From 9ecac99df40d0b5aa68141df8c0a63e1cc975b18 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Fernando=20Jim=C3=A9nez=20Moreno?= <ferjmoreno@gmail.com>
Date: Mon, 30 Jul 2018 13:31:58 +0200
Subject: [PATCH] Push silence to offline sink if nothing reaches the output

---
 audio/src/block.rs        | 4 ++++
 audio/src/offline_sink.rs | 8 +++++++-
 2 files changed, 11 insertions(+), 1 deletion(-)

diff --git a/audio/src/block.rs b/audio/src/block.rs
index ee8f9d3e..8ce86970 100644
--- a/audio/src/block.rs
+++ b/audio/src/block.rs
@@ -425,6 +425,10 @@ impl Block {
         }
         vec
     }
+
+    pub fn is_empty(&self) -> bool {
+        self.buffer.is_empty()
+    }
 }
 
 /// An iterator over frames in a block
diff --git a/audio/src/offline_sink.rs b/audio/src/offline_sink.rs
index 60012047..295c8176 100644
--- a/audio/src/offline_sink.rs
+++ b/audio/src/offline_sink.rs
@@ -54,13 +54,19 @@ impl AudioSink for OfflineAudioSink {
             || (self.rendered_blocks.get() >= (self.length / FRAMES_PER_BLOCK_USIZE))
     }
 
-    fn push_data(&self, chunk: Chunk) -> Result<(), ()> {
+    fn push_data(&self, mut chunk: Chunk) -> Result<(), ()> {
         {
             let offset = self.rendered_blocks.get() * FRAMES_PER_BLOCK_USIZE;
             let mut buffer = self.buffer.borrow_mut();
             if buffer.is_none() {
                 *buffer = Some(vec![0.; self.channel_count * self.length]);
             }
+            if chunk.len() == 0 {
+                chunk.blocks.push(Default::default());
+            }
+            if chunk.blocks[0].is_empty() {
+                chunk.blocks[0].explicit_silence();
+            }
             if let Some(ref mut buffer) = *buffer {
                 for channel_number in 0..self.channel_count {
                     let channel_offset = offset + (channel_number * self.length);