From ba9af4931c74e17830b0cb676039a1c31c5970a1 Mon Sep 17 00:00:00 2001
From: Casey Rodarmor <casey@rodarmor.com>
Date: Mon, 14 Sep 2026 12:43:36 -0700
Subject: [PATCH] Use lowercase hex literals

---
 src/encoder.rs      |  2 +-
 src/flac_builder.rs |  2 +-
 src/flac_decoder.rs |  2 +-
 src/head.rs         | 18 +++++++++---------
 src/jpeg_builder.rs |  4 ++--
 src/mp3_builder.rs  | 10 +++++-----
 src/mp3_decoder.rs  | 28 ++++++++++++++--------------
 src/mp4_decoder.rs  | 10 +++++-----
 src/orientation.rs  | 10 +++++-----
 src/webm_builder.rs | 34 +++++++++++++++++-----------------
 src/webm_decoder.rs | 14 +++++++-------
 11 files changed, 67 insertions(+), 67 deletions(-)

diff --git a/src/encoder.rs b/src/encoder.rs
index e64fbcd2..f018e47d 100644
--- a/src/encoder.rs
+++ b/src/encoder.rs
@@ -36,7 +36,7 @@ impl Encoder {
         for &byte in len.to_le_bytes()[..count].iter().rev() {
           self.buffer.push_front(byte);
         }
-        self.buffer.push_front((0xEF + count).try_into().unwrap());
+        self.buffer.push_front((0xef + count).try_into().unwrap());
       }
       Head::Reserved(value) => self.buffer.push_front(value),
     }
diff --git a/src/flac_builder.rs b/src/flac_builder.rs
index cd9f5315..eb490495 100644
--- a/src/flac_builder.rs
+++ b/src/flac_builder.rs
@@ -11,7 +11,7 @@ impl FlacBuilder {
     streaminfo.extend_from_slice(&4096u16.to_be_bytes());
     streaminfo.extend_from_slice(&4096u16.to_be_bytes());
     streaminfo.extend_from_slice(&[0; 6]);
-    streaminfo.extend_from_slice(&[0x0A, 0xC4, 0x42, 0xF0]);
+    streaminfo.extend_from_slice(&[0x0a, 0xc4, 0x42, 0xf0]);
     streaminfo.extend_from_slice(&self.samples.to_be_bytes());
     streaminfo.extend_from_slice(&[0; 16]);
 
diff --git a/src/flac_decoder.rs b/src/flac_decoder.rs
index e9c2604f..a21d9701 100644
--- a/src/flac_decoder.rs
+++ b/src/flac_decoder.rs
@@ -54,7 +54,7 @@ impl<'a> Iterator for Blocks<'a> {
     Some(Ok(Block {
       body,
       end,
-      ty: header[0] & 0x7F,
+      ty: header[0] & 0x7f,
     }))
   }
 }
diff --git a/src/head.rs b/src/head.rs
index 01f77295..971594cd 100644
--- a/src/head.rs
+++ b/src/head.rs
@@ -54,7 +54,7 @@ impl Head {
       Self::Medium(len) => {
         if len == 1 {
           ensure! {
-            *buffer.get(1).context(decode_error::Truncated)? > 0x7F,
+            *buffer.get(1).context(decode_error::Truncated)? > 0x7f,
             decode_error::Overlong,
           }
         }
@@ -76,7 +76,7 @@ impl Head {
 
         if count == 1 {
           ensure! {
-            len > 0x6F,
+            len > 0x6f,
             decode_error::Overlong,
           }
         }
@@ -92,9 +92,9 @@ impl From<u8> for Head {
   fn from(head: u8) -> Self {
     match head {
       0x00..0x80 => Self::Small,
-      0x80..0xF0 => Self::Medium((head - 0x80).into()),
-      0xF0..0xF8 => Self::Large((head - 0xEF).into()),
-      0xF8..=0xFF => Self::Reserved(head),
+      0x80..0xf0 => Self::Medium((head - 0x80).into()),
+      0xf0..0xf8 => Self::Large((head - 0xef).into()),
+      0xf8..=0xff => Self::Reserved(head),
     }
   }
 }
@@ -130,13 +130,13 @@ mod tests {
 
   #[test]
   fn head_parse() {
-    for i in 0..=0xFF {
+    for i in 0..=0xff {
       let head = Head::from(i);
       match i {
         0x00..0x80 => assert_eq!(head, Head::Small),
-        0x80..0xF0 => assert_eq!(head, Head::Medium((i - 0x80).into())),
-        0xF0..0xF8 => assert_eq!(head, Head::Large((i - 0xEF).into())),
-        0xF8..=0xFF => assert_eq!(head, Head::Reserved(i)),
+        0x80..0xf0 => assert_eq!(head, Head::Medium((i - 0x80).into())),
+        0xf0..0xf8 => assert_eq!(head, Head::Large((i - 0xef).into())),
+        0xf8..=0xff => assert_eq!(head, Head::Reserved(i)),
       }
     }
   }
diff --git a/src/jpeg_builder.rs b/src/jpeg_builder.rs
index 1cc32088..7a28038e 100644
--- a/src/jpeg_builder.rs
+++ b/src/jpeg_builder.rs
@@ -14,7 +14,7 @@ pub(crate) struct JpegBuilder {
 
 impl JpegBuilder {
   fn app1(header: &[u8], payload: &[u8]) -> Vec<u8> {
-    let mut segment = vec![0xFF, 0xE1];
+    let mut segment = vec![0xff, 0xe1];
     segment.extend_from_slice(
       &u16::try_from(header.len() + payload.len() + 2)
         .unwrap()
@@ -39,7 +39,7 @@ impl JpegBuilder {
     let mut bytes = buffer.into_inner();
 
     if let Some(sampling) = self.sampling {
-      let sof = bytes.windows(2).position(|w| w == [0xFF, 0xC0]).unwrap();
+      let sof = bytes.windows(2).position(|w| w == [0xff, 0xc0]).unwrap();
       bytes[sof + 11] = sampling;
     }
 
diff --git a/src/mp3_builder.rs b/src/mp3_builder.rs
index b0ecfbeb..f510716f 100644
--- a/src/mp3_builder.rs
+++ b/src/mp3_builder.rs
@@ -102,7 +102,7 @@ impl Mp3Builder {
   }
 
   fn standard() -> Vec<u8> {
-    let mut bytes = vec![0xFF, 0xFB, 0x90, 0x00];
+    let mut bytes = vec![0xff, 0xfb, 0x90, 0x00];
     bytes.resize(417, 0);
     bytes
   }
@@ -110,10 +110,10 @@ impl Mp3Builder {
   fn syncsafe(n: usize) -> [u8; 4] {
     let n = u32::try_from(n).unwrap();
     [
-      u8::try_from((n >> 21) & 0x7F).unwrap(),
-      u8::try_from((n >> 14) & 0x7F).unwrap(),
-      u8::try_from((n >> 7) & 0x7F).unwrap(),
-      u8::try_from(n & 0x7F).unwrap(),
+      u8::try_from((n >> 21) & 0x7f).unwrap(),
+      u8::try_from((n >> 14) & 0x7f).unwrap(),
+      u8::try_from((n >> 7) & 0x7f).unwrap(),
+      u8::try_from(n & 0x7f).unwrap(),
     ]
   }
 
diff --git a/src/mp3_decoder.rs b/src/mp3_decoder.rs
index f83c0b3c..1e5d4b9a 100644
--- a/src/mp3_decoder.rs
+++ b/src/mp3_decoder.rs
@@ -86,7 +86,7 @@ impl<'a> Mp3Decoder<'a> {
       .unwrap();
 
     ensure! {
-      header[0] == 0xFF && header[1] & 0xE0 == 0xE0,
+      header[0] == 0xff && header[1] & 0xe0 == 0xe0,
       mp3_error::Sync { offset },
     }
 
@@ -479,44 +479,44 @@ mod tests {
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xEB, 0x90, 0x00], 417),
+      Mp3Builder::new().frame([0xff, 0xeb, 0x90, 0x00], 417),
       Mp3Error::Version,
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xF9, 0x90, 0x00], 417),
+      Mp3Builder::new().frame([0xff, 0xf9, 0x90, 0x00], 417),
       Mp3Error::LayerInvalid,
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xFD, 0x90, 0x00], 417),
+      Mp3Builder::new().frame([0xff, 0xfd, 0x90, 0x00], 417),
       Mp3Error::LayerUnsupported { layer: 2 },
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xFF, 0x90, 0x00], 417),
+      Mp3Builder::new().frame([0xff, 0xff, 0x90, 0x00], 417),
       Mp3Error::LayerUnsupported { layer: 1 },
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xFB, 0x00, 0x00], 417),
+      Mp3Builder::new().frame([0xff, 0xfb, 0x00, 0x00], 417),
       Mp3Error::Bitrate { index: 0 },
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xFB, 0xF0, 0x00], 417),
+      Mp3Builder::new().frame([0xff, 0xfb, 0xf0, 0x00], 417),
       Mp3Error::Bitrate { index: 15 },
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xFB, 0x9C, 0x00], 417),
+      Mp3Builder::new().frame([0xff, 0xfb, 0x9c, 0x00], 417),
       Mp3Error::SampleRate,
     );
 
     case(
       Mp3Builder::new()
         .frames(1)
-        .frame([0xFF, 0xFB, 0x90, 0xC0], 417),
+        .frame([0xff, 0xfb, 0x90, 0xc0], 417),
       Mp3Error::ChannelsMismatch {
         actual: 1,
         expected: 2,
@@ -526,7 +526,7 @@ mod tests {
     case(
       Mp3Builder::new()
         .frames(1)
-        .frame([0xFF, 0xFB, 0x94, 0x00], 384),
+        .frame([0xff, 0xfb, 0x94, 0x00], 384),
       Mp3Error::SampleRateMismatch {
         actual: 48000,
         expected: 44100,
@@ -597,7 +597,7 @@ mod tests {
 
     case(
       Mp3Builder::new()
-        .frame([0xFF, 0xFB, 0x92, 0x00], 418)
+        .frame([0xff, 0xfb, 0x92, 0x00], 418)
         .frames(1),
       AudioProperties {
         channels: 2,
@@ -608,7 +608,7 @@ mod tests {
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xFB, 0x90, 0xC0], 417),
+      Mp3Builder::new().frame([0xff, 0xfb, 0x90, 0xc0], 417),
       AudioProperties {
         channels: 1,
         sample_rate: 44100,
@@ -618,7 +618,7 @@ mod tests {
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xF3, 0x90, 0x00], 261),
+      Mp3Builder::new().frame([0xff, 0xf3, 0x90, 0x00], 261),
       AudioProperties {
         channels: 2,
         sample_rate: 22050,
@@ -628,7 +628,7 @@ mod tests {
     );
 
     case(
-      Mp3Builder::new().frame([0xFF, 0xE3, 0x90, 0x00], 522),
+      Mp3Builder::new().frame([0xff, 0xe3, 0x90, 0x00], 522),
       AudioProperties {
         channels: 2,
         sample_rate: 11025,
diff --git a/src/mp4_decoder.rs b/src/mp4_decoder.rs
index ead12fff..40438235 100644
--- a/src/mp4_decoder.rs
+++ b/src/mp4_decoder.rs
@@ -311,11 +311,11 @@ mod tests {
       Some(config(8, ChromaSubsampling::Yuv420)),
     );
     case(
-      &[0x67, 100, 0, 31, 0xA6],
+      &[0x67, 100, 0, 31, 0xa6],
       Some(config(10, ChromaSubsampling::Yuv420)),
     );
     case(
-      &[0x67, 100, 0, 31, 0xB8],
+      &[0x67, 100, 0, 31, 0xb8],
       Some(config(8, ChromaSubsampling::Yuv422)),
     );
     case(
@@ -323,11 +323,11 @@ mod tests {
       Some(config(8, ChromaSubsampling::Yuv444)),
     );
     case(
-      &[0x67, 100, 0, 31, 0xE0],
+      &[0x67, 100, 0, 31, 0xe0],
       Some(config(8, ChromaSubsampling::Yuv400)),
     );
     case(
-      &[0x67, 100, 0, 0, 0x03, 0xA6],
+      &[0x67, 100, 0, 0, 0x03, 0xa6],
       Some(config(10, ChromaSubsampling::Yuv420)),
     );
     case(&[0x67, 100, 0, 31], None);
@@ -475,7 +475,7 @@ mod tests {
     assert_eq!(
       case(
         Mp4Builder::new()
-          .sps(&[0x67, 100, 0, 31, 0xA6])
+          .sps(&[0x67, 100, 0, 31, 0xa6])
           .video_track(2, 1),
       )
       .unwrap()
diff --git a/src/orientation.rs b/src/orientation.rs
index c14373c7..26cd0864 100644
--- a/src/orientation.rs
+++ b/src/orientation.rs
@@ -168,7 +168,7 @@ mod tests {
   fn from_exif_big_endian() {
     assert_eq!(
       Orientation::from_exif(&[
-        0x4D, 0x4D, 0x00, 0x2A, 0x00, 0x00, 0x00, 0x08, 0x00, 0x01, 0x01, 0x12, 0x00, 0x03, 0x00,
+        0x4d, 0x4d, 0x00, 0x2a, 0x00, 0x00, 0x00, 0x08, 0x00, 0x01, 0x01, 0x12, 0x00, 0x03, 0x00,
         0x00, 0x00, 0x01, 0x00, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       ])
       .unwrap(),
@@ -194,15 +194,15 @@ mod tests {
     case(b"foo", "invalid byte order");
     case(b"II", "truncated EXIF data");
     case(
-      &[0x49, 0x49, 0x2B, 0x00, 0x08, 0x00, 0x00, 0x00],
+      &[0x49, 0x49, 0x2b, 0x00, 0x08, 0x00, 0x00, 0x00],
       "expected magic 42 but found 43",
     );
     case(
-      &[0x49, 0x49, 0x2A, 0x00, 0x08, 0x00, 0x00, 0x00],
+      &[0x49, 0x49, 0x2a, 0x00, 0x08, 0x00, 0x00, 0x00],
       "truncated EXIF data",
     );
     case(
-      &[0x49, 0x49, 0x2A, 0x00, 0x08, 0x00, 0x00, 0x00, 0x01, 0x00],
+      &[0x49, 0x49, 0x2a, 0x00, 0x08, 0x00, 0x00, 0x00, 0x01, 0x00],
       "truncated EXIF data",
     );
     case(&exif(0), "invalid orientation value 0");
@@ -226,7 +226,7 @@ mod tests {
 
     assert_eq!(
       Orientation::from_exif(&[
-        0x49, 0x49, 0x2A, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+        0x49, 0x49, 0x2a, 0x00, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
       ])
       .unwrap(),
       Orientation::new(),
diff --git a/src/webm_builder.rs b/src/webm_builder.rs
index f951c4cd..68355b84 100644
--- a/src/webm_builder.rs
+++ b/src/webm_builder.rs
@@ -10,10 +10,10 @@ pub(crate) struct WebmBuilder {
 impl WebmBuilder {
   pub(crate) fn audio_settings(channels: u64, sampling_frequency: f64) -> Vec<u8> {
     Self::element(
-      &[0xE1],
+      &[0xe1],
       &[
-        Self::unsigned(&[0x9F], channels),
-        Self::float(&[0xB5], sampling_frequency),
+        Self::unsigned(&[0x9f], channels),
+        Self::float(&[0xb5], sampling_frequency),
       ]
       .concat(),
     )
@@ -36,7 +36,7 @@ impl WebmBuilder {
     let info = [
       self
         .timestamp_scale
-        .map(|timestamp_scale| Self::unsigned(&[0x2A, 0xD7, 0xB1], timestamp_scale))
+        .map(|timestamp_scale| Self::unsigned(&[0x2a, 0xd7, 0xb1], timestamp_scale))
         .unwrap_or_default(),
       self
         .duration
@@ -45,22 +45,22 @@ impl WebmBuilder {
       self
         .title
         .as_deref()
-        .map(|title| Self::string(&[0x7B, 0xA9], title))
+        .map(|title| Self::string(&[0x7b, 0xa9], title))
         .unwrap_or_default(),
-      Self::string(&[0x4D, 0x80], "foo"),
+      Self::string(&[0x4d, 0x80], "foo"),
       Self::string(&[0x57, 0x41], "bar"),
     ]
     .concat();
 
     let segment = [
-      Self::element(&[0x15, 0x49, 0xA9, 0x66], &info),
-      Self::element(&[0x16, 0x54, 0xAE, 0x6B], &self.tracks.concat()),
-      Self::element(&[0x1F, 0x43, 0xB6, 0x75], &self.blocks.concat()),
+      Self::element(&[0x15, 0x49, 0xa9, 0x66], &info),
+      Self::element(&[0x16, 0x54, 0xae, 0x6b], &self.tracks.concat()),
+      Self::element(&[0x1f, 0x43, 0xb6, 0x75], &self.blocks.concat()),
     ]
     .concat();
 
     [
-      Self::element(&[0x1A, 0x45, 0xDF, 0xA3], &header),
+      Self::element(&[0x1a, 0x45, 0xdf, 0xa3], &header),
       Self::element(&[0x18, 0x53, 0x80, 0x67], &segment),
     ]
     .concat()
@@ -97,7 +97,7 @@ impl WebmBuilder {
     payload.push(0x80);
     payload.extend_from_slice(data);
 
-    self.blocks.push(Self::element(&[0xA3], &payload));
+    self.blocks.push(Self::element(&[0xa3], &payload));
 
     self
   }
@@ -140,15 +140,15 @@ impl WebmBuilder {
     let number = u64::try_from(self.tracks.len() + 1).unwrap();
 
     let entry = [
-      Self::unsigned(&[0xD7], number),
-      Self::unsigned(&[0x73, 0xC5], number),
+      Self::unsigned(&[0xd7], number),
+      Self::unsigned(&[0x73, 0xc5], number),
       Self::unsigned(&[0x83], ty),
       Self::string(&[0x86], codec_id),
       settings.to_vec(),
     ]
     .concat();
 
-    self.tracks.push(Self::element(&[0xAE], &entry));
+    self.tracks.push(Self::element(&[0xae], &entry));
 
     self
   }
@@ -159,10 +159,10 @@ impl WebmBuilder {
 
   pub(crate) fn video_settings(width: u64, height: u64) -> Vec<u8> {
     Self::element(
-      &[0xE0],
+      &[0xe0],
       &[
-        Self::unsigned(&[0xB0], width),
-        Self::unsigned(&[0xBA], height),
+        Self::unsigned(&[0xb0], width),
+        Self::unsigned(&[0xba], height),
       ]
       .concat(),
     )
diff --git a/src/webm_decoder.rs b/src/webm_decoder.rs
index bf374e14..7f379869 100644
--- a/src/webm_decoder.rs
+++ b/src/webm_decoder.rs
@@ -672,24 +672,24 @@ mod tests {
       Some(config(12, ChromaSubsampling::Yuv420)),
     );
     case(
-      &[0xA2, 0x49, 0x83, 0x42, 0x08],
+      &[0xa2, 0x49, 0x83, 0x42, 0x08],
       Some(config(8, ChromaSubsampling::Yuv422)),
     );
     case(
-      &[0xA2, 0x49, 0x83, 0x42, 0x04],
+      &[0xa2, 0x49, 0x83, 0x42, 0x04],
       Some(config(8, ChromaSubsampling::Yuv440)),
     );
     case(
-      &[0xA2, 0x49, 0x83, 0x42, 0x00],
+      &[0xa2, 0x49, 0x83, 0x42, 0x00],
       Some(config(8, ChromaSubsampling::Yuv444)),
     );
     case(
-      &[0xA2, 0x49, 0x83, 0x42, 0xE0],
+      &[0xa2, 0x49, 0x83, 0x42, 0xe0],
       Some(config(8, ChromaSubsampling::Yuv444)),
     );
-    case(&[0xA2, 0x49, 0x83, 0x42, 0x0C], None);
-    case(&[0xA2, 0x49, 0x83, 0x42, 0x0A], None);
-    case(&[0x82, 0x49, 0x83, 0x42, 0xE0], None);
+    case(&[0xa2, 0x49, 0x83, 0x42, 0x0c], None);
+    case(&[0xa2, 0x49, 0x83, 0x42, 0x0a], None);
+    case(&[0x82, 0x49, 0x83, 0x42, 0xe0], None);
     case(&[0x82, 0x49, 0x83, 0x42], None);
     case(&[0x84, 0x49, 0x83, 0x42], None);
     case(&[0x88, 0x49, 0x83, 0x42], None);