avutil: add FF_DECODE_ERROR_CONCEALMENT_ACTIVE flag for AVFrame.decode_error_flags

FF_DECODE_ERROR_CONCEALMENT_ACTIVE is set when the decoded frame has error(s) but the returned value from
avcodec_receive_frame is zero i.e. concealed errors
Signed-off-by: Amir Pauker <amir@livelyvideo.tv>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

doc/APIchanges

@@ -15,6 +15,9 @@ libavutil:     2017-10-21
 
 API changes, most recent first:
 
+2019-06-14 - XXXXXXXXXX - lavu 56.29.100 - frame.h
+  Add FF_DECODE_ERROR_CONCEALMENT_ACTIVE
+
 2019-05-15 - b79b29ddb1 - lavu 56.28.100 - tx.h
   Add av_tx_init(), av_tx_uninit() and related definitions.
 

libavutil/frame.h

@@ -563,6 +563,7 @@ typedef struct AVFrame {
     int decode_error_flags;
 #define FF_DECODE_ERROR_INVALID_BITSTREAM   1
 #define FF_DECODE_ERROR_MISSING_REFERENCE   2
+#define FF_DECODE_ERROR_CONCEALMENT_ACTIVE  4
 
     /**
      * number of audio channels, only used for audio.

libavutil/version.h

@@ -79,7 +79,7 @@
  */
 
 #define LIBAVUTIL_VERSION_MAJOR  56
-#define LIBAVUTIL_VERSION_MINOR  28
+#define LIBAVUTIL_VERSION_MINOR  29
 #define LIBAVUTIL_VERSION_MICRO 100
 
 #define LIBAVUTIL_VERSION_INT   AV_VERSION_INT(LIBAVUTIL_VERSION_MAJOR, \