avcodec/mpegvideodata: Mark tables as hidden

This e.g. allows compilers to bake the offset implied
by using ff_mpeg12_dc_scale_table[3] (as the SpeedHQ encoder
does) into the general offset; for certain arches this is
also necessary in order to avoid building suboptimal code.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/mpegvideodata.h

@@ -21,6 +21,9 @@
 
 #include <stdint.h>
 
+#include "libavutil/attributes_internal.h"
+
+FF_VISIBILITY_PUSH_HIDDEN
 /* encoding scans */
 extern const uint8_t ff_alternate_horizontal_scan[64];
 extern const uint8_t ff_alternate_vertical_scan[64];
@@ -31,5 +34,6 @@ static const uint8_t *const ff_mpeg1_dc_scale_table = ff_mpeg12_dc_scale_table[0
 extern const uint8_t ff_mpeg2_non_linear_qscale[32];
 
 extern const uint8_t ff_default_chroma_qscale_table[32];
+FF_VISIBILITY_POP_HIDDEN
 
 #endif /* AVCODEC_MPEGVIDEODATA_H */