From a0846a75fdac01df21161ff4d76371544fab4c1a Mon Sep 17 00:00:00 2001
From: k-m_schindler <k-m_schindler@b956fd51-792f-4845-bead-9b4dfca2ff2c>
Date: Sun, 16 May 2010 21:57:58 +0000
Subject: arithmetic solution on bit level for AVERROR_SIGN. Delphi cannot
 handle the solution with directives. Still needs check on powerpc.

git-svn-id: svn://svn.code.sf.net/p/ultrastardx/svn/trunk@2377 b956fd51-792f-4845-bead-9b4dfca2ff2c
---
 src/lib/ffmpeg/avcodec.pas | 20 ++++++++++++++------
 src/lib/ffmpeg/avutil.pas  | 26 +++++++++++++++-----------
 2 files changed, 29 insertions(+), 17 deletions(-)

diff --git a/src/lib/ffmpeg/avcodec.pas b/src/lib/ffmpeg/avcodec.pas
index 175ed053..2c98f8fa 100644
--- a/src/lib/ffmpeg/avcodec.pas
+++ b/src/lib/ffmpeg/avcodec.pas
@@ -4693,13 +4693,21 @@ const
   {$ENDIF}
 {$ENDIF}
 
+(**
+ * We need the sign of of the error, because some platforms have 
+ * E* and errno already negated. The previous version failed
+ * with Delphi, because it needs EINVAL defined.
+ * Warning: This code is platform dependent and assumes constants 
+ * to be 32 bit.
+ * This version does the following steps:
+ * 1) shr 6:         shifts the sign bit to bit position 2
+ * 2) and $00000002: sets all other bits to zero
+ *                   positive EINVAL gives 0, negative gives 2
+ * 3) not:           inverts all bits. This gives -1 and -3
+ * 4) + 2:           positive EINVAL gives 1, negative -1
+ *)
 const
-{$IF EINVAL > 0}
-  AVERROR_SIGN = -1;
-{$ELSE}
-  {* Some platforms have E* and errno already negated. *}
-  AVERROR_SIGN =  1;
-{$IFEND}
+  AVERROR_SIGN = not((EINVAL shr 6) and $00000002) + 2;
 
 (*
 #if EINVAL > 0
diff --git a/src/lib/ffmpeg/avutil.pas b/src/lib/ffmpeg/avutil.pas
index 385b7e3d..0ad7dd31 100644
--- a/src/lib/ffmpeg/avutil.pas
+++ b/src/lib/ffmpeg/avutil.pas
@@ -161,10 +161,6 @@ type
 (* libavutil/error.h *)
 
 {$IF LIBAVUTIL_VERSION >= 50012000} // >= 50.12.0
-  {$DEFINE NEED_ERRORS_HERE}
-{$IFEND}
-
-{$IFDEF NEED_ERRORS_HERE}
 
 {* error handling *}
 
@@ -193,13 +189,21 @@ const
   {$ENDIF}
 {$ENDIF}
 
+(**
+ * We need the sign of of the error, because some platforms have 
+ * E* and errno already negated. The previous version failed
+ * with Delphi, because it needs EINVAL defined.
+ * Warning: This code is platform dependent and assumes constants 
+ * to be 32 bit.
+ * This version does the following steps:
+ * 1) shr 6:         shifts the sign bit to bit position 2
+ * 2) and $00000002: sets all other bits to zero
+ *                   positive EINVAL gives 0, negative gives 2
+ * 3) not:           inverts all bits. This gives -1 and -3
+ * 4) + 2:           positive EINVAL gives 1, negative -1
+ *)
 const
-{$IF EINVAL > 0}
-  AVERROR_SIGN = -1;
-{$ELSE}
-  {* Some platforms have E* and errno already negated. *}
-  AVERROR_SIGN =  1;
-{$IFEND}
+  AVERROR_SIGN = not((EINVAL shr 6) and $00000002) + 2;
 
 (*
 #if EINVAL > 0
@@ -227,7 +231,7 @@ const
   // Note: function calls as constant-initializers are invalid
   //AVERROR_PATCHWELCOME = -MKTAG('P','A','W','E'); {**< Not yet implemented in FFmpeg. Patches welcome. *}
   AVERROR_PATCHWELCOME = -(ord('P') or (ord('A') shl 8) or (ord('W') shl 16) or (ord('E') shl 24));
-{$ENDIF}
+{$IFEND}
 
 {$IF LIBAVUTIL_VERSION >= 50013000} // >= 50.13.0
 (*
-- 
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