Statistics
| Branch: | Revision:

ffmpeg / libavformat / avio.h @ d2062ff6

History | View | Annotate | Download (8.92 KB)

1
/*
2
 * unbuffered io for ffmpeg system
3
 * copyright (c) 2001 Fabrice Bellard
4
 *
5
 * This file is part of FFmpeg.
6
 *
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.
11
 *
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.
16
 *
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
20
 */
21
#ifndef AVIO_H
22
#define AVIO_H
23

    
24
#include <stdint.h>
25

    
26
/* output byte stream handling */
27

    
28
typedef int64_t offset_t;
29

    
30
/* unbuffered I/O */
31

    
32
struct URLContext {
33
    struct URLProtocol *prot;
34
    int flags;
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 */
37
    void *priv_data;
38
#if LIBAVFORMAT_VERSION_INT >= (52<<16)
39
    char *filename; /**< specified filename */
40
#else
41
    char filename[1]; /**< specified filename */
42
#endif
43
};
44

    
45
typedef struct URLContext URLContext;
46

    
47
typedef struct URLPollEntry {
48
    URLContext *handle;
49
    int events;
50
    int revents;
51
} URLPollEntry;
52

    
53
#define URL_RDONLY 0
54
#define URL_WRONLY 1
55
#define URL_RDWR   2
56

    
57
typedef int URLInterruptCB(void);
58

    
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);
66

    
67
/**
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.
71
 *
72
 * @param h file handle
73
 * @return maximum packet size in bytes
74
 */
75
int url_get_max_packet_size(URLContext *h);
76
void url_get_filename(URLContext *h, char *buf, int buf_size);
77

    
78
/**
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
83
 */
84
void url_set_interrupt_cb(URLInterruptCB *interrupt_cb);
85

    
86
/* not implemented */
87
int url_poll(URLPollEntry *poll_table, int n, int timeout);
88

    
89
/**
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.
93
 */
94
#define AVSEEK_SIZE 0x10000
95

    
96
typedef struct URLProtocol {
97
    const char *name;
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;
104
} URLProtocol;
105

    
106
extern URLProtocol *first_protocol;
107
extern URLInterruptCB *url_interrupt_cb;
108

    
109
int register_protocol(URLProtocol *protocol);
110

    
111
typedef struct {
112
    unsigned char *buffer;
113
    int buffer_size;
114
    unsigned char *buf_ptr, *buf_end;
115
    void *opaque;
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 */
123
    int is_streamed;
124
    int max_packet_size;
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
129
} ByteIOContext;
130

    
131
int init_put_byte(ByteIOContext *s,
132
                  unsigned char *buffer,
133
                  int buffer_size,
134
                  int write_flag,
135
                  void *opaque,
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));
139

    
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);
151

    
152
void put_strz(ByteIOContext *s, const char *buf);
153

    
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);
160

    
161
#define URL_EOF (-1)
162
/** @note return URL_EOF (-1) if EOF */
163
int url_fgetc(ByteIOContext *s);
164

    
165
/** @warning currently size is limited */
166
#ifdef __GNUC__
167
int url_fprintf(ByteIOContext *s, const char *fmt, ...) __attribute__ ((__format__ (__printf__, 2, 3)));
168
#else
169
int url_fprintf(ByteIOContext *s, const char *fmt, ...);
170
#endif
171

    
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);
175

    
176
void put_flush_packet(ByteIOContext *s);
177

    
178
int get_buffer(ByteIOContext *s, unsigned char *buf, int size);
179
int get_partial_buffer(ByteIOContext *s, unsigned char *buf, int size);
180

    
181
/** @note return 0 if EOF, so you cannot use it if EOF handling is
182
   necessary */
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);
188

    
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);
194

    
195
static inline int url_is_streamed(ByteIOContext *s)
196
{
197
    return s->is_streamed;
198
}
199

    
200
int url_fdopen(ByteIOContext *s, URLContext *h);
201

    
202
/** @warning must be called before any I/O */
203
int url_setbufsize(ByteIOContext *s, int buf_size);
204

    
205
/** @note when opened as read/write, the buffers are only used for
206
   reading */
207
int url_fopen(ByteIOContext *s, const char *filename, int flags);
208
int url_fclose(ByteIOContext *s);
209
URLContext *url_fileno(ByteIOContext *s);
210

    
211
/**
212
 * Return the maximum packet size associated to packetized buffered file
213
 * handle. If the file is not packetized (stream like http or file on
214
 * disk), then 0 is returned.
215
 *
216
 * @param h buffered file handle
217
 * @return maximum packet size in bytes
218
 */
219
int url_fget_max_packet_size(ByteIOContext *s);
220

    
221
int url_open_buf(ByteIOContext *s, uint8_t *buf, int buf_size, int flags);
222

    
223
/** return the written or read size */
224
int url_close_buf(ByteIOContext *s);
225

    
226
/**
227
 * Open a write only memory stream.
228
 *
229
 * @param s new IO context
230
 * @return zero if no error.
231
 */
232
int url_open_dyn_buf(ByteIOContext *s);
233

    
234
/**
235
 * Open a write only packetized memory stream with a maximum packet
236
 * size of 'max_packet_size'.  The stream is stored in a memory buffer
237
 * with a big endian 4 byte header giving the packet size in bytes.
238
 *
239
 * @param s new IO context
240
 * @param max_packet_size maximum packet size (must be > 0)
241
 * @return zero if no error.
242
 */
243
int url_open_dyn_packet_buf(ByteIOContext *s, int max_packet_size);
244

    
245
/**
246
 * Return the written size and a pointer to the buffer. The buffer
247
 *  must be freed with av_free().
248
 * @param s IO context
249
 * @param pointer to a byte buffer
250
 * @return the length of the byte buffer
251
 */
252
int url_close_dyn_buf(ByteIOContext *s, uint8_t **pbuffer);
253

    
254
unsigned long get_checksum(ByteIOContext *s);
255
void init_checksum(ByteIOContext *s, unsigned long (*update_checksum)(unsigned long c, const uint8_t *p, unsigned int len), unsigned long checksum);
256

    
257
/* file.c */
258
extern URLProtocol file_protocol;
259
extern URLProtocol pipe_protocol;
260

    
261
/* udp.c */
262
extern URLProtocol udp_protocol;
263
int udp_set_remote_url(URLContext *h, const char *uri);
264
int udp_get_local_port(URLContext *h);
265
int udp_get_file_handle(URLContext *h);
266

    
267
/* tcp.c  */
268
extern URLProtocol tcp_protocol;
269

    
270
/* http.c */
271
extern URLProtocol http_protocol;
272

    
273
#endif
274