On Tue, Nov 30, 2010 at 1:59 AM, Clemens Ladisch <clemens@xxxxxxxxxx> wrote: > Mark Rages wrote: >> I would like to play some audio sampled at 96 kHz. But I don't appear >> to have this enabled: >> >> markrages@markrages-desktop:~$ cat /proc/asound/card*/codec#0 | grep rates >> rates [0x7f]: 8000 11025 16000 22050 32000 44100 48000 >> rates [0x60]: 44100 48000 >> rates [0x7f]: 8000 11025 16000 22050 32000 44100 48000 >> >> But the same file lists "Codec: Analog Devices AD1986A". I looked up >> the datasheet, and the AD1986A is able to support 96 kHz sampling with >> "Double rate audio". > > "Double rate audio" is a special AC'97 mode that reuses some surround > channels to transport more samples for the two front channels. (AC'97 > doesn't have enough bandwidth for more channels at 96 kHz.) > > HDA assumes that all DACs can run at the same sample rate. However, it > looks as if this chip is just an AC'97 core that also has a HDA frontend, > so it cannot run all DACs at 96 kHz, so it completely disallows 96 kHz > when connected to a HDA controller. > > (All HDA controllers would support 96 kHz playback, but as for AC'97, > only the Intel driver has double-rate support.) > Excellent answer. Thank you. Regards, Mark markrages@gmail -- Mark Rages, Engineer Midwest Telecine LLC markrages@xxxxxxxxxxxxxxxxxxx _______________________________________________ Linux-audio-user mailing list Linux-audio-user@xxxxxxxxxxxxxxxxxxxx http://lists.linuxaudio.org/listinfo/linux-audio-user
