On Mon, 13 Jul 2020 23:17:02 +0200, Matthias Reichl wrote: > > Testing with vc4-hdmi / Raspberry Pi 4 showed that the iec958 plugin > was missing two features required for HDMI compatibility: > > HD audio bitstreams like DTS HD MA or Dolby True HD are usually packed > into 8-channel 192kHz 16-bit frames but are in fact a single IEC 61937 > stream at 768kHz frame rate. So the data in the 8-channel frame has to > be formatted as 4 contiguous IEC 60958 frames. > > If channel status bits weren't set, iec958 indicated a sample rate of > 48kHz in the channel status bits which the HDMI analyzer complained about > and caused issues with some HDMI devices if it didn't match the real > rate. That was a long outstanding FIXME since the iec958 plugin was added. > > With this series HD audio passthrough and PCM audio works fine with > the downstream 5.4 RPi kernel. > > Matthias Reichl (2): > pcm: iec958: implement HDMI HBR audio formatting > pcm: iec958: set channel status bits according to rate and format Both patches look like a nice improvement. Applied now. Thanks! Takashi
