| 1 | /* |
| 2 | * Concat URL protocol |
| 3 | * Copyright (c) 2006 Steve Lhomme |
| 4 | * Copyright (c) 2007 Wolfram Gloger |
| 5 | * Copyright (c) 2010 Michele OrrĂ¹ |
| 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 | }; |