Knowledge Bits

Here I maintain "helpful notes". Little bits of knowledge which can come handy at times.

Full trace of a process under linux:

strace
-fFittTvs300

followed by either -p procnum or a command, and adding -o file to route the output to a file. Insert -eraw=all to see arguments pointer as adress instead of content data.

Full trace of a process under solaris:

truss
-faed -vall -rall -wall

followed by either

-p
procnum

or a command, and adding

-o
file

to route the output to a file.

Full trace of a process under OpenBSD:

ktrace
-i

followed by either -d -p procnum or a command. To watch the trace use kdump -T. If yo want to observe the process while tracing, start kdump in a separate windows and add the -l option.

Generate random password openssl passwd -table -1 `openssl rand -base64 24`

"SSL Telnet" openssl s_client -host hostname -port portnumber
see also man s_client.

Set default font for gtk 2 Put gtk-font-name="Sans 6" into .gtkrc-2.0

Quicktime Pro/iMovie encoding for the web My preferite settings for encoding my DV movies for the web using iMovie HD are:

"Movie to QuickTime Movie"
Options...	Video	Settings...	H.264
			Frame rate: current
			Key frames: automatic frames
			Data rate: restrict to 1000 Kbit/sec
			Optimized for: Streaming
			Quality Encoding:Best quality (multi-pass)
		Filter...	None
		Size...	Use current size this is 784x576 for Pal DV movies, Deinterlace
	Sound	Settings...	Format: AAC
			Channels: Stereo (L R)
			Rate: 44.100 kHz
			AAC Encoder Settings:	Bit Rate Format: Variable Bit Rate
				Taget Bit Rate: 96 - 110 kbps
				Precedence: Bit Rate
				Quality: Best
	Prepare for Internet Streaming	Fast Start

with the above settings it takes about 50 minutes encoding time per minute of movie and the resulting file uses about 6 MByte per minute (approx 800 kbit/s). The following settings are used for preview movies. Encoding one minute of input takes now only 2 minutes and 1.7 MByte (approx 225 kbit/s).

"Movie to QuickTime Movie"
Options...	Video	Settings...	H.264
			Frame rate: 10
			Key frames: automatic frames
			Data rate: restrict to 192 Kbit/sec
			Optimized for: Streaming
			Quality Encoding:Best quality (multi-pass)
		Filter...	None
		Size...	196x144, Deinterlace
	Sound	Settings...	Format: AAC
			Channels: Mono
			Rate: 22.050 kHz
			AAC Encoder Settings:	Bit Rate Format: Constant Bit Rate
				Taget Bit Rate: 32 kbps
				Precedence: Bit Rate
				Quality: Best
	Prepare for Internet Streaming	Fast Start

Settings I used in the past

"Movie to QuickTime Movie"
Options...	Video	Settings...	MPEG-4 Video
			Quality=Best
			Frames per second: 15
			Key frame every 90 frames
			Limit data rate to 60 KByte/sec
		Filter...	None
		Size...	Use current size this is 720x576 for Pal DV movies
	Sound	Settings...	MPEG-4 Audio
			Rate: 44.100 kHz
			Size: 16 bit
			Use: Stereo
			Options...	Compressor: AAC (Low Complexity)
				Bit rate: 32 kbits/second
				Output Sample Rate: 16.000 kHz
				Encoder Quality: Best
Prepare for Internet Streaming	Fast Start