[PATCH 0/2] iec958 plugin enhancements for HDMI

[Takashi Iwai]

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