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 "libavutil/avstring.h"
25 #include "libavutil/mem.h"
26
27 #include "avformat.h"
28 #include "url.h"
29
30 #define AV_CAT_SEPARATOR "|"
31
32 struct concat_nodes {
33 URLContext *uc; ///< node's URLContext
34 int64_t size; ///< url filesize
35 };
36
37 struct concat_data {
38 struct concat_nodes *nodes; ///< list of nodes to concat
39 size_t length; ///< number of cat'ed nodes
40 size_t current; ///< index of currently read node
41 uint64_t total_size;
42 };
43
concat_close(URLContext * h)44 static av_cold int concat_close(URLContext *h)
45 {
46 int err = 0;
47 size_t i;
48 struct concat_data *data = h->priv_data;
49 struct concat_nodes *nodes = data->nodes;
50
51 for (i = 0; i != data->length; i++)
52 err |= ffurl_closep(&nodes[i].uc);
53
54 av_freep(&data->nodes);
55
56 return err < 0 ? -1 : 0;
57 }
58
concat_open(URLContext * h,const char * uri,int flags)59 static av_cold int concat_open(URLContext *h, const char *uri, int flags)
60 {
61 char *node_uri = NULL;
62 int err = 0;
63 int64_t size, total_size = 0;
64 size_t len, i;
65 URLContext *uc;
66 struct concat_data *data = h->priv_data;
67 struct concat_nodes *nodes;
68
69 if (!av_strstart(uri, "concat:", &uri)) {
70 av_log(h, AV_LOG_ERROR, "URL %s lacks prefix\n", uri);
71 return AVERROR(EINVAL);
72 }
73
74 for (i = 0, len = 1; uri[i]; i++) {
75 if (uri[i] == *AV_CAT_SEPARATOR) {
76 len++;
77 }
78 }
79
80 if (!(nodes = av_realloc_array(NULL, len, sizeof(*nodes))))
81 return AVERROR(ENOMEM);
82 else
83 data->nodes = nodes;
84
85 /* handle input */
86 if (!*uri)
87 err = AVERROR(ENOENT);
88 for (i = 0; *uri; i++) {
89 /* parsing uri */
90 len = strcspn(uri, AV_CAT_SEPARATOR);
91 if ((err = av_reallocp(&node_uri, len + 1)) < 0)
92 break;
93 av_strlcpy(node_uri, uri, len + 1);
94 uri += len + strspn(uri + len, AV_CAT_SEPARATOR);
95
96 /* creating URLContext */
97 err = ffurl_open_whitelist(&uc, node_uri, flags,
98 &h->interrupt_callback, NULL, h->protocol_whitelist, h->protocol_blacklist, h);
99 if (err < 0)
100 break;
101
102 /* creating size */
103 if ((size = ffurl_size(uc)) < 0) {
104 ffurl_close(uc);
105 err = AVERROR(ENOSYS);
106 break;
107 }
108
109 /* assembling */
110 nodes[i].uc = uc;
111 nodes[i].size = size;
112 total_size += size;
113 }
114 av_free(node_uri);
115 data->length = i;
116
117 if (err < 0)
118 concat_close(h);
119 else if (!(nodes = av_realloc(nodes, data->length * sizeof(*nodes)))) {
120 concat_close(h);
121 err = AVERROR(ENOMEM);
122 } else
123 data->nodes = nodes;
124 data->total_size = total_size;
125 return err;
126 }
127
concat_read(URLContext * h,unsigned char * buf,int size)128 static int concat_read(URLContext *h, unsigned char *buf, int size)
129 {
130 int result, total = 0;
131 struct concat_data *data = h->priv_data;
132 struct concat_nodes *nodes = data->nodes;
133 size_t i = data->current;
134
135 while (size > 0) {
136 result = ffurl_read(nodes[i].uc, buf, size);
137 if (result == AVERROR_EOF) {
138 if (i + 1 == data->length ||
139 ffurl_seek(nodes[++i].uc, 0, SEEK_SET) < 0)
140 break;
141 result = 0;
142 }
143 if (result < 0)
144 return total ? total : result;
145 total += result;
146 buf += result;
147 size -= result;
148 }
149 data->current = i;
150 return total ? total : result;
151 }
152
concat_seek(URLContext * h,int64_t pos,int whence)153 static int64_t concat_seek(URLContext *h, int64_t pos, int whence)
154 {
155 int64_t result;
156 struct concat_data *data = h->priv_data;
157 struct concat_nodes *nodes = data->nodes;
158 size_t i;
159
160 if ((whence & AVSEEK_SIZE))
161 return data->total_size;
162 switch (whence) {
163 case SEEK_END:
164 for (i = data->length - 1; i && pos < -nodes[i].size; i--)
165 pos += nodes[i].size;
166 break;
167 case SEEK_CUR:
168 /* get the absolute position */
169 for (i = 0; i != data->current; i++)
170 pos += nodes[i].size;
171 pos += ffurl_seek(nodes[i].uc, 0, SEEK_CUR);
172 whence = SEEK_SET;
173 /* fall through with the absolute position */
174 case SEEK_SET:
175 for (i = 0; i != data->length - 1 && pos >= nodes[i].size; i++)
176 pos -= nodes[i].size;
177 break;
178 default:
179 return AVERROR(EINVAL);
180 }
181
182 result = ffurl_seek(nodes[i].uc, pos, whence);
183 if (result >= 0) {
184 data->current = i;
185 while (i)
186 result += nodes[--i].size;
187 }
188 return result;
189 }
190
191 const URLProtocol ff_concat_protocol = {
192 .name = "concat",
193 .url_open = concat_open,
194 .url_read = concat_read,
195 .url_seek = concat_seek,
196 .url_close = concat_close,
197 .priv_data_size = sizeof(struct concat_data),
198 .default_whitelist = "concat,file,subfile",
199 };
200