Encode Array

17. 1. 2020

Irc this is called array expansion.

one, bad ↓

encode() {

    encarr=(ffmpeg)
    encarr+=(-i "$file")
    encarr+=(-vf yadif=0) # deinterlace
    encarr+=(-pix_fmt yuv420p)
    encarr+=(-c:v libx264)
    encarr+=(-preset slow)
    encarr+=(-tune film)
    encarr+=(-crf 18)
    encarr+=(-threads 0)
    encarr+=(-an)
    #encarr+=(-aspect 16:9)
    #encarr+=(-level 4.1)
    encarr+=("$tmpdir/$base.video.mp4")
    encarr+=(-movflags +faststart -loglevel panic -stats)

    echo "${encarr[@]}"

    when=$(date +%Y%m%d%H%M%S)
    FFREPORT=file="$log/$baseext.$when.$RANDOM.$me.log":level=40 \
    "${encarr[@]}" </dev/null

}

test ↓

#!/bin/bash

encode() {

    input="$HOME/tmp/t e s t.mp4"
    output="$HOME/tmp/out.mp4"

    encarr=("ffmpeg")
    encarr+=("-i ${input}")
    encarr+=("-vf yadif=0") # deinterlace
    encarr+=("-pix_fmt yuv420p")
    encarr+=("-c:v libx264")
    encarr+=("-preset slow")
    encarr+=("-tune film")
    encarr+=("-crf 18")
    encarr+=("-threads 0")
    encarr+=("-an")
    #encarr+=("-aspect 16:9")
    #encarr+=("-level 4.1")
    encarr+=("${output}")
    encarr+=("-movflags +faststart -loglevel panic -stats")

    # preview
    for i in "${!encarr[@]}"; do 
        printf "%s\t%s\n" "$i" "${encarr[$i]}"
    done
        
    # action
    ${encarr[@]}

}
encode

two, fails with filenames with spaces, omg ↓

encode() {

    encarr=("ffmpeg")
    encarr+=("-i ${file}")
    encarr+=("-vf yadif=0") # deinterlace
    encarr+=("-pix_fmt yuv420p")
    encarr+=("-c:v libx264")
    encarr+=("-preset slow")
    encarr+=("-tune film")
    encarr+=("-crf 18")
    encarr+=("-threads 0")
    encarr+=("-an")
    #encarr+=("-aspect 16:9")
    #encarr+=("-level 4.1")
    encarr+=("${tmpdir/$base.video.mp4}")
    encarr+=("-movflags +faststart -loglevel panic -stats")
        
    when=$(date +%Y%m%d%H%M%S)
    FFREPORT=file="$log/$baseext.$when.$RANDOM.$me.log":level=40 \
    ${encarr[@]} </dev/null

}

Note that quoted ${encarr[@]} doesn’t expand as expected.

test 2, this is working, but human-ugly ↓

#!/bin/bash

encode() {

    input="$HOME/tmp/t e s t.mp4"
    output="$HOME/tmp/out.mp4"

    encarr=(ffmpeg)
    encarr+=("-i $input")
    encarr+=(-vf yadif=0)
    encarr+=(-pix_fmt yuv420p)
    encarr+=(-c:v libx264)
    encarr+=(-preset slow)
    encarr+=(-tune film)
    encarr+=(-crf 18)
    encarr+=(-threads 0)
    encarr+=(-an)
    #encarr+=(-aspect 16:9)
    #encarr+=(-level 4.1)
    encarr+=("$output")
    encarr+=(-movflags +faststart -loglevel panic -stats)

    # preview
    for i in "${!encarr[@]}"; do 
        printf "%s\t%s\n" "$i" "${encarr[$i]}"
    done
        
    # action
    "${encarr[@]}"

}
encode

bash