From d6fa9218227f5e208dcd1641445630daaea6afe9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sebastian=20Dr=C3=B6ge?= <sebastian@centricular.com>
Date: Thu, 19 May 2022 13:26:34 +0300
Subject: [PATCH] fmp4mux: Use saturing_sub() in more places

On unclean input, PTS/DTS might go backwards a bit and in those cases
calculate a duration of 0 instead of panicking.
---
 generic/fmp4/src/fmp4mux/imp.rs | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/generic/fmp4/src/fmp4mux/imp.rs b/generic/fmp4/src/fmp4mux/imp.rs
index d5ecd411..0fef270c 100644
--- a/generic/fmp4/src/fmp4mux/imp.rs
+++ b/generic/fmp4/src/fmp4mux/imp.rs
@@ -414,7 +414,7 @@ impl FMP4Mux {
                 CAT,
                 obj: &stream.sinkpad,
                 "Queued full GOPs duration updated to {}",
-                prev_gop.end_pts - first_gop.earliest_pts,
+                prev_gop.end_pts.saturating_sub(first_gop.earliest_pts),
             );
         }
 
@@ -423,7 +423,7 @@ impl FMP4Mux {
             obj: &stream.sinkpad,
             "Queued duration updated to {}",
             Option::zip(stream.queued_gops.front(), stream.queued_gops.back())
-                .map(|(end, start)| end.end_pts - start.start_pts)
+                .map(|(end, start)| end.end_pts.saturating_sub(start.start_pts))
                 .unwrap_or(gst::ClockTime::ZERO)
         );
 
@@ -589,7 +589,7 @@ impl FMP4Mux {
                     CAT,
                     obj: &stream.sinkpad,
                     "Draining {} worth of buffers starting at PTS {} DTS {}, DTS offset {}",
-                    end_pts - earliest_pts,
+                    end_pts.saturating_sub(earliest_pts),
                     earliest_pts,
                     start_dts.display(),
                     dts_offset.display(),
@@ -603,7 +603,7 @@ impl FMP4Mux {
                         CAT,
                         obj: &stream.sinkpad,
                         "Queued full GOPs duration updated to {}",
-                        prev_gop.end_pts - first_gop.earliest_pts,
+                        prev_gop.end_pts.saturating_sub(first_gop.earliest_pts),
                     );
                 }
 
@@ -612,7 +612,7 @@ impl FMP4Mux {
                     obj: &stream.sinkpad,
                     "Queued duration updated to {}",
                     Option::zip(stream.queued_gops.front(), stream.queued_gops.back())
-                        .map(|(end, start)| end.end_pts - start.start_pts)
+                        .map(|(end, start)| end.end_pts.saturating_sub(start.start_pts))
                         .unwrap_or(gst::ClockTime::ZERO)
                 );