avcodec: remove the VLC DSP mask (except on Android on ARM)

libavutil will always check for all CPU features that it understands,
even those VLC masked. Thus masking features provides no savings.

libavutil runs more tests than VLC. Depending on the platform and
operating system combination, libavutil is either as conservative or
more conservative than VLC. As such masking features provides no extra
safety.

So overall, GetVlcDspMask() is useless, at least nowadays.

Android ARM NEON seems controversial so it is kept for now.

modules/access/Makefile.am

@@ -409,7 +409,7 @@ libaccess_realrtsp_plugin_la_LDFLAGS = $(AM_LDFLAGS) -rpath '$(accessdir)'
 access_LTLIBRARIES += $(LTLIBaccess_realrtsp)
 EXTRA_LTLIBRARIES += libaccess_realrtsp_plugin.la
 
-libavio_plugin_la_SOURCES = access/avio.c access/avio.h codec/avcodec/cpu.c
+libavio_plugin_la_SOURCES = access/avio.c access/avio.h
 libavio_plugin_la_CFLAGS = $(AM_CFLAGS) $(AVFORMAT_CFLAGS) $(AVUTIL_CFLAGS)
 libavio_plugin_la_LDFLAGS = $(AM_LDFLAGS) $(SYMBOLIC_LDFLAGS)
 libavio_plugin_la_LIBADD = $(AVFORMAT_LIBS) $(AVUTIL_LIBS) $(LIBM)

modules/codec/Makefile.am

@@ -244,7 +244,6 @@ libavcodec_plugin_la_SOURCES = \
 	codec/avcodec/video.c \
 	codec/avcodec/subtitle.c \
 	codec/avcodec/audio.c \
-	codec/avcodec/cpu.c \
 	codec/avcodec/fourcc.c \
 	codec/avcodec/chroma.c codec/avcodec/chroma.h \
 	codec/avcodec/va.c codec/avcodec/va.h \

modules/codec/avcodec/avcodec.c

@@ -301,11 +301,6 @@ static int OpenDecoder( vlc_object_t *p_this )
     p_context->debug = var_InheritInteger( p_dec, "avcodec-debug" );
     p_context->opaque = (void *)p_this;
 
-    /* set CPU capabilities */
-#if !LIBAVUTIL_VERSION_CHECK(51, 25, 0, 42, 100)
-    p_context->dsp_mask = GetVlcDspMask();
-#endif
-
     p_dec->b_need_packetized = true;
     switch( i_cat )
     {

modules/codec/avcodec/avcommon.h

@@ -36,8 +36,6 @@
 
 #include "avcommon_compat.h"
 
-unsigned GetVlcDspMask(void);
-
 #ifdef HAVE_LIBAVUTIL_AVUTIL_H
 # include <libavutil/avutil.h>
 # include <libavutil/dict.h>
@@ -83,9 +81,10 @@ static inline void vlc_init_avutil(vlc_object_t *obj)
 
     av_log_set_level(level);
 
-#if LIBAVUTIL_VERSION_CHECK(51, 25, 0, 42, 100)
-    av_set_cpu_flags_mask( INT_MAX & ~GetVlcDspMask() );
-#endif
+# if defined (__arm__) && defined (__ANDROID__)
+    if (!vlc_CPU_ARM_NEON())
+        av_set_cpu_flags(AV_CPU_FLAG_NEON);
+# endif
     msg_Dbg(obj, "CPU flags: 0x%08x", av_get_cpu_flags());
 }
 #endif

modules/codec/avcodec/cpu.c

-/*****************************************************************************
- * cpu.c: CPU capabilities for libavcodec
- *****************************************************************************
- * Copyright (C) 1999-2012 VLC authors and VideoLAN
- *
- * This program is free software; you can redistribute it and/or modify it
- * under the terms of the GNU Lesser General Public License as published by
- * the Free Software Foundation; either version 2.1 of the License, or
- * (at your option) any later version.
- *
- * This program is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
- * GNU Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public License
- * along with this program; if not, write to the Free Software Foundation,
- * Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
- *****************************************************************************/
-
-#ifdef HAVE_CONFIG_H
-# include "config.h"
-#endif
-
-#include <vlc_common.h>
-#include <vlc_cpu.h>
-
-#define HAVE_MMX 1
-#include <libavcodec/avcodec.h>
-#include "avcommon.h"
-
-/**
- * Maps CPU capabilities computed by VLC to libav DSP mask.
- */
-unsigned GetVlcDspMask( void )
-{
-    unsigned mask = 0;
-
-#if defined (__i386__) || defined (__x86_64__)
-    if( !vlc_CPU_MMX() )
-        mask |= AV_CPU_FLAG_MMX;
-    if( !vlc_CPU_MMXEXT() )
-        mask |= AV_CPU_FLAG_MMXEXT;
-    if( !vlc_CPU_3dNOW() )
-        mask |= AV_CPU_FLAG_3DNOW;
-    if( !vlc_CPU_SSE() )
-        mask |= AV_CPU_FLAG_SSE;
-    if( !vlc_CPU_SSE2() )
-        mask |= AV_CPU_FLAG_SSE2;
-# ifdef AV_CPU_FLAG_SSE3
-    if( !vlc_CPU_SSE3() )
-        mask |= AV_CPU_FLAG_SSE3;
-# endif
-# ifdef AV_CPU_FLAG_SSSE3
-    if( !vlc_CPU_SSSE3() )
-        mask |= AV_CPU_FLAG_SSSE3;
-# endif
-# ifdef AV_CPU_FLAG_SSE4
-    if( !vlc_CPU_SSE4_1() )
-        mask |= AV_CPU_FLAG_SSE4;
-# endif
-# ifdef AV_CPU_FLAG_SSE42
-    if( !vlc_CPU_SSE4_2() )
-        mask |= AV_CPU_FLAG_SSE42;
-# endif
-# ifdef AV_CPU_FLAG_AVX
-    if( !vlc_CPU_AVX() )
-        mask |= AV_CPU_FLAG_AVX;
-# endif
-# ifdef AV_CPU_FLAG_XOP
-    if( !vlc_CPU_XOP() )
-        mask |= AV_CPU_FLAG_XOP;
-# endif
-# ifdef AV_CPU_FLAG_FMA4
-    if( !vlc_CPU_FMA4() )
-        mask |= AV_CPU_FLAG_FMA4;
-# endif
-#endif
-
-#if defined (__ppc__) || defined (__ppc64__) || defined (__powerpc__)
-    if( !vlc_CPU_ALTIVEC() )
-        mask |= AV_CPU_FLAG_ALTIVEC;
-#endif
-
-#if defined ( __arm__)
-#if LIBAVUTIL_VERSION_INT >= AV_VERSION_INT(51, 29, 0)
-    if( !vlc_CPU_ARM_NEON() )
-        mask |= AV_CPU_FLAG_NEON;
-#endif
-#endif
-
-    return mask;
-}

modules/codec/avcodec/encoder.c

@@ -316,11 +316,6 @@ int OpenEncoder( vlc_object_t *p_this )
     p_context->debug = var_InheritInteger( p_enc, "avcodec-debug" );
     p_context->opaque = (void *)p_this;
 
-    /* set CPU capabilities */
-#if !LIBAVUTIL_VERSION_CHECK(51, 25, 0, 42, 100)
-    p_context->dsp_mask = GetVlcDspMask();
-#endif
-
     p_sys->i_key_int = var_GetInteger( p_enc, ENC_CFG_PREFIX "keyint" );
     p_sys->i_b_frames = var_GetInteger( p_enc, ENC_CFG_PREFIX "bframes" );
     p_sys->i_vtolerance = var_GetInteger( p_enc, ENC_CFG_PREFIX "vt" ) * 1000;

modules/demux/Makefile.am

@@ -133,7 +133,6 @@ demux_LTLIBRARIES += libcaf_plugin.la
 libavformat_plugin_la_SOURCES = demux/avformat/demux.c \
 	codec/avcodec/fourcc.c \
 	codec/avcodec/chroma.c \
-	codec/avcodec/cpu.c \
 	codec/avcodec/avcommon.h \
 	codec/avcodec/avcommon_compat.h \
 	demux/vobsub.h \