{player,output}_thread: fixed elapsed_time quirks

Right after seeking and song change, the elapsed_time shows old
information, because the output thread didn't finish a full chunk
yet.  This patch re-adds a second elapsed_time variable, and keeps
track of a fallback value, in case the output thread can't provide a
reliable value.

1 files changed, 2 insertions, 1 deletions

diff --git a/src/output_all.h b/src/output_all.h
index 2f5101f1..91b6f3f5 100644
--- a/src/output_all.h
+++ b/src/output_all.h
@@ -137,7 +137,8 @@ audio_output_all_cancel(void);
 
 /**
  * Returns the "elapsed_time" stamp of the most recently finished
- * chunk.
+ * chunk.  A negative value is returned when no chunk has been
+ * finished yet.
  */
 float
 audio_output_all_get_elapsed_time(void);