MP4 video editing with ffmpeg CLI

19 May 2012 No Comments

by feinanin Technology

ffmpeg is a very fast video and audio converter that can also grab from a live audio/video source. It can also convert between arbitrary sample rates and resize video on the fly with a high quality polyphase filter.

The following CLI will chop off the first 30 seconds of the video and record 4-minute video to the output file “cutted.mp4″.

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ffmpeg -i ~/Videos/M4H02608.MP4 -vcodec copy -ss 00:00:30 -t 00:04:00 cutted.mp4

How to Install Solr 3.6.0 on Ubuntu 12.04 LTS

19 May 2012 No Comments

by feinanin Technology

Apache Solr is a fast, open-source search solution. The following is to walk through setting up multi-core Solr with Apache Tomcat.

Apacha Solr requires Tomcat, so the first step, install the Tomcat server:

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sudo apt-get install tomcat6

Next you’ll want to get Solr and extract it to a temporary directory:

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mkdir -p ~/tmp/solr/
cd ~/tmp/solr/
wget http://apache.ziply.com/lucene/solr/3.6.0/apache-solr-3.6.0.tgz
tar xzvf apache-solr-3.6.0.tgz

All the solr cores and indexes will go in /var/solr:

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sudo mkdir -p /var/solr

Copy the Solr webapp and the example multicore configuration files:

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sudo cp apache-solr-3.6.0/dist/apache-solr-3.6.0.war /var/solr/solr.war
sudo cp -R apache-solr-3.6.0/example/multicore/* /var/solr/
sudo chown -R tomcat6 /var/solr/

Now just need to point Catalina at Solr:

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echo -e '<Context docBase="/var/solr/solr.war" debug="0" privileged="true" allowLinking="true" crossContext="true">\n<Environment name="solr/home" type="java.lang.String" value="/var/solr" override="true" />\n</Context>' | sudo tee -a /etc/tomcat6/Catalina/localhost/solr.xml
echo 'TOMCAT6_SECURITY=no' | sudo tee -a /etc/default/tomcat6

I edited the init script (/etc/init.d/tomcat6) to set solr.home, pointing it at /var/solr. I made this change near the top of the file other environment vars are set up:

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JAVA_OPTS="$JAVA_OPTS -Dsolr.home=/var/solr"

Restart Tomcat6 and luxuriate in your newfound power:

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sudo /etc/init.d/tomcat6 restart

Navigate to http://localhost:8080/solr/ – you should see it up and running.

Convert Encoding in Linux with iconv.h

23 Apr 2012 No Comments

by feinanin Technology

In Linux programming, users can convert encoding for a string buffer from one to another. The following example convert the input string from UTF-16 to UTF-8. The input is char** in_content, a pointer to pointer of the string. The string size is size_t in_content_size. The conversion will be made in-place and output would be written back to char** in_content.

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#include <iconv.h>
 
size_t Convert_UTF16_To_UTF8(char** in_content, size_t in_content_size)
{
	iconv_t icv;
	char* in_buf = malloc(in_content_size);
	char* in;
	size_t in_sz;
	char* out_buf = malloc(in_content_size);
	char* out;
	size_t out_sz;
 
	icv = iconv_open("UTF-8", "UTF-16");
 
	memcpy(in_buf, *in_content, in_content_size);
 
	in = in_buf;
	in_sz = in_content_size;
	out = (char*) out_buf;
	out_sz = in_content_size;
 
	size_t ret = iconv(icv, &in, &in_sz, &out, &out_sz);
 
	strcpy(*in_content, out_buf);
 
	free(in_buf);
	free(out_buf);
	iconv_close(icv);
 
	return ret;
}

Calculator with awk

15 Dec 2011 No Comments

by feinanin Technology

In your bash, do the following

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calc(){ awk "BEGIN{ print $* }" ; }

and then do the following:

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calc 2*1 - 12

or

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calc '2*(1 - 12)'

you can put this in your ~/.bash_profile too

Command – traceroute

09 Dec 2011 No Comments

by feinanin Technology

Traceroute is a command which can show you the path a packet of information takes from your computer to one you specify. It will list all the routers it passes through until it reaches its destination, or fails to and is discarded. In addition to this, it will tell you how long each hop from router to router takes.

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[root@sjc14-esx2-vm3 ~]# traceroute iph.csi2.c3w.tv
traceroute to iph.csi2.c3w.tv (192.118.77.180), 30 hops max, 40 byte packets
 1  172.29.96.1 (172.29.96.1)  3.150 ms  3.141 ms  3.135 ms
 2  sjc14-00lab-gw1-gig1-4.cisco.com (172.24.114.181)  3.120 ms  3.105 ms  3.094 ms
 3  sjc12-lab4-gw1-ten6-7.cisco.com (172.24.95.29)  3.086 ms  3.078 ms  3.067 ms
 4  sjc5-sbb4-gw1-ten8-6.cisco.com (171.71.241.174)  3.049 ms  3.045 ms  3.037 ms
 5  sjc12-rbb-gw4-ten7-4.cisco.com (171.71.241.254)  3.003 ms  2.997 ms  2.988 ms
 6  sjc12-gb1-ten2-2.cisco.com (10.112.4.157)  2.974 ms  3.924 ms  3.914 ms
 7  capnet-rtp10-sjc12-10ge.cisco.com (10.112.4.162)  78.649 ms  78.646 ms  79.351 ms
 8  rtp5-rbb-gw1-ten4-6.cisco.com (10.112.4.106)  81.145 ms  81.143 ms  81.863 ms
 9  rtp5-gb2-ten2-1.cisco.com (10.112.3.77)  79.921 ms  79.917 ms  79.911 ms
10  capnet-amsidc-rtp5-oc48.cisco.com (10.112.4.114)  167.285 ms  167.277 ms  167.263 ms
11  amsidc-rbb-gw2-ten2-1.cisco.com (10.112.4.202)  167.197 ms  167.194 ms  166.839 ms
12  amsidc-wan-gw1-ten6-2.cisco.com (144.254.78.14)  168.174 ms  167.671 ms  167.639 ms
13  amsidc-cw-pe1-oc48.cisco.com (10.61.40.18)  167.006 ms  167.087 ms  167.075 ms
14  ntn01-wan-gw1-ser1-0.cisco.com (144.254.136.193)  256.178 ms  256.308 ms  256.298 ms
15  ntn01-bb-gw2-gig2-7.cisco.com (64.103.115.205)  255.074 ms  254.828 ms  255.553 ms
16  ntn01-corp-gw1-gig0-2.cisco.com (64.103.116.14)  254.310 ms  254.302 ms  254.297 ms
17  ntn01-dmzbb-gw1-gig2-43.cisco.com (192.118.78.166)  260.572 ms  260.568 ms  257.431 ms
18  ntn01-dmznet-gw1-gig1-1.cisco.com (192.118.78.86)  254.664 ms  254.664 ms  254.655 ms
19  ntn01-dmzlab-gw1-gig1-1.cisco.com (192.118.76.26)  256.993 ms  257.295 ms  256.258 ms
20  csi-scp-dmz-gw.cisco.com (192.118.76.106)  257.160 ms  257.138 ms  256.874 ms
21  csi-scp-dmz-gw.cisco.com (192.118.76.106)  257.300 ms !X * *

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