On Fri, Aug 23, 2024 at 10:22 PM Tom Ritter <[email protected]> wrote:
> Sorry for not replying to the intent to prototype email, I've been out > for a bit. I was trying to figure out how much, if anything, this > exposed from a fingerprinting point of view - it seems to be almost > nothing, less actually than MediaCapabilities, but I did find the > following I wanted to check on: > > - > https://searchfox.org/mozilla-central/rev/ea91f336d0004ca28c909da948cb363f3e560877/dom/media/platforms/PEMFactory.cpp#80 > - This will expose if the user has EME enabled, which is not very > concerning, you can check that lots of ways > Web Codecs doesn't deal with EME at all, only with clear media. > > - > https://searchfox.org/mozilla-central/rev/ea91f336d0004ca28c909da948cb363f3e560877/dom/media/platforms/ffmpeg/FFmpegDataDecoder.cpp#310-313 > - It looks like this defers codec checking to libav, which is > subclassed based on the version of the library the user has? I doubt > this is different in practice, right? > On all OSes, this classes will use a subsetted version of FFmpeg that is vendored, for all royalty-free codecs. On Linux Desktop, this will load the system's libraries, and use them for non-royalty-free codec (downstream can make it so some royalty-free codecs will use the system libraries as well). The version itself isn't exposed. > > - > https://searchfox.org/mozilla-central/rev/ea91f336d0004ca28c909da948cb363f3e560877/dom/media/platforms/android/AndroidEncoderModule.cpp#19-26 > - This is probably the most worrisome to me, it seems like you'd be > able to determine if a user has hardware support for these codecs. > This isn't shipped (desktop only for now), and is going to return the same info as https://developer.mozilla.org/en-US/docs/Web/API/MediaCapabilities. We've added something based on the resist fingerprinting pref on the decode side a long time ago, we can very much do the same thing on the encode side, and verify it's all good at the same time. I filed https://bugzilla.mozilla.org/show_bug.cgi?id=1914839 to address this. Thanks, Paul. > > -tom > > On Wed, Aug 14, 2024 at 4:21 AM 'Paul Adenot' via > [email protected] <[email protected]> wrote: > > > > As of Firefox 130 I intend to turn Web Codecs API on by default on all > desktop platforms. It has been developed behind the > dom.media.webcodecs.enabled preference, and the part of the API related to > images is not shipping at this time, but has been implemented, it is likely > to ship later this year. Audio and Video, and encoding and decoding is > supported. The API has been shipping in Chromium for some time, and > implementation in WebKit is underway (https://wpt.fyi/results/webcodecs > shows the state of things). > > > > Bug to turn on by default: > http://bugzilla.mozilla.org/show_bug.cgi?id=1908572 is the bug to enable, > and https://bugzilla.mozilla.org/show_bug.cgi?id=webcodecs is the meta > bug for this. > > > > Standard: https://w3c.github.io/webcodecs/, in the W3C Media Working > Group > > > > This feature was previously discussed in this "Intent to prototype" > thread: > https://groups.google.com/a/mozilla.org/g/dev-platform/c/3g0fnn6682A > > > > Let me know if you have any questions, > > > > Paul. > > > > -- > > You received this message because you are subscribed to the Google > Groups "[email protected]" group. > > To unsubscribe from this group and stop receiving emails from it, send > an email to [email protected]. > > To view this discussion on the web visit > https://groups.google.com/a/mozilla.org/d/msgid/dev-platform/CANWt0Wpc1t1%3Dam19oQt%3DKDpts_Fbv7nqMZ3VB2KepPBUJQrWqw%40mail.gmail.com > . > -- You received this message because you are subscribed to the Google Groups "[email protected]" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To view this discussion on the web visit https://groups.google.com/a/mozilla.org/d/msgid/dev-platform/CANWt0WrLCWcKPS7MXjgJ%3DiQ7ftkepPnC4NFNFm%2Bc%2BCEF7MZ%2B%3DA%40mail.gmail.com.
