Bug 1482841 - P2. Fix opus in mp4 decoding. r=padenot

Differential Revision: https://phabricator.services.mozilla.com/D3233

dom/media/mp4/DecoderData.cpp

@@ -74,12 +74,16 @@ MP4AudioInfo::Update(const Mp4parseTrackInfo* track,
     // The Opus decoder expects the container's codec delay or
     // pre-skip value, in microseconds, as a 64-bit int at the
     // start of the codec-specific config blob.
-    MOZ_ASSERT(audio->extra_data.data);
-    MOZ_ASSERT(audio->extra_data.length >= 12);
-    uint16_t preskip =
-      mozilla::LittleEndian::readUint16(audio->extra_data.data + 10);
-    mozilla::OpusDataDecoder::AppendCodecDelay(mCodecSpecificConfig,
-        mozilla::FramesToUsecs(preskip, 48000).value());
+    if (audio->codec_specific_config.data &&
+        audio->codec_specific_config.length >= 12) {
+      uint16_t preskip = mozilla::LittleEndian::readUint16(
+        audio->codec_specific_config.data + 10);
+      mozilla::OpusDataDecoder::AppendCodecDelay(
+        mCodecSpecificConfig, mozilla::FramesToUsecs(preskip, 48000).value());
+    } else {
+      // This file will error later as it will be rejected by the opus decoder.
+      mozilla::OpusDataDecoder::AppendCodecDelay(mCodecSpecificConfig, 0);
+    }
   } else if (track->codec == MP4PARSE_CODEC_AAC) {
     mMimeType = NS_LITERAL_CSTRING("audio/mp4a-latm");
   } else if (track->codec == MP4PARSE_CODEC_FLAC) {

dom/media/test/manifest.js

@@ -283,6 +283,8 @@ var gPlayTests = [
   // Ambisonics AAC, requires AAC extradata to be set when creating decoder (see bug 1431169)
   // Also test 4.0 decoding.
   { name:"ambisonics.mp4", type:"audio/mp4", duration:16.48 },
+  // Opus in MP4 channel mapping=0 sample file
+  { name:"opus-sample.mp4", type:"audio/mp4; codecs=opus", duration:10.92 },
 
   { name:"small-shot.m4a", type:"audio/mp4", duration:0.29 },
   { name:"small-shot.mp3", type:"audio/mpeg", duration:0.27 },

dom/media/test/mochitest.ini

@@ -506,6 +506,8 @@ support-files =
   no-cues.webm^headers^
   notags.mp3
   notags.mp3^headers^
+  opus-sample.mp4
+  opus-sample.mp4^headers^
   owl-funnier-id3.mp3
   owl-funnier-id3.mp3^headers^
   owl-funny-id3.mp3

dom/media/test/opus-sample.mp4^headers^

@@ -0,0 +1 @@
+Cache-Control: no-store