Updated today …
Month: July 2015
How I used the Primesieve program to generate primes, and figure for 32000 CA numbers
It’s easier to count the primes up to some large number N such as 10^12 than to generate all the primes up to N. Sometimes, we need to generate all the primes up to N, and then prime-counting functions will not do. Many good algorithms to generate the primes up to N are known as… Continue reading How I used the Primesieve program to generate primes, and figure for 32000 CA numbers
New computations on 8000 colossally abundant numbers using Kim Walisch’s Primesieve program
header of new WAV file
I recorded a second WAV file of white noise: June26TvNoise.wav at 2,073,214,126 bytes length . Using decrypt04j.c (see below), I wrote the beginning bytes as unsigned numbers in base ten, from 0 to 255; using the ASCII table, we can find which character is represented and decipher the header of this WAV file: [david2@localhost JUNE_26_Tv_Noise]$… Continue reading header of new WAV file
Reference on *.wav audio files
I found all I needed to know about the header(s) of *.wav files and what they mean from this web page: http://www.topherlee.com/software/pcm-tut-wavformat.html It says there: “The header of a WAV (RIFF) file is 44 bytes long and has the following format:” . In the case of the *.wav file I had, the header was actually… Continue reading Reference on *.wav audio files
The C source code file makebin02a.c
/************************************************************************************* In the previous post, I explained how one can extract the least significant bit from the channel 1 16-bit PCM fields of stereo (2-channel) 32-bit per sample WAVE files, format *.wav, and write them as 1s and 0s at one bit per line in an output file, which in my case was: /home/david2/RANDOM/decrypt45.txt The… Continue reading The C source code file makebin02a.c
C source code to select list significant bit in *.wav file of white noise , at 2 channels and 16 bits/channel ; name = decrypt45.c
/**************************** the working directory was: /home/david2/RANDOM and the input white noise *wav file, at 2 channels audio and 16 bits of depth per pulse position modulated sample per audio channel, for a total of 32 bits per sample; the idea is to take the least significant bit from say Channel 1 and throw away channel… Continue reading C source code to select list significant bit in *.wav file of white noise , at 2 channels and 16 bits/channel ; name = decrypt45.c