[pulseaudio-discuss] [RFC PATCH 0/2] HDMI IEC61937 + HBR passthrough support

Pierre-Louis Bossart pierre-louis.bossart at linux.intel.com
Mon Aug 28 22:49:15 UTC 2017


HDMI passthrough needs some love. What works with ALSA is plain
broken with PulseAudio (no audio or random noise). Only the AC3
format seems to work, EAC3 is broken and HBR formats are not
supported yet.

Fix EAC3 issues where the AES non-audio bit is not set when opening
the alsa-sink. The fix is to force a suspend/resume when an actual
sink-input is connected. This is far from optimal since we suspend/resume
twice (once for rate, once on entering passthrough) but the state
machine is obviously quite racy.

Add definitions for Dolby TrueHD and DTSHD. This needs additional
work since ALSA will only enable the HBR passthrough mode with
8 channels and 192kHz. For now the ALSA sinks are only configured to
support 2 channels for passthrough and we'd need to switch between 2
and 8 channels depending on the format. I don't quite understand how
the profiles are managed and could use some help here.

Pierre-Louis Bossart (2):
  pulsecore: sink: force suspend/resume on passthrough transitions
  alsa: add support for Dolby TrueHD and DTS-HD HBR passthrough

 src/pulse/format.c          |  2 ++
 src/pulse/format.h          |  8 ++++++++
 src/pulsecore/core-format.c |  6 +++++-
 src/pulsecore/sink.c        | 24 ++++++++++++++++++++++++
 src/pulsecore/sink.h        |  1 +
 5 files changed, 40 insertions(+), 1 deletion(-)

-- 
2.9.3



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