configure: rename have_incompatible_fork_abi -> have_incompatible_libav_abi

"Fork" is an ambiguous term, since there may be more than one fork, also
"fork" could be confused with the corresponding function. Also it seems
important to point the name of the referenced fork in the symbol.

Note: the old --enable-incompatible-fork-abi command is retained for
compatibility, although it should be considered deprecated.

configure

@@ -102,6 +102,8 @@ Configuration options:
   --enable-gray            enable full grayscale support (slower color)
   --disable-swscale-alpha  disable alpha channel support in swscale
   --disable-all            disable building components, libraries and programs
+  --enable-incompatible-libav-abi enable incompatible Libav fork ABI [no]
+  --enable-incompatible-fork-abi  enable incompatible Libav fork ABI (deprecated) [no]
 
 Program options:
   --disable-programs       do not build command line programs
@@ -1259,6 +1261,7 @@ CONFIG_LIST="
     gpl
     gray
     hardcoded_tables
+    incompatible_libav_abi
     incompatible_fork_abi
     lsp
     lzo
@@ -1365,6 +1368,7 @@ HAVE_LIST_CMDLINE='
 HAVE_LIST_PUB='
     bigendian
     fast_unaligned
+    incompatible_libav_abi
     incompatible_fork_abi
 '
 
@@ -3700,6 +3704,10 @@ EOF
     exit 1;
 fi
 
+# backward compatibility layer for incompatible_libav/fork_abi
+enabled incompatible_fork_abi  && enable incompatible_libav_abi
+enabled incompatible_libav_abi && enable incompatible_fork_abi
+
 die_license_disabled() {
     enabled $1 || { enabled $2 && die "$2 is $1 and --enable-$1 is not specified."; }
 }

libavcodec/avcodec.h

@@ -4490,7 +4490,7 @@ enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt
                                             enum AVPixelFormat src_pix_fmt, int has_alpha, int *loss_ptr);
 
 attribute_deprecated
-#if AV_HAVE_INCOMPATIBLE_FORK_ABI
+#if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
                                               enum AVPixelFormat src_pix_fmt,
                                               int has_alpha, int *loss_ptr);

libavcodec/imgconvert.c

@@ -247,7 +247,7 @@ enum AVPixelFormat avcodec_find_best_pix_fmt_of_2(enum AVPixelFormat dst_pix_fmt
     return dst_pix_fmt;
 }
 
-#if AV_HAVE_INCOMPATIBLE_FORK_ABI
+#if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
 enum AVPixelFormat avcodec_find_best_pix_fmt2(enum AVPixelFormat *pix_fmt_list,
                                             enum AVPixelFormat src_pix_fmt,
                                             int has_alpha, int *loss_ptr){

libavcodec/vdpau.h

@@ -136,7 +136,7 @@ struct vdpau_render_state {
 
     int state; ///< Holds FF_VDPAU_STATE_* values.
 
-#if AV_HAVE_INCOMPATIBLE_FORK_ABI
+#if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
     /** picture parameter information for all supported codecs */
     union FFVdpPictureInfo info;
 #endif
@@ -148,7 +148,7 @@ struct vdpau_render_state {
     /** The user is responsible for freeing this buffer using av_freep(). */
     VdpBitstreamBuffer *bitstream_buffers;
 
-#if !AV_HAVE_INCOMPATIBLE_FORK_ABI
+#if !AV_HAVE_INCOMPATIBLE_LIBAV_ABI
     /** picture parameter information for all supported codecs */
     union FFVdpPictureInfo info;
 #endif

libavutil/pixfmt.h

@@ -245,7 +245,7 @@ enum AVPixelFormat {
 #endif
 };
 
-#if AV_HAVE_INCOMPATIBLE_FORK_ABI
+#if AV_HAVE_INCOMPATIBLE_LIBAV_ABI
 #define AV_PIX_FMT_YUVA422P AV_PIX_FMT_YUVA422P_LIBAV
 #define AV_PIX_FMT_YUVA444P AV_PIX_FMT_YUVA444P_LIBAV
 #endif