLProtocol *prot;
43 int is_streamed; /**< true if streamed (no seek possible), default = false */
44 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
46 char *filename; /**< specified filename */
49 typedef struct URLContext URLContext;
51 typedef struct URLPollEntry {
61 typedef int URLInterruptCB(void);
63 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
64 const char *filename, int flags);
65 int url_open(URLContext **h, const char *filename, int flags);
66 int url_read(URLContext *h, unsigned char *buf, int size);
67 int url_write(URLContext *h, unsigned char *buf, int size);
68 int64_t url_seek(URLContext *h, int64_t pos, int whence);
69 int url_close(URLContext *h);
70 int url_exist(const char *filename);
71 int64_t url_filesize(URLContext *h);
74 * Return the maximum packet size associated to packetized file
75 * handle. If the file is not packetized (stream like HTTP or file on
76 * disk), then 0 is returned.
78 * @param h file handle
79 * @return maximum packet size in bytes
81 int url_get_max_packet_size(URLContext *h);
82 void url_get_filename(URLContext *h, char *buf, int buf_size);
85 * The callback is called in blocking functions to test regulary if
86 * asynchronous interruption is needed. AVERROR(EINTR) is returned
87 * in this case by the interrupted function. 'NULL' means no interrupt
90 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
93 int url_poll(URLPollEntry *poll_table, int n, int timeout);
96 * Pause and resume playing - only meaningful if using a network streaming
97 * protocol (e.g. MMS).
98 * @param pause 1 for pause, 0 for resume
100 int av_url_read_pause(URLContext *h, int pause);
103 * Seek to a given timestamp relative to some component stream.
104 * Only meaningful if using a network streaming protocol (e.g. MMS.).
105 * @param stream_index The stream index that the timestamp is relative to.
106 * If stream_index is (-1) the timestamp should be in AV_TIME_BASE
107 * units from the beginning of the presentation.
108 * If a stream_index >= 0 is used and the protocol does not support
109 * seeking based on component streams, the call will fail with ENOTSUP.
110 * @param timestamp timestamp in AVStream.time_base units
111 * or if there is no stream specified then in AV_TIME_BASE units.
112 * @param flags Optional combination of AVSEEK_FLAG_BACKWARD, AVSEEK_FLAG_BYTE
113 * and AVSEEK_FLAG_ANY. The protocol may silently ignore
114 * AVSEEK_FLAG_BACKWARD and AVSEEK_FLAG_ANY, but AVSEEK_FLAG_BYTE will
115 * fail with ENOTSUP if used and not supported.
116 * @return >= 0 on success
117 * @see AVInputFormat::read_seek
119 int64_t av_url_read_seek(URLContext *h, int stream_index,
120 int64_t timestamp, int flags);
123 * Passing this as the "whence" parameter to a seek function causes it to
124 * return the filesize without seeking anywhere. Supporting this is optional.
125 * If it is not supported then the seek function will return <0.
127 #define AVSEEK_SIZE 0x10000
129 typedef struct URLProtocol {
131 int (*url_open)(URLContext *h, const char *filename, int flags);
132 int (*url_read)(URLContext *h, unsigned char *buf, int size);
133 int (*url_write)(URLContext *h, unsigned char *buf, int size);
134 int64_t (*url_seek)(URLContext *h, int64_t pos, int whence);
135 int (*url_close)(URLContext *h);
136 struct URLProtocol *next;
137 int (*url_read_pause)(URLContext *h, int pause);
138 int64_t (*url_read_seek)(URLContext *h, int stream_index,
139 int64_t timestamp, int flags);
142 #if LIBAVFORMAT_VERSION_MAJOR < 53
143 extern URLProtocol *first_protocol;
146 extern URLInterruptCB *url_interrupt_cb;
149 * If protocol is NULL, returns the first registered protocol,
150 * if protocol is non-NULL, returns the next registered protocol after protocol,
151 * or NULL if protocol is the last one.
153 URLProtocol *av_protocol_next(URLProtocol *p);
155 #if LIBAVFORMAT_VERSION_MAJOR < 53
157 * @deprecated Use av_register_protocol() instead.
159 attribute_deprecated int register_protocol(URLProtocol *protocol);
162 int av_register_protocol(URLProtocol *protocol);
165 * Bytestream IO Context.
166 * New fields can be added to the end with minor version bumps.
167 * Removal, reordering and changes to existing fields require a major
169 * sizeof(ByteIOContext) must not be used outside libav*.
172 unsigned char *buffer;
174 unsigned char *buf_ptr, *buf_end;
176 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
177 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
178 int64_t (*seek)(void *opaque, int64_t offset, int whence);
179 int64_t pos; /**< position in the file of the current buffer */
180 int must_flush; /**< true if the next seek should flush */
181 int eof_reached; /**< true if eof reached */
182 int write_flag; /**< true if open for writing */
185 unsigned long checksum;
186 unsigned char *checksum_ptr;
187 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
188 int error; ///< contains the error code or 0 if no error happened
189 int (*read_pause)(void *opaque, int pause);
190 int64_t (*read_seek)(void *opaque, int stream_index,
191 int64_t timestamp, int flags);
194 int init_put_byte(ByteIOContext *s,
195 unsigned char *buffer,
199 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
200 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
201 int64_t (*seek)(void *opaque, int64_t offset, int whence));
202 ByteIOContext *av_alloc_put_byte(
203 unsigned char *buffer,
207 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
208 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
209 int64_t (*seek)(void *opaque, int64_t offset, int whence));
211 void put_byte(ByteIOContext *s, int b);
212 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
213 void put_le64(ByteIOContext *s, uint64_t val);
214 void put_be64(ByteIOContext *s, uint64_t val);
215 void put_le32(ByteIOContext *s, unsigned int val);
216 void put_be32(ByteIOContext *s, unsigned int val);
217 void put_le24(ByteIOContext *s, unsigned int val);
218 void put_be24(ByteIOContext *s, unsigned int val);
219 void put_le16(ByteIOContext *s, unsigned int val);
220 void put_be16(ByteIOContext *s, unsigned int val);
221 void put_tag(ByteIOContext *s, const char *tag);
223 void put_strz(ByteIOContext *s, const char *buf);
226 * fseek() equivalent for ByteIOContext.
227 * @return new position or AVERROR.
229 int64_t url_fseek(ByteIOContext *s, int64_t offset, int whence);
232 * Skip given number of bytes forward.
233 * @param offset number of bytes
235 void url_fskip(ByteIOContext *s, int64_t offset);
238 * ftell() equivalent for ByteIOContext.
239 * @return position or AVERROR.
241 int64_t url_ftell(ByteIOContext *s);
245 * @return filesize or AVERROR
247 int64_t url_fsize(ByteIOContext *s);
250 * feof() equivalent for ByteIOContext.
251 * @return non zero if and only if end of file
253 int url_feof(ByteIOContext *s);
255 int url_ferror(ByteIOContext *s);
257 int av_url_read_fpause(ByteIOContext *h, int pause);
258 int64_t av_url_read_fseek(ByteIOContext *h, int stream_index,
259 int64_t timestamp, int flags);
262 /** @note return URL_EOF (-1) if EOF */
263 int url_fgetc(ByteIOContext *s);
265 /** @warning currently size is limited */
267 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
269 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
272 /** @note unlike fgets, the EOL character is not returned and a whole
273 line is parsed. return NULL if first char read was EOF */
274 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
276 void put_flush_packet(ByteIOContext *s);
280 * Reads size bytes from ByteIOContext into buf.
281 * @returns number of bytes read or AVERROR
283 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
286 * Reads size bytes from ByteIOContext into buf.
287 * This reads at most 1 packet. If that is not enough fewer bytes will be
289 * @returns number of bytes read or AVERROR
291 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
293 /** @note return 0 if EOF, so you cannot use it if EOF handling is
295 int get_byte(ByteIOContext *s);
296 unsigned int get_le24(ByteIOContext *s);
297 unsigned int get_le32(ByteIOContext *s);
298 uint64_t get_le64(ByteIOContext *s);
299 unsigned int get_le16(ByteIOContext *s);
301 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
302 unsigned int get_be16(ByteIOContext *s);
303 unsigned int get_be24(ByteIOContext *s);
304 unsigned int get_be32(ByteIOContext *s);
305 uint64_t get_be64(ByteIOContext *s);
307 uint64_t ff_get_v(ByteIOContext *bc);
309 static inline int url_is_streamed(ByteIOContext *s)
311 return s->is_streamed;
314 /** @note when opened as read/write, the buffers are only used for
316 int url_fdopen(ByteIOContext **s, URLContext *h);
318 /** @warning must be called before any I/O */
319 int url_setbufsize(ByteIOContext *s, int buf_size);
320 /** Reset the buffer for reading or writing.
321 * @note Will drop any data currently in the buffer without transmitting it.
322 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
323 * to set up the buffer for writing. */
324 int url_resetbuf(ByteIOContext *s, int flags);
326 /** @note when opened as read/write, the buffers are only used for
328 int url_fopen(ByteIOContext **s, const char *filename, int flags);
329 int url_fclose(ByteIOContext *s);
330 URLContext *url_fileno(ByteIOContext *s);
333 * Return the maximum packet size associated to packetized buffered file
334 * handle. If the file is not packetized (stream like http or file on
335 * disk), then 0 is returned.
337 * @param s buffered file handle
338 * @return maximum packet size in bytes
340 int url_fget_max_packet_size(ByteIOContext *s);
342 int url_open_buf(ByteIOContext **s, uint8_t *buf, int buf_size, int flags);
344 /** return the written or read size */
345 int url_close_buf(ByteIOContext *s);
348 * Open a write only memory stream.
350 * @param s new IO context
351 * @return zero if no error.
353 int url_open_dyn_buf(ByteIOContext **s);
356 * Open a write only packetized memory stream with a maximum packet
357 * size of 'max_packet_size'. The stream is stored in a memory buffer
358 * with a big endian 4 byte header giving the packet size in bytes.
360 * @param s new IO context
361 * @param max_packet_size maximum packet size (must be > 0)
362 * @return zero if no error.
364 int url_open_dyn_packet_buf(ByteIOContext **s, int max_packet_size);
367 * Return the written size and a pointer to the buffer. The buffer
368 * must be freed with av_free().
369 * @param s IO context
370 * @param pbuffer pointer to a byte buffer
371 * @return the length of the byte buffer
373 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
375 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf,
377 unsigned long get_checksum(ByteIOContext *s);
378 void init_checksum(ByteIOContext *s,
379 unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len),
380 unsigned long checksum);
383 int udp_set_remote_url(URLContext *h, const char *uri);
384 int udp_get_local_port(URLContext *h);
385 int udp_get_file_handle(URLContext *h);
387 #endif /* AVFORMAT_AVIO_H */