twitch_stream.sh

#! /bin/bash

# Inspired on:
# http://www.thegameengine.org/miscellaneous/streaming-twitch-tv-ubuntu/
# https://wiki.archlinux.org/index.php/Streaming_to_twitch.tv

if [ ! -f ~/.twitch_key ]; then
    echo "Error: Could not find file: ~/.twitch_key"
    echo "Please create this file and copy past your stream key into it. Open this script for more details."
    exit 1;
fi

INRES="1920x1080" # input resolution
OUTRES="1920x1080" # output resolution
FPS="15" # target FPS
GOP="30" # i-frame interval, should be double of FPS, 
GOPMIN="15" # min i-frame interval, should be equal to fps, 
THREADS="2" # max 6
CBR="1000k" # constant bitrate (should be between 1000k - 3000k)
QUALITY="ultrafast"  # one of the many FFMPEG preset
AUDIO_RATE="44100"
STREAM_KEY=$(cat ~/.twitch_key)
SERVER="live-fra" # twitch server in frankfurt, see http://bashtech.net/twitch/ingest.php for list

ffmpeg -f x11grab \
-s "$INRES" \
-r "$FPS" \
-i :0.0 \
-f alsa -i pulse \
-f flv -ac 2 \
-ar $AUDIO_RATE \
       -vcodec libx264 -g $GOP -keyint_min $GOPMIN -b:v $CBR -minrate $CBR -maxrate $CBR -pix_fmt yuv420p\
       -s $OUTRES -preset $QUALITY -tune film -acodec libmp3lame -threads $THREADS -strict normal \
       -bufsize $CBR "rtmp://$SERVER.twitch.tv/app/$STREAM_KEY"