According to Moxie[1], TextSecure does not pass media on to anything involving stagefright, unless/until you tell it to open it (which will popup a warning that things are leaving TS's sandbox).

1: https://github.com/WhisperSystems/TextSecure/issues/3817

This has been my experience using the app. If that's the case, then I think I should be fine.

I was just looking at the settings the other day. Per other comments in this topic, I'd look at disabling the MMS features; IIRC TextSecure also has user settings for this.

Edit: Just had a look. I do not have TextSecure as my default client. There is MMS configuration information, but not a simple "disable automatic retrieval" or similar setting, as there is in my default SMS/MMS client. I don't know whether one appears when TextSecure is the default client; I suspect not, and maybe this should be addressed?

It turns out that media attached to an MMS message is not decoded until you actually open the attachment. See: https://github.com/WhisperSystems/TextSecure/issues/3817

Thanks, moxie (he's on HN).

Maybe I will make TextSecure my default app. I'll give "the hype" a day or two to start sorting itself, while I have the "auto" stuff disabled in my current default app.

As an additional datapoint:

In my -and my lady friend's- experience, TextSecure is the the only app to correctly handle MMS group chat. We tried the stock Android app, the stock Samsung app, and Hangouts. They all failed to do the right thing in one way or the other.

I don't see any option to disable it and I use it as my default client.

According to this ticket TextSecure should auto download MMS:

http://support.whispersystems.org/customer/portal/questions/...

I, too was confused by that setting. It turns out that media attached to an MMS message is not decoded until you actually open the attachment. See: https://github.com/WhisperSystems/TextSecure/issues/3817