libavformat/data_uri.c

   1 /*
   2  * Copyright (c) 2012 Nicolas George
   3  *
   4  * This file is part of FFmpeg.
   5  *
   6  * FFmpeg is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public License
   8  * as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * FFmpeg is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14  * GNU Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public License
  17  * along with FFmpeg; if not, write to the Free Software Foundation, Inc.,
  18  * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  19  */
  20
  21 #include <string.h>
  22 #include "libavutil/avstring.h"
  23 #include "libavutil/avutil.h"
  24 #include "libavutil/base64.h"
  25 #include "libavutil/mem.h"
  26 #include "url.h"
  27
  28 typedef struct {
  29     const uint8_t *data;
  30     void *tofree;
  31     size_t size;
  32     size_t pos;
  33 } DataContext;
  34
  35 static av_cold int data_open(URLContext *h, const char *uri, int flags)
  36 {
  37     DataContext *dc = h->priv_data;
  38     const char *data, *opt, *next;
  39     char *ddata;
  40     int ret, base64 = 0;
  41     size_t in_size;
  42
  43     /* data:content/type[;base64],payload */
  44
  45     av_strstart(uri, "data:", &uri);
  46     data = strchr(uri, ',');
  47     if (!data) {
  48         av_log(h, AV_LOG_ERROR, "No ',' delimiter in URI\n");
  49         return AVERROR(EINVAL);
  50     }
  51     opt = uri;
  52     while (opt < data) {
  53         next = av_x_if_null(memchr(opt, ';', data - opt), data);
  54         if (opt == uri) {
  55             if (!memchr(opt, '/', next - opt)) { /* basic validity check */
  56                 av_log(h, AV_LOG_ERROR, "Invalid content-type '%.*s'\n",
  57                        (int)(next - opt), opt);
  58                 return AVERROR(EINVAL);
  59             }
  60             av_log(h, AV_LOG_VERBOSE, "Content-type: %.*s\n",
  61                    (int)(next - opt), opt);
  62         } else {
  63             if (!av_strncasecmp(opt, "base64", next - opt)) {
  64                 base64 = 1;
  65             } else {
  66                 av_log(h, AV_LOG_VERBOSE, "Ignoring option '%.*s'\n",
  67                        (int)(next - opt), opt);
  68             }
  69         }
  70         opt = next + 1;
  71     }
  72
  73     data++;
  74     in_size = strlen(data);
  75     if (base64) {
  76         size_t out_size = 3 * (in_size / 4) + 1;
  77
  78         if (out_size > INT_MAX || !(ddata = av_malloc(out_size)))
  79             return AVERROR(ENOMEM);
  80         if ((ret = av_base64_decode(ddata, data, out_size)) < 0) {
  81             av_free(ddata);
  82             av_log(h, AV_LOG_ERROR, "Invalid base64 in URI\n");
  83             return ret;
  84         }
  85         dc->data = dc->tofree = ddata;
  86         dc->size = ret;
  87     } else {
  88         dc->data = data;
  89         dc->size = in_size;
  90     }
  91     return 0;
  92 }
  93
  94 static av_cold int data_close(URLContext *h)
  95 {
  96     DataContext *dc = h->priv_data;
  97
  98     av_freep(&dc->tofree);
  99     return 0;
 100 }
 101
 102 static int data_read(URLContext *h, unsigned char *buf, int size)
 103 {
 104     DataContext *dc = h->priv_data;
 105
 106     if (dc->pos >= dc->size)
 107         return AVERROR_EOF;
 108     size = FFMIN(size, dc->size - dc->pos);
 109     memcpy(buf, dc->data + dc->pos, size);
 110     dc->pos += size;
 111     return size;
 112 }
 113
 114 const URLProtocol ff_data_protocol = {
 115     .name           = "data",
 116     .url_open       = data_open,
 117     .url_close      = data_close,
 118     .url_read       = data_read,
 119     .priv_data_size = sizeof(DataContext),
 120 };