More bug fixes in ffmpeg.

Author: neumatho

Source/Ports/FFmpeg/LibAvUtil/SampleFmt.cs

@@ -174,7 +174,7 @@ public static c_int Av_Samples_Get_Buffer_Size(CPointer<c_int> lineSize, c_int n
 			}
 
 			// Check for integer overflow
-			if ((nb_Channels > (c_int.MaxValue / align)) || (((int64_t)nb_Samples * nb_Samples) > ((c_int.MaxValue - (align * nb_Samples)) / sample_Size)))
+			if ((nb_Channels > (c_int.MaxValue / align)) || (((int64_t)nb_Channels * nb_Samples) > ((c_int.MaxValue - (align * nb_Channels)) / sample_Size)))
 				return Error.EINVAL;
 
 			c_int line_Size = planar != 0 ? Macros.FFAlign(nb_Samples * sample_Size, align) : Macros.FFAlign(nb_Samples * sample_Size * nb_Channels, align);

Source/Ports/FFmpeg/LibSwResample/SwResample.cs

@@ -317,6 +317,8 @@ public static c_int Swr_Init(SwrContext s)//XX 138
 				goto Fail;
 			}
 
+			const c_int RSC = 1;
+
 			if (s.In.Ch_Count == 0)
 				s.In.Ch_Count = s.In_Ch_Layout.Nb_Channels;
 
@@ -353,6 +355,8 @@ public static c_int Swr_Init(SwrContext s)//XX 138
 				goto Fail;
 			}
 
+			s.Resample_First = ((RSC * s.Out.Ch_Count / s.Used_Ch_Layout.Nb_Channels) - RSC) < ((s.Out_Sample_Rate / (c_float)s.In_Sample_Rate) - 1.0f) ? 1 : 0;
+
 			s.In.CopyTo(s.In_Buffer);
 			s.In.CopyTo(s.Silence);
 			s.Out.CopyTo(s.Drop_Temp);