It is now possible to use the system's H264 decoder for webrtc calls, we should enable it by default. It allows for low-latency, typically hardware accelerated calls with webrtc peers using h264.

Great. How about we flip the pref for Nightly users on Mac? The other question is if with this change then H264 with hardware should be preferred over VP8? I assume we don't have any means to switch dynamically in the middle of the call if the hardware decoder fails. It would be great if we would have the ability to fall back to available software decoders in that case.

(In reply to Nils Ohlmeier [:drno] from comment #1) > Great. How about we flip the pref for Nightly users on Mac? > it works on all platform. > The other question is if with this change then H264 with hardware should be > preferred over VP8? H264 is almost universally HW accelerated on both mac and windows, on linux it will still be SW. VP8 can be HW accelerated only on recent Intel (generation 6 and later) and on windows only. > > I assume we don't have any means to switch dynamically in the middle of the > call if the hardware decoder fails. It would be great if we would have the > ability to fall back to available software decoders in that case. Actually, you can. If the HW decoder fail we have mechanism to retry (requiring a keyframe) and fallback to SW automatically.

(In reply to Nils Ohlmeier [:drno] from comment #1) > Great. How about we flip the pref for Nightly users on Mac? > > The other question is if with this change then H264 with hardware should be > preferred over VP8? I actually have a bug open to make VP9 the default if the machine has HW decoders (bug 1392962)

All H264 system's decoders now handle low latency mode and are typically hardware accelerated. Depends on D12431

Pushed by jyavenard@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/05fd55926206 P1. Use ffmpeg decoder for h264 in low latency mode. r=padenot https://hg.mozilla.org/integration/autoland/rev/1d3eb26cfeac P2. Use system's h264 decoder for webrtc call. r=padenot

Backed out for GTest crashes on [@ mozilla::AppleDecoderModule::Init()] Push link: https://treeherder.mozilla.org/#/jobs?repo=autoland&resultStatus=testfailed%2Cbusted%2Cexception%2Crunnable&searchStr=os%2Cx%2C10.10%2Cdebug%2Ctest-macosx64%2Fdebug-gtest%2C%28gtest%29&revision=1d3eb26cfeac0fd13ab376ab86cc1b2ccd1fdc82 Backout link: https://hg.mozilla.org/integration/autoland/rev/eb6978b0841764e17373c645ca5d29b5127ef3d5 Log link: https://treeherder.mozilla.org/logviewer.html#?job_id=212952160&repo=autoland&lineNumber=21993

There were also crashes on [@ mozilla::WMFDecoderModule::Init()] Log link: https://treeherder.mozilla.org/logviewer.html#?job_id=212963900&repo=autoland&lineNumber=22073

Also triggered a mda perma failure on test_peerConnection_basicH264Video.html Log link: https://treeherder.mozilla.org/logviewer.html#?job_id=212964686&repo=autoland&lineNumber=20007

While typically those will always be, when using through gtest it won't. Depends on D12432

The fake H.264 GMP encoder creates dummy frames that can't be decoded by anything but the fake GMP decoder. Depends on D12519

So that we can disable just the H264 decoders while allowing VP8 or VP9.

Pushed by jyavenard@mozilla.com: https://hg.mozilla.org/integration/autoland/rev/92a1eb79716c P1. Use ffmpeg decoder for h264 in low latency mode. r=padenot https://hg.mozilla.org/integration/autoland/rev/e89c4b9db24d P2. Use system's h264 decoder for webrtc call. r=padenot https://hg.mozilla.org/integration/autoland/rev/99321f96fd0c P3. Ensure gfxVars and gfxPrefs are always initialized when using PDMFactory. r=gerald https://hg.mozilla.org/integration/autoland/rev/7f62a35b4171 P4. Split preferences to enable WebRTC with MediaDataDecoder. r=padenot https://hg.mozilla.org/integration/autoland/rev/95d5bb21c934 P5. Don't use real H264 decoder with fake GMP encoder. r=dminor

https://hg.mozilla.org/mozilla-central/rev/92a1eb79716c https://hg.mozilla.org/mozilla-central/rev/e89c4b9db24d https://hg.mozilla.org/mozilla-central/rev/99321f96fd0c https://hg.mozilla.org/mozilla-central/rev/7f62a35b4171 https://hg.mozilla.org/mozilla-central/rev/95d5bb21c934