Record sound

From Rosetta Code
Revision as of 01:33, 23 September 2011 by rosettacode>Kernigh (Add note to task description about variations in the sound format.)
Task
Record sound
You are encouraged to solve this task according to the task description, using any language you may know.

Record a monophonic 16-bit PCM sound into either memory space, a file or array.

(This task neglects to specify the sample rate, and whether to use signed samples. The programs in this page might use signed 16-bit or unsigned 16-bit samples, at 8000 Hz, 44100 Hz, or any other sample rate. Therefore, these programs might not record sound in the same format.)

C

Read/write raw device /dev/dsp. On Linux you need access to said device, meaning probably you should be in audio user group. <lang c>#include <stdlib.h>

  1. include <unistd.h>
  2. include <sys/types.h>
  3. include <fcntl.h>

void * record(size_t bytes) { int fd; if (-1 == (fd = open("/dev/dsp", O_RDONLY))) return 0; void *a = malloc(bytes); read(fd, a, bytes); close(fd); return a; }

int play(void *buf, size_t len) { int fd; if (-1 == (fd = open("/dev/dsp", O_WRONLY))) return 0; write(fd, buf, len); close(fd); return 1; }

int main() { void *p = record(65536); play(p, 65536); return 0; }</lang>

PicoLisp

<lang PicoLisp>(in '(rec -q -c1 -tu16 - trim 0 2) # Record 2 seconds

  (make
     (while (rd 2)
        (link @) ) ) )</lang>

Output:

-> (16767 19071 17279 ... 5503 9343 14719)  # 96000 numbers

Python

<lang python>import pyaudio

chunk = 1024 FORMAT = pyaudio.paInt16 CHANNELS = 1 RATE = 44100

p = pyaudio.PyAudio()

stream = p.open(format = FORMAT,

               channels = CHANNELS,
               rate = RATE,
               input = True,
               frames_per_buffer = chunk)

data = stream.read(chunk) print [ord(i) for i in data]</lang>

Tcl

Library: Snack

<lang tcl>package require sound

  1. Helper to do a responsive wait

proc delay t {after $t {set ::doneDelay ok}; vwait ::doneDelay}

  1. Make an in-memory recording object

set recording [snack::sound -encoding "Lin16" -rate 44100 -channels 1]

  1. Set it doing the recording, wait for a second, and stop

$recording record -append true delay 1000 $recording stop

  1. Convert the internal buffer to viewable numbers, and print them out

binary scan [$recording data -byteorder littleEndian] s* words puts [join $words ", "]

  1. Destroy the recording object

$recording destroy</lang>