twitch_stream.sh

##! /bin/bash

# modified script for streaming on Linux via ffmpeg.
# Original see here: https://gist.github.com/oseparovic/2db2aaa737cd37e7c068
# see http://ubuntuguide.org/wiki/Screencasts for full documentation
# see http://www.thegameengine.org/miscellaneous/streaming-twitch-tv-ubuntu/
# for instructions on how to use this gist

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

# input resolution, set it manually in the format "WIDTHxHEIGHT" instead.
INRES="1920x1080"

# output resolution.
# keep the aspect ratio the same or your stream will not fill the display.
OUTRES="800x600"

# input audio. You can use "/dev/dsp" for your primary audio input.
INAUD="pulse"

# target fps
FPS="30"

# video preset quality level.
# more FFMPEG presets available in /usr/share/ffmpeg
# According to trac.ffmpeg.org/wiki/x264EncodingGuide the presets are ultrafast, superfast, veryfast, faster, fast, medium, slow, slower, 
# veryslow, placebo
QUAL="fast"

# stream key. You can set this manually, or reference it from a hidden file like what is done here.
STREAM_KEY=$(cat ~/.twitch_key)

# stream url. Note the formats for twitch.tv and justin.tv
# twitch:"rtmp://live.twitch.tv/app/$STREAM_KEY"
# justin:"rtmp://live.justin.tv/app/$STREAM_KEY"
STREAM_URL="rtmp://live.twitch.tv/app/$STREAM_KEY"

ffmpeg \
-f alsa -ac 2 -i "$INAUD" \
-f x11grab -s "$INRES" -r "$FPS" -i :0.0 \
-vcodec libx264 -pix_fmt yuv420p -s "$OUTRES" -preset "$QUAL" -g 2 \
-acodec libmp3lame -threads 6 -b:a 128KB \
-f flv -ar 44100 "$STREAM_URL"