tttocea608: be more conservative when inserting spaces

We don't need to insert a space when starting a new line,
or before punctuation.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/474>

1 files changed, 10 insertions, 0 deletions

diff --git a/video/closedcaption/src/tttocea608/imp.rs b/video/closedcaption/src/tttocea608/imp.rs
index 50be30821..f6d61d539 100644
--- a/video/closedcaption/src/tttocea608/imp.rs
+++ b/video/closedcaption/src/tttocea608/imp.rs
@@ -29,6 +29,10 @@ use std::sync::Mutex;
 
 use crate::ttutils::{Cea608Mode, Chunk, Line, Lines, TextStyle};
 
+fn is_punctuation(word: &str) -> bool {
+    word == "." || word == "," || word == "?" || word == "!" || word == ";" || word == ":"
+}
+
 fn is_basicna(cc_data: u16) -> bool {
     0x0000 != (0x6000 & cc_data)
 }
@@ -525,6 +529,8 @@ impl TtToCea608 {
             state.underline = chunk.underline;
             state.send_roll_up_preamble = false;
             ret = false;
+        } else if *col == self.settings.lock().unwrap().origin_column {
+            ret = false;
         }
 
         if self.open_chunk(element, state, chunk, bufferlist, *col) {
@@ -657,6 +663,10 @@ impl TtToCea608 {
                     col += 1;
                 }
 
+                if is_punctuation(&chunk.text) {
+                    prepend_space = false;
+                }
+
                 let text = {
                     if prepend_space {
                         let mut text = " ".to_string();