我需要在
linux上监听我的音频线路,并且在音频播放的情况下,声音必须被记录并保存到一个文件中.类似于
motion如何监视视频Feed.
有可能用bash吗？一些沿着以下方向的东西：
#!/bin/bash # audio device device=/dev/audio-line-in # below this threshold audio will not be recorded. noise_threshold=10 # folder where recordings are stored storage_folder=~/recordings # run indefenitly,until Ctrl-C is pressed while true; do # noise_level() represents a function to determine # the noise level from device if noise_level( $device ) > $noise_threshold; then # stream from device to file,can be encoded to mp3 later. cat $device > $storage_folder/$(date +%FT%T).raw fi; done;
编辑：我想从这个程序获得的流程是
a. when noise > threshold,start recording b. stop recording when noise < threshold for 10 seconds c. save recorded piece to separate file
解决方法
SoX是瑞士军刀的声音处理.您可以利用它来分析录音.以下解决方案的唯一缺点是：
>您需要将录音分割成固定大小的块
>您可能会丢失录音时间(由于杀死/分析/重新启动录音)
因此,进一步的改进可能是分析异步,尽管这将使工作复杂化.
#!/bin/bash
record_interval=5
noise_threshold=3
storage_folder=~/recordings
exec 2>/dev/null # no default error output
while true; do
rec out.wav &
sleep $record_interval
kill -KILL %1
max_level="$(sox out.wav -n stats -s 16 2>&1|awk '/^Max\ level/ {print int($3)}')"
if [ $max_level -gt $noise_threshold ];then
mv out.wav ${storage_folder}/recording-$(date +%FT%T).wav;
else
rm out.wav
fi
done
更新：
以下解决方案使用fifo作为rec的输出.通过在这个管道上使用拆分来获取块,应该没有丢失录音时间：
#!/bin/bash
noise_threshold=3
storage_folder=~/recordings
raw_folder=~/recordings/tmp
split_folder=~/recordings/split
sox_raw_options="-t raw -r 48k -e signed -b 16"
split_size=1048576 # 1M
mkdir -p ${raw_folder} ${split_folder}
test -a ${raw_folder}/in.raw || mkfifo ${raw_folder}/in.raw
# start recording and spliting in background
rec ${sox_raw_options} - >${raw_folder}/in.raw 2>/dev/null &
split -b ${split_size} - <${raw_folder}/in.raw ${split_folder}/piece &
while true; do
# check each finished raw file
for raw in $(find ${split_folder} -size ${split_size}c);do
max_level="$(sox $sox_raw_options ${raw} -n stats -s 16 2>&1|awk '/^Max\ level/ {print int($3)}')"
if [ $max_level -gt $noise_threshold ];then
sox ${sox_raw_options} ${raw} ${storage_folder}/recording-$(date +%FT%T).wav;
fi
rm ${raw}
done
sleep 1
done1
