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
24 /* output byte stream handling */
26 typedef int64_t offset_t;
31 struct URLProtocol *prot;
33 int is_streamed; /**< true if streamed (no seek possible), default = false */
34 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
36 #if LIBAVFORMAT_VERSION_INT >= (52<<16)
37 char *filename; /**< specified filename */
39 char filename[1]; /**< specified filename */
43 typedef struct URLContext URLContext;
45 typedef struct URLPollEntry {
55 typedef int URLInterruptCB(void);
57 int url_open(URLContext **h, const char *filename, int flags);
58 int url_read(URLContext *h, unsigned char *buf, int size);
59 int url_write(URLContext *h, unsigned char *buf, int size);
60 offset_t url_seek(URLContext *h, offset_t pos, int whence);
61 int url_close(URLContext *h);
62 int url_exist(const char *filename);
63 offset_t url_filesize(URLContext *h);
66 * Return the maximum packet size associated to packetized file
67 * handle. If the file is not packetized (stream like http or file on
68 * disk), then 0 is returned.
70 * @param h file handle
71 * @return maximum packet size in bytes
73 int url_get_max_packet_size(URLContext *h);
74 void url_get_filename(URLContext *h, char *buf, int buf_size);
77 * the callback is called in blocking functions to test regulary if
78 * asynchronous interruption is needed. AVERROR(EINTR) is returned
79 * in this case by the interrupted function. 'NULL' means no interrupt
80 * callback is given. i
82 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
85 int url_poll(URLPollEntry *poll_table, int n, int timeout);
88 * passing this as the "whence" parameter to a seek function causes it to
89 * return the filesize without seeking anywhere, supporting this is optional
90 * if its not supprted then the seek function will return <0
92 #define AVSEEK_SIZE 0x10000
94 typedef struct URLProtocol {
96 int (*url_open)(URLContext *h, const char *filename, int flags);
97 int (*url_read)(URLContext *h, unsigned char *buf, int size);
98 int (*url_write)(URLContext *h, unsigned char *buf, int size);
99 offset_t (*url_seek)(URLContext *h, offset_t pos, int whence);
100 int (*url_close)(URLContext *h);
101 struct URLProtocol *next;
104 extern URLProtocol *first_protocol;
105 extern URLInterruptCB *url_interrupt_cb;
107 int register_protocol(URLProtocol *protocol);
110 unsigned char *buffer;
112 unsigned char *buf_ptr, *buf_end;
114 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
115 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
116 offset_t (*seek)(void *opaque, offset_t offset, int whence);
117 offset_t pos; /**< position in the file of the current buffer */
118 int must_flush; /**< true if the next seek should flush */
119 int eof_reached; /**< true if eof reached */
120 int write_flag; /**< true if open for writing */
123 unsigned long checksum;
124 unsigned char *checksum_ptr;
125 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
126 int error; ///< contains the error code or 0 if no error happened
129 int init_put_byte(ByteIOContext *s,
130 unsigned char *buffer,
134 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
135 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
136 offset_t (*seek)(void *opaque, offset_t offset, int whence));
138 void put_byte(ByteIOContext *s, int b);
139 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
140 void put_le64(ByteIOContext *s, uint64_t val);
141 void put_be64(ByteIOContext *s, uint64_t val);
142 void put_le32(ByteIOContext *s, unsigned int val);
143 void put_be32(ByteIOContext *s, unsigned int val);
144 void put_le24(ByteIOContext *s, unsigned int val);
145 void put_be24(ByteIOContext *s, unsigned int val);
146 void put_le16(ByteIOContext *s, unsigned int val);
147 void put_be16(ByteIOContext *s, unsigned int val);
148 void put_tag(ByteIOContext *s, const char *tag);
150 void put_strz(ByteIOContext *s, const char *buf);
152 offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence);
153 void url_fskip(ByteIOContext *s, offset_t offset);
154 offset_t url_ftell(ByteIOContext *s);
155 offset_t url_fsize(ByteIOContext *s);
156 int url_feof(ByteIOContext *s);
157 int url_ferror(ByteIOContext *s);
160 /** @note return URL_EOF (-1) if EOF */
161 int url_fgetc(ByteIOContext *s);
163 /** @warning currently size is limited */
165 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
167 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
170 /** @note unlike fgets, the EOL character is not returned and a whole
171 line is parsed. return NULL if first char read was EOF */
172 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
174 void put_flush_packet(ByteIOContext *s);
176 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
177 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
179 /** @note return 0 if EOF, so you cannot use it if EOF handling is
181 int get_byte(ByteIOContext *s);
182 unsigned int get_le24(ByteIOContext *s);
183 unsigned int get_le32(ByteIOContext *s);
184 uint64_t get_le64(ByteIOContext *s);
185 unsigned int get_le16(ByteIOContext *s);
187 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
188 unsigned int get_be16(ByteIOContext *s);
189 unsigned int get_be24(ByteIOContext *s);
190 unsigned int get_be32(ByteIOContext *s);
191 uint64_t get_be64(ByteIOContext *s);
193 static inline int url_is_streamed(ByteIOContext *s)
195 return s->is_streamed;
198 int url_fdopen(ByteIOContext *s, URLContext *h);
200 /** @warning must be called before any I/O */
201 int url_setbufsize(ByteIOContext *s, int buf_size);
203 /** @note when opened as read/write, the buffers are only used for
205 int url_fopen(ByteIOContext *s, const char *filename, int flags);
206 int url_fclose(ByteIOContext *s);
207 URLContext *url_fileno(ByteIOContext *s);
210 * Return the maximum packet size associated to packetized buffered file
211 * handle. If the file is not packetized (stream like http or file on
212 * disk), then 0 is returned.
214 * @param h buffered file handle
215 * @return maximum packet size in bytes
217 int url_fget_max_packet_size(ByteIOContext *s);
219 int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags);
221 /** return the written or read size */
222 int url_close_buf(ByteIOContext *s);
225 * Open a write only memory stream.
227 * @param s new IO context
228 * @return zero if no error.
230 int url_open_dyn_buf(ByteIOContext *s);
233 * Open a write only packetized memory stream with a maximum packet
234 * size of 'max_packet_size'. The stream is stored in a memory buffer
235 * with a big endian 4 byte header giving the packet size in bytes.
237 * @param s new IO context
238 * @param max_packet_size maximum packet size (must be > 0)
239 * @return zero if no error.
241 int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size);
244 * Return the written size and a pointer to the buffer. The buffer
245 * must be freed with av_free().
246 * @param s IO context
247 * @param pointer to a byte buffer
248 * @return the length of the byte buffer
250 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
252 unsigned long get_checksum(ByteIOContext *s);
253 void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum);
256 extern URLProtocol file_protocol;
257 extern URLProtocol pipe_protocol;
260 extern URLProtocol udp_protocol;
261 int udp_set_remote_url(URLContext *h, const char *uri);
262 int udp_get_local_port(URLContext *h);
263 int udp_get_file_handle(URLContext *h);
266 extern URLProtocol tcp_protocol;
269 extern URLProtocol http_protocol;