makemovie.sh

#!/bin/sh
# ------------------------------------------------------------------------------
# Uses FFmpeg to create an H.264 encoded MPEG-4 movie at 30 fps from 
# an image sequence; filesize/quality can be tuned with the second parameter.
#
# ------------------------------------------------------------------------------
# Usage:
# > sh makemovie.sh imageFolder 20
# - imageFolder is a folder containing the images
# - 20 is an optional constant rate factor value,
#   lower values mean better quality but bigger file sizes, defaults to 23
# - outputs a file like “imageFolder_20.mp4”
#
# Note:
# The images inside the folder should be generated with leading zeroes
# to avoid reordering:
# 000.png, 001.png, 002.png, etc.
#
# ------------------------------------------------------------------------------
# Resources:
# https://trac.ffmpeg.org/wiki/Encode/H.264

FOLDER=$1         # arg 1
QUALITY=${2:-23}  # arg 2, defaults to 23

ffmpeg \
	-framerate 30 \
	-pattern_type glob \
	-i "$FOLDER/*.png" \
	-c:v h264 \
	-pix_fmt yuv420p \
	-tune animation \
	-preset:v slow \
	-profile:v baseline \
	-crf $QUALITY \
	-movflags +faststart \
	-an \
	"$FOLDER_$QUALITY.mp4"

# ----------- codecs: ----------------------------------------------------------
# -c:v h264
# -c:v h264_videotoolbox              (hardware accelerated but worse results?)
# -c:v libx265                        (see usage below)
# -c:v h265_videotoolbox
#
# ----------- tune: -----------------------------------------------------------
# -tune animation
# -an (disable audio)
#
# ----------- color: -----------------------------------------------------------
# -vf format=yuv420p                  (alias: -pix_fmt yuv420p)
# -vf format=gray                     (alias: -pix_fmt gray)
#
# ----------- bitrate: ---------------------------------------------------------
# -crf 23                             (vconstant rate factor)
# -b:v 7M                             (variable)
#
# ----------- (up)scale: VF 8k, 4k, HD -----------------------------------------
# -vf scale=4320x7680:flags=neighbor  (uses neighbor sampling)
# -vf scale=2160x3840:flags=neighbor
# -vf scale=1080x1920:flags=neighbor
#
# ----------- libx265 examples: ------------------------------------------------
# ffmpeg -framerate 60 -pattern_type glob -i "$1/*.png" -c:v libx265 -crf 30 -tag:v hvc1 -pix_fmt yuv400p -color_primaries 1 -color_trc 1 -colorspace 1 -movflags +faststart -an "$1.mp4"
# ffmpeg -framerate 60 -pattern_type glob -i "$1/*.png" -c:v libx265 -crf 25 -tag:v hvc1 -pix_fmt gray -tune animation "$1.mp4"
# ffmpeg -framerate 60 -pattern_type glob -i "$1/*.png" -vf scale=4320x7680:flags=neighbor -c:v libx265 -crf 25 -tag:v hvc1 -pix_fmt gray -tune animation "$1.mp4"