read pages

opustags.c

@@ -1,5 +1,45 @@
+#include <errno.h>
+#include <stdio.h>
 #include <stdlib.h>
+#include <string.h>
+#include <ogg/ogg.h>
 
 int main(int argc, char **argv){
+    FILE *in = fopen(argv[1], "r");
+    if(!in){
+        perror("fopen");
+        return EXIT_FAILURE;
+    }
+    ogg_sync_state oy;
+    ogg_page og;
+    ogg_sync_init(&oy);
+    char *buf;
+    size_t len;
+    char *error = NULL;
+    while(error == NULL && !feof(in)){
+        // Read until we complete a page.
+        if(ogg_sync_pageout(&oy, &og) != 1){
+            buf = ogg_sync_buffer(&oy, 65536);
+            if(buf == NULL){
+                error = "ogg_sync_buffer: out of memory";
+                break;
+            }
+            len = fread(buf, 1, 65536, in);
+            if(ferror(in))
+                error = strerror(errno);
+            ogg_sync_wrote(&oy, len);
+            if(ogg_sync_check(&oy) != 0)
+                error = "ogg_sync_check: internal error";
+            continue;
+        }
+        // We got a page.
+        puts("got a page");
+    }
+    ogg_sync_clear(&oy);
+    fclose(in);
+    if(error){
+        fprintf(stderr, "%s\n", error);
+        return EXIT_FAILURE;
+    }
     return EXIT_SUCCESS;
 }