Changeset c891eaca in mainline for uspace/app/dplay/dplay.c

Timestamp:

2011-12-07T14:04:34Z (12 years ago)

Author:

Jan Vesely <jano.vesely@…>

Branches:

lfn, master, serial, ticket/834-toolchain-update, topic/msim-upgrade, topic/simplify-dev-export

Children:

46d9d13

Parents:

7a5ab20

Message:

dplay: Use octo buffering instead of double buffering.

Improves sound quality on qemu.

File:

• uspace/app/dplay/dplay.c (modified) (2 diffs)

uspace/app/dplay/dplay.c

@@ -56 +56 @@
 {
         assert(device);
-        const size_t half_buf = size / 2;
+        const size_t update_size = size / 8;
 
         /* Time to play half the buffer. */
         const suseconds_t interval = 1000000 /
-            (sampling_rate /  (half_buf / (channels * (sample_size / 8))));
+            (sampling_rate /  (update_size / (channels * (sample_size / 8))));
         printf("Time to play half buffer: %ld us.\n", interval);
         /* Initialize buffer. */
@@ -88 +88 @@
 
                 const size_t bytes =
-                    fread(buffer_place, sizeof(uint8_t), half_buf, source);
+                    fread(buffer_place, sizeof(uint8_t), update_size, source);
                 if (bytes == 0)
                         break;
-                if (bytes < half_buf) {
-                        bzero(buffer_place + bytes, half_buf - bytes);
+                if (bytes < update_size) {
+                        bzero(buffer_place + bytes, update_size - bytes);
                 }
-                if (buffer_place == buffer) {
-                        buffer_place = buffer + half_buf;
-                } else {
+                buffer_place += update_size;
+
+                if (buffer_place == buffer + size) {
                         buffer_place = buffer;
                 }