| #!/bin/bash |
| set -euo pipefail |
|
|
| fail() { |
| printf 'android-sips-linux: %s\n' "$1" >&2 |
| exit "${2:-1}" |
| } |
|
|
| if [[ $# -ne 9 || |
| "$1" != "-s" || "$2" != "format" || "$3" != "jpeg" || |
| "$4" != "-s" || "$5" != "formatOptions" || "$6" != "best" || |
| "$8" != "--out" ]]; then |
| fail "unsupported arguments" 2 |
| fi |
|
|
| input_path="$7" |
| output_path="$9" |
| convert_bin="/usr/bin/convert" |
| identify_bin="/usr/bin/identify" |
|
|
| [[ "$input_path" == /* && "$output_path" == /* ]] || |
| fail "input and output paths must be absolute" 2 |
| [[ "$input_path" != "$output_path" ]] || fail "input and output paths must differ" 2 |
| [[ -f "$input_path" && ! -L "$input_path" ]] || fail "input is not a regular file" |
| [[ ! -e "$output_path" && ! -L "$output_path" ]] || fail "output already exists" |
| [[ -d "${output_path%/*}" ]] || fail "output directory does not exist" |
|
|
| [[ -x "$convert_bin" && -x "$identify_bin" ]] || |
| fail "fixed ImageMagick executables are unavailable" 2 |
|
|
| if ! input_dimensions="$("$identify_bin" -ping -format '%w %h' "$input_path" 2>/dev/null)"; then |
| fail "input is not a readable image" |
| fi |
| read -r input_width input_height extra <<<"$input_dimensions" |
| [[ "$input_width" =~ ^[1-9][0-9]*$ && "$input_height" =~ ^[1-9][0-9]*$ && -z "${extra:-}" ]] || |
| fail "input dimensions are invalid" |
|
|
| umask 077 |
| temporary_dir="$(mktemp -d "${output_path}.tmp.XXXXXX")" |
| temporary_output="$temporary_dir/output.jpg" |
| cleanup() { |
| rm -rf "$temporary_dir" |
| } |
| trap cleanup EXIT |
|
|
| if ! "$convert_bin" "$input_path" \ |
| -colorspace sRGB \ |
| -background white \ |
| -alpha remove \ |
| -alpha off \ |
| -type TrueColor \ |
| -quality 95 \ |
| "jpeg:$temporary_output" >/dev/null 2>&1; then |
| fail "ImageMagick conversion failed" |
| fi |
|
|
| if ! output_description="$( |
| "$identify_bin" +ping -format '%m|%w|%h|%[colorspace]|%[type]|%[channels]|%Q' \ |
| "$temporary_output" 2>/dev/null |
| )"; then |
| fail "converted output is not a readable image" |
| fi |
| IFS='|' read -r output_format output_width output_height output_colorspace \ |
| output_type output_channels output_quality <<<"$output_description" |
| output_colorspace="$(printf '%s' "$output_colorspace" | tr '[:upper:]' '[:lower:]')" |
| output_channels="$(printf '%s' "$output_channels" | tr '[:upper:]' '[:lower:]')" |
|
|
| [[ "$output_format" == "JPEG" ]] || fail "converted output is not JPEG" |
| [[ "$output_width" == "$input_width" && "$output_height" == "$input_height" ]] || |
| fail "converted output dimensions changed" |
| [[ "$output_colorspace" == "srgb" ]] || fail "converted output is not sRGB" |
| [[ "$output_type" == "TrueColor" ]] || fail "converted output is not true color" |
| [[ "$output_channels" != *a* ]] || fail "converted output retained an alpha channel" |
| [[ "$output_quality" =~ ^[0-9]+$ && "$output_quality" -ge 90 ]] || |
| fail "converted output quality is too low" |
|
|
| mv "$temporary_output" "$output_path" |
|
|
