libavformat/avio.c

   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
  22 #include "libavutil/avstring.h"
  23 #include "libavcodec/opt.h"
  24 #include "os_support.h"
  25 #include "avformat.h"
  26
  27 #if LIBAVFORMAT_VERSION_MAJOR >= 53
  28 /** @name Logging context. */
  29 /*@{*/
  30 static const char *urlcontext_to_name(void *ptr)
  31 {
  32     URLContext *h = (URLContext *)ptr;
  33     if(h->prot) return h->prot->name;
  34     else        return "NULL";
  35 }
  36 static const AVOption options[] = {{NULL}};
  37 static const AVClass urlcontext_class =
  38         { "URLContext", urlcontext_to_name, options };
  39 /*@}*/
  40 #endif
  41
  42 static int default_interrupt_cb(void);
  43
  44 URLProtocol *first_protocol = NULL;
  45 URLInterruptCB *url_interrupt_cb = default_interrupt_cb;
  46
  47 URLProtocol *av_protocol_next(URLProtocol *p)
  48 {
  49     if(p) return p->next;
  50     else  return first_protocol;
  51 }
  52
  53 int av_register_protocol(URLProtocol *protocol)
  54 {
  55     URLProtocol **p;
  56     p = &first_protocol;
  57     while (*p != NULL) p = &(*p)->next;
  58     *p = protocol;
  59     protocol->next = NULL;
  60     return 0;
  61 }
  62
  63 #if LIBAVFORMAT_VERSION_MAJOR < 53
  64 int register_protocol(URLProtocol *protocol)
  65 {
  66     return av_register_protocol(protocol);
  67 }
  68 #endif
  69
  70 int url_open_protocol (URLContext **puc, struct URLProtocol *up,
  71                        const char *filename, int flags)
  72 {
  73     URLContext *uc;
  74     int err;
  75
  76     uc = av_malloc(sizeof(URLContext) + strlen(filename) + 1);
  77     if (!uc) {
  78         err = AVERROR(ENOMEM);
  79         goto fail;
  80     }
  81 #if LIBAVFORMAT_VERSION_MAJOR >= 53
  82     uc->av_class = &urlcontext_class;
  83 #endif
  84     uc->filename = (char *) &uc[1];
  85     strcpy(uc->filename, filename);
  86     uc->prot = up;
  87     uc->flags = flags;
  88     uc->is_streamed = 0; /* default = not streamed */
  89     uc->max_packet_size = 0; /* default: stream file */
  90     err = up->url_open(uc, filename, flags);
  91     if (err < 0) {
  92         av_free(uc);
  93         *puc = NULL;
  94         return err;
  95     }
  96
  97     //We must be carefull here as url_seek() could be slow, for example for http
  98     if(   (flags & (URL_WRONLY | URL_RDWR))
  99        || !strcmp(up->name, "file"))
 100         if(!uc->is_streamed && url_seek(uc, 0, SEEK_SET) < 0)
 101             uc->is_streamed= 1;
 102     *puc = uc;
 103     return 0;
 104  fail:
 105     *puc = NULL;
 106     return err;
 107 }
 108
 109 int url_open(URLContext **puc, const char *filename, int flags)
 110 {
 111     URLProtocol *up;
 112     const char *p;
 113     char proto_str[128], *q;
 114
 115     p = filename;
 116     q = proto_str;
 117     while (*p != '\0' && *p != ':') {
 118         /* protocols can only contain alphabetic chars */
 119         if (!isalpha(*p))
 120             goto file_proto;
 121         if ((q - proto_str) < sizeof(proto_str) - 1)
 122             *q++ = *p;
 123         p++;
 124     }
 125     /* if the protocol has length 1, we consider it is a dos drive */
 126     if (*p == '\0' || is_dos_path(filename)) {
 127     file_proto:
 128         strcpy(proto_str, "file");
 129     } else {
 130         *q = '\0';
 131     }
 132
 133     up = first_protocol;
 134     while (up != NULL) {
 135         if (!strcmp(proto_str, up->name))
 136             return url_open_protocol (puc, up, filename, flags);
 137         up = up->next;
 138     }
 139     *puc = NULL;
 140     return AVERROR(ENOENT);
 141 }
 142
 143 int url_read(URLContext *h, unsigned char *buf, int size)
 144 {
 145     int ret;
 146     if (h->flags & URL_WRONLY)
 147         return AVERROR(EIO);
 148     ret = h->prot->url_read(h, buf, size);
 149     return ret;
 150 }
 151
 152 int url_read_complete(URLContext *h, unsigned char *buf, int size)
 153 {
 154     int ret, len;
 155
 156     len = 0;
 157     while (len < size) {
 158         ret = url_read(h, buf+len, size-len);
 159         if (ret < 1)
 160             return ret;
 161         len += ret;
 162     }
 163     return len;
 164 }
 165
 166 int url_write(URLContext *h, unsigned char *buf, int size)
 167 {
 168     int ret;
 169     if (!(h->flags & (URL_WRONLY | URL_RDWR)))
 170         return AVERROR(EIO);
 171     /* avoid sending too big packets */
 172     if (h->max_packet_size && size > h->max_packet_size)
 173         return AVERROR(EIO);
 174     ret = h->prot->url_write(h, buf, size);
 175     return ret;
 176 }
 177
 178 int64_t url_seek(URLContext *h, int64_t pos, int whence)
 179 {
 180     int64_t ret;
 181
 182     if (!h->prot->url_seek)
 183         return AVERROR(EPIPE);
 184     ret = h->prot->url_seek(h, pos, whence);
 185     return ret;
 186 }
 187
 188 int url_close(URLContext *h)
 189 {
 190     int ret = 0;
 191     if (!h) return 0; /* can happen when url_open fails */
 192
 193     if (h->prot->url_close)
 194         ret = h->prot->url_close(h);
 195     av_free(h);
 196     return ret;
 197 }
 198
 199 int url_exist(const char *filename)
 200 {
 201     URLContext *h;
 202     if (url_open(&h, filename, URL_RDONLY) < 0)
 203         return 0;
 204     url_close(h);
 205     return 1;
 206 }
 207
 208 int64_t url_filesize(URLContext *h)
 209 {
 210     int64_t pos, size;
 211
 212     size= url_seek(h, 0, AVSEEK_SIZE);
 213     if(size<0){
 214         pos = url_seek(h, 0, SEEK_CUR);
 215         if ((size = url_seek(h, -1, SEEK_END)) < 0)
 216             return size;
 217         size++;
 218         url_seek(h, pos, SEEK_SET);
 219     }
 220     return size;
 221 }
 222
 223 int url_get_file_handle(URLContext *h)
 224 {
 225     if (!h->prot->url_get_file_handle)
 226         return -1;
 227     return h->prot->url_get_file_handle(h);
 228 }
 229
 230 int url_get_max_packet_size(URLContext *h)
 231 {
 232     return h->max_packet_size;
 233 }
 234
 235 void url_get_filename(URLContext *h, char *buf, int buf_size)
 236 {
 237     av_strlcpy(buf, h->filename, buf_size);
 238 }
 239
 240
 241 static int default_interrupt_cb(void)
 242 {
 243     return 0;
 244 }
 245
 246 void url_set_interrupt_cb(URLInterruptCB *interrupt_cb)
 247 {
 248     if (!interrupt_cb)
 249         interrupt_cb = default_interrupt_cb;
 250     url_interrupt_cb = interrupt_cb;
 251 }
 252
 253 int av_url_read_pause(URLContext *h, int pause)
 254 {
 255     if (!h->prot->url_read_pause)
 256         return AVERROR(ENOSYS);
 257     return h->prot->url_read_pause(h, pause);
 258 }
 259
 260 int64_t av_url_read_seek(URLContext *h,
 261         int stream_index, int64_t timestamp, int flags)
 262 {
 263     if (!h->prot->url_read_seek)
 264         return AVERROR(ENOSYS);
 265     return h->prot->url_read_seek(h, stream_index, timestamp, flags);
 266 }