rust: add SMPTE-TT encoder skeleton

Author: dhanush varma

src/rust/src/encoder/mod.rs

@@ -7,6 +7,8 @@ use std::os::raw::{c_int, c_uchar};
 pub mod common;
 pub mod g608;
 pub mod simplexml;
+pub mod smptett;
+
 /// # Safety
 /// This function is unsafe because it deferences to raw pointers and performs operations on pointer slices.
 #[no_mangle]

src/rust/src/encoder/smptett.rs

@@ -0,0 +1,75 @@
+use crate::bindings::{
+    cc_subtitle,
+    eia608_screen,
+    encoder_ctx,
+};
+
+use crate::encoder::common::encode_line;
+use crate::libccxr_exports::time::ccxr_millis_to_time;
+
+use std::os::raw::c_int;
+
+/// Core helper: write a SMPTE-TT paragraph from text + times
+fn write_stringz_as_smptett(
+    text: &str,
+    context: &mut encoder_ctx,
+    ms_start: i64,
+    ms_end: i64,
+) {
+    let mut h1 = 0;
+    let mut m1 = 0;
+    let mut s1 = 0;
+    let mut ms1 = 0;
+
+    let mut h2 = 0;
+    let mut m2 = 0;
+    let mut s2 = 0;
+    let mut ms2 = 0;
+
+    unsafe {
+        ccxr_millis_to_time(ms_start, &mut h1, &mut m1, &mut s1, &mut ms1);
+        ccxr_millis_to_time(ms_end, &mut h2, &mut m2, &mut s2, &mut ms2);
+    }
+
+    let header = format!(
+        "<p begin=\"{:02}:{:02}:{:02}.{:03}\" end=\"{:02}:{:02}:{:02}.{:03}\">",
+        h1, m1, s1, ms1,
+        h2, m2, s2, ms2
+    );
+
+    encode_line(context, &mut context.buffer, header.as_bytes());
+
+        encode_line(context, &mut context.buffer, line.as_bytes());
+    encode_line(context, &mut context.buffer, &context.encoded_crlf);
+}
+for line in text.split('\n') {
+    encode_line(context, &mut context.buffer, line.as_bytes());
+    encode_line(context, &mut context.buffer, &context.encoded_crlf[..]);
+}
+
+    encode_line(context, &mut context.buffer, b"</p>");
+}
+
+/// SMPTE-TT encoder entry for CC buffer (CEA-608)
+pub fn write_cc_buffer_as_smptett(
+    _data: &mut eia608_screen,
+    _context: &mut encoder_ctx,
+) -> c_int {
+    0
+}
+
+/// SMPTE-TT encoder entry for subtitle list (text-based)
+pub fn write_cc_subtitle_as_smptett(
+    _sub: &mut cc_subtitle,
+    _context: &mut encoder_ctx,
+) -> c_int {
+    0
+}
+
+/// SMPTE-TT encoder entry for bitmap subtitles (OCR)
+pub fn write_cc_bitmap_as_smptett(
+    _sub: &mut cc_subtitle,
+    _context: &mut encoder_ctx,
+) -> c_int {
+    0
+}