refact: move y4mmuxer to seperate file

src/bin/muxer/mod.rs

@@ -7,12 +7,12 @@
 // Media Patent License 1.0 was not distributed with this source code in the
 // PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 
-mod muxer;
-pub use muxer::*;
-
 mod ivf;
 use self::ivf::IvfMuxer;
 
+mod y4m;
+pub use self::y4m::write_y4m_frame;
+
 use std::io;
 
 pub trait Muxer {

src/bin/muxer/muxer.rs → src/bin/muxer/y4m.rs

@@ -8,9 +8,9 @@
 // PATENTS file, you can obtain it at www.aomedia.org/license/patent.
 
 use crate::decoder::VideoDetails;
-use rav1e::*;
 use std::io::Write;
 use std::slice;
+use rav1e::*;
 
 pub fn write_y4m_frame<T: Pixel>(y4m_enc: &mut y4m::Encoder<'_, Box<dyn Write>>, rec: &rav1e::Frame<T>, y4m_details: VideoDetails) {
   let pitch_y = if y4m_details.bit_depth > 8 { y4m_details.width * 2 } else { y4m_details.width };