On Wed, Jul 19, 2023 at 02:39:44PM +0200, Takashi Iwai wrote: > On Wed, 19 Jul 2023 14:27:21 +0200, > Ico Bukvic wrote: > > > > > > Thank you, Takashi. > > > > On Raspberry Pi 400 (one with built-in keyboard, although any RPi or Linux > > computer with HDMI monitor with loudspeakers will do), open pd-l2ork (a > > variant of pure-data available at http://bit.ly/pd-l2ork; pure-data also has > > this same problem) and enable DSP. Do the same after changing audio settings > > via the Preferences window (Edit->Preferences), where you can switch among > > backends (ALSA vs Portaudio, vs JACK; JACK does not work with any setting). If > > you have proper audio settings (0 in, 2 out, and a supported SR, r.g. > > 44,1kHz), you will hear the buzz, and will also hear the desired audio > > produced (e.g. by running Media->Audio Tester) faintly, with buzz bring at the > > forefront. Or, you will hear everything OK (default Pulse settings), or > > nothing. ALSA and PortAudio settings are default Raspbian(RPi)/Ubuntu > > (desktop). Thank you. > > Well, the question is how the ALSA PCM device is opened, how > configured and how played. As Geraldo already suggested, VC4 HDMI on > RPi has a special format with IEC958 encoding. Also it has IEC958 > status bit setups. So, for example, if you'd need to play a normal > PCM stream with aplay, you'd need to open the device with "hdmi:$CARD" > device -- then the rest is done in alsa-lib's plugin, and that's > almost equivalent with what PA does. Hi Takashi, thanks for taking Ico's report. Perhaps the right configuration that he needs to use aplay could be: https://github.com/alsa-project/alsa-lib/blob/master/src/conf/cards/vc4-hdmi.conf That is, if I understand correctly? Thanks, Geraldo Nascimento
