ogg_reader::read_page()

src/ogg.cc

@@ -14,6 +14,25 @@ ot::ogg_reader::~ogg_reader()
 	ogg_stream_clear(&stream);
 }
 
+ot::status ot::ogg_reader::read_page()
+{
+	while (ogg_sync_pageout(&sync, &page) != 1) {
+		if (feof(file))
+			return status::end_of_file;
+		char* buf = ogg_sync_buffer(&sync, 65536);
+		if (buf == nullptr)
+			return status::libogg_error;
+		size_t len = fread(buf, 1, 65536, file);
+		if (ferror(file))
+			return status::standard_error;
+		if (ogg_sync_wrote(&sync, len) != 0)
+			return status::libogg_error;
+		if (ogg_sync_check(&sync) != 0)
+			return status::libogg_error;
+	}
+	return status::ok;
+}
+
 ot::ogg_writer::ogg_writer()
 {
 	memset(&stream, 0, sizeof(stream));

src/opustags.cc

@@ -193,29 +193,20 @@ int main(int argc, char **argv){
         }
     }
     ot::opus_tags tags;
-    char *buf;
-    size_t len;
     const char *error = NULL;
     int packet_count = -1;
     while(error == NULL){
-        // Read until we complete a page.
-        if(ogg_sync_pageout(&reader.sync, &reader.page) != 1){
-            if(feof(reader.file))
-                break;
-            buf = ogg_sync_buffer(&reader.sync, 65536);
-            if(buf == NULL){
-                error = "ogg_sync_buffer: out of memory";
-                break;
-            }
-            len = fread(buf, 1, 65536, reader.file);
-            if(ferror(reader.file))
+        // Read the next page.
+        ot::status rc = reader.read_page();
+        if (rc == ot::status::end_of_file) {
+            break;
+        } else if (rc != ot::status::ok) {
+            if (rc == ot::status::standard_error)
                 error = strerror(errno);
-            ogg_sync_wrote(&reader.sync, len);
-            if(ogg_sync_check(&reader.sync) != 0)
-                error = "ogg_sync_check: internal error";
-            continue;
+            else
+                error = "error reading the next ogg page";
+            break;
         }
-        // We got a page.
         // Short-circuit when the relevant packets have been read.
         if(packet_count >= 2 && writer.file){
             if(ot::write_page(&reader.page, writer.file) == -1){

src/opustags.h

@@ -69,6 +69,8 @@ struct ogg_reader {
 	/**
 	 * Initialize the sync state and zero-initialize the stream. You'll need to initialize the
 	 * stream yourself once you have the serialno.
+	 *
+	 * \todo Take a FILE*.
 	 */
 	ogg_reader();
 	/**
@@ -78,6 +80,12 @@ struct ogg_reader {
 	 * The input file is not closed.
 	 */
 	~ogg_reader();
+	/**
+	 * Read the next page from the input file. The result, provided the status is #status::ok,
+	 * is available in the #page field, is owned by the Ogg reader, and is valid until the next
+	 * call to #read_page. Make sure you also check #status::end_of_file.
+	 */
+	status read_page();
 	/**
 	 * The file is our source of binary data. It is not integrated to libogg, so we need to
 	 * handle it ourselves.