[libav-devel] [PATCH] libfdk-aac: Don't use defined() in a #define

Martin Storsjö martin at martin.st
Wed Sep 12 22:23:36 CEST 2018


MSVC expands the preprocessor directives differently, making the
version check fail in the previous form.
---
I'm pretty sure I've seen a better description of this issue somewhere,
I don't remember off-hand right now where that was. But I think the
gist of it was that the previous form was undefined according to the
C standard, even if GCC and clang handle it in the same way.
---
 libavcodec/libfdk-aacdec.c | 9 ++++++---
 libavcodec/libfdk-aacenc.c | 9 ++++++---
 2 files changed, 12 insertions(+), 6 deletions(-)

diff --git a/libavcodec/libfdk-aacdec.c b/libavcodec/libfdk-aacdec.c
index ca70a49ad4..63856232d9 100644
--- a/libavcodec/libfdk-aacdec.c
+++ b/libavcodec/libfdk-aacdec.c
@@ -25,10 +25,13 @@
 #include "avcodec.h"
 #include "internal.h"
 
+#ifdef AACDECODER_LIB_VL0
 #define FDKDEC_VER_AT_LEAST(vl0, vl1) \
-    (defined(AACDECODER_LIB_VL0) && \
-        ((AACDECODER_LIB_VL0 > vl0) || \
-         (AACDECODER_LIB_VL0 == vl0 && AACDECODER_LIB_VL1 >= vl1)))
+    ((AACDECODER_LIB_VL0 > vl0) || \
+     (AACDECODER_LIB_VL0 == vl0 && AACDECODER_LIB_VL1 >= vl1))
+#else
+#define FDKDEC_VER_AT_LEAST(vl0, vl1) 0
+#endif
 
 #if !FDKDEC_VER_AT_LEAST(2, 5) // < 2.5.10
 #define AAC_PCM_MAX_OUTPUT_CHANNELS AAC_PCM_OUTPUT_CHANNELS
diff --git a/libavcodec/libfdk-aacenc.c b/libavcodec/libfdk-aacenc.c
index f71a276403..3b492ef8f4 100644
--- a/libavcodec/libfdk-aacenc.c
+++ b/libavcodec/libfdk-aacenc.c
@@ -26,10 +26,13 @@
 #include "audio_frame_queue.h"
 #include "internal.h"
 
+#ifdef AACENCODER_LIB_VL0
 #define FDKENC_VER_AT_LEAST(vl0, vl1) \
-    (defined(AACENCODER_LIB_VL0) && \
-        ((AACENCODER_LIB_VL0 > vl0) || \
-         (AACENCODER_LIB_VL0 == vl0 && AACENCODER_LIB_VL1 >= vl1)))
+    ((AACENCODER_LIB_VL0 > vl0) || \
+     (AACENCODER_LIB_VL0 == vl0 && AACENCODER_LIB_VL1 >= vl1))
+#else
+#define FDKENC_VER_AT_LEAST(vl0, vl1) 0
+#endif
 
 typedef struct AACContext {
     const AVClass *class;
-- 
2.15.2 (Apple Git-101.1)



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