modules/access/avio.c

   1 /*****************************************************************************
   2  * avio.c: access using libavformat library
   3  *****************************************************************************
   4  * Copyright (C) 2009 Laurent Aimar
   5  * $Id$
   6  *
   7  * Authors: Laurent Aimar <fenrir _AT_ videolan _DOT_ org>
   8  *
   9  * This program is free software; you can redistribute it and/or modify
  10  * it under the terms of the GNU General Public License as published by
  11  * the Free Software Foundation; either version 2 of the License, or
  12  * (at your option) any later version.
  13  *
  14  * This program is distributed in the hope that it will be useful,
  15  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  16  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17  * GNU General Public License for more details.
  18  *
  19  * You should have received a copy of the GNU General Public License
  20  * along with this program; if not, write to the Free Software
  21  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
  22  *****************************************************************************/
  23
  24 #ifdef HAVE_CONFIG_H
  25 # include "config.h"
  26 #endif
  27 #include <assert.h>
  28
  29 #include <vlc_common.h>
  30 #include <vlc_plugin.h>
  31 #include <vlc_access.h>
  32 #include <vlc_avcodec.h>
  33
  34 #include "avio.h"
  35
  36 /*****************************************************************************
  37  * Module descriptor
  38  *****************************************************************************/
  39 #ifndef MERGE_FFMPEG
  40 vlc_module_begin()
  41     AVIO_MODULE
  42 vlc_module_end()
  43 #endif
  44
  45 /*****************************************************************************
  46  * Local prototypes
  47  *****************************************************************************/
  48 static ssize_t Read   (access_t *, uint8_t *, size_t);
  49 static int     Seek   (access_t *, int64_t);
  50 static int     Control(access_t *, int, va_list);
  51
  52 static int     SetupAvio(access_t *);
  53
  54 struct access_sys_t {
  55     URLContext *context;
  56 };
  57
  58 /* */
  59 int OpenAvio(vlc_object_t *object)
  60 {
  61     access_t *access = (access_t*)object;
  62     access_sys_t *sys;
  63
  64     /* */
  65     access->p_sys = sys = malloc(sizeof(*sys));
  66     if (!sys)
  67         return VLC_ENOMEM;
  68
  69     /* We can either accept only one user (actually) or multiple ones
  70      * with an exclusive lock */
  71     if (SetupAvio(access)) {
  72         msg_Err(access, "Module aready in use");
  73         return VLC_EGENERIC;
  74     }
  75
  76     /* */
  77     vlc_avcodec_lock();
  78     av_register_all();
  79     vlc_avcodec_unlock();
  80
  81     /* We accept:
  82      * - avio://full_url
  83      * - url (only a subset of available protocols).
  84      */
  85     char *url;
  86     if (!strcmp(access->psz_access, "avio"))
  87         url = strdup(access->psz_path);
  88     else if (asprintf(&url, "%s://%s", access->psz_access, access->psz_path) < 0)
  89         url = NULL;
  90
  91     if (!url)
  92         goto error;
  93
  94     msg_Dbg(access, "Opening '%s'", url);
  95     if (url_open(&sys->context, url, URL_RDONLY) < 0 )
  96         sys->context = NULL;
  97     free(url);
  98
  99     if (!sys->context) {
 100         msg_Err(access, "Failed to open url using libavformat");
 101         goto error;
 102     }
 103     const int64_t size = url_filesize(sys->context);
 104     msg_Dbg(access, "is_streamed=%d size=%"PRIi64, sys->context->is_streamed, size);
 105
 106     /* */
 107     access_InitFields(access);
 108     access->info.i_size = size > 0 ? size : 0;
 109
 110     access->pf_read = Read;
 111     access->pf_block = NULL;
 112     access->pf_control = Control;
 113     access->pf_seek = Seek;
 114     access->p_sys = sys;
 115
 116     return VLC_SUCCESS;
 117
 118 error:
 119     SetupAvio(NULL);
 120     free(sys);
 121     return VLC_EGENERIC;
 122 }
 123
 124
 125 void CloseAvio(vlc_object_t *object)
 126 {
 127     access_t *access = (access_t*)object;
 128     access_sys_t *sys = access->p_sys;
 129
 130     url_close(sys->context);
 131
 132     SetupAvio(NULL);
 133
 134     free(sys);
 135 }
 136
 137
 138 static ssize_t Read(access_t *access, uint8_t *data, size_t size)
 139 {
 140     /* FIXME I am unsure of the meaning of the return value in case
 141      * of error.
 142      */
 143     int r = url_read(access->p_sys->context, data, size);
 144     access->info.b_eof = r <= 0;
 145     if (r < 0)
 146         return -1;
 147     access->info.i_pos += r;
 148     return r;
 149 }
 150
 151
 152 static int Seek(access_t *access, int64_t position)
 153 {
 154     access_sys_t *sys = access->p_sys;
 155
 156     if (url_seek(sys->context, position, SEEK_SET) < 0) {
 157         msg_Err(access, "Seek to %"PRIi64" failed\n", position);
 158         if (access->info.i_size <= 0 || position != access->info.i_size)
 159             return VLC_EGENERIC;
 160     }
 161     access->info.i_pos = position;
 162     access->info.b_eof = false;
 163     return VLC_SUCCESS;
 164 }
 165
 166
 167 static int Control(access_t *access, int query, va_list args)
 168 {
 169     access_sys_t *sys = access->p_sys;
 170
 171     switch (query) {
 172     case ACCESS_CAN_SEEK:
 173     case ACCESS_CAN_FASTSEEK: { /* FIXME how to do that ? */
 174         bool *b = va_arg(args, bool *);
 175         *b = !sys->context->is_streamed;
 176         return VLC_SUCCESS;
 177     }
 178     case ACCESS_CAN_PAUSE: {
 179         bool *b = va_arg(args, bool *);
 180         *b = sys->context->prot->url_read_pause != NULL; /* FIXME Unsure */
 181         return VLC_SUCCESS;
 182     }
 183     case ACCESS_CAN_CONTROL_PACE: {
 184         bool *b = va_arg(args, bool *);
 185         *b = true; /* FIXME */
 186         return VLC_SUCCESS;
 187     }
 188     case ACCESS_GET_PTS_DELAY: {
 189         int64_t *delay = va_arg(args, int64_t *);
 190         *delay = DEFAULT_PTS_DELAY; /* FIXME */
 191     }
 192     case ACCESS_SET_PAUSE_STATE: {
 193         bool is_paused = va_arg(args, int);
 194         if (av_url_read_pause(sys->context, is_paused)< 0)
 195             return VLC_EGENERIC;
 196         return VLC_SUCCESS;
 197     }
 198     case ACCESS_GET_TITLE_INFO:
 199     case ACCESS_GET_META:
 200     case ACCESS_GET_CONTENT_TYPE:
 201     case ACCESS_GET_SIGNAL:
 202     case ACCESS_SET_TITLE:
 203     case ACCESS_SET_SEEKPOINT:
 204     case ACCESS_SET_PRIVATE_ID_STATE:
 205     case ACCESS_SET_PRIVATE_ID_CA:
 206     case ACCESS_GET_PRIVATE_ID_STATE:
 207     default:
 208         return VLC_EGENERIC;
 209     }
 210 }
 211
 212 /* */
 213 static vlc_mutex_t avio_lock = VLC_STATIC_MUTEX;
 214 static access_t *current_access = NULL;
 215
 216
 217 static int UrlInterruptCallback(void)
 218 {
 219     assert(current_access);
 220     return !vlc_object_alive(current_access);
 221 }
 222
 223
 224 static int SetupAvio(access_t *access)
 225 {
 226     vlc_mutex_lock(&avio_lock);
 227     assert(!access != !current_access);
 228     if (access && current_access) {
 229         vlc_mutex_unlock(&avio_lock);
 230         return VLC_EGENERIC;
 231     }
 232     url_set_interrupt_cb(access ? UrlInterruptCallback : NULL);
 233     current_access = access;
 234     vlc_mutex_unlock(&avio_lock);
 235
 236     return VLC_SUCCESS;
 237 }
 238