diff --git a/libavformat/au.c b/libavformat/au.c
index 24bdb62c7c9740bd6b2f80fccf102ea277ee703b..7f119e9a4cf7839fdd7bb4b5321092dac5bcdd5a 100644
--- a/libavformat/au.c
+++ b/libavformat/au.c
@@ -44,7 +44,7 @@ static const AVCodecTag codec_au_tags[] = {
     { CODEC_ID_PCM_F32BE, 6 },
     { CODEC_ID_PCM_F64BE, 7 },
     { CODEC_ID_PCM_ALAW, 27 },
-    { 0, 0 },
+    { CODEC_ID_NONE, 0 },
 };
 
 #if CONFIG_AU_MUXER
diff --git a/libavformat/caf.c b/libavformat/caf.c
index 98f7f78fa318a36e00360f82450491ba480cceb2..931a779469bc3c34c787eb44dafc9d42956ffad4 100644
--- a/libavformat/caf.c
+++ b/libavformat/caf.c
@@ -54,5 +54,5 @@ const AVCodecTag ff_codec_caf_tags[] = {
   /*{ MPEG4CELP                 MKBETAG('c','e','l','p') },*/
   /*{ MPEG4HVXC                 MKBETAG('h','v','x','c') },*/
   /*{ MPEG4TwinVQ               MKBETAG('t','w','v','q') },*/
-    { 0, 0 },
+    { CODEC_ID_NONE,            0 },
 };
diff --git a/libavformat/gxfenc.c b/libavformat/gxfenc.c
index 501691e78d3bc5055702ddb067d6745b10a0c0ac..603f595b32219e62e26053af8cd8dd4ac91f433c 100644
--- a/libavformat/gxfenc.c
+++ b/libavformat/gxfenc.c
@@ -93,7 +93,7 @@ static const AVCodecTag gxf_media_types[] = {
     { CODEC_ID_MPEG2VIDEO,  20 }, /* MPEG HD */
     { CODEC_ID_MPEG1VIDEO,  22 }, /* NTSC */
     { CODEC_ID_MPEG1VIDEO,  23 }, /* PAL */
-    { 0, 0 },
+    { CODEC_ID_NONE,         0 },
 };
 
 #define SERVER_PATH "EXT:/PDR/default/"
diff --git a/libavformat/isom.c b/libavformat/isom.c
index 23d716fef31ea3ee7bfaf7214cbe64829828af78..f6b504d4d3967a74f53ee3450610afb30f730687 100644
--- a/libavformat/isom.c
+++ b/libavformat/isom.c
@@ -54,7 +54,7 @@ const AVCodecTag ff_mp4_obj_type[] = {
     { CODEC_ID_VORBIS    , 0xDD }, /* non standard, gpac uses it */
     { CODEC_ID_DVD_SUBTITLE, 0xE0 }, /* non standard, see unsupported-embedded-subs-2.mp4 */
     { CODEC_ID_QCELP     , 0xE1 },
-    { 0, 0 },
+    { CODEC_ID_NONE      ,    0 },
 };
 
 const AVCodecTag codec_movvideo_tags[] = {
diff --git a/libavformat/nsvdec.c b/libavformat/nsvdec.c
index 61a21ae178e7fcdc628bb85f7e0e8807e0187b84..9c215cd58fa10ff231583bc07a55e8d18057168e 100644
--- a/libavformat/nsvdec.c
+++ b/libavformat/nsvdec.c
@@ -201,7 +201,7 @@ static const AVCodecTag nsv_codec_video_tags[] = {
 */
     { CODEC_ID_MPEG4, MKTAG('X', 'V', 'I', 'D') }, /* cf sample xvid decoder from nsv_codec_sdk.zip */
     { CODEC_ID_RAWVIDEO, MKTAG('R', 'G', 'B', '3') },
-    { 0, 0 },
+    { CODEC_ID_NONE, 0 },
 };
 
 static const AVCodecTag nsv_codec_audio_tags[] = {
@@ -210,7 +210,7 @@ static const AVCodecTag nsv_codec_audio_tags[] = {
     { CODEC_ID_AAC,       MKTAG('A', 'A', 'C', 'P') },
     { CODEC_ID_SPEEX,     MKTAG('S', 'P', 'X', ' ') },
     { CODEC_ID_PCM_U16LE, MKTAG('P', 'C', 'M', ' ') },
-    { 0, 0 },
+    { CODEC_ID_NONE,      0 },
 };
 
 //static int nsv_load_index(AVFormatContext *s);
diff --git a/libavformat/riff.c b/libavformat/riff.c
index c5506d9b8b90fcbaf70b1ac767a587a6feceae62..b6feb133532238d469f0aecec4452f72a0f4db0b 100644
--- a/libavformat/riff.c
+++ b/libavformat/riff.c
@@ -271,7 +271,7 @@ const AVCodecTag ff_codec_wav_tags[] = {
     { CODEC_ID_PCM_S16LE, MKTAG('R', 'A', 'W', 'A') },
     { CODEC_ID_MP3,       MKTAG('L', 'A', 'M', 'E') },
     { CODEC_ID_MP3,       MKTAG('M', 'P', '3', ' ') },
-    { 0, 0 },
+    { CODEC_ID_NONE,      0 },
 };
 
 #if CONFIG_MUXERS
diff --git a/libavformat/riff.h b/libavformat/riff.h
index eac0d254702f1f825d3bd657c1aaad6c57587ce1..876c22f31b55f2e0b6ea8e0cb053929421fa80a9 100644
--- a/libavformat/riff.h
+++ b/libavformat/riff.h
@@ -35,7 +35,7 @@ int64_t ff_start_tag(ByteIOContext *pb, const char *tag);
 void ff_end_tag(ByteIOContext *pb, int64_t start);
 
 typedef struct AVCodecTag {
-    int id;
+    enum CodecID id;
     unsigned int tag;
 } AVCodecTag;
 
diff --git a/libavformat/swf.h b/libavformat/swf.h
index 69064a281c146f20661ffb8df2e0e93b806b2799..affebe9c732a64aaca989cd8f9a2e2aff10c5c5b 100644
--- a/libavformat/swf.h
+++ b/libavformat/swf.h
@@ -81,7 +81,7 @@ typedef struct {
 static const AVCodecTag swf_codec_tags[] = {
     {CODEC_ID_FLV1, 0x02},
     {CODEC_ID_VP6F, 0x04},
-    {0, 0},
+    {CODEC_ID_NONE,    0},
 };
 
 static const AVCodecTag swf_audio_codec_tags[] = {
@@ -90,7 +90,7 @@ static const AVCodecTag swf_audio_codec_tags[] = {
     {CODEC_ID_MP3,        0x02},
     {CODEC_ID_PCM_S16LE,  0x03},
   //{CODEC_ID_NELLYMOSER, 0x06},
-    {0, 0},
+    {CODEC_ID_NONE,          0},
 };
 
 #endif /* AVFORMAT_SWF_H */
diff --git a/libavformat/voc.c b/libavformat/voc.c
index 7ebfa711c95b33d441ee2a0cfa2afb85a2f639e7..eed8db8cc7d740fe10ae05fb4f5b297eb7af8108 100644
--- a/libavformat/voc.c
+++ b/libavformat/voc.c
@@ -32,5 +32,5 @@ const AVCodecTag ff_voc_codec_tags[] = {
     {CODEC_ID_PCM_ALAW,      0x06},
     {CODEC_ID_PCM_MULAW,     0x07},
     {CODEC_ID_ADPCM_CT,    0x0200},
-    {0, 0},
+    {CODEC_ID_NONE,             0},
 };