From 02c77d2e44ee5389b1ea0dc1d4031c037c445b29 Mon Sep 17 00:00:00 2001
From: Seungha Yang <seungha@centricular.com>
Date: Fri, 16 Jun 2023 00:48:39 +0900
Subject: [PATCH] mccparse: Map timecode to PTS directly without offset

Assumes that caption stream's timeline starts from zero,
and maps timecode time_since_daily_jam() to PTS directly without
subtracting the first seen timecode.

Part-of: <https://gitlab.freedesktop.org/gstreamer/gst-plugins-rs/-/merge_requests/1246>
---
 video/closedcaption/src/mcc_parse/imp.rs | 18 ------------------
 1 file changed, 18 deletions(-)

diff --git a/video/closedcaption/src/mcc_parse/imp.rs b/video/closedcaption/src/mcc_parse/imp.rs
index 6bbbf0d9..99fcbcaf 100644
--- a/video/closedcaption/src/mcc_parse/imp.rs
+++ b/video/closedcaption/src/mcc_parse/imp.rs
@@ -60,7 +60,6 @@ struct State {
     format: Option<Format>,
     need_segment: bool,
     pending_events: Vec<gst::Event>,
-    start_position: Option<gst::ClockTime>,
     last_position: Option<gst::ClockTime>,
     last_timecode: Option<gst_video::ValidVideoTimeCode>,
     timecode_rate: Option<(u8, bool)>,
@@ -86,7 +85,6 @@ impl Default for State {
             format: None,
             need_segment: true,
             pending_events: Vec::new(),
-            start_position: None,
             last_position: None,
             last_timecode: None,
             timecode_rate: None,
@@ -204,21 +202,6 @@ impl State {
     /// not produce timestamps jumping backwards
     fn update_timestamp(&mut self, imp: &MccParse, timecode: &gst_video::ValidVideoTimeCode) {
         let nsecs = timecode.time_since_daily_jam();
-        if self.start_position.is_none() {
-            self.start_position = Some(nsecs);
-        }
-        let start_position = self.start_position.expect("checked above");
-
-        let nsecs = nsecs.checked_sub(start_position).unwrap_or_else(|| {
-            gst::fixme!(
-                CAT,
-                imp: imp,
-                "New position {} < start position {}",
-                nsecs,
-                start_position,
-            );
-            start_position
-        });
 
         if self
             .last_position
@@ -849,7 +832,6 @@ impl MccParse {
         state.segment = gst::FormattedSegment::new();
         state.need_segment = true;
         state.pending_events.clear();
-        state.start_position = Some(gst::ClockTime::ZERO);
         state.last_position = None;
         state.last_timecode = None;
         state.timecode_rate = None;