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data_uri.c
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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/base64.h"
24 #include "url.h"
25 
26 typedef struct {
27  const uint8_t *data;
28  void *tofree;
29  size_t size;
30  size_t pos;
31 } DataContext;
32 
33 static av_cold int data_open(URLContext *h, const char *uri, int flags)
34 {
35  DataContext *dc = h->priv_data;
36  const char *data, *opt, *next;
37  char *ddata;
38  int ret, base64 = 0;
39  size_t in_size;
40 
41  /* data:content/type[;base64],payload */
42 
43  av_strstart(uri, "data:", &uri);
44  data = strchr(uri, ',');
45  if (!data) {
46  av_log(h, AV_LOG_ERROR, "No ',' delimiter in URI\n");
47  return AVERROR(EINVAL);
48  }
49  opt = uri;
50  while (opt < data) {
51  next = av_x_if_null(memchr(opt, ';', data - opt), data);
52  if (opt == uri) {
53  if (!memchr(opt, '/', next - opt)) { /* basic validity check */
54  av_log(h, AV_LOG_ERROR, "Invalid content-type '%.*s'\n",
55  (int)(next - opt), opt);
56  return AVERROR(EINVAL);
57  }
58  av_log(h, AV_LOG_VERBOSE, "Content-type: %.*s\n",
59  (int)(next - opt), opt);
60  } else {
61  if (!av_strncasecmp(opt, "base64", next - opt)) {
62  base64 = 1;
63  } else {
64  av_log(h, AV_LOG_VERBOSE, "Ignoring option '%.*s'\n",
65  (int)(next - opt), opt);
66  }
67  }
68  opt = next + 1;
69  }
70 
71  data++;
72  in_size = strlen(data);
73  if (base64) {
74  size_t out_size = 3 * (in_size / 4) + 1;
75 
76  if (out_size > INT_MAX || !(ddata = av_malloc(out_size)))
77  return AVERROR(ENOMEM);
78  if ((ret = av_base64_decode(ddata, data, out_size)) < 0) {
79  av_free(ddata);
80  av_log(h, AV_LOG_ERROR, "Invalid base64 in URI\n");
81  return ret;
82  }
83  dc->data = dc->tofree = ddata;
84  dc->size = ret;
85  } else {
86  dc->data = data;
87  dc->size = in_size;
88  }
89  return 0;
90 }
91 
93 {
94  DataContext *dc = h->priv_data;
95 
96  av_freep(&dc->tofree);
97  return 0;
98 }
99 
100 static int data_read(URLContext *h, unsigned char *buf, int size)
101 {
102  DataContext *dc = h->priv_data;
103 
104  if (dc->pos >= dc->size)
105  return AVERROR_EOF;
106  size = FFMIN(size, dc->size - dc->pos);
107  memcpy(buf, dc->data + dc->pos, size);
108  dc->pos += size;
109  return size;
110 }
111 
113  .name = "data",
114  .url_open = data_open,
115  .url_close = data_close,
116  .url_read = data_read,
117  .priv_data_size = sizeof(DataContext),
118 };