Script to preprocess videos for HLS or RTMP streaming

convert-for-streaming-cfr

#!/bin/bash

# This is useful when storage is cheaper than compute and you wish to stream
# to later stream to a RTMP target as cheaply as possible.

# To stream
# ffmpeg -re -i <source> -c copy -bsf:a -bsf:a aac_adtstoasc -f flv rtmp://...

RES_X=1920
RES_Y=1080
INPUT=$(realpath "${1}")
TMP_OUTPUT="${INPUT%.*}_TEMP.cfr.ts"
OUTPUT="${INPUT%.*}.cfr.ts"
FFMPEG_INPUT="file:${INPUT}"
FFMPEG_OUTPUT="file:${TMP_OUTPUT}"
ffmpeg \
    -y \
    -fflags +igndts \
    -fflags +genpts \
    -fflags +discardcorrupt \
    -err_detect ignore_err \
    -i "${FFMPEG_INPUT}" \
    -c:v libx264 \
    -b:v 3500k \
    -bsf:v h264_mp4toannexb \
    -profile:v high \
    -level 4.2 \
    -pix_fmt yuv420p \
    -preset medium \
    -tune film \
    -movflags +faststart \
    -deinterlace \
    -r 30 \
    -g 60 \
    -vsync cfr \
    -c:a aac \
    -b:a 192k \
    -ac 2 \
    -ar 44100 \
    -threads 0 \
    -crf 21 \
    -vf "scale=${RES_X}:${RES_Y}:flags=lanczos:force_original_aspect_ratio=1,pad=${RES_X}:${RES_Y}:(ow-iw)/2:(oh-ih)/2" \
    -reset_timestamps 1 \
    -f mpegts \
    "${FFMPEG_OUTPUT}"
mv -fv "${TMP_OUTPUT}" "${OUTPUT}"