diff --git a/libmpcodecs/ae_lavc.c b/libmpcodecs/ae_lavc.c
index fd565b4edb..ba21bf220d 100644
--- a/libmpcodecs/ae_lavc.c
+++ b/libmpcodecs/ae_lavc.c
@@ -29,8 +29,20 @@ extern int  lavc_param_audio_global_header;
 extern int  avcodec_inited;
 static int compressed_frame_size = 0;
 #if defined(USE_LIBAVFORMAT) ||  defined(USE_LIBAVFORMAT_SO)
-extern unsigned int codec_get_wav_tag(int id);
-extern const int mp_wav_tags[];
+#ifdef USE_LIBAVFORMAT_SO
+#include <ffmpeg/avformat.h>
+typedef struct CodecTag {
+    int id;
+    unsigned int tag;
+    unsigned int invalid_asf : 1;
+} CodecTag;
+unsigned int codec_get_wav_tag(int id);
+unsigned int codec_get_tag(const CodecTag *tags, int id);
+#else
+#include "libavformat/avformat.h"
+#include "libavformat/riff.h"
+#endif
+extern const CodecTag mp_wav_tags[];
 #endif
 
 static int bind_lavc(audio_encoder_t *encoder, muxer_stream_t *mux_a)
diff --git a/libmpdemux/muxer_lavf.c b/libmpdemux/muxer_lavf.c
index 97c3558a37..0bf7990d3b 100644
--- a/libmpdemux/muxer_lavf.c
+++ b/libmpdemux/muxer_lavf.c
@@ -19,14 +19,21 @@
 #include "m_option.h"
 #ifdef USE_LIBAVFORMAT_SO
 #include <ffmpeg/avformat.h>
+typedef struct CodecTag {
+    int id;
+    unsigned int tag;
+    unsigned int invalid_asf : 1;
+} CodecTag;
+unsigned int codec_get_wav_tag(int id);
+enum CodecID codec_get_bmp_id(unsigned int tag);
+enum CodecID codec_get_wav_id(unsigned int tag);
+enum CodecID codec_get_id(const CodecTag *tags, unsigned int tag);
 #else
 #include "avformat.h"
+#include "libavformat/riff.h"
 #endif
 
-extern unsigned int codec_get_wav_tag(int id);
-extern enum CodecID codec_get_bmp_id(unsigned int tag);
-extern enum CodecID codec_get_wav_id(unsigned int tag);
-extern const int mp_wav_tags[];
+extern const CodecTag mp_wav_tags[];
 
 extern char *info_name;
 extern char *info_artist;