From 6dae341e96fb10dbffd5099fd92c24381ec40946 Mon Sep 17 00:00:00 2001
From: "Leigh B. Stoller" <stoller@flux.utah.edu>
Date: Wed, 11 May 2005 14:04:11 +0000
Subject: [PATCH] Aside from cleanup, the main change is that instead of using
vlc to transcode a motion jpeg into mpeg (very CPU intensive), I know know
how to alter the camera frame rate on the fly using a wget call. The downside
is that this affects the camera globally (mpeg rate), but thats okay since
the grabwebcams script only allows itself to be run once at a time to avoid
conflict.
Still not hooked into experiment path; waiting for terrabytes of disk
storage!
---
utils/grabwebcams.in | 131 ++++++++++++++++++++++++-------------------
1 file changed, 74 insertions(+), 57 deletions(-)
diff --git a/utils/grabwebcams.in b/utils/grabwebcams.in
index 307ed3df4c..831f9887fb 100755
--- a/utils/grabwebcams.in
+++ b/utils/grabwebcams.in
@@ -6,7 +6,7 @@
#
use English;
use Getopt::Std;
-use Errno;
+use Errno qw(ESRCH);
use POSIX ":sys_wait_h";
use BSD::Resource;
@@ -27,10 +27,11 @@ sub usage()
"pid eid - Project and Experiment (for use with swapin)\n");
exit(-1);
}
-my $optlist = "dt:vkm";
+my $optlist = "dt:vkmf:";
my $debug = 0;
my $verbose = 0;
my $timeout = 0;
+my $fps = 0;
my $killmode = 0;
my $movie = 0;
my $pid;
@@ -44,7 +45,7 @@ my $TBOPS = "@TBOPSEMAIL@";
my $TBLOGS = "@TBLOGSEMAIL@";
my $VLC = "/usr/X11R6/bin/vlc";
my $WGET = "/usr/local/bin/wget";
-my $PIDDIR = "/var/run/emulab/grabwebcams";
+my $PIDFILE = "/var/run/emulab/grabwebcams.pid";
# We don't want to run this script unless its the real version.
if ($EUID != 0) {
@@ -80,7 +81,6 @@ $libdb::DBQUERY_MAXTRIES = 30;
#
# Locals
#
-my $PIDFILE;
my $logfile;
my %webcams = ();
my %children = ();
@@ -102,13 +102,14 @@ if (defined($options{"v"})) {
if (defined($options{"t"})) {
$timeout = $options{"t"};
}
+if (defined($options{"f"})) {
+ $fps = $options{"f"};
+}
if (defined($options{"m"})) {
$movie = 1;
}
if (defined($options{"k"})) {
$killmode = 1;
- usage()
- if (! @ARGV);
}
if (@ARGV) {
usage()
@@ -128,7 +129,6 @@ if (@ARGV) {
else {
die("Bad data in argument: $eid.");
}
- $PIDFILE = "$PIDDIR/${pid}_${eid}.pid";
}
#
@@ -147,15 +147,24 @@ if ($killmode) {
}
unlink($PIDFILE);
- if (kill($epid, 0) == 0 || $Errno::errno != $Errno::ESRCH) {
+ if (kill(0, $epid) || ! $!{ESRCH}) {
if (! kill('TERM', $epid)) {
- fatal("Failed to stop webcam capture ($epid) for $pid/$eid!\n");
+ fatal("Failed to stop webcam capture ($epid)!\n");
}
}
}
exit(0);
}
+#
+# XXX Since we change the frame rate, do not allow this script to be
+# run more then once at a time ... I'll change this later to support
+# running multiple versions as long as the frame rate is the same.
+#
+if (-e $PIDFILE) {
+ fatal("Another grabwebcams is in progress. Must stop that one first!");
+}
+
# Making a movie for an experiment ...
if (defined($pid)) {
#
@@ -198,16 +207,6 @@ while (my %row = $query_result->fetchhash()) {
$webcams{$id} = $server;
}
-#
-# Make sure the pid directory exists.
-#
-if (! -d $PIDDIR) {
- if (system("mkdir -p -m 775 $PIDDIR")) {
- die("*** $0:\n".
- " Could not mkdir $PIDDIR\n");
- }
-}
-
# Go to ground.
if (! $debug) {
$logfile = TBMakeLogname("grabwebcams");
@@ -220,8 +219,7 @@ if (! $debug) {
#
# Write out the pid file and then drop privs.
#
-if (defined($PIDFILE) &&
- system("echo '$PID' > $PIDFILE")) {
+if (system("echo '$PID' > $PIDFILE")) {
fatal("Could not create $PIDFILE!");
}
if (! $movie) {
@@ -229,22 +227,6 @@ if (! $movie) {
}
$EUID = $UID;
-#
-# First, get the video.sdp files for each camera, which we feed to vlc.
-#
-foreach my $id (keys(%webcams)) {
- my $server = $webcams{$id};
- my $URL = "http://${server}/mpeg4/video.sdp";
- my $file = "video-${id}.sdp";
-
- unlink($file);
- print "Getting $URL ...\n";
- system("$WGET -T 30 --non-verbose -O $file $URL");
- if ($?) {
- fatal("Could not get video.sdp from camera $id ($server)");
- }
-}
-
#
# Handler to catch signal and kill children.
#
@@ -254,7 +236,7 @@ sub handler ($) {
foreach my $id (keys(%children)) {
my $pid = $children{$id};
- if (kill($pid, 0) == 0 || $Errno::errno != $Errno::ESRCH) {
+ if (kill(0, $pid) || ! $!{ESRCH}) {
if (! kill('TERM', $pid)) {
notify("Failed to stop vlc process $pid!");
}
@@ -264,15 +246,34 @@ sub handler ($) {
}
$SIG{TERM} = \&handler;
+#
+# Set the frame rate. This is why we only allow one at a time for now.
+# I am hoping for a better solution at some point, cause this causes
+# an update to the flash, which the Axis people say is only good for
+# 100000 writes. I suppose I could ask the camera what the framerate is
+# and then change it if needed, but thats too much considering how little
+# the robot testbed is currently used.
+#
+if (!$fps) {
+ $fps = ($movie ? 24 : 2);
+}
+foreach my $id (keys(%webcams)) {
+ my $server = $webcams{$id};
+
+ SetFrameRate($server, $fps);
+}
+
#
# Now fire off vlc to capture the multicast output.
#
foreach my $id (keys(%webcams)) {
my $server = $webcams{$id};
my $file = "video-${id}.mpg";
- my $sdp = "video-${id}.sdp";
- my $URL;
+ my $URL = "rtsp://${server}/mpeg4/1/media.amp";
my $syspid;
+ my $cmdstr = "$VLC " . ($verbose ? "-v -v " : "-q ") .
+ "-I dummy --no-sap-parse --sout ".
+ "#duplicate{dst=std{access=file,mux=ts,url=\"$file\"}} $URL";
if ($syspid = fork()) {
#
@@ -281,23 +282,6 @@ foreach my $id (keys(%webcams)) {
$children{$id} = $syspid;
}
else {
- my $cmdstr = "$VLC " . ($verbose ? "-v -v " : "-q ") .
- "-I dummy --no-sap-parse ";
-
- if ($movie) {
- $URL = "http://${server}/axis-cgi/mjpg/video.cgi?".
- "fps=24&compression=50&date=1&clock=1";
-
- $cmdstr .= "--mjpeg-fps 24 --sout ".
- "#transcode{vcodec=mp2v,fps=24,scale=1}:".
- "duplicate{dst=std{access=file,mux=ps,url=\"$file\"}} $URL";
- }
- else {
- $URL = "rtsp://${server}/mpeg4/1/media.amp";
- $cmdstr .= "--sout ".
- "#duplicate{dst=std{access=file,mux=ts,url=\"$file\"}} $URL";
- }
-
print "Running '$cmdstr'\n";
my @cmdargs = split(" ", $cmdstr);
exec(@cmdargs);
@@ -322,6 +306,7 @@ do {
unlink($logfile)
if (defined($logfile) && -e $logfile);
+unlink($PIDFILE);
exit(0);
sub fatal($)
@@ -343,6 +328,7 @@ sub fatal($)
($logfile));
unlink($logfile);
}
+ unlink($PIDFILE);
exit(1);
}
@@ -362,4 +348,35 @@ sub notify($)
$TBOPS);
}
+#
+# Set the frame rate. This affects the camera globably, but in our context
+# that is not too bad, since the robot lab is currently single use.
+#
+sub SetFrameRate($$)
+{
+ my ($server, $rate) = @_;
+
+ my $BASEURL = "http://operator:Frazzle69\@${server}/axis-cgi";
+ my $FPSURL = "${BASEURL}/admin/setparam.cgi?".
+ "root.Image.I0.Stream.FPS=${rate}";
+ my $RESTART = "${BASEURL}/mpeg4/restart_stream.cgi";
+
+ print "Setting $server frame rate to $rate fps.\n";
+ print "Using URL '$FPSURL'\n"
+ if ($debug);
+
+ system("$WGET -T 30 --non-verbose -O /dev/null $FPSURL");
+ if ($?) {
+ fatal("Could not change framerate on camera $server");
+ }
+
+ print "Restarting mpeg stream on camera $server\n";
+ print "Using URL '$RESTART'\n"
+ if ($debug);
+ system("$WGET -T 30 --non-verbose -O /dev/null $RESTART");
+ if ($?) {
+ fatal("Could not restart mpeg stream on camera $server");
+ }
+ return 0;
+}
--
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