Fix building previous versions

Author: AdrianEddy

src/codec/context.rs

@@ -102,7 +102,9 @@ impl Context {
             (*self.as_mut_ptr()).thread_type = config.kind.into();
             (*self.as_mut_ptr()).thread_count = config.count as c_int;
             #[cfg(not(feature = "ffmpeg_6_0"))]
-            { (*self.as_mut_ptr()).thread_safe_callbacks = if config.safe { 1 } else { 0 }; }
+            {
+                (*self.as_mut_ptr()).thread_safe_callbacks = if config.safe { 1 } else { 0 };
+            }
         }
     }
 

src/filter/filter.rs

@@ -47,7 +47,12 @@ impl Filter {
             if ptr.is_null() {
                 None
             } else {
-                Some(PadIter::new((*self.as_ptr()).inputs, (*self.as_ptr()).nb_inputs as isize))
+                #[cfg(not(feature = "ffmpeg_6_0"))]
+                let nb_inputs = avfilter_pad_count((*self.as_ptr()).inputs) as isize;
+                #[cfg(feature = "ffmpeg_6_0")]
+                let nb_inputs = (*self.as_ptr()).nb_inputs as isize;
+
+                Some(PadIter::new((*self.as_ptr()).inputs, nb_inputs))
             }
         }
     }
@@ -59,7 +64,12 @@ impl Filter {
             if ptr.is_null() {
                 None
             } else {
-                Some(PadIter::new((*self.as_ptr()).outputs, (*self.as_ptr()).nb_outputs as isize))
+                #[cfg(not(feature = "ffmpeg_6_0"))]
+                let nb_outputs = avfilter_pad_count((*self.as_ptr()).outputs) as isize;
+                #[cfg(feature = "ffmpeg_6_0")]
+                let nb_outputs = (*self.as_ptr()).nb_outputs as isize;
+
+                Some(PadIter::new((*self.as_ptr()).outputs, nb_outputs))
             }
         }
     }