Subversion Repositories Kolibri OS

Rev

Go to most recent revision | Blame | Last modification | View Log | RSS feed

  1. /*
  2.  * Concat URL protocol
  3.  * Copyright (c) 2006 Steve Lhomme
  4.  * Copyright (c) 2007 Wolfram Gloger
  5.  * Copyright (c) 2010 Michele Orrù
  6.  *
  7.  * This file is part of FFmpeg.
  8.  *
  9.  * FFmpeg is free software; you can redistribute it and/or
  10.  * modify it under the terms of the GNU Lesser General Public
  11.  * License as published by the Free Software Foundation; either
  12.  * version 2.1 of the License, or (at your option) any later version.
  13.  *
  14.  * FFmpeg 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 GNU
  17.  * Lesser General Public License for more details.
  18.  *
  19.  * You should have received a copy of the GNU Lesser General Public
  20.  * License along with FFmpeg; if not, write to the Free Software
  21.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  22.  */
  23.  
  24. #include "avformat.h"
  25. #include "libavutil/avstring.h"
  26. #include "libavutil/mem.h"
  27. #include "url.h"
  28.  
  29. #define AV_CAT_SEPARATOR "|"
  30.  
  31. struct concat_nodes {
  32.     URLContext *uc;                ///< node's URLContext
  33.     int64_t     size;              ///< url filesize
  34. };
  35.  
  36. struct concat_data {
  37.     struct concat_nodes *nodes;    ///< list of nodes to concat
  38.     size_t               length;   ///< number of cat'ed nodes
  39.     size_t               current;  ///< index of currently read node
  40. };
  41.  
  42. static av_cold int concat_close(URLContext *h)
  43. {
  44.     int err = 0;
  45.     size_t i;
  46.     struct concat_data  *data  = h->priv_data;
  47.     struct concat_nodes *nodes = data->nodes;
  48.  
  49.     for (i = 0; i != data->length; i++)
  50.         err |= ffurl_close(nodes[i].uc);
  51.  
  52.     av_freep(&data->nodes);
  53.  
  54.     return err < 0 ? -1 : 0;
  55. }
  56.  
  57. static av_cold int concat_open(URLContext *h, const char *uri, int flags)
  58. {
  59.     char *node_uri = NULL;
  60.     int err = 0;
  61.     int64_t size;
  62.     size_t  len, i;
  63.     URLContext *uc;
  64.     struct concat_data  *data = h->priv_data;
  65.     struct concat_nodes *nodes;
  66.  
  67.     av_strstart(uri, "concat:", &uri);
  68.  
  69.     for (i = 0, len = 1; uri[i]; i++)
  70.         if (uri[i] == *AV_CAT_SEPARATOR)
  71.             /* integer overflow */
  72.             if (++len == UINT_MAX / sizeof(*nodes)) {
  73.                 av_freep(&h->priv_data);
  74.                 return AVERROR(ENAMETOOLONG);
  75.             }
  76.  
  77.     if (!(nodes = av_realloc(NULL, sizeof(*nodes) * len))) {
  78.         return AVERROR(ENOMEM);
  79.     } else
  80.         data->nodes = nodes;
  81.  
  82.     /* handle input */
  83.     if (!*uri)
  84.         err = AVERROR(ENOENT);
  85.     for (i = 0; *uri; i++) {
  86.         /* parsing uri */
  87.         len = strcspn(uri, AV_CAT_SEPARATOR);
  88.         if ((err = av_reallocp(&node_uri, len + 1)) < 0)
  89.             break;
  90.         av_strlcpy(node_uri, uri, len+1);
  91.         uri += len + strspn(uri+len, AV_CAT_SEPARATOR);
  92.  
  93.         /* creating URLContext */
  94.         if ((err = ffurl_open(&uc, node_uri, flags,
  95.                               &h->interrupt_callback, NULL)) < 0)
  96.             break;
  97.  
  98.         /* creating size */
  99.         if ((size = ffurl_size(uc)) < 0) {
  100.             ffurl_close(uc);
  101.             err = AVERROR(ENOSYS);
  102.             break;
  103.         }
  104.  
  105.         /* assembling */
  106.         nodes[i].uc   = uc;
  107.         nodes[i].size = size;
  108.     }
  109.     av_free(node_uri);
  110.     data->length = i;
  111.  
  112.     if (err < 0)
  113.         concat_close(h);
  114.     else if (!(nodes = av_realloc(nodes, data->length * sizeof(*nodes)))) {
  115.         concat_close(h);
  116.         err = AVERROR(ENOMEM);
  117.     } else
  118.         data->nodes = nodes;
  119.     return err;
  120. }
  121.  
  122. static int concat_read(URLContext *h, unsigned char *buf, int size)
  123. {
  124.     int result, total = 0;
  125.     struct concat_data  *data  = h->priv_data;
  126.     struct concat_nodes *nodes = data->nodes;
  127.     size_t i = data->current;
  128.  
  129.     while (size > 0) {
  130.         result = ffurl_read(nodes[i].uc, buf, size);
  131.         if (result < 0)
  132.             return total ? total : result;
  133.         if (!result)
  134.             if (i + 1 == data->length ||
  135.                 ffurl_seek(nodes[++i].uc, 0, SEEK_SET) < 0)
  136.                 break;
  137.         total += result;
  138.         buf   += result;
  139.         size  -= result;
  140.     }
  141.     data->current = i;
  142.     return total;
  143. }
  144.  
  145. static int64_t concat_seek(URLContext *h, int64_t pos, int whence)
  146. {
  147.     int64_t result;
  148.     struct concat_data  *data  = h->priv_data;
  149.     struct concat_nodes *nodes = data->nodes;
  150.     size_t i;
  151.  
  152.     switch (whence) {
  153.     case SEEK_END:
  154.         for (i = data->length - 1;
  155.              i && pos < -nodes[i].size;
  156.              i--)
  157.             pos += nodes[i].size;
  158.         break;
  159.     case SEEK_CUR:
  160.         /* get the absolute position */
  161.         for (i = 0; i != data->current; i++)
  162.             pos += nodes[i].size;
  163.         pos += ffurl_seek(nodes[i].uc, 0, SEEK_CUR);
  164.         whence = SEEK_SET;
  165.         /* fall through with the absolute position */
  166.     case SEEK_SET:
  167.         for (i = 0; i != data->length - 1 && pos >= nodes[i].size; i++)
  168.             pos -= nodes[i].size;
  169.         break;
  170.     default:
  171.         return AVERROR(EINVAL);
  172.     }
  173.  
  174.     result = ffurl_seek(nodes[i].uc, pos, whence);
  175.     if (result >= 0) {
  176.         data->current = i;
  177.         while (i)
  178.             result += nodes[--i].size;
  179.     }
  180.     return result;
  181. }
  182.  
  183. URLProtocol ff_concat_protocol = {
  184.     .name           = "concat",
  185.     .url_open       = concat_open,
  186.     .url_read       = concat_read,
  187.     .url_seek       = concat_seek,
  188.     .url_close      = concat_close,
  189.     .priv_data_size = sizeof(struct concat_data),
  190. };
  191.