repeat=true: give more helpful error message (#53)

Author: Asd-g

AviSynth/lwlibav_source.cpp

@@ -151,16 +151,17 @@ LWLibavVideoSource::LWLibavVideoSource
     indicator.update = (progress) ? update_indicator : NULL;
     indicator.close  = (progress) ? close_indicator : NULL;
     /* Construct index. */
+    const int orig_apply_repeat_flag = opt->apply_repeat_flag;
     int ret = lwlibav_construct_index( &lwh, vdhp, vohp, adhp.get(), aohp.get(), lhp, opt, &indicator, NULL );
     free_audio_decode_handler();
     free_audio_output_handler();
     if (ret < 0)
         env->ThrowError("LWLibavVideoSource: failed to construct index for %s.", lwh.file_path );
     /* Eliminate silent failure: if apply_repeat_flag == 1, then fail if repeat is not applied. */
-    if (opt->apply_repeat_flag == 1)
+    if (orig_apply_repeat_flag == 1)
     {
         if (vohp->repeat_requested && !vohp->repeat_control)
-            env->ThrowError("LWLibavVideoSource: repeat requested for %d frames by input video, but unable to obey (try repeat=false to get a VFR clip).", vohp->repeat_requested);
+            env->ThrowError("LWLibavVideoSource: frame %d has mismatched field order (try repeat=false to get a VFR clip).", opt->apply_repeat_flag);
     }
     /* Get the desired video track. */
     if( lwlibav_video_get_desired_track( lwh.file_path, vdhp, lwh.threads ) < 0 )

VapourSynth/lwlibav_source.c

@@ -426,12 +426,12 @@ void VS_CC vs_lwlibavsource_create( const VSMap *in, VSMap *out, void *user_data
         return;
     }
     /* Eliminate silent failure: if apply_repeat_flag == 1, then fail if repeat is not applied. */
-    if ( opt.apply_repeat_flag == 1 )
+    if ( apply_repeat_flag == 1 )
     {
         if ( vohp->repeat_requested && !vohp->repeat_control )
         {
             free_handler( &hp );
-            set_error_on_init( out, vsapi, "lsmas: repeat requested for %d frames by input video, but unable to obey (try repeat=0 to get a VFR clip).", vohp->repeat_requested );
+            set_error_on_init( out, vsapi, "lsmas: frame %d has mismatched field order (try repeat=0 to get a VFR clip).", opt.apply_repeat_flag );
             return;
         }
     }

common/lwindex.c

@@ -1009,8 +1009,11 @@ static void create_video_frame_order_list
                 complete_frame ^= 1;
                 order_count    -= 1;
             }
-            else if( !repeat_field )
+            else if (!repeat_field)
+            {
+                opt->apply_repeat_flag = i;
                 goto disable_repeat;
+            }
         }
         if( opt->apply_repeat_flag )
             switch( repeat_pict )