From 56bc156be4ce11f3cc6250563ddd4f391865a589 Mon Sep 17 00:00:00 2001
From: Rafael Caricio <rafael@caricio.com>
Date: Wed, 11 May 2022 23:17:43 +0200
Subject: [PATCH] Define Splice Descriptor using Deku

Implements the generic Splice Descriptor definition using the Deku
declarative library macros.

I've implemented only the generic variant of the Splice Descriptors to
check how it would look like using Deku.
---
 src/data.rs | 84 ++++++++++++++++++++++++++++++++++++++++++++---------
 src/time.rs |  4 +--
 2 files changed, 71 insertions(+), 17 deletions(-)

diff --git a/src/data.rs b/src/data.rs
index 09af197..e741cae 100644
--- a/src/data.rs
+++ b/src/data.rs
@@ -1,34 +1,25 @@
 use deku::prelude::*;
 
 #[derive(Debug, Clone, PartialEq, DekuRead, DekuWrite)]
-#[deku(endian = "big", type="u8", bits = "1")]
+#[deku(endian = "big", type = "u8", bits = "1")]
 pub(crate) enum SpliceTime {
-
     #[deku(id = "1")]
     TimeSpecified {
-
         #[deku(bits = "6", assert_eq = "0x3f")]
         reserved: u8,
-
         #[deku(bits = "33")]
         pts_time: u64,
-
     },
-
     #[deku(id = "0")]
     NoTimeSpecified {
-
         #[deku(bits = "7", assert_eq = "0x7f")]
         reserved: u8,
-
-    }
+    },
 }
 
 impl Default for SpliceTime {
     fn default() -> Self {
-        Self::NoTimeSpecified {
-            reserved: 0x7f
-        }
+        Self::NoTimeSpecified { reserved: 0x7f }
     }
 }
 
@@ -36,11 +27,44 @@ impl SpliceTime {
     fn new(pts_time: u64) -> Self {
         Self::TimeSpecified {
             reserved: 0x3f,
-            pts_time
+            pts_time,
         }
     }
 }
 
+#[derive(Debug, Clone, PartialEq, DekuRead, DekuWrite)]
+#[deku(type = "u8")]
+pub(crate) enum SpliceDescriptor {
+    // #[deku(id = "0x02")]
+    // SegmentationDescriptor {
+    //     #[deku(update = "deku::rest")]
+    //     descriptor_length: u8,
+    //     identifier: u32,
+    //
+    // },
+    #[deku(id_pat = "_")]
+    Template(GenericDescriptor),
+}
+
+impl SpliceDescriptor {
+    pub(crate) fn update(&mut self) -> Result<(), deku::DekuError> {
+        match self {
+            SpliceDescriptor::Template(s) => s.update(),
+        }
+    }
+}
+
+#[derive(Debug, Clone, PartialEq, DekuRead, DekuWrite)]
+#[deku(endian = "big")]
+pub(crate) struct GenericDescriptor {
+    id: u8,
+    #[deku(update = "self.private_bytes.len() + 2")]
+    descriptor_length: u8,
+    identifier: u32,
+    #[deku(count = "descriptor_length - 2")]
+    private_bytes: Vec<u8>,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
@@ -68,4 +92,36 @@ mod tests {
 
         assert_eq!(st, SpliceTime::new(0x072bd0050));
     }
-}
\ No newline at end of file
+
+    #[test]
+    fn write_generic_descriptor() {
+        let mut sd = SpliceDescriptor::Template(GenericDescriptor {
+            id: 0xff,
+            descriptor_length: 0,
+            identifier: 0x43554549,
+            private_bytes: vec![0x01],
+        });
+
+        sd.update().unwrap();
+
+        let data: Vec<u8> = sd.try_into().unwrap();
+
+        assert_eq!(hex::encode(data.as_slice()), "ff034355454901");
+    }
+
+    #[test]
+    fn read_generic_descriptor() {
+        let data = hex::decode("ff034355454901").unwrap();
+        let sd = SpliceDescriptor::try_from(data.as_slice()).unwrap();
+
+        assert_eq!(
+            sd,
+            SpliceDescriptor::Template(GenericDescriptor {
+                id: 0xff,
+                descriptor_length: 3,
+                identifier: 0x43554549,
+                private_bytes: vec![0x01]
+            })
+        );
+    }
+}
diff --git a/src/time.rs b/src/time.rs
index 7f48633..8b7ccf7 100644
--- a/src/time.rs
+++ b/src/time.rs
@@ -87,7 +87,6 @@ mod test {
 
     #[test]
     fn encode_time_signal() {
-
         let mut st = SpliceTime::default();
 
         let mut data = Vec::new();
@@ -98,7 +97,6 @@ mod test {
 
     #[test]
     fn encode_time_signal_with_time() {
-
         let mut st = SpliceTime::from(0x072bd0050);
 
         let mut data = Vec::new();
@@ -106,4 +104,4 @@ mod test {
 
         assert_eq!(hex::encode(data.as_slice()), "fe72bd0050")
     }
-}
\ No newline at end of file
+}