streaming

This issue report complains that Edge doesn’t stream AAC files and instead tries to download them. It notes that, in contrast, URLs that point to MP3s result in a simple audio player loading inside the browser.

Edge has always supported AAC so what’s going on?

The issue here isn’t about AAC, per-se; it’s instead about whether or not the browser, upon direct navigation to an audio stream, will accommodate that by generating a wrapper HTML page with an <audio> element pointed at that audio stream URL.

PlaceholderPage

A site that wants to play streaming AAC in Edge (or, frankly, any media type, for any browser) should consider creating a HTML page with an appropriate Audio or Video element pointed at the stream.

The list of audio types for which Edge will automatically generate a wrapper page does not include AAC:

audio/mp4, audio/x-m4a, audio/mp3, audio/x-mp3, audio/mpeg,
audio/mpeg3, audio/x-mpeg, audio/wav, audio/wave, audio/x-wav,
audio/vnd.wave, audio/3gpp, audio/3gpp2

In contrast, Chrome creates the MediaDocument page for a broader set of known audio types:

static const char* const kStandardAudioTypes[] = {
 "audio/aac",  "audio/aiff", "audio/amr",  "audio/basic",  "audio/flac",
 "audio/midi",  "audio/mp3",  "audio/mp4",  "audio/mpeg",  "audio/mpeg3", 
 "audio/ogg", "audio/vorbis",  "audio/wav",  "audio/webm",  "audio/x-m4a",
 "audio/x-ms-wma",  "audio/vnd.rn-realaudio",  "audio/vnd.wave"};

If the the response sends Content-Type: application/octet-stream, includes a Content-Dispostion: attachment, or puts a download attribute on the anchor <a> element that leads to the media, Edge will download the media file instead of playing it in the browser.

Note: In Windows 10 RS5, the extension model is capable enough that it’s possible to write a browser extension that intercepts navigation directly to audio/video Media types and renavigates to a wrapper page. [Sample code]

-Eric

PS: Edge has similar special handling for video types:

"application/mp4","video/mp4","video/x-m4v","video/3gpp",
"video/3gpp2","video/quicktime"