transcode: Tolerate mpeg errors when re-encoding to I-frames around c…

…ut points

If a recording has a cutlist and is transcoded using that cutlist then
if there are MPEG decoding errors around the cut point the process of
re-coding to I frames can fail and the whole transcoding fails.

This patch makes the function MPEG2fixup::ConvertToI tolerant to
decoding errors and just skips the offending frames.

Fixes #10863

Signed-off-by: Lawrence Rust <lvr@softsystem.co.uk>
Signed-off-by: Gavin Hurlbut <ghurlbut@mythtv.org>

mythtv/programs/mythtranscode/mpeg2fix.cpp

@@ -1655,7 +1655,11 @@ int MPEG2fixup::ConvertToI(FrameList *orderedFrames, int headPos)
     {
         int i = GetFrameNum((*it));
         if ((spare = DecodeToFrame(i, headPos == 0)) == NULL)
-            return 1;
+        {
+            LOG(VB_GENERAL, LOG_WARNING,
+                QString("ConvertToI skipping undecoded frame #%1").arg(i));
+            continue;
+        }
 
         if (GetFrameTypeT(spare) == 'I')
             continue;