scan: increase sensitivity to video flags

We were mis-detecting framerate often because we did not see enough
samples of various video flags while scanning previews.  So move
sampling of these flags into the inner video decode loop and collect
more samples.

1 files changed, 34 insertions, 26 deletions

diff --git a/libhb/scan.c b/libhb/scan.c
index 34805a30a..53f03daa1 100644
--- a/libhb/scan.c
+++ b/libhb/scan.c
@@ -524,6 +524,7 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title, int flush )
     int                pulldown_count = 0;
     int                doubled_frame_count = 0;
     int                interlaced_preview_count = 0;
+    int                vid_samples = 0;
     int                frame_wait = 0;
     int                cc_wait = 10;
     int                frames;
@@ -732,6 +733,36 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title, int flush )
                     //    additional frames to find the CCs.
                     if (vid_buf != NULL && (frame_wait || cc_wait))
                     {
+                        hb_work_info_t vid_info;
+                        if (vid_decoder->info(vid_decoder, &vid_info))
+                        {
+                            if (is_close_to(vid_info.rate.den, 900900, 100) &&
+                                (vid_buf->s.flags & PIC_FLAG_REPEAT_FIRST_FIELD))
+                            {
+                                /* Potentially soft telecine material */
+                                pulldown_count++;
+                            }
+
+                            if (vid_buf->s.flags & PIC_FLAG_REPEAT_FRAME)
+                            {
+                                // AVCHD-Lite specifies that all streams are
+                                // 50 or 60 fps.  To produce 25 or 30 fps, camera
+                                // makers are repeating all frames.
+                                doubled_frame_count++;
+                            }
+
+                            if (is_close_to(vid_info.rate.den, 1126125, 100 ))
+                            {
+                                // Frame FPS is 23.976 (meaning it's
+                                // progressive), so start keeping track of
+                                // how many are reporting at that speed. When
+                                // enough show up that way, we want to make
+                                // that the overall title FPS.
+                                progressive_count++;
+                            }
+                            vid_samples++;
+                        }
+
                         if (frames > 0 && vid_buf->s.frametype == HB_FRAME_I)
                             frame_wait = 0;
                         if (frame_wait || cc_wait)
@@ -781,29 +812,6 @@ static int DecodePreviews( hb_scan_t * data, hb_title_t * title, int flush )
 
         remember_info( info_list, &vid_info );
 
-        if( is_close_to( vid_info.rate.den, 900900, 100 ) &&
-            ( vid_buf->s.flags & PIC_FLAG_REPEAT_FIRST_FIELD ) )
-        {
-            /* Potentially soft telecine material */
-            pulldown_count++;
-        }
-
-        if( vid_buf->s.flags & PIC_FLAG_REPEAT_FRAME )
-        {
-            // AVCHD-Lite specifies that all streams are
-            // 50 or 60 fps.  To produce 25 or 30 fps, camera
-            // makers are repeating all frames.
-            doubled_frame_count++;
-        }
-
-        if( is_close_to( vid_info.rate.den, 1126125, 100 ) )
-        {
-            // Frame FPS is 23.976 (meaning it's progressive), so start keeping
-            // track of how many are reporting at that speed. When enough 
-            // show up that way, we want to make that the overall title FPS.
-            progressive_count++;
-        }
-
         hb_buffer_list_close(&list_es);
 
         /* Check preview for interlacing artifacts */
@@ -949,12 +957,12 @@ skip_preview:
             title->vrate = vid_info.rate;
             if( vid_info.rate.den == 900900 )
             {
-                if( npreviews >= 4 && pulldown_count >= npreviews / 4 )
+                if (vid_samples >= 4 && pulldown_count >= vid_samples / 4)
                 {
                     title->vrate.den = 1126125;
                     hb_deep_log( 2, "Pulldown detected, setting fps to 23.976" );
                 }
-                if( npreviews >= 2 && progressive_count >= npreviews / 2 )
+                if (vid_samples >= 2 && progressive_count >= vid_samples / 2)
                 {
                     // We've already deduced that the frame rate is 23.976,
                     // so set it back again.
@@ -962,7 +970,7 @@ skip_preview:
                     hb_deep_log( 2, "Title's mostly NTSC Film, setting fps to 23.976" );
                 }
             }
-            if( npreviews >= 2 && doubled_frame_count >= 3 * npreviews / 4 )
+            if (vid_samples >= 2 && doubled_frame_count >= 3 * vid_samples / 4)
             {
                 // We've detected that a significant number of the frames
                 // have been doubled in duration by repeat flags.