avcodec: deprecate AVCodecContext.debug_mv

It's been unused for almost three years now.

Signed-off-by: James Almer <jamrial@gmail.com>

doc/APIchanges

@@ -15,6 +15,10 @@ libavutil:     2017-10-21
 
 API changes, most recent first:
 
+2021-01-25 - xxxxxxxxxx - lavc 58.119.100 - avcodec.h
+  Deprecate AVCodecContext.debug_mv, FF_DEBUG_VIS_MV_P_FOR, FF_DEBUG_VIS_MV_B_FOR,
+  FF_DEBUG_VIS_MV_B_BACK
+
 2021-01-11 - xxxxxxxxxx - lavc 58.116.100 - avcodec.h
   Add FF_PROFILE_VVC_MAIN_10 and FF_PROFILE_VVC_MAIN_10_444.
 

libavcodec/avcodec.h

@@ -2141,15 +2141,16 @@ typedef struct AVCodecContext {
      */
     int seek_preroll;
 
+#if FF_API_DEBUG_MV
     /**
-     * debug motion vectors
-     * - encoding: Set by user.
-     * - decoding: Set by user.
+     * @deprecated unused
      */
+    attribute_deprecated
     int debug_mv;
 #define FF_DEBUG_VIS_MV_P_FOR  0x00000001 //visualize forward predicted MVs of P frames
 #define FF_DEBUG_VIS_MV_B_FOR  0x00000002 //visualize forward predicted MVs of B frames
 #define FF_DEBUG_VIS_MV_B_BACK 0x00000004 //visualize backward predicted MVs of B frames
+#endif
 
     /**
      * custom intra quantization matrix

libavcodec/pthread_frame.c

@@ -342,7 +342,6 @@ static int update_context_from_user(AVCodecContext *dst, AVCodecContext *src)
 
     dst->opaque   = src->opaque;
     dst->debug    = src->debug;
-    dst->debug_mv = src->debug_mv;
 
     dst->slice_flags = src->slice_flags;
     dst->flags2      = src->flags2;

libavcodec/version.h

@@ -28,7 +28,7 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR  58
-#define LIBAVCODEC_VERSION_MINOR 118
+#define LIBAVCODEC_VERSION_MINOR 119
 #define LIBAVCODEC_VERSION_MICRO 100
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
@@ -147,5 +147,8 @@
 #ifndef FF_API_THREAD_SAFE_CALLBACKS
 #define FF_API_THREAD_SAFE_CALLBACKS (LIBAVCODEC_VERSION_MAJOR < 60)
 #endif
+#ifndef FF_API_DEBUG_MV
+#define FF_API_DEBUG_MV          (LIBAVCODEC_VERSION_MAJOR < 60)
+#endif
 
 #endif /* AVCODEC_VERSION_H */