Some FFmpeg changes

- Make FFmpeg initialization called from creator, not from functions
  which requires FFmpeg. Makes it easier to follow when initialization
  should happen.

- Enable DNxHD codec. It was commented a while ago due to some strange
  behavior on some platforms. Re-tested it on Linux and Windows and
  it seemd to be working quite nice. Would let it be tested further,
  if it wouldn't be stable enough, easy to comment it again.

- Make non-error messages from writeffmpeg.c printed only if ffmpeg
  debug argument was passed to blender. Reduces console pollution
  with messages which are not useful for general troubleshooting.
  Error messages would still be printed to the console.

- Show FFmpeg error message when video stream failed to allocate.
  makes it easier to understand what exactly is wrong from Blender
  interface, no need to restart blender with FFmpeg debug flag and
  check for console messages.

  Used custom log callback for this which stores last error message
  in static variable. This is not thread safe, but with current
  design FFmpeg routines could not be called form several threads
  anyway, so think it's fine solution/

1 files changed, 14 insertions, 5 deletions

diff --git a/source/blender/blenlib/intern/string.c b/source/blender/blenlib/intern/string.c
index 7a750a74a33..8501db7c8b8 100644
--- a/source/blender/blenlib/intern/string.c
+++ b/source/blender/blenlib/intern/string.c
@@ -78,22 +78,31 @@ char *BLI_strncpy(char *dst, const char *src, const size_t maxncpy)
 	return dst;
 }
 
-size_t BLI_snprintf(char *buffer, size_t count, const char *format, ...)
+size_t BLI_vsnprintf(char *buffer, size_t count, const char *format, va_list arg)
 {
 	size_t n;
-	va_list arg;
 
-	va_start(arg, format);
 	n = vsnprintf(buffer, count, format, arg);
-	
+
 	if (n != -1 && n < count) {
 		buffer[n] = '\0';
 	}
 	else {
 		buffer[count - 1] = '\0';
 	}
-	
+
+	return n;
+}
+
+size_t BLI_snprintf(char *buffer, size_t count, const char *format, ...)
+{
+	size_t n;
+	va_list arg;
+
+	va_start(arg, format);
+	n = BLI_vsnprintf(buffer, count, format, arg);
 	va_end(arg);
+
 	return n;
 }