JS1k: The JavaScript code golfing competition

S=String.fromCharCode
A=32,O=127
f=function(l,v){for(k=l*(v?2:3);k--;)m+='ÿó$ÀZZ`'+(v?'$':'ZZ')+'ZZZZþÐ'+Array(34).join('Z');for(;k++<l*2646;u++)d+=S(Math.sin(k*.085)*!!v*A+O)}
with(document.body.children[0])with(getContext('2d'))r=function(E){if(E){d=m='',v=[],u=i=j=0
s=prompt('Message to encode:','SOS 1K dead ahead!')
for(f(9);g=x=2,c=s[Y='charCodeAt'](i);i++,f(g))for(e=c-A?'~^NFB@`px|'[Y](c-48)||'\x0a04$ .(,:"268'[Y](95&c-65):f(2),v[i]=u;e>3;e>>=1,g*=s.substr(i-x--,3)!='SOS')f(e&2|1,1),f(1)
for(w=['RIFF','WAVEfmt ZZZ
Z
ZD¬ZZD¬ZZ
ZZdata'];h=[u+36,u][j];j++)for(i=4;i--;h>>=8)w[j]+=S(h&255)
with(a=new Audio)play(src='data:'+(canPlayType(t='audio/wav')?t:t='')+';base64,'+btoa((t?w.join('')+d:m).replace(/Z/g,'\x00')))}width=W=500;font='20pt X';beginPath(p=a.currentTime*44100|0);for(moveTo(i=0,A);i++<W;)lineTo(i,(d[Y](p+i*50-W*25>>6<<6)-O|0)+A);stroke(lineTo(W,A));for(i in v)fillText(S(s[Y](i)),(v[i]-p)/50+W/2|0,85);p<u&&setTimeout('r()',9)||r(1)}
r(1)

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

/**
 * Plays message as Morse code WAV/MP3 (cross-browser), displays the waveform
 * Chris Smoak, chris.smoak@gmail.com, @chrissmoak
 * August 13, 2010
 * 
 * Enter your message at the prompt, wait a few seconds, and then listen and 
 * watch your message play back as morse code. The message will be converted 
 * to Morse code, encoded as a WAV or MP3 depending on browser, and the 
 * waveform will scroll across the screen. 
 *
 * Features:
 * . Cross-browser support through creation of both WAV and MP3
 * . Supports A-Z,a-z,0-9
 * . Handles SOS prosign correctly, with no character-length silences
 * . Packed by hand, actually looks like JS!
 * 
 * Algorithm:
 * - get the input string from the user
 * - loop through each character; for each recognized character:
 *     - if it's a space, emit word-length silence
 *     - otherwise, look up in the number and/or letter dictionary:
 *         - emit dits and dahs based on the dictionary entry
 *     - emit character-length silence unless we're in the middle of an 'SOS'
 *     where emit is:
 *         - create and append MP3 frames for the sound or silence
 *         - create and append WAV samples for the sound or silence
 *         - map character to WAV sample index for later use in display
 * - fill in the missing WAV header fields
 * - create the audio element
 * - use canPlayType to determine which data to use
 * - create the data uri and replace 'Z' with '\x00'
 * - start playing the audio
 * - until the audio has stopped:
 *     - clear the canvas
 *     - start with the audio current playhead
 *     - draw the waveform amplitude across the width of the canvas
 *     - for each character in the input:
 *         - draw the character under the waveform
 *
 * Morse code dictionary:
 * each mapped character takes 1 byte. least significant bit is 0 to ease
 * calculation of 1 or 3 for dit/dah length. each bit after LSb is 1 for dah, 
 * 0 for dit. the bit after all tone bits is 1, indicating end of character. 
 * to read, repeatedly read the byte & 2 | 1 for the length of the tone, 
 * shift right and continue until byte <= 2.
 * Ideas from: http://www.ioccc.org/1998/dorssel.hint2
 *
 * WAV
 * an 8-bit 44.1khz mono WAV is created. tones are sampled from a 600hz sine 
 * wave.
 * Ideas from: http://acko.net/blog/javascript-audio-synthesis-with-html-5
 *
 * MP3
 * a 16kbps mono MP3 sampled at 24khz is created. the structure of each frame 
 * is as follows:
 * - header = '\xff\xf3\x24\xc0'
 *   - sync bits: 1111 1111 111
 *   - version: 10 (MPEG2)
 *   - layer: 01 (layer III)
 *   - CRC?: 1 (no crc)
 *   - bit rate: 0010 (16kbps)
 *   - sampling rate: 01 (24khz)
 *   - use padding: 0 (no)
 *   - private bit: 0
 *   - channel mode: 11 (mono)
 *   - mode extension: 00 (none)
 *   - copyright: 0 (false)
 *   - original 0 (false)
 *   - emphasis: 00 (none)
 * - side info = 
 *       '\x00\x00\x60' 
 *       + (volume ? '\x03\x24' : '\x00\x00') 
 *       + '\x00\x00\x00\x00'
 *   - main_data_begin: 0000 0000
 *   - private: 0
 *   - part2_3_length: 0000 0000 1100
 *   - big_values: 0000 0000 0
 *   - global_gain: volume ? 1100 1001 : 0000 0000
 *   - scalefac_compress: 0000 0000 0
 *   - window_switching_flag: 0
 *   - table_select[0..2]: 0000 0, 0000 0, 0000 0
 *   - region0_count: 0000
 *   - region1_count: 000
 *   - scalefac_scale: 0
 *   - count1table_select: 0
 * - main data = '\xfe\xd0'
 *   - scale factors: no bits used
 *   - big_values: no bits used
 *   - +1/0/-1 region: 1111 1110 1101
 * - padding to end of frame = '\x00' x 33
 */