sync: sanitize subtitles in OutputBuffer

1 files changed, 53 insertions, 31 deletions

diff --git a/libhb/sync.c b/libhb/sync.c
index ad27ac755..5320c7131 100644
--- a/libhb/sync.c
+++ b/libhb/sync.c
@@ -150,6 +150,9 @@ static void UpdateSearchState( sync_common_t * common, int64_t start,
                                int frame_count );
 static hb_buffer_t * FilterAudioFrame( sync_stream_t * stream,
                                        hb_buffer_t *buf );
+static hb_buffer_t * sanitizeSubtitle(sync_stream_t        * stream,
+                                      hb_buffer_t          * sub);
+
 
 static int fillQueues( sync_common_t * common )
 {
@@ -724,6 +727,29 @@ static void streamFlush( sync_stream_t * stream )
             if (stream->type == SYNC_TYPE_AUDIO)
             {
                 buf = FilterAudioFrame(stream, buf);
+                if (buf == NULL)
+                {
+                    // FilterAudioFrame can consume the buffer with no output
+                    continue;
+                }
+            }
+            int64_t subtitle_next_pts = AV_NOPTS_VALUE;
+            if (stream->type == SYNC_TYPE_SUBTITLE)
+            {
+                buf = sanitizeSubtitle(stream, buf);
+                if (buf == NULL)
+                {
+                    // sanitizeSubtitle can consume the buffer with no output
+                    continue;
+                }
+                // sanitizeSubtitle can return a list of subtitles.
+                // Find the pts of the last subtitle in the list
+                hb_buffer_t * sub = buf;
+                while (sub != NULL)
+                {
+                    subtitle_next_pts = sub->s.start;
+                    sub = sub->next;
+                }
             }
             if (stream->type == SYNC_TYPE_AUDIO ||
                 stream->type == SYNC_TYPE_VIDEO)
@@ -734,13 +760,7 @@ static void streamFlush( sync_stream_t * stream )
             }
             else
             {
-                // Last ditch effort to prevent timestamps from going backwards
-                // This can (and should only) affect subtitle streams.
-                if (buf->s.start < stream->next_pts)
-                {
-                    buf->s.start = stream->next_pts;
-                }
-                stream->next_pts = buf->s.start;
+                stream->next_pts = subtitle_next_pts;
             }
 
             if (buf->s.stop > 0)
@@ -1084,10 +1104,28 @@ static void OutputBuffer( sync_common_t * common )
             buf = FilterAudioFrame(out_stream, buf);
             if (buf == NULL)
             {
-                // FilterAudioFrame can conume the buffer with no output
+                // FilterAudioFrame can consume the buffer with no output
                 continue;
             }
         }
+        int64_t subtitle_next_pts = AV_NOPTS_VALUE;
+        if (out_stream->type == SYNC_TYPE_SUBTITLE)
+        {
+            buf = sanitizeSubtitle(out_stream, buf);
+            if (buf == NULL)
+            {
+                // sanitizeSubtitle can consume the buffer with no output
+                continue;
+            }
+            // sanitizeSubtitle can return a list of subtitles.
+            // Find the pts of the last subtitle in the list
+            hb_buffer_t * sub = buf;
+            while (sub != NULL)
+            {
+                subtitle_next_pts = sub->s.start;
+                sub = sub->next;
+            }
+        }
         if (out_stream->type == SYNC_TYPE_AUDIO ||
             out_stream->type == SYNC_TYPE_VIDEO)
         {
@@ -1097,21 +1135,9 @@ static void OutputBuffer( sync_common_t * common )
         }
         else
         {
-            // Last ditch effort to prevent timestamps from going backwards
-            // This can (and should only) affect subtitle streams.
-            if (buf->s.start < out_stream->next_pts)
-            {
-                buf->s.start = out_stream->next_pts;
-            }
-            if (buf->s.stop != AV_NOPTS_VALUE &&
-                buf->s.stop < out_stream->next_pts)
-            {
-                buf->s.stop = out_stream->next_pts;
-            }
-            out_stream->next_pts = buf->s.start;
+            out_stream->next_pts = subtitle_next_pts;
         }
 
-
         if (buf->s.stop > 0)
         {
             out_stream->current_duration = buf->s.stop -
@@ -2372,16 +2398,16 @@ static int syncSubtitleWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
 
     if (pv->common->done)
     {
-        hb_buffer_list_append(&pv->stream->out_queue, hb_buffer_eof_init());
-        in = hb_buffer_list_clear(&pv->stream->out_queue);
-        *buf_out = sanitizeSubtitle(pv->stream, in);
+        *buf_out = hb_buffer_list_clear(&pv->stream->out_queue);
         return HB_WORK_DONE;
     }
     if (in->s.flags & HB_BUF_FLAG_EOF)
     {
+        // sanitizeSubtitle requires EOF buffer to recognize that
+        // it needs to flush all subtitles.
+        hb_list_add(pv->stream->in_queue, hb_buffer_eof_init());
         streamFlush(pv->stream);
-        in = hb_buffer_list_clear(&pv->stream->out_queue);
-        *buf_out = sanitizeSubtitle(pv->stream, in);
+        *buf_out = hb_buffer_list_clear(&pv->stream->out_queue);
         if (pv->common->job->indepth_scan)
         {
             // When doing subtitle indepth scan, the pipeline ends at sync.
@@ -2394,11 +2420,7 @@ static int syncSubtitleWork( hb_work_object_t * w, hb_buffer_t ** buf_in,
     *buf_in = NULL;
     QueueBuffer(pv->stream, in);
     Synchronize(pv->common);
-    in = hb_buffer_list_clear(&pv->stream->out_queue);
-    if (in != NULL)
-    {
-        *buf_out = sanitizeSubtitle(pv->stream, in);
-    }
+    *buf_out = hb_buffer_list_clear(&pv->stream->out_queue);
 
     return HB_WORK_OK;
 }