Bash script for rendering video from CCapture.js for Twitter

ccapture_twitter.sh

#!/bin/bash

# Requirements:
#    ffmpeg
#    identify
#    mktemp
#    tar

# Generate .tar of frames using https://github.com/spite/ccapture.js/
# Use the path of the .tar file as the first and only arguement in this script
# Should be a UUID, so something like:
# bash ccapture_twitter.sh 82413b97-686b-c58b-2338-2becc7da4092.tar [twitter.mp4]
FRAMERATE=24

TAR_FILE="${1}"
VIDEO_FILE="${2}"

if [ "${TAR_FILE}" == "" ]; then
	echo "Please include a .tar archive."
	exit 1
fi

if [ "${VIDEO_FILE}" == "" ]; then
	VIDEO_FILE="twitter.mp4"
fi

UNCOMP_FILE=`mktemp`.mp4
TAR_DIR=`mktemp -d`

mkdir -p "${TAR_DIR}"

echo "Extracting ${TAR_FILE}..."
tar -xf "${TAR_FILE}" -C "${TAR_DIR}"

echo "Determining image size..."
IMAGE_SIZE=`identify "${TAR_DIR}/0000000.png" | awk '{print $3}'`

if [[ *"x"* == "${IMAGE_SIZE}" ]]; then
	IMAGE_SIZE_ARG=""
	IMAGE_SIZE=""
else
	IMAGE_SIZE_ARG="-s ${IMAGE_SIZE}"
fi

echo "Rendering uncompressed ${IMAGE_SIZE} video..."
ffmpeg \
	-loglevel panic \
	-r ${FRAMERATE} \
	-f image2 ${IMAGE_SIZE_ARG} \
	-i "${TAR_DIR}/%07d.png" \
	-vcodec libx264 \
	-crf 1 \
	-pix_fmt yuv422p \
	"${UNCOMP_FILE}"

echo "Transcoding video for Twitter as ${VIDEO_FILE}..."
ffmpeg \
	-loglevel panic \
	-i "${UNCOMP_FILE}" \
	-pix_fmt yuv420p \
	-vcodec libx264 \
	-acodec aac \
	-vb 2048k\
	-minrate 1024k \
	-maxrate 4096k \
	-bufsize 1024k \
	-ar 44100  \
	-ac 2  \
	-strict experimental \
	-r ${FRAMERATE} \
	"${VIDEO_FILE}"

echo "Cleaning up..."
rm "${UNCOMP_FILE}"
rm -r "${TAR_DIR}"

echo "Created ${VIDEO_FILE}."