mirror of
https://git.ffmpeg.org/ffmpeg.git
synced 2026-06-11 08:13:06 +00:00
Niklas Haas
56de70a2e6
This adds a new protocol shared:URI which is distinct from the existing `cache:` in that it is explicity designed to be thread-safe and cross-process, enabling multiple ffmpeg processes (or multiple ffmpeg decoders within the same process) to share a single cache file, for e.g. a remote HTTP stream. As such, it uses a radically different internal design. To facilitate zero-knowledge cross-process interoperability, the cache file itself is just a memory-mapped representation of the underlying file data, which has the side benefit that the resulting cache file will contain a working copy of the streamed file (assuming the stream was read to completion). To keep track of which regions are cached and which are not, we use a secondary file that contains a minimal header along with a static bytemap of blocks within the file. This secondary file is also used to store metadata such as the filesize, if known, as well as marking "failed" blocks. Both files can grow dynamically in order to accommodate larger/growing files, and can be atomically updated (through the use of shared space maps). I have extensively checked the space map initalization and update code for race conditions, and I believe the current design to be solid. That said, it is the user's responsibility to some extent to ensure that the same URI is not used for different streams, as we rely on the URI to uniquely identify the cache files. That said, we use a cryptographic hash with sufficient collision resistance to protect against possible abuse. The lack of any implicit default on `-cache_dir` also means that `shared:` can't be enabled via URL injection to possibly access random files on the disk (or intentionally leak content from other streams with similar URIs, even if the cryptograhic hash function is broken).
148 lines
4.9 KiB
C
148 lines
4.9 KiB
C
/*
|
|
* 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 <string.h>
|
|
|
|
#include "libavutil/avstring.h"
|
|
#include "libavutil/log.h"
|
|
#include "libavutil/mem.h"
|
|
|
|
#include "url.h"
|
|
|
|
extern const URLProtocol ff_android_content_protocol;
|
|
extern const URLProtocol ff_async_protocol;
|
|
extern const URLProtocol ff_bluray_protocol;
|
|
extern const URLProtocol ff_cache_protocol;
|
|
extern const URLProtocol ff_concat_protocol;
|
|
extern const URLProtocol ff_concatf_protocol;
|
|
extern const URLProtocol ff_crypto_protocol;
|
|
extern const URLProtocol ff_data_protocol;
|
|
extern const URLProtocol ff_fd_protocol;
|
|
extern const URLProtocol ff_ffrtmpcrypt_protocol;
|
|
extern const URLProtocol ff_ffrtmphttp_protocol;
|
|
extern const URLProtocol ff_file_protocol;
|
|
extern const URLProtocol ff_ftp_protocol;
|
|
extern const URLProtocol ff_gopher_protocol;
|
|
extern const URLProtocol ff_gophers_protocol;
|
|
extern const URLProtocol ff_http_protocol;
|
|
extern const URLProtocol ff_httpproxy_protocol;
|
|
extern const URLProtocol ff_https_protocol;
|
|
extern const URLProtocol ff_icecast_protocol;
|
|
extern const URLProtocol ff_mmsh_protocol;
|
|
extern const URLProtocol ff_mmst_protocol;
|
|
extern const URLProtocol ff_md5_protocol;
|
|
extern const URLProtocol ff_pipe_protocol;
|
|
extern const URLProtocol ff_prompeg_protocol;
|
|
extern const URLProtocol ff_rtmp_protocol;
|
|
extern const URLProtocol ff_rtmpe_protocol;
|
|
extern const URLProtocol ff_rtmps_protocol;
|
|
extern const URLProtocol ff_rtmpt_protocol;
|
|
extern const URLProtocol ff_rtmpte_protocol;
|
|
extern const URLProtocol ff_rtmpts_protocol;
|
|
extern const URLProtocol ff_rtp_protocol;
|
|
extern const URLProtocol ff_shared_protocol;
|
|
extern const URLProtocol ff_sctp_protocol;
|
|
extern const URLProtocol ff_srtp_protocol;
|
|
extern const URLProtocol ff_subfile_protocol;
|
|
extern const URLProtocol ff_tee_protocol;
|
|
extern const URLProtocol ff_tcp_protocol;
|
|
extern const URLProtocol ff_tls_protocol;
|
|
extern const URLProtocol ff_dtls_protocol;
|
|
extern const URLProtocol ff_udp_protocol;
|
|
extern const URLProtocol ff_udplite_protocol;
|
|
extern const URLProtocol ff_unix_protocol;
|
|
extern const URLProtocol ff_libamqp_protocol;
|
|
extern const URLProtocol ff_librist_protocol;
|
|
extern const URLProtocol ff_librtmp_protocol;
|
|
extern const URLProtocol ff_librtmpe_protocol;
|
|
extern const URLProtocol ff_librtmps_protocol;
|
|
extern const URLProtocol ff_librtmpt_protocol;
|
|
extern const URLProtocol ff_librtmpte_protocol;
|
|
extern const URLProtocol ff_libsrt_protocol;
|
|
extern const URLProtocol ff_libssh_protocol;
|
|
extern const URLProtocol ff_libsmbclient_protocol;
|
|
extern const URLProtocol ff_libzmq_protocol;
|
|
extern const URLProtocol ff_ipfs_gateway_protocol;
|
|
extern const URLProtocol ff_ipns_gateway_protocol;
|
|
|
|
#include "libavformat/protocol_list.c"
|
|
|
|
const AVClass *ff_urlcontext_child_class_iterate(void **iter)
|
|
{
|
|
const AVClass *ret = NULL;
|
|
uintptr_t i;
|
|
|
|
for (i = (uintptr_t)*iter; url_protocols[i]; i++) {
|
|
ret = url_protocols[i]->priv_data_class;
|
|
if (ret)
|
|
break;
|
|
}
|
|
|
|
*iter = (void*)(uintptr_t)(url_protocols[i] ? i + 1 : i);
|
|
return ret;
|
|
}
|
|
|
|
const char *avio_enum_protocols(void **opaque, int output)
|
|
{
|
|
uintptr_t i;
|
|
|
|
for (i = (uintptr_t)*opaque; url_protocols[i]; i++) {
|
|
const URLProtocol *p = url_protocols[i];
|
|
if ((output && p->url_write) || (!output && p->url_read)) {
|
|
*opaque = (void*)(uintptr_t)(i + 1);
|
|
return p->name;
|
|
}
|
|
}
|
|
*opaque = NULL;
|
|
return NULL;
|
|
}
|
|
|
|
const AVClass *avio_protocol_get_class(const char *name)
|
|
{
|
|
int i = 0;
|
|
for (i = 0; url_protocols[i]; i++) {
|
|
if (!strcmp(url_protocols[i]->name, name))
|
|
return url_protocols[i]->priv_data_class;
|
|
}
|
|
return NULL;
|
|
}
|
|
|
|
const URLProtocol **ffurl_get_protocols(const char *whitelist,
|
|
const char *blacklist)
|
|
{
|
|
const URLProtocol **ret;
|
|
int i, ret_idx = 0;
|
|
|
|
ret = av_calloc(FF_ARRAY_ELEMS(url_protocols), sizeof(*ret));
|
|
if (!ret)
|
|
return NULL;
|
|
|
|
for (i = 0; url_protocols[i]; i++) {
|
|
const URLProtocol *up = url_protocols[i];
|
|
|
|
if (whitelist && *whitelist && !av_match_name(up->name, whitelist))
|
|
continue;
|
|
if (blacklist && *blacklist && av_match_name(up->name, blacklist))
|
|
continue;
|
|
|
|
ret[ret_idx++] = up;
|
|
}
|
|
|
|
return ret;
|
|
}
|