From 757cb4f06908a1dfd2e4b23639ded5c254e439ae Mon Sep 17 00:00:00 2001
From: Manish Goregaokar <manishsmail@gmail.com>
Date: Mon, 13 Aug 2018 18:08:19 -0700
Subject: [PATCH] Set channel count for destination node in offline audio
 context

Otherwise we will crash for offline contexts with > 2 channels
---
 audio/src/context.rs          | 8 ++++----
 audio/src/destination_node.rs | 3 ++-
 audio/src/graph.rs            | 4 ++--
 audio/src/node.rs             | 1 -
 audio/src/render_thread.rs    | 2 --
 5 files changed, 8 insertions(+), 10 deletions(-)

diff --git a/audio/src/context.rs b/audio/src/context.rs
index fba24007..8c09ea79 100644
--- a/audio/src/context.rs
+++ b/audio/src/context.rs
@@ -114,14 +114,14 @@ pub struct AudioContext<B> {
 impl<B: AudioBackend + 'static> AudioContext<B> {
     /// Constructs a new audio context.
     pub fn new(options: AudioContextOptions) -> Self {
-        let sample_rate = match options {
-            AudioContextOptions::RealTimeAudioContext(ref options) => options.sample_rate,
-            AudioContextOptions::OfflineAudioContext(ref options) => options.sample_rate
+        let (sample_rate, channels) = match options {
+            AudioContextOptions::RealTimeAudioContext(ref options) => (options.sample_rate, 2),
+            AudioContextOptions::OfflineAudioContext(ref options) => (options.sample_rate, options.channels)
         };
 
         let (sender, receiver) = mpsc::channel();
         let sender_ = sender.clone();
-        let graph = AudioGraph::new();
+        let graph = AudioGraph::new(channels);
         let dest_node = graph.dest_id();
         Builder::new()
             .name("AudioRenderThread".to_owned())
diff --git a/audio/src/destination_node.rs b/audio/src/destination_node.rs
index 6feb0c78..150b6420 100644
--- a/audio/src/destination_node.rs
+++ b/audio/src/destination_node.rs
@@ -9,10 +9,11 @@ pub(crate) struct DestinationNode {
 }
 
 impl DestinationNode {
-    pub fn new() -> Self {
+    pub fn new(channel_count: u8) -> Self {
         DestinationNode {
             channel_info: ChannelInfo {
                 mode: ChannelCountMode::Explicit,
+                count: channel_count,
                 ..Default::default()
             },
             chunk: None,
diff --git a/audio/src/graph.rs b/audio/src/graph.rs
index 16492603..ffeecb09 100644
--- a/audio/src/graph.rs
+++ b/audio/src/graph.rs
@@ -145,9 +145,9 @@ struct Connection {
 }
 
 impl AudioGraph {
-    pub fn new() -> Self {
+    pub fn new(channel_count: u8) -> Self {
         let mut graph = StableGraph::new();
-        let dest_id = NodeId(graph.add_node(Node::new(Box::new(DestinationNode::new()))));
+        let dest_id = NodeId(graph.add_node(Node::new(Box::new(DestinationNode::new(channel_count)))));
         AudioGraph { graph, dest_id }
     }
 
diff --git a/audio/src/node.rs b/audio/src/node.rs
index e20d959f..5a8f13a8 100644
--- a/audio/src/node.rs
+++ b/audio/src/node.rs
@@ -19,7 +19,6 @@ pub enum AudioNodeInit {
     ConstantSourceNode,
     ConvolverNode,
     DelayNode,
-    DestinationNode,
     DynamicsCompressionNode,
     GainNode(GainNodeOptions),
     IIRFilterNode,
diff --git a/audio/src/render_thread.rs b/audio/src/render_thread.rs
index 337b0246..9c9c3c66 100644
--- a/audio/src/render_thread.rs
+++ b/audio/src/render_thread.rs
@@ -2,7 +2,6 @@ use block::{Chunk, Tick, FRAMES_PER_BLOCK};
 use buffer_source_node::AudioBufferSourceNode;
 use channel_node::{ChannelMergerNode, ChannelSplitterNode};
 use context::{AudioContextOptions, ProcessingState, StateChangeResult};
-use destination_node::DestinationNode;
 use gain_node::GainNode;
 use graph::{AudioGraph, InputPort, NodeId, OutputPort, PortId};
 use node::BlockInfo;
@@ -131,7 +130,6 @@ impl<B: AudioBackend + 'static> AudioRenderThread<B> {
             AudioNodeInit::AudioBufferSourceNode(options) => {
                 Box::new(AudioBufferSourceNode::new(options))
             }
-            AudioNodeInit::DestinationNode => Box::new(DestinationNode::new()),
             AudioNodeInit::GainNode(options) => Box::new(GainNode::new(options)),
             AudioNodeInit::OscillatorNode(options) => Box::new(OscillatorNode::new(options)),
             AudioNodeInit::ChannelMergerNode(options) => Box::new(ChannelMergerNode::new(options)),