osx_write.c: fix pre_select()

The old code was just a quick hack. Good enough for para_write, but
it had no chance to work for para_audiod. Fix it by looking at the
number of bytes left in the current from buffer and calculating the
delay accordingly.

diff --git a/osx_write.c b/osx_write.c
index 39af500077a939a28109e7535868560487f63b1d..287601c7639b5bdf4d393988de56fdc308cb9871 100644 (file)
--- a/osx_write.c
+++ b/osx_write.c
@@ -44,7 +44,7 @@ struct osx_buffer {
        long remaining;
        struct osx_buffer *next;
 };
-typedef struct osx_buffer osx_buffer;
+typedef struct osx_buffer osx_buffer; /* FIXME */
 
 struct private_osx_write_data {
        long size;
@@ -103,7 +103,6 @@ static void fill_buffer(osx_buffer *b, short *source, long size)
 
        if (b->remaining) /* Non empty buffer, must still be playing */
                return;
-       PARA_INFO_LOG("%ld\n", size);
        if (b->size != size) {
                b->buffer = para_realloc(b->buffer, size * sizeof(float));
                b->size = size;
@@ -146,7 +145,7 @@ static OSStatus osx_callback(void * inClientData,
                                        /* wait for the results */
                                        usleep(2000);
                        }
-                       PARA_INFO_LOG("buf %p: n = %ld, m= %ld\n", powd->from->buffer, n, m);
+//                     PARA_INFO_LOG("buf %p: n = %ld, m= %ld\n", powd->from->buffer, n, m);
                        /*
                         * we dump what we can. In fact, just the necessary
                         * should be sufficient
@@ -308,8 +307,28 @@ static int osx_write_post_select(__a_unused struct sched *s,
 
 static int osx_write_pre_select(struct sched *s, __a_unused struct writer_node *wn)
 {
+       struct private_osx_write_data *powd = wn->private_data;
+       struct writer_node_group *wng = wn->wng;
+       size_t numbytes = powd->to->remaining * sizeof(short);
+       struct timeval tmp = {.tv_sec = 1, .tv_usec = 0}, delay = tmp;
+       unsigned long divisor;
+
+       if (!numbytes && *wng->loaded >= sizeof(short))
+               goto min_delay; /* there's a buffer to fill */
+       if (!numbytes)
+               return 1;
+       divisor = powd->samplerate * powd->channels * 2 / numbytes;
+       if (divisor)
+               tv_divide(divisor, &tmp, &delay);
+       if (tv_diff(&s->timeout, &delay, NULL) > 0)
+               s->timeout = delay;
+//     PARA_DEBUG_LOG("delay: %lu:%lu\n", (long unsigned) s->timeout.tv_sec,
+//             (long unsigned) s->timeout.tv_usec);
+       return 1;
+min_delay:
+       PARA_DEBUG_LOG("%s\n", "minimal delay");
        s->timeout.tv_sec = 0;
-       s->timeout.tv_usec = 20;
+       s->timeout.tv_usec = 1;
        return 1;
 }