decoder/faad: remove workaround for ancient libfaad2 ABI bug

Many years ago, FAAD had a serious ABI bug: the NeAACDecInit() prototype in its header declared the "samplerate" parameter to be "unsigned long *", but internally, the function assumed it was "uint32_t *" instead. On 32 bit machines, that was no difference, but on 64 bit, this left one portion of the return value uninitialized; and worse, on big-endian, the wrong word was filled. This bug had to be worked around in MPD (commit 9c4e97a6). A few months later, the bug was fixed in the FAAD CVS in commit 1.117 on file libfaad/decoder.c; the commit message was: "Use public headers internally to prevent duplicate declarations" The commit message was too brief at best; the problem was not duplicate declarations, but a prototype mismatch. No mention of the bug fix in the ChangeLog. The MPD project never learned about this bug fix, and so MPD would always pass a "uin32_t *" dressed up as a "unsigned long *". Nearly 6 years later, it's about time to fix this second ABI problem. Let's kill the workaround!

decoder/faad: remove workaround for ancient libfaad2 ABI bug
f6b2899d · Max Kellermann · bccd4ef2 · f6b2899d · f6b2899d · f6b2899d
Commit f6b2899d authored Oct 25, 2014 by Max Kellermann
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Showing with 4 additions and 40 deletions

NEWS NEWS +1 -0

faad.m4 m4/faad.m4 +1 -30

FaadDecoderPlugin.cxx src/decoder/FaadDecoderPlugin.cxx +2 -10

No files found.
--- a/NEWS
+++ b/NEWS
 ver 0.18.17 (not yet released)
 * decoder
+  - faad: remove workaround for ancient libfaad2 ABI bug
  - ffmpeg: recognize MIME type audio/aacp

 ver 0.18.16 (2014/09/26)

--- a/m4/faad.m4
+++ b/m4/faad.m4
@@ -62,36 +62,7 @@ int main() {
 	CPPFLAGS=$oldcppflags
 fi

-if test x$enable_aac = xyes; then
-	oldcflags=$CFLAGS
-	oldlibs=$LIBS
-	oldcppflags=$CPPFLAGS
-	CFLAGS="$CFLAGS $FAAD_CFLAGS -Werror"
-	LIBS="$LIBS $FAAD_LIBS"
-	CPPFLAGS=$CFLAGS
-
-	AC_MSG_CHECKING(for broken libfaad headers)
-	AC_COMPILE_IFELSE([AC_LANG_SOURCE([
-#include <faad.h>
-#include <stddef.h>
-#include <stdint.h>
-
-int main() {
-	unsigned char channels;
-	uint32_t sample_rate;
-
-	NeAACDecInit2(NULL, NULL, 0, &sample_rate, &channels);
-	return 0;
-}
-	])],
-		[AC_MSG_RESULT(correct)],
-		[AC_MSG_RESULT(broken);
-		AC_DEFINE(HAVE_FAAD_LONG, 1, [Define if faad.h uses the broken "unsigned long" pointers])])
-
-	CFLAGS=$oldcflags
-	LIBS=$oldlibs
-	CPPFLAGS=$oldcppflags
-else
+if test x$enable_aac = xno; then
 	FAAD_LIBS=""
 	FAAD_CFLAGS=""
 fi

--- a/src/decoder/FaadDecoderPlugin.cxx
+++ b/src/decoder/FaadDecoderPlugin.cxx
@@ -277,20 +277,12 @@ faad_decoder_init(NeAACDecHandle decoder, DecoderBuffer *buffer,
 	}

 	uint8_t channels;
-	uint32_t sample_rate;
-#ifdef HAVE_FAAD_LONG
-	/* neaacdec.h declares all arguments as "unsigned long", but
-	   internally expects uint32_t pointers.  To avoid gcc
-	   warnings, use this workaround. */
-	unsigned long *sample_rate_p = (unsigned long *)(void *)&sample_rate;
-#else
-	uint32_t *sample_rate_p = &sample_rate;
-#endif
+	unsigned long sample_rate;
 	long nbytes = NeAACDecInit(decoder,
 				   /* deconst hack, libfaad requires this */
 				   const_cast<unsigned char *>(data),
 				   length,
-				   sample_rate_p, &channels);
+				   &sample_rate, &channels);
 	if (nbytes < 0) {
 		error.Set(faad_decoder_domain, "Not an AAC stream");
 		return false;