From a77506ae215df09ed02c30f39a3be663a3180d5b Mon Sep 17 00:00:00 2001
From: Max Kellermann <max@duempel.org>
Date: Fri, 6 Aug 2010 22:18:01 +0200
Subject: [PATCH] output/httpd: forced flush after 32 kB of input data
Avoid buffer underruns on the streaming client, if the encoder is "too
efficient" (e.g. when encoding silence while paused).
---
src/output/httpd_internal.h | 8 ++++++++
src/output/httpd_output_plugin.c | 15 +++++++++++++++
2 files changed, 23 insertions(+)
diff --git a/src/output/httpd_internal.h b/src/output/httpd_internal.h
index 55843e73f..14a5cf350 100644
--- a/src/output/httpd_internal.h
+++ b/src/output/httpd_internal.h
@@ -51,6 +51,14 @@ struct httpd_output {
*/
struct encoder *encoder;
+ /**
+ * Number of bytes which were fed into the encoder, without
+ * ever receiving new output. This is used to estimate
+ * whether MPD should manually flush the encoder, to avoid
+ * buffer underruns in the client.
+ */
+ size_t unflushed_input;
+
/**
* The MIME type produced by the #encoder.
*/
diff --git a/src/output/httpd_output_plugin.c b/src/output/httpd_output_plugin.c
index 140ea7d82..a71e21604 100644
--- a/src/output/httpd_output_plugin.c
+++ b/src/output/httpd_output_plugin.c
@@ -262,12 +262,22 @@ httpd_output_read_page(struct httpd_output *httpd)
{
size_t size = 0, nbytes;
+ if (httpd->unflushed_input >= 65536) {
+ /* we have fed a lot of input into the encoder, but it
+ didn't give anything back yet - flush now to avoid
+ buffer underruns */
+ encoder_flush(httpd->encoder, NULL);
+ httpd->unflushed_input = 0;
+ }
+
do {
nbytes = encoder_read(httpd->encoder, httpd->buffer + size,
sizeof(httpd->buffer) - size);
if (nbytes == 0)
break;
+ httpd->unflushed_input = 0;
+
size += nbytes;
} while (size < sizeof(httpd->buffer));
@@ -292,6 +302,9 @@ httpd_output_encoder_open(struct httpd_output *httpd,
bytes of encoder output after opening it, because it has to
be sent to every new client */
httpd->header = httpd_output_read_page(httpd);
+
+ httpd->unflushed_input = 0;
+
return true;
}
@@ -451,6 +464,8 @@ httpd_output_encode_and_play(struct httpd_output *httpd,
if (!success)
return false;
+ httpd->unflushed_input += size;
+
httpd_output_encoder_to_clients(httpd);
return true;