From 084eb95fd5eacb2eba653210c8e460b2a3d9a729 Mon Sep 17 00:00:00 2001 From: Michele Orrù Date: Sun, 7 Feb 2010 10:25:58 +0000 Subject: Implement a physical concatenation protocol. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Patch by Michele Orrù reverse(). Originally committed as revision 21666 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavformat/concat.c | 198 +++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 198 insertions(+) create mode 100644 libavformat/concat.c (limited to 'libavformat/concat.c') diff --git a/libavformat/concat.c b/libavformat/concat.c new file mode 100644 index 0000000000..ed64b6e675 --- /dev/null +++ b/libavformat/concat.c @@ -0,0 +1,198 @@ +/* + * Concat URL protocol + * Copyright (c) 2006 Steve Lhomme + * Copyright (c) 2007 Wolfram Gloger + * Copyright (c) 2010 Michele Orrù + * + * This file is part of FFmpeg. + * + * FFmpeg is free software; you can redistribute it and/or + * modify it under the terms of the GNU Lesser General Public + * License as published by the Free Software Foundation; either + * version 2.1 of the License, or (at your option) any later version. + * + * FFmpeg is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Lesser General Public License for more details. + * + * You should have received a copy of the GNU Lesser General Public + * License along with FFmpeg; if not, write to the Free Software + * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA + */ + +#include "avformat.h" +#include "libavutil/avstring.h" +#include "libavutil/mem.h" + +#define AV_CAT_SEPARATOR "|" + +struct concat_nodes { + URLContext *uc; ///< node's URLContext + int64_t size; ///< url filesize +}; + +struct concat_data { + struct concat_nodes *nodes; ///< list of nodes to concat + size_t length; ///< number of cat'ed nodes + size_t current; ///< index of currently read node +}; + +static av_cold int concat_close(URLContext *h) +{ + int err = 0; + size_t i; + struct concat_data *data = h->priv_data; + struct concat_nodes *nodes = data->nodes; + + for (i = 0; i != data->length; i++) + err |= url_close(nodes[i].uc); + + av_freep(&data->nodes); + av_freep(&h->priv_data); + + return err < 0 ? -1 : 0; +} + +static av_cold int concat_open(URLContext *h, const char *uri, int flags) +{ + char *node_uri = NULL, *tmp_uri; + int err = 0; + int64_t size; + size_t len, i; + URLContext *uc; + struct concat_data *data; + struct concat_nodes *nodes; + + av_strstart(uri, "concat:", &uri); + + /* creating data */ + if (!(data = av_mallocz(sizeof(*data)))) + return AVERROR(ENOMEM); + h->priv_data = data; + + for (i = 0, len = 1; uri[i]; i++) + if (uri[i] == *AV_CAT_SEPARATOR) + /* integer overflow */ + if (++len == UINT_MAX / sizeof(*nodes)) { + av_freep(&h->priv_data); + return AVERROR(ENAMETOOLONG); + } + + if (!(nodes = av_malloc(sizeof(*nodes) * len))) { + av_freep(&h->priv_data); + return AVERROR(ENOMEM); + } else + data->nodes = nodes; + + /* handle input */ + if (!*uri) + err = AVERROR(ENOENT); + for (i = 0; *uri; i++) { + /* parsing uri */ + len = strcspn(uri, AV_CAT_SEPARATOR); + if (!(tmp_uri = av_realloc(node_uri, len+1))) { + err = AVERROR(ENOMEM); + break; + } else + node_uri = tmp_uri; + av_strlcpy(node_uri, uri, len+1); + uri += len + strspn(uri+len, AV_CAT_SEPARATOR); + + /* creating URLContext */ + if ((err = url_open(&uc, node_uri, flags)) < 0) + break; + + /* creating size */ + if ((size = url_filesize(uc)) < 0) { + url_close(uc); + err = AVERROR(ENOSYS); + break; + } + + /* assembling */ + nodes[i].uc = uc; + nodes[i].size = size; + } + av_free(node_uri); + data->length = i; + + if (err < 0) + concat_close(h); + else if (!(nodes = av_realloc(nodes, data->length * sizeof(*nodes)))) { + concat_close(h); + err = AVERROR(ENOMEM); + } else + data->nodes = nodes; + return err; +} + +static int concat_read(URLContext *h, unsigned char *buf, int size) +{ + int result, total = 0; + struct concat_data *data = h->priv_data; + struct concat_nodes *nodes = data->nodes; + size_t i = data->current; + + while (size > 0) { + result = url_read(nodes[i].uc, buf, size); + if (result < 0) + return total ? total : result; + if (!result) + if (i + 1 == data->length || + url_seek(nodes[++i].uc, 0, SEEK_SET) < 0) + break; + total += result; + buf += result; + size -= result; + } + data->current = i; + return total; +} + +static int64_t concat_seek(URLContext *h, int64_t pos, int whence) +{ + int64_t result; + struct concat_data *data = h->priv_data; + struct concat_nodes *nodes = data->nodes; + size_t i; + + switch (whence) { + case SEEK_END: + for (i = data->length - 1; + i && pos < -nodes[i-1].size; + i--) + pos += nodes[i-1].size; + break; + case SEEK_CUR: + /* get the absolute position */ + for (i = 0; i != data->current; i++) + pos += nodes[i].size; + pos += url_seek(nodes[i].uc, 0, SEEK_CUR); + whence = SEEK_SET; + /* fall through with the absolute position */ + case SEEK_SET: + for (i = 0; i != data->length - 1 && pos >= nodes[i].size; i++) + pos -= nodes[i].size; + break; + default: + return AVERROR(EINVAL); + } + + result = url_seek(nodes[i].uc, pos, whence); + if (result >= 0) { + data->current = i; + while (i) + result += nodes[i--].size; + } + return result; +} + +URLProtocol concat_protocol = { + "concat", + concat_open, + concat_read, + NULL, + concat_seek, + concat_close, +}; -- cgit v1.2.3