summaryrefslogtreecommitdiff
path: root/libavformat/avio.c
blob: 0dd7e63f2a341c7a38dd563b31b29c17947ddf1f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
/*
 * Unbuffered io for ffmpeg system
 * Copyright (c) 2001 Fabrice Bellard
 *
 * This file is part of FFmpeg.
 *
 * FFmpeg is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation; either
 * version 2.1 of the License, or (at your option) any later version.
 *
 * FFmpeg is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with FFmpeg; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
 */
#include "avformat.h"

static int default_interrupt_cb(void);

URLProtocol *first_protocol = NULL;
URLInterruptCB *url_interrupt_cb = default_interrupt_cb;

int register_protocol(URLProtocol *protocol)
{
    URLProtocol **p;
    p = &first_protocol;
    while (*p != NULL) p = &(*p)->next;
    *p = protocol;
    protocol->next = NULL;
    return 0;
}

int url_open(URLContext **puc, const char *filename, int flags)
{
    URLContext *uc;
    URLProtocol *up;
    const char *p;
    char proto_str[128], *q;
    int err;

    p = filename;
    q = proto_str;
    while (*p != '\0' && *p != ':') {
        /* protocols can only contain alphabetic chars */
        if (!isalpha(*p))
            goto file_proto;
        if ((q - proto_str) < sizeof(proto_str) - 1)
            *q++ = *p;
        p++;
    }
    /* if the protocol has length 1, we consider it is a dos drive */
    if (*p == '\0' || (q - proto_str) <= 1) {
    file_proto:
        strcpy(proto_str, "file");
    } else {
        *q = '\0';
    }

    up = first_protocol;
    while (up != NULL) {
        if (!strcmp(proto_str, up->name))
            goto found;
        up = up->next;
    }
    err = -ENOENT;
    goto fail;
 found:
    uc = av_malloc(sizeof(URLContext) + strlen(filename) + 1);
    if (!uc) {
        err = -ENOMEM;
        goto fail;
    }
#if LIBAVFORMAT_VERSION_INT >= (52<<16)
    uc->filename = (char *) &uc[1];
#endif
    strcpy(uc->filename, filename);
    uc->prot = up;
    uc->flags = flags;
    uc->is_streamed = 0; /* default = not streamed */
    uc->max_packet_size = 0; /* default: stream file */
    err = up->url_open(uc, filename, flags);
    if (err < 0) {
        av_free(uc);
        *puc = NULL;
        return err;
    }
    *puc = uc;
    return 0;
 fail:
    *puc = NULL;
    return err;
}

int url_read(URLContext *h, unsigned char *buf, int size)
{
    int ret;
    if (h->flags & URL_WRONLY)
        return AVERROR_IO;
    ret = h->prot->url_read(h, buf, size);
    return ret;
}

#if defined(CONFIG_MUXERS) || defined(CONFIG_PROTOCOLS)
int url_write(URLContext *h, unsigned char *buf, int size)
{
    int ret;
    if (!(h->flags & (URL_WRONLY | URL_RDWR)))
        return AVERROR_IO;
    /* avoid sending too big packets */
    if (h->max_packet_size && size > h->max_packet_size)
        return AVERROR_IO;
    ret = h->prot->url_write(h, buf, size);
    return ret;
}
#endif //CONFIG_MUXERS || CONFIG_PROTOCOLS

offset_t url_seek(URLContext *h, offset_t pos, int whence)
{
    offset_t ret;

    if (!h->prot->url_seek)
        return -EPIPE;
    ret = h->prot->url_seek(h, pos, whence);
    return ret;
}

int url_close(URLContext *h)
{
    int ret;

    ret = h->prot->url_close(h);
    av_free(h);
    return ret;
}

int url_exist(const char *filename)
{
    URLContext *h;
    if (url_open(&h, filename, URL_RDONLY) < 0)
        return 0;
    url_close(h);
    return 1;
}

offset_t url_filesize(URLContext *h)
{
    offset_t pos, size;

    size= url_seek(h, 0, AVSEEK_SIZE);
    if(size<0){
        pos = url_seek(h, 0, SEEK_CUR);
        if ((size = url_seek(h, -1, SEEK_END)) < 0)
            return size;
        size++;
        url_seek(h, pos, SEEK_SET);
    }
    return size;
}

/*
 * Return the maximum packet size associated to packetized file
 * handle. If the file is not packetized (stream like http or file on
 * disk), then 0 is returned.
 *
 * @param h file handle
 * @return maximum packet size in bytes
 */
int url_get_max_packet_size(URLContext *h)
{
    return h->max_packet_size;
}

void url_get_filename(URLContext *h, char *buf, int buf_size)
{
    pstrcpy(buf, buf_size, h->filename);
}


static int default_interrupt_cb(void)
{
    return 0;
}

/**
 * The callback is called in blocking functions to test regulary if
 * asynchronous interruption is needed. -EINTR is returned in this
 * case by the interrupted function. 'NULL' means no interrupt
 * callback is given.
 */
void url_set_interrupt_cb(URLInterruptCB *interrupt_cb)
{
    if (!interrupt_cb)
        interrupt_cb = default_interrupt_cb;
    url_interrupt_cb = interrupt_cb;
}