lavc/mips: temporally disable ac3 downmix

doc/libav-merge.txt

@@ -102,6 +102,7 @@ Collateral damage that needs work locally:
 - Merge proresdec2.c and proresdec_lgpl.c
 - Merge proresenc_anatoliy.c and proresenc_kostya.c
 - Remove ADVANCED_PARSER in libavcodec/hevc_parser.c
+- Fix MIPS AC3 downmix
 
 Extra changes needed to be aligned with Libav:
 ----------------------------------------------

libavcodec/mips/ac3dsp_mips.c

@@ -409,7 +409,7 @@ void ff_ac3dsp_init_mips(AC3DSPContext *c, int bit_exact) {
 #if HAVE_MIPSFPU
 #if !HAVE_MIPS32R6 && !HAVE_MIPS64R6
     c->float_to_fixed24 = float_to_fixed24_mips;
-    c->downmix          = ac3_downmix_mips;
+    //c->downmix          = ac3_downmix_mips;
 #endif
 #endif