dsputil: set STRIDE_ALIGN to 16 for x86 also.

This fixes crashes in e.g. PNG decoding with SSE2 enabled. In fact, many
x86 optimizations for codecs assume that our buffer strides are 16-byte
aligned.

libavcodec/dsputil.h

@@ -655,23 +655,9 @@ void ff_intrax8dsp_init(DSPContext* c, AVCodecContext *avctx);
 void ff_mlp_init(DSPContext* c, AVCodecContext *avctx);
 void ff_mlp_init_x86(DSPContext* c, AVCodecContext *avctx);
 
-#if ARCH_ARM
-
-#if HAVE_NEON
+#if (ARCH_ARM && HAVE_NEON) || ARCH_PPC || HAVE_MMI || HAVE_MMX
 #   define STRIDE_ALIGN 16
-#endif
-
-#elif ARCH_PPC
-
-#define STRIDE_ALIGN 16
-
-#elif HAVE_MMI
-
-#define STRIDE_ALIGN 16
-
-#endif
-
-#ifndef STRIDE_ALIGN
+#else
 #   define STRIDE_ALIGN 8
 #endif
 

libavcodec/utils.c

@@ -234,18 +234,6 @@ void avcodec_align_dimensions2(AVCodecContext *s, int *width, int *height,
 
     for (i = 0; i < 4; i++)
         linesize_align[i] = STRIDE_ALIGN;
-//STRIDE_ALIGN is 8 for SSE* but this does not work for SVQ1 chroma planes
-//we could change STRIDE_ALIGN to 16 for x86/sse but it would increase the
-//picture size unneccessarily in some cases. The solution here is not
-//pretty and better ideas are welcome!
-#if HAVE_MMX
-    if(s->codec_id == CODEC_ID_SVQ1 || s->codec_id == CODEC_ID_VP5 ||
-       s->codec_id == CODEC_ID_VP6 || s->codec_id == CODEC_ID_VP6F ||
-       s->codec_id == CODEC_ID_VP6A) {
-        for (i = 0; i < 4; i++)
-            linesize_align[i] = 16;
-    }
-#endif
 }
 
 void avcodec_align_dimensions(AVCodecContext *s, int *width, int *height){