use std::ffi::{OsStr, OsString};
use std::io::{Cursor, Read, Write};
use std::path::Path;
use std::process::ExitCode;
use std::time::Instant;
use lexopt::prelude::{Long, Short, Value};
use tiny_webp::{Alpha, Options};
const USAGE: &str = "\
usage: tiny-webp [options] <input> -o <output.webp>
-q <0..100>, --quality <0..100> quality, default 75
-o <file>, --output <file> output path, or - for stdout
-noalpha drop the alpha plane
-quiet no output on success
-v print dimensions, bytes, and encode time
-version, --version
-h, --help
";
const PROGRAM_PREFIX: &str = "tiny-webp: ";
const VERSION_PREFIX: &str = "tiny-webp ";
const LONG_FLAG_PREFIX: &str = "--";
const SHORT_FLAG_PREFIX: &str = "-";
const STDOUT_NAME: &str = "stdout";
const UNKNOWN_FLAG: &str = "Unknown flag {flag}. Expected a supported option.";
const UNKNOWN_OPTION: &str = "Unknown command line option. Expected a supported option.";
const INVALID_QUALITY: &str = "Invalid quality {quality}. Expected a whole number from 0 to 100.";
const MISSING_QUALITY: &str =
"Missing value for -q. Pass a quality integer between zero and one hundred.";
const MISSING_OUTPUT_VALUE: &str = "Missing value for -o. Expected an output path or -.";
const MISSING_INPUT: &str = "Missing input path. Pass a file or - for stdin.";
const MISSING_OUTPUT: &str = "Missing output path. Pass -o <file> or -o - for stdout.";
const SECOND_INPUT: &str = "Unexpected input path {name}. tiny-webp reads one input path.";
const READ_PATH: &str = "Could not read {name}. Check that the input path is readable.";
const READ_STDIN: &str = "Could not read stdin. Check that standard input is readable.";
const UNSUPPORTED: &str = "Could not decode {name}. Expected PNG, JPEG, or WebP bytes.";
const PNG_ERROR: &str = "Could not decode {name} as PNG.";
const JPEG_ERROR: &str = "Could not decode {name} as JPEG.";
const CMYK_ERROR: &str = "Could not decode {name}. CMYK JPEG input is unsupported.";
const WEBP_ERROR: &str = "Could not decode {name} as WebP.";
const ANIMATED_ERROR: &str = "Could not decode {name}. Animated WebP input is unsupported.";
const ENCODE_ERROR: &str = "Could not encode {name}. The decoded image dimensions are unsupported.";
const WRITE_PATH: &str = "Could not write {name}. Check that the output path is writable.";
const WRITE_STDOUT: &str = "Could not write stdout. Check that standard output is writable.";
const SUMMARY: &str = "tiny-webp: wrote {bytes} bytes to {output}";
const VERBOSE_SUMMARY: &str = "tiny-webp: {width}x{height}, {bytes} bytes, {ms}.{micros} ms";
enum Action {
Help,
Version,
Encode(Cli),
}
struct Cli {
input: OsString,
output: OsString,
options: Options,
quiet: bool,
verbose: bool,
}
enum Pixels {
Rgb(Vec<u8>),
Rgba(Vec<u8>),
}
struct Image {
pixels: Pixels,
width: u32,
height: u32,
}
struct Success {
width: u32,
height: u32,
byte_count: usize,
micros: u128,
output: OsString,
quiet: bool,
verbose: bool,
}
fn main() -> ExitCode {
match parse(std::env::args_os().skip(1)) {
Ok(Action::Help) => {
print!("{USAGE}");
ExitCode::SUCCESS
}
Ok(Action::Version) => {
println!("{VERSION_PREFIX}{}", env!("CARGO_PKG_VERSION"));
ExitCode::SUCCESS
}
Ok(Action::Encode(cli)) => match encode(cli) {
Ok(success) => {
if !success.quiet {
eprintln!("{}", summary(&success));
}
ExitCode::SUCCESS
}
Err(problem) => {
eprintln!("{PROGRAM_PREFIX}{problem}");
ExitCode::from(1)
}
},
Err(problem) => {
eprintln!("{PROGRAM_PREFIX}{problem}");
eprint!("{USAGE}");
ExitCode::from(2)
}
}
}
fn parse<I>(args: I) -> Result<Action, String>
where
I: IntoIterator<Item = OsString>,
{
let mut input: Option<OsString> = None;
let mut output: Option<OsString> = None;
let mut options = Options::default();
let mut quiet = false;
let mut verbose = false;
let args = args.into_iter().map(expand_single_dash);
let mut parser = lexopt::Parser::from_args(args);
while let Some(arg) = parser.next().map_err(|_| UNKNOWN_OPTION.to_owned())? {
match arg {
Short('h') | Long("help") => return Ok(Action::Help),
Long("version") => return Ok(Action::Version),
Short('q') | Long("quality") => {
let raw = parser.value().map_err(|_| MISSING_QUALITY.to_owned())?;
options.quality = parse_quality(&raw)?;
}
Short('o') | Long("output") => {
output = Some(
parser
.value()
.map_err(|_| MISSING_OUTPUT_VALUE.to_owned())?,
);
}
Long("noalpha") => options.alpha = Alpha::Discard,
Long("quiet") => quiet = true,
Short('v') => verbose = true,
Long(flag) => return Err(unknown_long_flag(flag)),
Short(flag) => return Err(unknown_short_flag(flag)),
Value(path) => {
if input.replace(path.clone()).is_some() {
return Err(named_problem(SECOND_INPUT, &path));
}
}
}
}
let input = input.ok_or_else(|| MISSING_INPUT.to_owned())?;
let output = output.ok_or_else(|| MISSING_OUTPUT.to_owned())?;
Ok(Action::Encode(Cli {
input,
output,
options,
quiet,
verbose,
}))
}
fn expand_single_dash(arg: OsString) -> OsString {
let bytes = arg.as_os_str().as_encoded_bytes();
if bytes.len() > 2 && bytes[0] == b'-' && bytes[1] != b'-' {
let mut expanded = OsString::from("-");
expanded.push(arg);
expanded
} else {
arg
}
}
fn parse_quality(raw: &OsStr) -> Result<u8, String> {
let text = raw.to_string_lossy();
match text.parse::<u8>() {
Ok(quality) if quality <= 100 => Ok(quality),
_ => Err(INVALID_QUALITY.replace("{quality}", &text)),
}
}
fn unknown_long_flag(flag: &str) -> String {
let mut name = String::from(LONG_FLAG_PREFIX);
name.push_str(flag);
UNKNOWN_FLAG.replace("{flag}", &name)
}
fn unknown_short_flag(flag: char) -> String {
let mut name = String::from(SHORT_FLAG_PREFIX);
name.push(flag);
UNKNOWN_FLAG.replace("{flag}", &name)
}
fn encode(cli: Cli) -> Result<Success, String> {
let bytes = read_input(&cli.input)?;
let image = decode_input(&bytes, &cli.input)?;
let started = Instant::now();
let encoded = match &image.pixels {
Pixels::Rgb(pixels) => {
tiny_webp::encode_rgb(pixels, image.width, image.height, &cli.options)
}
Pixels::Rgba(pixels) => {
tiny_webp::encode_rgba(pixels, image.width, image.height, &cli.options)
}
}
.map_err(|_| named_problem(ENCODE_ERROR, &cli.input))?;
let micros = started.elapsed().as_micros();
write_output(&cli.output, &encoded)?;
Ok(Success {
width: image.width,
height: image.height,
byte_count: encoded.len(),
micros,
output: cli.output,
quiet: cli.quiet,
verbose: cli.verbose,
})
}
fn read_input(input: &OsStr) -> Result<Vec<u8>, String> {
if input == OsStr::new("-") {
let mut bytes = Vec::new();
std::io::stdin()
.read_to_end(&mut bytes)
.map_err(|_| READ_STDIN.to_owned())?;
Ok(bytes)
} else {
std::fs::read(input).map_err(|_| named_problem(READ_PATH, input))
}
}
fn decode_input(bytes: &[u8], input: &OsStr) -> Result<Image, String> {
if bytes.starts_with(b"\x89PNG\r\n\x1a\n") {
decode_png(bytes).map_err(|_| named_problem(PNG_ERROR, input))
} else if bytes.starts_with(&[0xff, 0xd8]) {
decode_jpeg(bytes, input)
} else if bytes.len() >= 12 && &bytes[..4] == b"RIFF" && &bytes[8..12] == b"WEBP" {
decode_webp(bytes, input)
} else {
Err(named_problem(UNSUPPORTED, input))
}
}
fn decode_png(bytes: &[u8]) -> Result<Image, ()> {
let mut decoder = png::Decoder::new(Cursor::new(bytes));
decoder.set_transformations(png::Transformations::normalize_to_color8());
let mut reader = decoder.read_info().map_err(|_| ())?;
let size = reader.output_buffer_size().ok_or(())?;
let mut pixels = vec![0; size];
let info = reader.next_frame(&mut pixels).map_err(|_| ())?;
pixels.truncate(info.buffer_size());
let pixels = match info.color_type {
png::ColorType::Rgb => Pixels::Rgb(pixels),
png::ColorType::Rgba => Pixels::Rgba(pixels),
png::ColorType::Grayscale => Pixels::Rgb(expand_gray(&pixels)),
png::ColorType::GrayscaleAlpha => Pixels::Rgba(expand_gray_alpha(&pixels)),
png::ColorType::Indexed => return Err(()),
};
Ok(Image {
pixels,
width: info.width,
height: info.height,
})
}
fn decode_jpeg(bytes: &[u8], input: &OsStr) -> Result<Image, String> {
let mut decoder = jpeg_decoder::Decoder::new(Cursor::new(bytes));
let pixels = decoder
.decode()
.map_err(|_| named_problem(JPEG_ERROR, input))?;
let info = decoder
.info()
.ok_or_else(|| named_problem(JPEG_ERROR, input))?;
let pixels = match info.pixel_format {
jpeg_decoder::PixelFormat::L8 => Pixels::Rgb(expand_gray(&pixels)),
jpeg_decoder::PixelFormat::RGB24 => Pixels::Rgb(pixels),
jpeg_decoder::PixelFormat::CMYK32 => {
return Err(named_problem(CMYK_ERROR, input));
}
_ => return Err(named_problem(JPEG_ERROR, input)),
};
Ok(Image {
pixels,
width: u32::from(info.width),
height: u32::from(info.height),
})
}
fn decode_webp(bytes: &[u8], input: &OsStr) -> Result<Image, String> {
let mut decoder = image_webp::WebPDecoder::new(Cursor::new(bytes))
.map_err(|_| named_problem(WEBP_ERROR, input))?;
if decoder.is_animated() {
return Err(named_problem(ANIMATED_ERROR, input));
}
let (width, height) = decoder.dimensions();
let has_alpha = decoder.has_alpha();
let channels = if has_alpha { 4 } else { 3 };
let mut pixels = vec![0; width as usize * height as usize * channels];
decoder
.read_image(&mut pixels)
.map_err(|_| named_problem(WEBP_ERROR, input))?;
Ok(Image {
pixels: if has_alpha {
Pixels::Rgba(pixels)
} else {
Pixels::Rgb(pixels)
},
width,
height,
})
}
fn expand_gray(gray: &[u8]) -> Vec<u8> {
let mut rgb = Vec::with_capacity(gray.len() * 3);
for value in gray {
rgb.extend_from_slice(&[*value; 3]);
}
rgb
}
fn expand_gray_alpha(gray_alpha: &[u8]) -> Vec<u8> {
let mut rgba = Vec::with_capacity(gray_alpha.len() * 2);
for pixel in gray_alpha.chunks_exact(2) {
rgba.extend_from_slice(&[pixel[0], pixel[0], pixel[0], pixel[1]]);
}
rgba
}
fn write_output(output: &OsStr, bytes: &[u8]) -> Result<(), String> {
if output == OsStr::new("-") {
let mut stdout = std::io::stdout().lock();
stdout
.write_all(bytes)
.and_then(|()| stdout.flush())
.map_err(|_| WRITE_STDOUT.to_owned())
} else {
std::fs::write(Path::new(output), bytes).map_err(|_| named_problem(WRITE_PATH, output))
}
}
fn named_problem(template: &str, name: &OsStr) -> String {
template.replace("{name}", &name.to_string_lossy())
}
fn summary(success: &Success) -> String {
if success.verbose {
VERBOSE_SUMMARY
.replace("{width}", &success.width.to_string())
.replace("{height}", &success.height.to_string())
.replace("{bytes}", &success.byte_count.to_string())
.replace("{ms}", &(success.micros / 1000).to_string())
.replace("{micros}", &three_digits((success.micros % 1000) as u16))
} else {
let output = if success.output == OsStr::new("-") {
STDOUT_NAME.into()
} else {
success.output.to_string_lossy()
};
SUMMARY
.replace("{bytes}", &success.byte_count.to_string())
.replace("{output}", &output)
}
}
fn three_digits(value: u16) -> String {
let mut output = String::with_capacity(3);
output.push(char::from(b'0' + (value / 100) as u8));
output.push(char::from(b'0' + ((value / 10) % 10) as u8));
output.push(char::from(b'0' + (value % 10) as u8));
output
}