path: root/bin/loop+encode+stream

#!/bin/sh

# TODO: Handle audio from secondary input

set -e

INPUT=../tmp/omni/show0/earth.yuv

HOST=${1:-morla}
if [ "$HOST" = "$(hostname --short)" ]; then
    IP=127.0.0.1
else
    IP=$(host "$HOST" | grep -Po 'address \K\S+')
fi

FIRSTPORT=${2:-5002} # even number - next 3 ports used too

ACHANNELS=2
AFRAMERATE_OPUS=48000
ABITRATE_OPUS=48000

# TODO
HEIGHT=360

# * height steps and bitrates based on https://developer.apple.com/library/content/documentation/General/Reference/HLSAuthoringSpec/Requirements.html
# * speeds tuned to just below 100% cpu usage for each combination on a multi-core computer
# TODO: adjust height steps or bitrates for 4:3 aspect ratio
# TODO: resolve steps from source height using http://aarmstrong.org/tutorials/aspect-ratios-and-h264
# TODO: Externalize speeds to site-specific configfile
if [ $HEIGHT -le 234 ]; then
 VBITRATE=145000
 SPEED_VP8=2
elif [ $HEIGHT -le 270 ]; then
 VBITRATE=365000
 SPEED_VP8=2
elif [ $HEIGHT -le 360 ]; then
 VBITRATE=730000
 SPEED_VP8=3
elif [ $HEIGHT -le 432 ]; then
 VBITRATE=1100000
 SPEED_VP8=4
elif [ $HEIGHT -le 540 ]; then
 VBITRATE=2000000
 SPEED_VP8=5
elif [ $HEIGHT -le 720 ]; then
 VBITRATE=3000000
 SPEED_VP8=15
fi

# based on http://www.webmproject.org/docs/encoder-parameters/#real-time-cbr-encoding-and-streaming
# + Add 1s latency (deadline)
# + Use same RTP payload types as GStreamer
ffmpeg -hide_banner -threads auto -re \
 -stream_loop -1 -i "$INPUT" \
 -map '0:a' \
 -codec:a libopus -ac "$ACHANNELS" -ar "$AFRAMERATE_OPUS" -b:a "$ABITRATE_OPUS" \
 -f rtp -payload_type 111 "rtp://$IP:$FIRSTPORT?pkt_size=1200" \
 -map '0:v' \
 -pix_fmt yuv420p \
 -codec:v vp8 -quality realtime -deadline 1000000 -cpu-used "$SPEED_VP8" \
 -b:v "$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"