[FIX] Widen avc cc_count to uint16_t/u16 to prevent overflow on multi-SEI frames

src/lib_ccx/avc_functions.h

@@ -1,9 +1,11 @@
 #ifndef AVC_FUNCTION_H
 #define AVC_FUNCTION_H
 
+#include <stdint.h>
+
 struct avc_ctx
 {
-	unsigned char cc_count;
+	uint16_t cc_count;
 	// buffer to hold cc data
 	unsigned char *cc_data;
 	int64_t cc_databufsize;

src/rust/src/avc/common_types.rs

@@ -4,7 +4,7 @@ pub const MAXBFRAMES: i32 = 50;
 
 #[derive(Debug, Clone)]
 pub struct AvcContextRust {
-    pub cc_count: u8,
+    pub cc_count: u16,
     pub cc_data: Vec<u8>,
     pub cc_databufsize: usize,
     pub cc_buffer_saved: bool,

src/rust/src/avc/core.rs

@@ -442,7 +442,7 @@ pub fn copy_ccdata_to_buffer(ctx: &mut AvcContextRust, source: &[u8], new_cc_cou
 
     if start_idx + copy_len <= ctx.cc_data.len() {
         ctx.cc_data[start_idx..start_idx + copy_len].copy_from_slice(&source[..copy_len]);
-        ctx.cc_count += new_cc_count as u8;
+        ctx.cc_count += new_cc_count as u16;
         ctx.cc_buffer_saved = false;
     }
 }
@@ -796,4 +796,18 @@ mod tests {
         let buf = [0x00, 0x00, 0x02, 0x00, 0x00, 0x01, 0x65];
         assert_eq!(find_nal_start_code(&buf), Some(5));
     }
+
+    #[test]
+    fn test_copy_ccdata_to_buffer_beyond_u8_max() {
+        let mut ctx = AvcContextRust::default();
+        ctx.cc_data = vec![0u8; 1024];
+        ctx.cc_databufsize = 1024;
+        ctx.cc_count = 250;
+
+        let dummy_source = vec![0xFA; 64]; // 20 triplets = 60 + 1 = 61 bytes
+        copy_ccdata_to_buffer(&mut ctx, &dummy_source, 20);
+
+        // 250 + 20 = 270 triplets. If it were u8, it would wrap to 14.
+        assert_eq!(ctx.cc_count, 270);
+    }
 }