Merge pull request #1379 from stream-labs/feature/channel-map-validation

Validate audio channel map before applying
shogo4405 · Feb 16, 2024 · 44770d6 · 44770d6
2 parents 338b260 + 5b3018e
commit 44770d6
Showing 1 changed file with 13 additions and 1 deletion.
diff --git a/Sources/IO/IOAudioResampler.swift b/Sources/IO/IOAudioResampler.swift
@@ -35,7 +35,7 @@ struct IOAudioResamplerSettings {
         if converter.downmix != downmix {
             converter.downmix = downmix
         }
-        if let channelMap {
+        if let channelMap = validatedChannelMap(converter) {
             converter.channelMap = channelMap
         } else {
             switch converter.outputFormat.channelCount {
@@ -60,6 +60,18 @@ struct IOAudioResamplerSettings {
             interleaved: inputFormat.isInterleaved
         )
     }
+
+    private func validatedChannelMap(_ converter: AVAudioConverter) -> [NSNumber]? {
+        guard let channelMap, channelMap.count == converter.outputFormat.channelCount else {
+            return nil
+        }
+        for inputChannel in channelMap {
+            if inputChannel.intValue >= converter.inputFormat.channelCount {
+                return nil
+            }
+        }
+        return channelMap
+    }
 }
 
 final class IOAudioResampler<T: IOAudioResamplerDelegate> {