stream.sh

#!/bin/bash
# Script for live HLS streaming lossy audio as AAC and archiving lossless audio as FLAC  

RAWFS=/mnt/rd/pbsorca/raw
WEBFS=/mnt/rd/pbsorca/web

WEB_SEGMENT_DURATION=30     # Seconds, web segment for streaming
WEB_SEGMENTS=6          # Number of web segments
FLAC_CULLTIME=120            # Minutes, FLAC older then this will be deleted from local storage
FLAC_DURATION=5         # Minutes, duration for FLAC files

LAG=$(( WEB_SEGMENTS*WEB_SEGMENT_DURATION ))
CHOP_M3U8_LINES=$(( WEB_SEGMENTS*(-2) ))
NODE_NAME=`hostname`
SAMPLE_RATE=44000
STREAM_RATE=22050
CHANNELS=1
# arecord -l to list devices
AUDIO_HW_ID="hw:1"

# Get current timestamp
timestamp=$(date +%s)

#### Set up local output directories
rm -rf $RAWFS/$NODE_NAME
rm -rf $WEBFS/$NODE_NAME
mkdir -p $RAWFS/$NODE_NAME
mkdir -p $WEBFS/$NODE_NAME

# Output timestamp for this (latest) stream
echo $timestamp > $RAWFS/$NODE_NAME/last-started.txt

echo "Node $NODE_NAME started at $timestamp"

## Streaming HLS segments and FLAC archive
while true
do
    echo Starting FFMPEG!
    
    ffmpeg -f alsa -ac $CHANNELS -ar $SAMPLE_RATE -thread_queue_size 1024 -i $AUDIO_HW_ID -ac $CHANNELS -ar $SAMPLE_RATE -sample_fmt s32 -acodec flac \
    -f segment -segment_time "00:$FLAC_DURATION:00.00" -strftime 1 "$RAWFS/$NODE_NAME/$NODE_NAME.%Y%m%d_%H%M%S.flac" \
    -f segment -segment_list "$WEBFS/$NODE_NAME/live.m3u8" -segment_wrap 10 -segment_list_flags +live -segment_time $WEB_SEGMENT_DURATION -segment_format mpegts -ar $STREAM_RATE -ac $CHANNELS -acodec aac "$WEBFS/$NODE_NAME/live%03d.ts" &

    sleep 8
    while [ $(pgrep ffmpeg) ] 
    do
        sleep 30
        #azure-storage-azcopy copy --recursive "$WEBFS" "$WEBFS_SAS" --log-level warning
        #azure-storage-azcopy copy --recursive "$RAWFS" "$RAWFS_SAS" --log-level warning
        EXPIRY=$(($FLAC_DURATION-2))
        cutoffdate=`date -d "$EXPIRY minutes ago" '+%Y-%m-%dT%H:%MZ'`
        az storage blob upload-batch -d audio -s $RAWFS/$NODE_NAME --sas-token "$RAWFS_CLI_TOKEN" --account-name orcaaudio --if-unmodified-since $cutoffdate
        
        #cutoffdate=`date -d "30 seconds ago" '+%Y-%m-%dT%H:%MZ'`
        az storage blob upload-batch -d "\$web" -s $RAWFS/$NODE_NAME --sas-token "$WEBFS_CLI_TOKEN" --account-name orcaaudio --only-show-errors

        # Delete FLAC files older then CULLTIME
        find $RAWFS/$NODE_NAME -daystart -maxdepth 1 -mmin +$FLAC_CULLTIME -type f -name "*.flac" \
            -exec rm -f {} \;
    done
done