From 44dcbbb1cd615634c09d1bf31c124332795903a8 Mon Sep 17 00:00:00 2001 From: Daniel Mack Date: Wed, 17 Apr 2013 00:01:39 +0800 Subject: ALSA: snd-usb: add support for bit-reversed byte formats There is quite some confusion around the bit-ordering in DSD samples, and no general agreement that defines whether hardware is supposed to expect the oldest sample in the MSB or the LSB of a byte. ALSA will hence set the rule that on the software API layer, bytes always carry the oldest bit in the most significant bit of a byte, and the driver has to translate that at runtime in order to match the hardware layout. This patch adds support for this by adding a boolean flag to the audio format struct. Signed-off-by: Daniel Mack Signed-off-by: Takashi Iwai --- sound/usb/card.h | 1 + 1 file changed, 1 insertion(+) (limited to 'sound/usb/card.h') diff --git a/sound/usb/card.h b/sound/usb/card.h index ac55477ce6dd..bf2889a2cae5 100644 --- a/sound/usb/card.h +++ b/sound/usb/card.h @@ -29,6 +29,7 @@ struct audioformat { unsigned char clock; /* associated clock */ struct snd_pcm_chmap_elem *chmap; /* (optional) channel map */ bool dsd_dop; /* add DOP headers in case of DSD samples */ + bool dsd_bitrev; /* reverse the bits of each DSD sample */ }; struct snd_usb_substream; -- cgit v1.2.3