av1an_core/encoder/

mod.rs

#[cfg(test)]
mod tests;

use std::{
    borrow::Cow,
    cmp,
    fmt::Display,
    iter::Iterator,
    path::PathBuf,
    process::Command,
    sync::OnceLock,
};

use arrayvec::ArrayVec;
use cfg_if::cfg_if;
use itertools::chain;
use once_cell::sync::Lazy;
use serde::{Deserialize, Serialize};
use thiserror::Error;
static SVT_AV1_QUARTER_STEP_SUPPORT: OnceLock<bool> = OnceLock::new();

pub static USE_OLD_SVT_AV1: Lazy<bool> = Lazy::new(|| {
    let version = Command::new("SvtAv1EncApp")
        .arg("--version")
        .output()
        .expect("failed to run svt-av1");

    if let Some((major, minor, _)) = parse_svt_av1_version(&version.stdout) {
        match major {
            0 => minor < 9,
            1.. => false,
        }
    } else {
        // If the version failed to parse, check if it accepts old arguments
        let output = Command::new("SvtAv1EncApp")
            .arg("--cdef-level")
            .arg("0")
            .output()
            .expect("failed to run svt-av1");

        let out = if output.stdout.is_empty() {
            output.stderr
        } else {
            output.stdout
        };
        // assume an old version of SVT-AV1 if the version and unprocessed tokens failed
        // to parse, as the format for v0.9.0+ should be the same
        parse_svt_av1_unprocessed_tokens(&out).is_none_or(|tokens| tokens.is_empty())
    }
});

use crate::{
    ffmpeg::{compose_ffmpeg_pipe, FFPixelFormat},
    inplace_vec,
    into_array,
    into_vec,
    list_index,
};

const NULL: &str = if cfg!(windows) { "nul" } else { "/dev/null" };

// Encoder Maximum Speed Values
const MAXIMUM_SPEED_AOM: u8 = 6;
const MAXIMUM_SPEED_RAV1E: u8 = 10;
const MAXIMUM_SPEED_VPX: u8 = 9;
const MAXIMUM_SPEED_OLD_SVT_AV1: u8 = 8;
const MAXIMUM_SPEED_SVT_AV1: u8 = 12;
const MAXIMUM_SPEED_X264: &str = "medium";
const MAXIMUM_SPEED_X265: &str = "fast";

#[expect(non_camel_case_types)]
#[derive(
    Clone,
    Copy,
    PartialEq,
    Eq,
    Serialize,
    Deserialize,
    Debug,
    strum::EnumString,
    strum::IntoStaticStr,
)]
pub enum Encoder {
    aom,
    rav1e,
    vpx,
    #[strum(serialize = "svt-av1")]
    svt_av1,
    x264,
    x265,
}

#[tracing::instrument(level = "debug")]
pub(crate) fn parse_svt_av1_version(version: &[u8]) -> Option<(u32, u32, u32)> {
    let v_idx = memchr::memchr(b'v', version)?;
    let s = version.get(v_idx + 1..)?;
    let s = simdutf8::basic::from_utf8(s).ok()?;
    let version = s
        .split_ascii_whitespace()
        .next()?
        .split('.')
        .filter_map(|s| s.split('-').next())
        .filter_map(|s| s.parse::<u32>().ok())
        .collect::<ArrayVec<u32, 3>>();

    if let [major, minor, patch] = version[..] {
        Some((major, minor, patch))
    } else {
        None
    }
}

#[tracing::instrument(level = "debug")]
pub(crate) fn parse_svt_av1_unprocessed_tokens(output: &[u8]) -> Option<Vec<String>> {
    let start_idx = memchr::memmem::find(output, b"Unprocessed tokens:")?;
    let sub_output = output.get(start_idx..)?;
    let end_idx = sub_output.iter().position(|&b| b == b'\n')?;
    let unprocessed_tokens_line = simdutf8::basic::from_utf8(sub_output.get(0..end_idx)?).ok()?;
    let unprocessed_tokens = unprocessed_tokens_line
        .split_ascii_whitespace()
        .skip(2)
        .map(String::from)
        .collect::<Vec<_>>();

    Some(unprocessed_tokens)
}

#[tracing::instrument(level = "debug")]
pub(crate) fn svt_av1_supports_quarter_steps(temp: &str) -> bool {
    *SVT_AV1_QUARTER_STEP_SUPPORT.get_or_init(|| {
        use std::{fs, io::Write, path::Path, process::Stdio};

        let test_file = Path::new(temp).join("test_q.y4m");
        let result = (|| -> Option<bool> {
            let mut f = fs::File::create(&test_file).ok()?;
            writeln!(f, "YUV4MPEG2 W320 H240 F30:1 Ip A0:0 C420jpeg").ok()?;
            writeln!(f, "FRAME").ok()?;
            f.write_all(&vec![0u8; 320 * 240 + 2 * 160 * 120]).ok()?;
            drop(f);

            Command::new("SvtAv1EncApp")
                .args(["-i", test_file.to_str()?, "--crf", "50.75", "-b", NULL])
                .stdout(Stdio::null())
                .stderr(Stdio::null())
                .status()
                .ok()
                .map(|s| s.success())
        })();

        let _ = fs::remove_file(test_file);
        result.unwrap_or(false)
    })
}

pub(crate) fn format_q(q: f32) -> String {
    if q.fract().abs() < 1e-6 {
        format!("{:.0}", q)
    } else {
        format!("{:.2}", q)
    }
}

impl Display for Encoder {
    #[inline]
    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
        f.write_str(<&'static str>::from(self))
    }
}

impl Encoder {
    /// Composes 1st pass command for 1 pass encoding
    #[inline]
    pub fn compose_1_1_pass(self, params: Vec<String>, output: String) -> Vec<String> {
        match self {
            Self::aom => chain!(into_array!["aomenc", "--passes=1"], params, into_array![
                "-o", output, "-"
            ],)
            .collect(),
            Self::rav1e => chain!(into_array!["rav1e", "-", "-y"], params, into_array![
                "--output", output
            ])
            .collect(),
            Self::vpx => chain!(into_array!["vpxenc", "--passes=1"], params, into_array![
                "-o", output, "-"
            ])
            .collect(),
            Self::svt_av1 => chain!(
                into_array!["SvtAv1EncApp", "-i", "stdin", "--progress", "2"],
                params,
                into_array!["-b", output],
            )
            .collect(),
            Self::x264 => chain!(
                into_array!["x264", "--stitchable", "--log-level", "error", "--demuxer", "y4m",],
                params,
                into_array!["-", "-o", output]
            )
            .collect(),
            Self::x265 => chain!(into_array!["x265", "--y4m"], params, into_array![
                "--input", "-", "-o", output
            ])
            .collect(),
        }
    }

    /// Composes 1st pass command for 2 pass encoding
    #[inline]
    pub fn compose_1_2_pass(self, params: Vec<String>, fpf: &str) -> Vec<String> {
        match self {
            Self::aom => chain!(
                into_array!["aomenc", "--passes=2", "--pass=1"],
                params,
                into_array![format!("--fpf={fpf}.log"), "-o", NULL, "-"],
            )
            .collect(),
            Self::rav1e => chain!(
                into_array!["rav1e", "-", "-y", "--quiet",],
                params,
                into_array!["--first-pass", format!("{fpf}.stat"), "--output", NULL]
            )
            .collect(),
            Self::vpx => chain!(
                into_array!["vpxenc", "--passes=2", "--pass=1"],
                params,
                into_array![format!("--fpf={fpf}.log"), "-o", NULL, "-"],
            )
            .collect(),
            Self::svt_av1 => chain!(
                into_array![
                    "SvtAv1EncApp",
                    "-i",
                    "stdin",
                    "--progress",
                    "2",
                    "--irefresh-type",
                    "2",
                ],
                params,
                into_array!["--pass", "1", "--stats", format!("{fpf}.stat"), "-b", NULL,],
            )
            .collect(),
            Self::x264 => chain!(
                into_array![
                    "x264",
                    "--stitchable",
                    "--log-level",
                    "error",
                    "--pass",
                    "1",
                    "--demuxer",
                    "y4m",
                ],
                params,
                into_array!["--stats", format!("{fpf}.log"), "-", "-o", NULL]
            )
            .collect(),
            Self::x265 => chain!(
                into_array![
                    "x265",
                    "--repeat-headers",
                    "--log-level",
                    "error",
                    "--pass",
                    "1",
                    "--y4m",
                ],
                params,
                into_array![
                    "--stats",
                    format!("{fpf}.log"),
                    "--analysis-reuse-file",
                    format!("{fpf}_analysis.dat"),
                    "--input",
                    "-",
                    "-o",
                    NULL
                ]
            )
            .collect(),
        }
    }

    /// Composes 2st pass command for 2 pass encoding
    #[inline]
    pub fn compose_2_2_pass(self, params: Vec<String>, fpf: &str, output: String) -> Vec<String> {
        match self {
            Self::aom => chain!(
                into_array!["aomenc", "--passes=2", "--pass=2"],
                params,
                into_array![format!("--fpf={fpf}.log"), "-o", output, "-"],
            )
            .collect(),
            Self::rav1e => chain!(
                into_array!["rav1e", "-", "-y", "--quiet",],
                params,
                into_array!["--second-pass", format!("{fpf}.stat"), "--output", output]
            )
            .collect(),
            Self::vpx => chain!(
                into_array!["vpxenc", "--passes=2", "--pass=2"],
                params,
                into_array![format!("--fpf={fpf}.log"), "-o", output, "-"],
            )
            .collect(),
            Self::svt_av1 => chain!(
                into_array![
                    "SvtAv1EncApp",
                    "-i",
                    "stdin",
                    "--progress",
                    "2",
                    "--irefresh-type",
                    "2",
                ],
                params,
                into_array!["--pass", "2", "--stats", format!("{fpf}.stat"), "-b", output,],
            )
            .collect(),
            Self::x264 => chain!(
                into_array![
                    "x264",
                    "--stitchable",
                    "--log-level",
                    "error",
                    "--pass",
                    "2",
                    "--demuxer",
                    "y4m",
                ],
                params,
                into_array!["--stats", format!("{fpf}.log"), "-", "-o", output]
            )
            .collect(),
            Self::x265 => chain!(
                into_array![
                    "x265",
                    "--repeat-headers",
                    "--log-level",
                    "error",
                    "--pass",
                    "2",
                    "--y4m",
                ],
                params,
                into_array![
                    "--stats",
                    format!("{fpf}.log"),
                    "--analysis-reuse-file",
                    format!("{fpf}_analysis.dat"),
                    "--input",
                    "-",
                    "-o",
                    output
                ]
            )
            .collect(),
        }
    }

    /// Returns default settings for the encoder
    #[inline]
    pub fn get_default_arguments(self, (cols, rows): (u32, u32)) -> Vec<String> {
        match self {
            // aomenc automatically infers the correct bit depth, and thus for aomenc, not
            // specifying the bit depth is actually more accurate because if for example
            // you specify `--pix-format yuv420p`, aomenc will encode 10-bit when that
            // is not actually the desired pixel format.
            Encoder::aom => {
                let defaults: Vec<String> = into_vec![
                    "--threads=8",
                    "--cpu-used=6",
                    "--end-usage=q",
                    "--cq-level=30",
                    "--disable-kf",
                    "--kf-max-dist=9999"
                ];

                if cols > 1 || rows > 1 {
                    let columns = cols.ilog2();
                    let rows = rows.ilog2();

                    let aom_tiles: Vec<String> = into_vec![
                        format!("--tile-columns={columns}"),
                        format!("--tile-rows={rows}")
                    ];
                    chain!(defaults, aom_tiles).collect()
                } else {
                    defaults
                }
            },
            Encoder::rav1e => {
                let defaults: Vec<String> = into_vec![
                    "--speed",
                    "6",
                    "--quantizer",
                    "100",
                    "--keyint",
                    "0",
                    "--no-scene-detection",
                ];

                if cols > 1 || rows > 1 {
                    let tiles: Vec<String> =
                        into_vec!["--tiles", format!("{tiles}", tiles = cols * rows)];
                    chain!(defaults, tiles).collect()
                } else {
                    defaults
                }
            },
            // vpxenc does not infer the pixel format from the input, so `-b 10` is still required
            // to work with the default pixel format (yuv420p10le).
            Encoder::vpx => {
                let defaults = into_vec![
                    "--codec=vp9",
                    "-b",
                    "10",
                    "--profile=2",
                    "--threads=4",
                    "--cpu-used=2",
                    "--end-usage=q",
                    "--cq-level=30",
                    "--row-mt=1",
                    "--auto-alt-ref=6",
                    "--disable-kf",
                    "--kf-max-dist=9999"
                ];

                if cols > 1 || rows > 1 {
                    let columns = cols.ilog2();
                    let rows = rows.ilog2();

                    let aom_tiles: Vec<String> = into_vec![
                        format!("--tile-columns={columns}"),
                        format!("--tile-rows={rows}")
                    ];
                    chain!(defaults, aom_tiles).collect()
                } else {
                    defaults
                }
            },
            Encoder::svt_av1 => {
                let defaults = into_vec![
                    "--preset", "4", "--keyint", "0", "--scd", "0", "--rc", "0", "--crf", "25"
                ];
                if cols > 1 || rows > 1 {
                    let columns = cols.ilog2();
                    let rows = rows.ilog2();

                    let tiles: Vec<String> = into_vec![
                        "--tile-columns",
                        columns.to_string(),
                        "--tile-rows",
                        rows.to_string()
                    ];
                    chain!(defaults, tiles).collect()
                } else {
                    defaults
                }
            },
            Encoder::x264 => into_vec![
                "--preset",
                "slow",
                "--crf",
                "25",
                "--keyint",
                "infinite",
                "--scenecut",
                "0",
            ],
            Encoder::x265 => into_vec![
                "--preset",
                "slow",
                "--crf",
                "25",
                "-D",
                "10",
                "--level-idc",
                "5.0",
                "--keyint",
                "-1",
                "--scenecut",
                "0",
            ],
        }
    }

    /// Return number of default passes for encoder
    #[inline]
    pub const fn get_default_pass(self) -> u8 {
        match self {
            Self::aom | Self::vpx => 2,
            _ => 1,
        }
    }

    /// Default quantizer range target quality mode
    #[inline]
    pub const fn get_default_cq_range(self) -> (usize, usize) {
        match self {
            Self::aom | Self::vpx => (15, 55),
            Self::rav1e => (50, 140),
            Self::svt_av1 => (15, 50),
            Self::x264 | Self::x265 => (15, 35),
        }
    }

    /// Returns quantizer percentage (0-1) relative to entire range for encoder
    #[inline]
    pub fn get_cq_relative_percentage(self, quantizer: usize) -> f64 {
        let percentage = match self {
            Self::aom | Self::vpx | Self::svt_av1 => quantizer as f64 / 64.0, // 0-63
            Self::rav1e => quantizer as f64 / 256.0,                          // 0-255
            Self::x264 | Self::x265 => quantizer as f64 / 52.0,               // 0-51
        };

        // Clamp to 0-1 in case quantizer is out of expected range
        percentage.clamp(0.0, 1.0)
    }

    /// Returns help command for encoder
    #[inline]
    pub const fn help_command(self) -> [&'static str; 2] {
        match self {
            Self::aom => ["aomenc", "--help"],
            Self::rav1e => ["rav1e", "--help"],
            Self::vpx => ["vpxenc", "--help"],
            Self::svt_av1 => ["SvtAv1EncApp", "--help"],
            Self::x264 => ["x264", "--fullhelp"],
            Self::x265 => ["x265", "--fullhelp"],
        }
    }

    /// Returns version text for encoder, or None if encoder is not available in
    /// PATH
    #[inline]
    pub fn version_text(self) -> Option<String> {
        match self {
            Self::aom => {
                let result = Command::new("aomenc").arg("--help").output().ok()?;
                let stdout = String::from_utf8_lossy(&result.stdout);
                let version_line = stdout.lines().find(|line| line.starts_with("    av1"))?;
                Some(
                    version_line
                        .split_once('-')
                        .expect("unexpected aom version string format")
                        .1
                        .replace("(default)", "")
                        .trim()
                        .to_string(),
                )
            },
            Self::rav1e => {
                let result = Command::new("rav1e").arg("--version").output().ok()?;
                let stdout = String::from_utf8_lossy(&result.stdout);
                let version_line = stdout.lines().find(|line| line.starts_with("rav1e"))?;
                Some(version_line.to_string())
            },
            Self::vpx => {
                let result = Command::new("vpxenc").arg("--help").output().ok()?;
                let stdout = String::from_utf8_lossy(&result.stdout);
                let version_line = stdout.lines().find(|line| line.starts_with("    vp9"))?;
                Some(
                    version_line
                        .split_once('-')
                        .expect("unexpected vpx version string format")
                        .1
                        .replace("(default)", "")
                        .trim()
                        .to_string(),
                )
            },
            Self::svt_av1 => {
                let result = Command::new("SvtAv1EncApp").arg("--version").output().ok()?;
                let stdout = String::from_utf8_lossy(&result.stdout);
                let version_line = stdout.lines().find(|line| line.starts_with("SVT-AV1"))?;
                Some(version_line.to_string())
            },
            Self::x264 => {
                let result = Command::new("x264").arg("--version").output().ok()?;
                let stdout = String::from_utf8_lossy(&result.stdout);
                let version_line = stdout.lines().find(|line| line.starts_with("x264"))?;
                Some(version_line.to_string())
            },
            Self::x265 => {
                let result = Command::new("x265").arg("--version").output().ok()?;
                let stderr = String::from_utf8_lossy(&result.stderr);
                let version_line = stderr.lines().find(|line| line.starts_with("x265"))?;
                Some(
                    version_line
                        .split_once(':')
                        .expect("unexpected x265 version string format")
                        .1
                        .trim()
                        .to_string(),
                )
            },
        }
    }

    /// Get the name of the executable/binary for the encoder
    #[inline]
    pub const fn bin(self) -> &'static str {
        match self {
            Self::aom => "aomenc",
            Self::rav1e => "rav1e",
            Self::vpx => "vpxenc",
            Self::svt_av1 => "SvtAv1EncApp",
            Self::x264 => "x264",
            Self::x265 => "x265",
        }
    }

    /// Get the name of the video format associated with the encoder
    #[inline]
    pub const fn format(self) -> &'static str {
        match self {
            Self::aom | Self::rav1e | Self::svt_av1 => "av1",
            Self::vpx => "vpx",
            Self::x264 => "h264",
            Self::x265 => "h265",
        }
    }

    /// Get the default output extension for the encoder
    #[inline]
    pub const fn output_extension(&self) -> &'static str {
        match &self {
            Self::aom | Self::rav1e | Self::vpx | Self::svt_av1 => "ivf",
            Self::x264 => "264",
            Self::x265 => "hevc",
        }
    }

    /// Returns function pointer used for matching Q/CRF arguments in command
    /// line
    fn q_match_fn(self) -> fn(&str) -> bool {
        match self {
            Self::aom | Self::vpx => |p| p.starts_with("--cq-level="),
            Self::rav1e => |p| p == "--quantizer",
            Self::svt_av1 => |p| matches!(p, "--qp" | "-q" | "--crf"),
            Self::x264 | Self::x265 => |p| p == "--crf",
        }
    }

    fn replace_q(self, index: usize, q: f32) -> (usize, String) {
        match self {
            Self::aom | Self::vpx => (index, format!("--cq-level={}", q.round() as usize)),
            Self::rav1e => (index + 1, (q.round() as usize).to_string()),
            Self::svt_av1 | Self::x265 | Self::x264 => {
                let q_str = format_q(q);
                (index + 1, q_str)
            },
        }
    }

    fn insert_q(self, q: f32) -> ArrayVec<String, 2> {
        let mut output = ArrayVec::new();
        match self {
            Self::aom | Self::vpx => {
                output.push(format!("--cq-level={}", q.round() as usize));
            },
            Self::rav1e => {
                output.push("--quantizer".into());
                output.push((q.round() as usize).to_string());
            },
            Self::svt_av1 | Self::x264 | Self::x265 => {
                output.push("--crf".into());
                let q_str = format_q(q);
                output.push(q_str);
            },
        }
        output
    }

    /// Returns changed q/crf in command line arguments
    #[inline]
    pub fn man_command(self, mut params: Vec<String>, q: f32) -> Vec<String> {
        let index = list_index(&params, self.q_match_fn());
        if let Some(index) = index {
            let (replace_index, replace_q) = self.replace_q(index, q);
            params[replace_index] = replace_q;
        } else {
            let args = self.insert_q(q);
            params.extend_from_slice(&args);
        }

        params
    }

    /// Parses the number of encoded frames
    pub(crate) fn parse_encoded_frames(self, line: &str) -> Option<u64> {
        use crate::parse::*;

        match self {
            Self::aom | Self::vpx => {
                cfg_if! {
                  if #[cfg(any(target_arch = "x86", target_arch = "x86_64"))] {
                    if is_x86_feature_detected!("sse4.1") && is_x86_feature_detected!("ssse3") {
                      // SAFETY: We verified that the CPU has the required feature set
                      return unsafe { parse_aom_vpx_frames_sse41(line.as_bytes()) };
                    }
                  }
                }

                parse_aom_vpx_frames(line)
            },
            Self::rav1e => parse_rav1e_frames(line),
            Self::svt_av1 => parse_svt_av1_frames(line),
            Self::x264 | Self::x265 => parse_x26x_frames(line),
        }
    }

    /// Returns command used for target quality probing
    #[inline]
    pub fn construct_target_quality_command(
        self,
        threads: usize,
        q: f32,
    ) -> Vec<Cow<'static, str>> {
        match &self {
            Self::aom => inplace_vec![
                "aomenc",
                "--passes=1",
                format!("--threads={threads}"),
                "--tile-columns=2",
                "--tile-rows=1",
                "--end-usage=q",
                "-b",
                "8",
                format!("--cpu-used={}", MAXIMUM_SPEED_AOM),
                format!("--cq-level={q}"),
                "--enable-filter-intra=0",
                "--enable-smooth-intra=0",
                "--enable-paeth-intra=0",
                "--enable-cfl-intra=0",
                "--enable-angle-delta=0",
                "--reduced-tx-type-set=1",
                "--enable-intra-edge-filter=0",
                "--enable-order-hint=0",
                "--enable-flip-idtx=0",
                "--enable-global-motion=0",
                "--enable-cdef=0",
                "--max-reference-frames=3",
                "--cdf-update-mode=2",
                "--enable-tpl-model=0",
                "--sb-size=64",
                "--min-partition-size=32",
                "--disable-kf",
                "--kf-max-dist=9999"
            ],
            Self::rav1e => inplace_vec![
                "rav1e",
                "-y",
                "-s",
                MAXIMUM_SPEED_RAV1E.to_string(),
                "--threads",
                threads.to_string(),
                "--tiles",
                "16",
                "--quantizer",
                (q.round() as usize).to_string(),
                "--low-latency",
                "--rdo-lookahead-frames",
                "5",
                "--no-scene-detection",
            ],
            Self::vpx => inplace_vec![
                "vpxenc",
                "-b",
                "10",
                "--profile=2",
                "--passes=1",
                "--pass=1",
                "--codec=vp9",
                format!("--threads={threads}"),
                format!("--cpu-used={}", MAXIMUM_SPEED_VPX),
                "--end-usage=q",
                format!("--cq-level={q}"),
                "--row-mt=1",
                "--disable-kf",
                "--kf-max-dist=9999"
            ],
            Self::svt_av1 => {
                if *USE_OLD_SVT_AV1 {
                    inplace_vec![
                        "SvtAv1EncApp",
                        "-i",
                        "stdin",
                        "--lp",
                        threads.to_string(),
                        "--preset",
                        MAXIMUM_SPEED_OLD_SVT_AV1.to_string(),
                        "--keyint",
                        "240",
                        "--crf",
                        format_q(q),
                        "--tile-rows",
                        "1",
                        "--tile-columns",
                        "2",
                        "--pred-struct",
                        "0",
                        "--sg-filter-mode",
                        "0",
                        "--enable-restoration-filtering",
                        "0",
                        "--cdef-level",
                        "0",
                        "--disable-dlf",
                        "0",
                        "--mrp-level",
                        "0",
                        "--enable-mfmv",
                        "0",
                        "--enable-local-warp",
                        "0",
                        "--enable-global-motion",
                        "0",
                        "--enable-interintra-comp",
                        "0",
                        "--obmc-level",
                        "0",
                        "--rdoq-level",
                        "0",
                        "--filter-intra-level",
                        "0",
                        "--enable-intra-edge-filter",
                        "0",
                        "--enable-pic-based-rate-est",
                        "0",
                        "--pred-me",
                        "0",
                        "--bipred-3x3",
                        "0",
                        "--compound",
                        "0",
                        "--ext-block",
                        "0",
                        "--hbd-md",
                        "0",
                        "--palette-level",
                        "0",
                        "--umv",
                        "0",
                        "--tf-level",
                        "3",
                    ]
                } else {
                    inplace_vec![
                        "SvtAv1EncApp",
                        "-i",
                        "stdin",
                        "--lp",
                        threads.to_string(),
                        "--preset",
                        MAXIMUM_SPEED_SVT_AV1.to_string(),
                        "--keyint",
                        "240",
                        "--crf",
                        format_q(q),
                        "--tile-rows",
                        "1",
                        "--tile-columns",
                        "2",
                    ]
                }
            },
            Self::x264 => inplace_vec![
                "x264",
                "--log-level",
                "error",
                "--demuxer",
                "y4m",
                "-",
                "--no-progress",
                "--threads",
                threads.to_string(),
                "--preset",
                MAXIMUM_SPEED_X264,
                "--crf",
                format!("{:.2}", q),
            ],
            Self::x265 => inplace_vec![
                "x265",
                "--log-level",
                "0",
                "--no-progress",
                "--y4m",
                "--frame-threads",
                cmp::min(threads, 16).to_string(),
                "--preset",
                MAXIMUM_SPEED_X265,
                "--crf",
                format!("{:.2}", q),
                "--input",
                "-",
            ],
        }
    }

    /// Returns command used for target quality probing (slow, correctness
    /// focused version)
    #[inline]
    pub fn construct_target_quality_command_probe_slow(self, q: f32) -> Vec<Cow<'static, str>> {
        match &self {
            Self::aom => {
                inplace_vec!["aomenc", "--passes=1", format!("--cq-level={}", q.round() as usize)]
            },
            Self::rav1e => {
                inplace_vec!["rav1e", "-y", "--quantizer", (q.round() as usize).to_string()]
            },
            Self::vpx => inplace_vec![
                "vpxenc",
                "--passes=1",
                "--pass=1",
                "--codec=vp9",
                "--end-usage=q",
                format!("--cq-level={}", q.round() as usize),
            ],
            Self::svt_av1 => {
                inplace_vec!["SvtAv1EncApp", "-i", "stdin", "--crf", format_q(q),]
            },
            Self::x264 => inplace_vec![
                "x264",
                "--log-level",
                "error",
                "--demuxer",
                "y4m",
                "-",
                "--no-progress",
                "--crf",
                format!("{:.2}", q),
            ],
            Self::x265 => inplace_vec![
                "x265",
                "--log-level",
                "0",
                "--no-progress",
                "--y4m",
                "--crf",
                format!("{:.2}", q),
                "--input",
                "-",
            ],
        }
    }

    /// Function `remove_patterns` that takes in args and patterns and removes
    /// all instances of the patterns from the args.
    #[inline]
    pub fn remove_patterns(args: &mut Vec<String>, patterns: &[&str]) {
        for pattern in patterns {
            if let Some(index) = args.iter().position(|value| value.contains(pattern)) {
                args.remove(index);
                // If pattern does not contain =, we need to remove the index that follows.
                if !pattern.contains('=') {
                    args.remove(index);
                }
            }
        }
    }

    #[expect(clippy::too_many_arguments)]
    #[inline]
    /// Constructs tuple of commands for target quality probing
    pub fn probe_cmd(
        self,
        temp: String,
        chunk_index: usize,
        q: f32,
        pix_fmt: FFPixelFormat,
        probing_rate: usize,
        vmaf_threads: usize,
        custom_video_params: Option<Vec<String>>,
    ) -> (Option<Vec<String>>, Vec<Cow<'static, str>>) {
        let filters = if probing_rate > 1 {
            vec![
                "-vf".to_string(),
                format!("select=not(mod(n\\,{probing_rate}))"),
                "-vsync".to_string(),
                "0".to_string(),
            ]
        } else {
            Vec::new()
        };

        let pipe = Some(compose_ffmpeg_pipe(filters, pix_fmt));

        let extension = match self {
            Encoder::x264 => "264",
            Encoder::x265 => "hevc",
            _ => "ivf",
        };
        let q_str = format_q(q);
        let probe_name = format!("v_{index:05}_{q_str}.{extension}", index = chunk_index);

        let probe = PathBuf::from(temp).join("split").join(&probe_name);
        let probe_path = probe.to_string_lossy().to_string();

        let params: Vec<Cow<str>> = custom_video_params.map_or_else(
            || self.construct_target_quality_command(vmaf_threads, q),
            |mut video_params| {
                let quantizer_patterns =
                    ["--cq-level=", "--passes=", "--pass=", "--crf", "--quantizer"];
                Self::remove_patterns(&mut video_params, &quantizer_patterns);

                let mut ps = self.construct_target_quality_command_probe_slow(q);

                ps.reserve(video_params.len());
                for arg in video_params {
                    ps.push(Cow::Owned(arg));
                }

                ps
            },
        );

        let output: Vec<Cow<str>> = match self {
            Self::svt_av1 => chain!(params, into_array!["-b", probe_path]).collect(),
            Self::aom | Self::rav1e | Self::vpx | Self::x264 => {
                chain!(params, into_array!["-o", probe_path, "-"]).collect()
            },
            Self::x265 => chain!(params, into_array!["-o", probe_path]).collect(),
        };

        (pipe, output)
    }

    #[inline]
    pub fn get_format_bit_depth(
        self,
        format: FFPixelFormat,
    ) -> Result<usize, UnsupportedPixelFormatError> {
        macro_rules! impl_this_function {
      ($($encoder:ident),*) => {
        match self {
          $(
            Encoder::$encoder => pastey::paste! { [<get_ $encoder _format_bit_depth>](format) },
          )*
        }
      };
    }
        impl_this_function!(x264, x265, vpx, aom, rav1e, svt_av1)
    }
}

#[derive(Error, Debug)]
pub enum UnsupportedPixelFormatError {
    #[error("{0} does not support {1:?}")]
    UnsupportedFormat(Encoder, FFPixelFormat),
}

macro_rules! create_get_format_bit_depth_function {
  ($encoder:ident, 8: $_8bit_fmts:expr, 10: $_10bit_fmts:expr, 12: $_12bit_fmts:expr) => {
    pastey::paste! {
      pub fn [<get_ $encoder _format_bit_depth>](format: FFPixelFormat) -> Result<usize, UnsupportedPixelFormatError> {
        use FFPixelFormat::*;
        if $_8bit_fmts.contains(&format) {
          Ok(8)
        } else if $_10bit_fmts.contains(&format) {
          Ok(10)
        } else if $_12bit_fmts.contains(&format) {
          Ok(12)
        } else {
          Err(UnsupportedPixelFormatError::UnsupportedFormat(Encoder::$encoder, format))
        }
      }
    }
  };
}

// The supported bit depths are taken from ffmpeg,
// e.g.: `ffmpeg -h encoder=libx264`
create_get_format_bit_depth_function!(
  x264,
   8: [YUV420P, YUVJ420P, YUV422P, YUVJ422P, YUV444P, YUVJ444P, NV12, NV16, NV21, GRAY8],
  10: [YUV420P10LE, YUV422P10LE, YUV444P10LE, NV20LE, GRAY10LE],
  12: []
);
create_get_format_bit_depth_function!(
  x265,
   8: [YUV420P, YUVJ420P, YUV422P, YUVJ422P, YUV444P, YUVJ444P, GBRP, GRAY8],
  10: [YUV420P10LE, YUV422P10LE, YUV444P10LE, GBRP10LE, GRAY10LE],
  12: [YUV420P12LE, YUV422P12LE, YUV444P12LE, GBRP12LE, GRAY12LE]
);
create_get_format_bit_depth_function!(
  vpx,
   8: [YUV420P, YUVA420P, YUV422P, YUV440P, YUV444P, GBRP],
  10: [YUV420P10LE, YUV422P10LE, YUV440P10LE, YUV444P10LE, GBRP10LE],
  12: [YUV420P12LE, YUV422P12LE, YUV440P12LE, YUV444P12LE, GBRP12LE]
);
create_get_format_bit_depth_function!(
  aom,
   8: [YUV420P, YUV422P, YUV444P, GBRP, GRAY8],
  10: [YUV420P10LE, YUV422P10LE, YUV444P10LE, GBRP10LE, GRAY10LE],
  12: [YUV420P12LE, YUV422P12LE, YUV444P12LE, GBRP12LE, GRAY12LE,]
);
create_get_format_bit_depth_function!(
  rav1e,
   8: [YUV420P, YUVJ420P, YUV422P, YUVJ422P, YUV444P, YUVJ444P],
  10: [YUV420P10LE, YUV422P10LE, YUV444P10LE],
  12: [YUV420P12LE, YUV422P12LE, YUV444P12LE,]
);
create_get_format_bit_depth_function!(
  svt_av1,
   8: [YUV420P],
  10: [YUV420P10LE],
  12: []
);