MP3 stream of spoken time

mp3time.sh

#!/bin/bash

# Outputs a continuous MP3 stream with spoken current time on stdout.
# Requirements: text2wave (from festival) and ffmpeg (some old version)

# Speak interval. Must be higher than the length of the spoken time.
INTERVAL=5

RATE=48000
TS=$(($(date +%s) + $INTERVAL))
BYTESPERSPEAK=$((2 * $RATE * $INTERVAL)) # S16_LE
TMP=$(tempfile)
while true
do
	date -d @$TS +%-H:%M:%S | text2wave -otype raw -f $RATE > $TMP
	LEN=$(wc -c < $TMP)
	cat $TMP
	head -c $(($BYTESPERSPEAK - $LEN)) /dev/zero
	TS=$(($TS + $INTERVAL))
done | ffmpeg -v error -f s16le -ar $RATE -ac 1 -i - -f mp3 -ar 11025 -ab 8000 -
rm $TMP