Migrate grain synth code to external crate and allow chroma grain synth (#653)

* Migrate grain parsing and generation code to external crate

* Add `--chroma-noise` option to enable chroma grain synth

This implementation is simplistic in that it only enables chroma scaling
from luma noise based on the `--photon-noise` strength. However, it's
100% more chroma noise capability than av1an had previously.

* Disable unnecessary feature in av1-grain

* Fix unit test code

Author: shssoichiro

Cargo.lock

@@ -347,6 +347,10 @@ pub struct CliOpts {
   #[clap(long, help_heading = "ENCODING")]
   pub photon_noise: Option<u8>,
 
+  /// Adds chroma grain synthesis to the grain table generated by `--photon-noise`. (Default: false)
+  #[clap(long, help_heading = "ENCODING", requires = "photon-noise")]
+  pub chroma_noise: bool,
+
   /// Determines method used for concatenating encoded chunks and audio into output file
   ///
   /// ffmpeg - Uses ffmpeg for concatenation. Unfortunately, ffmpeg sometimes produces files
@@ -618,6 +622,7 @@ pub fn parse_cli(args: CliOpts) -> anyhow::Result<Vec<EncodeArgs>> {
       photon_noise: args
         .photon_noise
         .and_then(|arg| if arg == 0 { None } else { Some(arg) }),
+      chroma_noise: args.chroma_noise,
       sc_pix_format: args.sc_pix_format,
       keep: args.keep,
       max_tries: args.max_tries,

av1an-cli/src/lib.rs

@@ -20,6 +20,9 @@ arrayvec = "0.7.2"
 atty = "0.2.14"
 av-format = "0.3.1"
 av-ivf = "0.2.2"
+av1-grain = { version = "0.1.1", default-features = false, features = [
+  "create",
+] }
 memchr = "2.4.1"
 anyhow = "1.0.42"
 rand = "0.8.4"

av1an-core/Cargo.toml

@@ -35,9 +35,9 @@ use std::time::Instant;
 
 use ::ffmpeg::color::TransferCharacteristic;
 use anyhow::Context;
+use av1_grain::TransferFunction;
 use chunk::Chunk;
 use dashmap::DashMap;
-use grain::TransferFunction;
 use once_cell::sync::OnceCell;
 use serde::{Deserialize, Serialize};
 use strum::{Display, EnumString, IntoStaticStr};
@@ -52,7 +52,6 @@ pub mod chunk;
 pub mod concat;
 pub mod encoder;
 pub mod ffmpeg;
-mod grain;
 pub(crate) mod parse;
 pub mod progress_bar;
 pub mod scene_detect;

av1an-core/src/grain.rs

@@ -271,6 +271,7 @@ fn get_test_args() -> EncodeArgs {
     encoder: Encoder::aom,
     extra_splits_len: Some(100),
     photon_noise: Some(10),
+    chroma_noise: false,
     sc_pix_format: None,
     keep: false,
     max_tries: 3,