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
26 /* output byte stream handling */
28 typedef int64_t offset_t;
33 struct URLProtocol *prot;
35 int is_streamed; /**< true if streamed (no seek possible), default = false */
36 int max_packet_size; /**< if non zero, the stream is packetized with this max packet size */
38 #if LIBAVFORMAT_VERSION_INT >= (52<<16)
39 char *filename; /**< specified filename */
41 char filename[1]; /**< specified filename */
45 typedef struct URLContext URLContext;
47 typedef struct URLPollEntry {
57 typedef int URLInterruptCB(void);
59 int url_open(URLContext **h, const char *filename, int flags);
60 int url_read(URLContext *h, unsigned char *buf, int size);
61 int url_write(URLContext *h, unsigned char *buf, int size);
62 offset_t url_seek(URLContext *h, offset_t pos, int whence);
63 int url_close(URLContext *h);
64 int url_exist(const char *filename);
65 offset_t url_filesize(URLContext *h);
68 * Return the maximum packet size associated to packetized file
69 * handle. If the file is not packetized (stream like http or file on
70 * disk), then 0 is returned.
72 * @param h file handle
73 * @return maximum packet size in bytes
75 int url_get_max_packet_size(URLContext *h);
76 void url_get_filename(URLContext *h, char *buf, int buf_size);
79 * the callback is called in blocking functions to test regulary if
80 * asynchronous interruption is needed. AVERROR(EINTR) is returned
81 * in this case by the interrupted function. 'NULL' means no interrupt
82 * callback is given. i
84 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
87 int url_poll(URLPollEntry *poll_table, int n, int timeout);
90 * Passing this as the "whence" parameter to a seek function causes it to
91 * return the filesize without seeking anywhere. Supporting this is optional.
92 * If it is not supported then the seek function will return <0.
94 #define AVSEEK_SIZE 0x10000
96 typedef struct URLProtocol {
98 int (*url_open)(URLContext *h, const char *filename, int flags);
99 int (*url_read)(URLContext *h, unsigned char *buf, int size);
100 int (*url_write)(URLContext *h, unsigned char *buf, int size);
101 offset_t (*url_seek)(URLContext *h, offset_t pos, int whence);
102 int (*url_close)(URLContext *h);
103 struct URLProtocol *next;
106 extern URLProtocol *first_protocol;
107 extern URLInterruptCB *url_interrupt_cb;
109 int register_protocol(URLProtocol *protocol);
112 unsigned char *buffer;
114 unsigned char *buf_ptr, *buf_end;
116 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size);
117 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size);
118 offset_t (*seek)(void *opaque, offset_t offset, int whence);
119 offset_t pos; /**< position in the file of the current buffer */
120 int must_flush; /**< true if the next seek should flush */
121 int eof_reached; /**< true if eof reached */
122 int write_flag; /**< true if open for writing */
125 unsigned long checksum;
126 unsigned char *checksum_ptr;
127 unsigned long (*update_checksum)(unsigned long checksum, const uint8_t *buf, unsigned int size);
128 int error; ///< contains the error code or 0 if no error happened
131 int init_put_byte(ByteIOContext *s,
132 unsigned char *buffer,
136 int (*read_packet)(void *opaque, uint8_t *buf, int buf_size),
137 int (*write_packet)(void *opaque, uint8_t *buf, int buf_size),
138 offset_t (*seek)(void *opaque, offset_t offset, int whence));
140 void put_byte(ByteIOContext *s, int b);
141 void put_buffer(ByteIOContext *s, const unsigned char *buf, int size);
142 void put_le64(ByteIOContext *s, uint64_t val);
143 void put_be64(ByteIOContext *s, uint64_t val);
144 void put_le32(ByteIOContext *s, unsigned int val);
145 void put_be32(ByteIOContext *s, unsigned int val);
146 void put_le24(ByteIOContext *s, unsigned int val);
147 void put_be24(ByteIOContext *s, unsigned int val);
148 void put_le16(ByteIOContext *s, unsigned int val);
149 void put_be16(ByteIOContext *s, unsigned int val);
150 void put_tag(ByteIOContext *s, const char *tag);
152 void put_strz(ByteIOContext *s, const char *buf);
154 offset_t url_fseek(ByteIOContext *s, offset_t offset, int whence);
155 void url_fskip(ByteIOContext *s, offset_t offset);
156 offset_t url_ftell(ByteIOContext *s);
157 offset_t url_fsize(ByteIOContext *s);
158 int url_feof(ByteIOContext *s);
159 int url_ferror(ByteIOContext *s);
162 /** @note return URL_EOF (-1) if EOF */
163 int url_fgetc(ByteIOContext *s);
165 /** @warning currently size is limited */
167 int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
169 int url_fprintf(ByteIOContext *s, const char *fmt, ...);
172 /** @note unlike fgets, the EOL character is not returned and a whole
173 line is parsed. return NULL if first char read was EOF */
174 char *url_fgets(ByteIOContext *s, char *buf, int buf_size);
176 void put_flush_packet(ByteIOContext *s);
178 int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
179 int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
181 /** @note return 0 if EOF, so you cannot use it if EOF handling is
183 int get_byte(ByteIOContext *s);
184 unsigned int get_le24(ByteIOContext *s);
185 unsigned int get_le32(ByteIOContext *s);
186 uint64_t get_le64(ByteIOContext *s);
187 unsigned int get_le16(ByteIOContext *s);
189 char *get_strz(ByteIOContext *s, char *buf, int maxlen);
190 unsigned int get_be16(ByteIOContext *s);
191 unsigned int get_be24(ByteIOContext *s);
192 unsigned int get_be32(ByteIOContext *s);
193 uint64_t get_be64(ByteIOContext *s);
195 uint64_t ff_get_v(ByteIOContext *bc);
197 static inline int url_is_streamed(ByteIOContext *s)
199 return s->is_streamed;
202 /** @note when opened as read/write, the buffers are only used for
204 int url_fdopen(ByteIOContext *s, URLContext *h);
206 /** @warning must be called before any I/O */
207 int url_setbufsize(ByteIOContext *s, int buf_size);
208 /** Reset the buffer for reading or writing.
209 * @note Will drop any data currently in the buffer without transmitting it.
210 * @param flags URL_RDONLY to set up the buffer for reading, or URL_WRONLY
211 * to set up the buffer for writing. */
212 int url_resetbuf(ByteIOContext *s, int flags);
214 /** @note when opened as read/write, the buffers are only used for
216 int url_fopen(ByteIOContext *s, const char *filename, int flags);
217 int url_fclose(ByteIOContext *s);
218 URLContext *url_fileno(ByteIOContext *s);
221 * Return the maximum packet size associated to packetized buffered file
222 * handle. If the file is not packetized (stream like http or file on
223 * disk), then 0 is returned.
225 * @param s buffered file handle
226 * @return maximum packet size in bytes
228 int url_fget_max_packet_size(ByteIOContext *s);
230 int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags);
232 /** return the written or read size */
233 int url_close_buf(ByteIOContext *s);
236 * Open a write only memory stream.
238 * @param s new IO context
239 * @return zero if no error.
241 int url_open_dyn_buf(ByteIOContext *s);
244 * Open a write only packetized memory stream with a maximum packet
245 * size of 'max_packet_size'. The stream is stored in a memory buffer
246 * with a big endian 4 byte header giving the packet size in bytes.
248 * @param s new IO context
249 * @param max_packet_size maximum packet size (must be > 0)
250 * @return zero if no error.
252 int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size);
255 * Return the written size and a pointer to the buffer. The buffer
256 * must be freed with av_free().
257 * @param s IO context
258 * @param pointer to a byte buffer
259 * @return the length of the byte buffer
261 int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
263 unsigned long ff_crc04C11DB7_update(unsigned long checksum, const uint8_t *buf, unsigned int len);
264 unsigned long get_checksum(ByteIOContext *s);
265 void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum);
268 int udp_set_remote_url(URLContext *h, const char *uri);
269 int udp_get_local_port(URLContext *h);
270 int udp_get_file_handle(URLContext *h);
272 #endif /* FFMPEG_AVIO_H */