Reduce reliance on duplicate hardcoded constants

2 files changed, 11 insertions, 5 deletions

diff --git a/include/xas/riff.h b/include/xas/riff.h
index 693aa9a..6e097c3 100644
--- a/include/xas/riff.h
+++ b/include/xas/riff.h
@@ -6,6 +6,11 @@
 
 #include <xas/audio.h>
 
+#define XAS_RIFF_HEADER_MAIN_ID      "RIFF"
+#define XAS_RIFF_HEADER_WAVE_ID      "WAVE"
+#define XAS_RIFF_HEADER_WAVE_FMT_ID  "fmt "
+#define XAS_RIFF_HEADER_WAVE_DATA_ID "data"
+
 #define XAS_RIFF_WAVE_DEFAULT_TYPE 1
 
 #pragma pack(1)
diff --git a/src/riff.c b/src/riff.c
index fc4e4c3..77def32 100644
--- a/src/riff.c
+++ b/src/riff.c
@@ -19,19 +19,20 @@ static int header_write(xas_riff *riff) {
     xas_riff_wave_header header = {
         .riff = {
             {
-                .id    = "RIFF",
+                .id    = XAS_RIFF_HEADER_MAIN_ID,
                 .size = sizeof(xas_riff_main_chunk)
                       + sizeof(xas_riff_wave_chunk)
                       + riff->size
             },
 
-            .type = "WAVE"
+            .type = XAS_RIFF_HEADER_WAVE_ID,
         },
 
         .wave = {
             {
-                .id   = "fmt ",
-                .size = 16
+                .id   = XAS_RIFF_HEADER_WAVE_FMT_ID,
+                .size = sizeof(xas_riff_wave_chunk)
+                      - sizeof(xas_riff_chunk)
             },
 
             .type             = XAS_RIFF_WAVE_DEFAULT_TYPE,
@@ -43,7 +44,7 @@ static int header_write(xas_riff *riff) {
         },
 
         {
-            .id   = "data",
+            .id   = XAS_RIFF_HEADER_WAVE_DATA_ID,
             .size = riff->size
         }
     };