dshow: attempt to build shared as well as static

Signed-off-by: rogerdpack <rogerpack2005@gmail.com>

libavformat/libavformat.v

@@ -32,5 +32,8 @@ LIBAVFORMAT_$MAJOR {
                 ff_timefilter_reset;
                 get_*;
                 put_*;
+                ff_codec_bmp_tags;
+                ff_raw_pix_fmt_tags;
+                ff_codec_get_id;
         local: *;
 };

libavformat/riff.h

@@ -51,7 +51,7 @@ int ff_put_wav_header(AVIOContext *pb, AVCodecContext *enc);
 enum AVCodecID ff_wav_codec_get_id(unsigned int tag, int bps);
 int ff_get_wav_header(AVIOContext *pb, AVCodecContext *codec, int size);
 
-extern const AVCodecTag ff_codec_bmp_tags[];
+extern av_export const AVCodecTag ff_codec_bmp_tags[];
 extern const AVCodecTag ff_codec_wav_tags[];
 
 void ff_parse_specific_params(AVCodecContext *stream, int *au_rate, int *au_ssize, int *au_scale);