From: Jussi Laako <jussi@sonarnerd.net>
To: Jurgen Kramer <gtmkramer@xs4all.nl>, Takashi Iwai <tiwai@suse.de>
Cc: alsa-devel@alsa-project.org
Subject: Re: [PATCH] pcm: add new 32-bit DSD sample format
Date: Thu, 20 Nov 2014 21:07:06 +0200 [thread overview]
Message-ID: <546E3BDA.2040601@sonarnerd.net> (raw)
In-Reply-To: <1416501288.2996.1.camel@xs4all.nl>
On 20.11.2014 18:34, Jurgen Kramer wrote:
> DSD is a bit odd wrt LE/BE. Both formats are allowed and used.
> The device (XMOS based/Marantz+Denon) want the following order of
> samples:
> L1 L2 L3 L4 R1 R2 R3 R4. Where Lx/Rx are 8-bit DSD samples, L1-L4 are
> packed to 1 32-bit sample.
What you described is precisely interleaved big endian U32 sample
format. L1 is the MSB byte and L4 is the LSB byte of big-endian U32.
So "L1 L2 L3 L4" is equal to DSD_U32_BE. The currently advertised
DSD_U32_LE would be "L4 L3 L2 L1".
> I do think real BE will not work.
Why? Your description precisely matches U32_BE. And seems to work
correctly for me...
Constructing the U32 by having oldest bit in MSB and newest bit in LSB
and sending it out as little-endian results in incorrect output. Adding
byteswap to big-endian format results in correct output (either using
__builtin_byteswap32() or htonl()).
- Jussi
next prev parent reply other threads:[~2014-11-20 19:07 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-10 7:00 [PATCH] pcm: add new 32-bit DSD sample format Jurgen Kramer
2014-11-19 19:50 ` Jussi Laako
2014-11-20 9:58 ` Takashi Iwai
2014-11-20 16:34 ` Jurgen Kramer
2014-11-20 19:07 ` Jussi Laako [this message]
2014-11-21 9:11 ` Jussi Laako
2014-11-21 9:54 ` Takashi Iwai
2014-11-20 18:59 ` Jussi Laako
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=546E3BDA.2040601@sonarnerd.net \
--to=jussi@sonarnerd.net \
--cc=alsa-devel@alsa-project.org \
--cc=gtmkramer@xs4all.nl \
--cc=tiwai@suse.de \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox