[vlc-devel] commit: Decompression demuxer. Supports gzip and bzip2 at this point. ( Rémi Denis-Courmont )
git version control
git at videolan.org
Sat Oct 11 17:18:53 CEST 2008
vlc | branch: master | Rémi Denis-Courmont <rdenis at simphalempin.com> | Sat Oct 11 18:16:29 2008 +0300| [fab9038a92dbcc434bf75e6790171f4f1d057a99] | committer: Rémi Denis-Courmont
Decompression demuxer. Supports gzip and bzip2 at this point.
There seems to be pretty awful bugs in stream_Demux or input or
something though. Sometimes, the input is killed almost immediately.
Other times (e.g. when trying to STOP), Close() never gets called.
> http://git.videolan.org/gitweb.cgi/vlc.git/?a=commit;h=fab9038a92dbcc434bf75e6790171f4f1d057a99
---
modules/demux/Modules.am | 1 +
modules/demux/decomp.c | 298 ++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 299 insertions(+), 0 deletions(-)
diff --git a/modules/demux/Modules.am b/modules/demux/Modules.am
index 268dc08..72f51fb 100644
--- a/modules/demux/Modules.am
+++ b/modules/demux/Modules.am
@@ -29,6 +29,7 @@ SOURCES_tta = tta.c
SOURCES_vc1 = vc1.c
SOURCES_demux_cdg = cdg.c
SOURCES_smf = smf.c
+SOURCES_decomp = decomp.c
libvlc_LTLIBRARIES += \
libaiff_plugin.la \
diff --git a/modules/demux/decomp.c b/modules/demux/decomp.c
new file mode 100644
index 0000000..a1929f2
--- /dev/null
+++ b/modules/demux/decomp.c
@@ -0,0 +1,298 @@
+/*****************************************************************************
+ * decomp.c : Decompression module for vlc
+ *****************************************************************************
+ * Copyright © 2008 Rémi Denis-Courmont
+ *
+ * This program 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.
+ *
+ * This program 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 General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
+ *****************************************************************************/
+
+#ifdef HAVE_CONFIG_H
+# include "config.h"
+#endif
+
+#include <vlc_common.h>
+#include <vlc_plugin.h>
+#include <vlc_demux.h>
+#include <vlc_stream.h>
+#include <vlc_network.h>
+#include <unistd.h>
+#include <fcntl.h>
+#include <spawn.h>
+#include <sys/wait.h>
+#include <sys/ioctl.h>
+
+#include <assert.h>
+
+static int OpenGzip (vlc_object_t *);
+static int OpenBzip2 (vlc_object_t *);
+static void Close (vlc_object_t *);
+
+vlc_module_begin ();
+ set_description (N_("Decompression"));
+ set_category (CAT_INPUT);
+ set_subcategory (SUBCAT_INPUT_DEMUX);
+ set_capability ("demux", 20);
+ set_callbacks (OpenBzip2, Close);
+ /* TODO: shortnames */
+ /* --demux support */
+
+ add_submodule ();
+ set_callbacks (OpenGzip, Close);
+vlc_module_end ();
+
+static int Demux (demux_t *);
+static int Control (demux_t *, int i_query, va_list args);
+
+struct demux_sys_t
+{
+ stream_t *out;
+ vlc_thread_t thread;
+ pid_t pid;
+ int write_fd, read_fd;
+};
+
+static void cloexec (int fd)
+{
+ int flags = fcntl (fd, F_GETFD);
+ fcntl (fd, F_SETFD, O_CLOEXEC | (flags != -1) ? flags : 0);
+}
+
+extern char **environ;
+
+static void cleanup_fd (void *data)
+{
+ close ((intptr_t)data);
+}
+
+static void *Thread (void *data)
+{
+ demux_t *demux = data;
+ demux_sys_t *p_sys = demux->p_sys;
+ int fd = p_sys->write_fd;
+
+ vlc_cleanup_push (cleanup_fd, (void *)(intptr_t)fd);
+
+ for (;;)
+ {
+#ifdef __linux__
+ /* TODO: mmap() + vmsplice() */
+#endif
+ unsigned char buf[65536];
+ int canc = vlc_savecancel ();
+ ssize_t len = stream_Read (demux->s, buf, sizeof (buf));
+
+ vlc_restorecancel (canc);
+
+ if (len <= 0)
+ break;
+
+ for (ssize_t i = 0, j = 0; i < len; i += j)
+ {
+ j = write (fd, buf + i, len - i);
+ if (j == -1)
+ {
+ msg_Err (demux, "cannot write data (%m)");
+ break;
+ }
+ }
+ }
+
+ vlc_cleanup_run (); /* close(fd) */
+ return NULL;
+}
+
+
+#define MIN_BLOCK (1 << 10)
+#define MAX_BLOCK (1 << 20)
+/**
+ * Read data, decompress it, and forward
+ * @return -1 in case of error, 0 in case of EOF, 1 otherwise.
+ */
+static int Demux (demux_t *demux)
+{
+ demux_sys_t *p_sys = demux->p_sys;
+ int length, fd = p_sys->read_fd;
+
+#ifdef TIOCINQ
+ if (ioctl (fd, TIOCINQ, &length) == 0)
+ {
+ if (length > MAX_BLOCK)
+ length = MAX_BLOCK;
+ else
+ if (length < MIN_BLOCK)
+ length = MIN_BLOCK;
+ }
+ else
+#endif
+ length = MIN_BLOCK;
+
+ block_t *block = block_Alloc (length);
+ if (block == NULL)
+ return VLC_ENOMEM;
+
+ length = net_Read (demux, fd, NULL, block->p_buffer, length, false);
+ if (length <= 0)
+ return 0;
+ block->i_buffer = length;
+ stream_DemuxSend (p_sys->out, block);
+ return 1;
+}
+
+
+/*****************************************************************************
+ * Control:
+ *****************************************************************************/
+static int Control (demux_t *demux, int query, va_list args)
+{
+ /*demux_sys_t *p_sys = demux->p_sys;*/
+ (void)demux;
+ (void)query; (void)args;
+ return VLC_EGENERIC;
+}
+
+/**
+ * Pipe data through an external executable.
+ * @param demux the demux object.
+ * @param path path to the executable.
+ */
+static int Open (demux_t *demux, const char *path)
+{
+ demux_sys_t *p_sys = demux->p_sys = malloc (sizeof (*p_sys));
+ if (p_sys == NULL)
+ return VLC_ENOMEM;
+
+ demux->pf_demux = Demux;
+ demux->pf_control = Control;
+
+ /* I am not a big fan of the pyramid style, but I cannot think of anything
+ * better here. There are too many failure cases. */
+ int ret = VLC_EGENERIC;
+ int comp[2];
+ if (pipe (comp) == 0)
+ {
+ cloexec (comp[1]);
+ p_sys->write_fd = comp[1];
+
+ int uncomp[2];
+ if (pipe (uncomp) == 0)
+ {
+ cloexec (uncomp[0]);
+ p_sys->read_fd = uncomp[0];
+
+ posix_spawn_file_actions_t actions;
+ if (posix_spawn_file_actions_init (&actions) == 0)
+ {
+ char *const argv[] = { (char *)path, NULL };
+
+ if (!posix_spawn_file_actions_adddup2 (&actions, comp[0], 0)
+ && !posix_spawn_file_actions_addclose (&actions, comp[0])
+ && !posix_spawn_file_actions_adddup2 (&actions, uncomp[1], 1)
+ && !posix_spawn_file_actions_addclose (&actions, comp[1])
+ && !posix_spawnp (&p_sys->pid, path, &actions, NULL, argv,
+ environ))
+ {
+ p_sys->out = stream_DemuxNew (demux, "", demux->out);
+ if (p_sys->out != NULL)
+ {
+ if (vlc_clone (&p_sys->thread, Thread, demux,
+ VLC_THREAD_PRIORITY_INPUT) == 0)
+ ret = VLC_SUCCESS;
+ else
+ stream_DemuxDelete (p_sys->out);
+ }
+ else
+ msg_Err (demux, "Cannot create demux");
+ }
+ else
+ msg_Err (demux, "Cannot execute %s", path);
+ posix_spawn_file_actions_destroy (&actions);
+ }
+ if (ret != VLC_SUCCESS)
+ {
+ close (comp[1]);
+ close (comp[0]);
+ }
+ }
+ if (ret != VLC_SUCCESS)
+ close (uncomp[0]);
+ close (uncomp[1]);
+ }
+ return ret;
+}
+
+
+/**
+ * Releases allocate resources.
+ */
+static void Close (vlc_object_t *obj)
+{
+ demux_t *demux = (demux_t *)obj;
+ demux_sys_t *p_sys = demux->p_sys;
+ int status;
+
+ vlc_cancel (p_sys->thread);
+ stream_DemuxDelete (p_sys->out);
+ close (p_sys->read_fd);
+ vlc_join (p_sys->thread, NULL);
+
+ msg_Dbg (obj, "waiting for PID %u", (unsigned)p_sys->pid);
+ while (waitpid (p_sys->pid, &status, 0) == -1);
+ msg_Dbg (obj, "exit status %d", status);
+
+ free (p_sys);
+}
+
+
+/**
+ * Detects gzip file format
+ */
+static int OpenGzip (vlc_object_t *obj)
+{
+ demux_t *demux = (demux_t *)obj;
+ stream_t *stream = demux->s;
+ const uint8_t *peek;
+
+ if (stream_Peek (stream, &peek, 3) < 3)
+ return VLC_EGENERIC;
+
+ if (memcmp (peek, "\x1f\x8b\x08", 3))
+ return VLC_EGENERIC;
+
+ msg_Dbg (obj, "detected gzip compressed stream");
+ return Open (demux, "zcat");
+}
+
+
+/**
+ * Detects bzip2 file format
+ */
+static int OpenBzip2 (vlc_object_t *obj)
+{
+ demux_t *demux = (demux_t *)obj;
+ stream_t *stream = demux->s;
+ const uint8_t *peek;
+
+ /* (Try to) parse the bzip2 header */
+ if (stream_Peek (stream, &peek, 10) < 10)
+ return VLC_EGENERIC;
+
+ if (memcmp (peek, "BZh", 3) || (peek[3] < '1') || (peek[3] > '9')
+ || memcmp (peek, "\x31\x41\x59\x26\x53\x59", 6))
+ return VLC_EGENERIC;
+
+ msg_Dbg (obj, "detected bzip2 compressed stream");
+ return Open (demux, "bzcat");
+}
+
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