1 /*****************************************************************************
2 * decomp.c : Decompression module for vlc
3 *****************************************************************************
4 * Copyright © 2008 Rémi Denis-Courmont
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU Lesser General Public License as published by
8 * the Free Software Foundation; either version 2.1 of the License, or
9 * (at your option) any later version.
11 * This program 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 General Public License for more details.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
19 *****************************************************************************/
25 #include <vlc_common.h>
26 #include <vlc_plugin.h>
27 #include <vlc_stream.h>
28 #include <vlc_network.h>
33 #include <sys/ioctl.h>
36 # include <sys/mman.h>
41 static int OpenGzip (vlc_object_t *);
42 static int OpenBzip2 (vlc_object_t *);
43 static void Close (vlc_object_t *);
46 set_description (N_("Decompression"))
47 set_category (CAT_INPUT)
48 set_subcategory (SUBCAT_INPUT_STREAM_FILTER)
49 set_capability ("stream_filter", 20)
50 set_callbacks (OpenBzip2, Close)
51 /* TODO: access shortnames for stream_UrlNew() */
54 set_callbacks (OpenGzip, Close)
62 int write_fd, read_fd;
65 static void cloexec (int fd)
67 int flags = fcntl (fd, F_GETFD);
68 fcntl (fd, F_SETFD, FD_CLOEXEC | ((flags != -1) ? flags : 0));
71 extern char **environ;
73 static const size_t bufsize = 65536;
74 static void cleanup_mmap (void *addr)
76 munmap (addr, bufsize);
80 static void *Thread (void *data)
82 stream_t *stream = data;
83 stream_sys_t *p_sys = stream->p_sys;
84 int fd = p_sys->write_fd;
90 int canc = vlc_savecancel ();
92 unsigned char *buf = mmap (NULL, bufsize, PROT_READ|PROT_WRITE,
93 MAP_PRIVATE|MAP_ANONYMOUS, -1, 0);
94 vlc_cleanup_push (cleanup_mmap, buf);
96 unsigned char buf[bufsize];
99 len = stream_Read (stream->p_source, buf, bufsize);
100 vlc_restorecancel (canc);
105 for (ssize_t i = 0, j = 0; i < len; i += j)
107 struct iovec iov[1] = { { buf + i, len - i, } };
110 j = vmsplice (fd, iov, 1, SPLICE_F_GIFT);
112 j = writev (fd, iov, 1);
118 msg_Err (stream, "cannot write data (%m)");
124 vlc_cleanup_run (); /* munmap (buf, bufsize) */
129 msg_Dbg (stream, "compressed stream at EOF");
134 #define MIN_BLOCK (1 << 10)
135 #define MAX_BLOCK (1 << 20)
137 * Reads decompressed from the decompression program
138 * @return -1 for EAGAIN, 0 for EOF, byte count otherwise.
140 static int Read (stream_t *stream, void *buf, unsigned int buflen)
142 stream_sys_t *p_sys = stream->p_sys;
147 if ((peeked = p_sys->peeked) != NULL)
149 bonus = (buflen > peeked->i_buffer) ? peeked->i_buffer : buflen;
150 memcpy (buf, peeked->p_buffer, bonus);
151 peeked->p_buffer += bonus;
152 peeked->i_buffer -= bonus;
153 if (peeked->i_buffer == 0)
155 block_Release (peeked);
156 p_sys->peeked = NULL;
160 length = net_Read (stream, p_sys->read_fd, NULL, buf, buflen, false);
161 return bonus + ((length >= 0) ? length : 0);
167 static int Peek (stream_t *stream, const uint8_t **pbuf, unsigned int len)
169 stream_sys_t *p_sys = stream->p_sys;
170 block_t *peeked = p_sys->peeked;
172 int fd = p_sys->read_fd;
175 peeked = block_Alloc (len);
176 else if ((curlen = peeked->i_buffer) < len)
177 peeked = block_Realloc (peeked, 0, len);
179 if ((p_sys->peeked = peeked) == NULL)
184 ssize_t val = net_Read (stream, fd, NULL, peeked->p_buffer + curlen,
189 peeked->i_buffer = curlen;
192 *pbuf = peeked->p_buffer;
199 static int Control (stream_t *stream, int query, va_list args)
201 /*stream_sys_t *p_sys = stream->p_sys;*/
203 (void)query; (void)args;
208 * Pipe data through an external executable.
209 * @param stream the stream filter object.
210 * @param path path to the executable.
212 static int Open (stream_t *stream, const char *path)
214 stream_sys_t *p_sys = stream->p_sys = malloc (sizeof (*p_sys));
218 stream->pf_read = Read;
219 stream->pf_peek = Peek;
220 stream->pf_control = Control;
221 p_sys->peeked = NULL;
224 /* I am not a big fan of the pyramid style, but I cannot think of anything
225 * better here. There are too many failure cases. */
226 int ret = VLC_EGENERIC;
229 if (pipe (comp) == 0)
232 p_sys->write_fd = comp[1];
235 if (pipe (uncomp) == 0)
238 p_sys->read_fd = uncomp[0];
240 posix_spawn_file_actions_t actions;
241 if (posix_spawn_file_actions_init (&actions) == 0)
243 char *const argv[] = { (char *)path, NULL };
245 if (!posix_spawn_file_actions_adddup2 (&actions, comp[0], 0)
246 && !posix_spawn_file_actions_addclose (&actions, comp[0])
247 && !posix_spawn_file_actions_adddup2 (&actions, uncomp[1], 1)
248 && !posix_spawn_file_actions_addclose (&actions, uncomp[1])
249 && !posix_spawnp (&p_sys->pid, path, &actions, NULL, argv,
252 if (vlc_clone (&p_sys->thread, Thread, stream,
253 VLC_THREAD_PRIORITY_INPUT) == 0)
258 msg_Err (stream, "Cannot execute %s", path);
261 posix_spawn_file_actions_destroy (&actions);
264 if (ret != VLC_SUCCESS)
268 if (ret != VLC_SUCCESS)
271 if (p_sys->pid != -1)
272 while (waitpid (p_sys->pid, &(int){ 0 }, 0) == -1);
280 * Releases allocate resources.
282 static void Close (vlc_object_t *obj)
284 stream_t *stream = (stream_t *)obj;
285 stream_sys_t *p_sys = stream->p_sys;
288 vlc_cancel (p_sys->thread);
289 close (p_sys->read_fd);
290 vlc_join (p_sys->thread, NULL);
291 close (p_sys->write_fd);
293 msg_Dbg (obj, "waiting for PID %u", (unsigned)p_sys->pid);
294 while (waitpid (p_sys->pid, &status, 0) == -1);
295 msg_Dbg (obj, "exit status %d", status);
298 block_Release (p_sys->peeked);
304 * Detects gzip file format
306 static int OpenGzip (vlc_object_t *obj)
308 stream_t *stream = (stream_t *)obj;
311 if (stream_Peek (stream->p_source, &peek, 3) < 3)
314 if (memcmp (peek, "\x1f\x8b\x08", 3))
317 msg_Dbg (obj, "detected gzip compressed stream");
318 return Open (stream, "zcat");
323 * Detects bzip2 file format
325 static int OpenBzip2 (vlc_object_t *obj)
327 stream_t *stream = (stream_t *)obj;
330 /* (Try to) parse the bzip2 header */
331 if (stream_Peek (stream->p_source, &peek, 10) < 10)
334 if (memcmp (peek, "BZh", 3) || (peek[3] < '1') || (peek[3] > '9')
335 || memcmp (peek + 4, "\x31\x41\x59\x26\x53\x59", 6))
338 msg_Dbg (obj, "detected bzip2 compressed stream");
339 return Open (stream, "bzcat");