bin/stream



#!/bin/sh

set -e

# TODO: Externalize to site-specific configfile
[ $# -gt 0 ] || set -- morla 5002 -- dvcam ../../content/icon_small.png

exit1() {
    echo >&2 "ERROR: $1"
    exit 1
}

while [ $# -gt 0 ]; do
    case $1 in
      --)
        shift; break;;
      *)
        if [ -z "$HOST" ]; then
            HOST=$1
        elif [ -z "$FIRSTPORT" ]; then
            FIRSTPORT=$1
        else
            exit1 "Too many arguments: Max. 2 about target"
        fi
        ;;
    esac
    shift
done

# TODO: Externalize to site-specific configfile
[ $# -gt 0 ] || set -- dvcam ../../content/icon_small.png

while [ $# -gt 0 ]; do
    case $1 in
        alsa=*) ALSA=${1#*=}; AINPUT=$((AINPUT+1));;
        alsa) ALSA=default; AINPUT=$((AINPUT+1));;
        dvcam=*) DVCAM=${1#*=}; XINPUT=$((XINPUT+1));;
        dvcam) DVCAM=auto; XINPUT=$((XINPUT+1));;
        *.png) LOGO=$1; WINPUT=$((WINPUT+1));;
        --) shift; break;;
        *) exit1 "Unsupported input: $1";;
    esac
    shift
done

HOST=${HOST:-127.0.0.1}
if [ "$HOST" = "$(hostname --short)" ]; then
    IP=127.0.0.1
else
    IP=$(host "$HOST" | grep -Po 'address \K\S+')
fi

[ -n "$AINPUT$VINPUT$XINPUT" ] || exit1 "Too few arguments: Min. 1 A/V source"
[ -z "$AINPUT" ] || [ -z "$VINPUT" ] || [ -z "$XINPUT" ] || exit1 "Too many arguments: Max. 2 A/V sources"
[ -z "$AINPUT" ] || [ $AINPUT -eq 1 ] || exit1 "Too many arguments: Max. 1 audio source"
[ -z "$VINPUT" ] || [ $VINPUT -eq 1 ] || exit1 "Too many arguments: Max. 1 video source"
[ -z "$WINPUT" ] || [ $WINPUT -eq 1 ] || exit1 "Too many arguments: Max. 1 watermark source"
[ -z "$XINPUT" ] || [ $XINPUT -eq 1 ] || exit1 "Too many arguments: Max. 1 multimedia source"
VSTREAMINDEX=1
[ -n "$AINPUT" ] || VSTREAMINDEX=0

FIRSTPORT=${FIRSTPORT:-5002} # even number - next 3 ports used too

ACHANNELS=2
AFRAMERATE=48000
ABITRATE=32000

HEIGHT=360
VBITRATE=256000

# based on http://www.webmproject.org/docs/encoder-parameters/#real-time-cbr-encoding-and-streaming
# + scale+watermark trick based on http://stackoverflow.com/a/10937357
# + Add 1s latency (deadline)
# + Use same RTP payload types as GStreamer
ffmpeg -hide_banner -threads auto -re \
 ${ALSA:+-f alsa -sample_rate "$AFRAMERATE" -channels "$ACHANNELS" -thread_queue_size 1024 -i "$ALSA"} \
 ${DVCAM:+-f iec61883 -i $DVCAM} \
 ${LOGO:+-i "$LOGO"} \
 -filter_complex \
 "[$VSTREAMINDEX:v]scale=-1:$HEIGHT[bg]${LOGO:+;
  [bg][$((VSTREAMINDEX+1)):v]overlay=main_w-overlay_w-20:main_h-overlay_h-20[v]}" \
 -map '0:a' \
 -codec:a libopus -ac "$ACHANNELS" -ar "$AFRAMERATE" -b:a "$ABITRATE" \
 -f rtp -payload_type 111 "rtp://$IP:$FIRSTPORT?pkt_size=1200" \
 -map '[v]' \
 -pix_fmt yuv420p \
 -codec:v vp8 -quality realtime -deadline 1000000 -cpu-used 15 \
 -b:v "$VBITRATE" -minrate "$VBITRATE" -maxrate "$VBITRATE" \
 -undershoot-pct 95 -bufsize $((6000*VBITRATE/1000)) -rc_init_occupancy $((4000*VBITRATE/1000)) \
 -max-intra-rate 0 \
 -qmin 4 -qmax 56 \
 -f rtp -payload_type 100 "rtp://$IP:$((FIRSTPORT+2))?pkt_size=1200"