From: Clemens Ladisch <clemens@ladisch.de>
To: Zhang wei <zhangwei@vimicro.com>
Cc: alsa-devel@alsa-project.org
Subject: Re: what is the difference between SNDRV_PCM_FMTBIT_S24_LE and SNDRV_PCM_FMTBIT_S24_3LE
Date: Thu, 11 Apr 2013 11:35:57 +0200 [thread overview]
Message-ID: <516683FD.4000804@ladisch.de> (raw)
In-Reply-To: <6B947C8AC4195040A8C6876A496C644A082F1EEE@BJ-MAIL-04.vimicro.com>
(please do not drop the mailing list from replies.)
Zhang wei wrote:
> I do not really understand. For example,an codec is wm8985 ...
The SNDRV_PCM_* symbols specify the format in which samples are
stored in memory.
I do not know how ASoC maps these symbols to on-the-wire formats.
>>Most devices that support 24 bits use SNDRV_PCM_FORMAT_S32_LE, which
>>stores the sample's bits in the upper bits of a 32-bit word.
>
> But how to distinguish the SNDRV_PCM_FORMAT_S24_LE and the REAL
> SNDRV_PCM_FORMAT_S32_LE?
If a 24-bit sample with the value 0x123456 is stored in memory, it looks
like this:
SNDRV_PCM_FORMAT_S24_LE: 56 34 12 00
SNDRV_PCM_FORMAT_S32_LE: 00 56 34 12
Regards,
Clemens
next prev parent reply other threads:[~2013-04-11 9:35 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2013-04-11 8:55 what is the difference between SNDRV_PCM_FMTBIT_S24_LE and SNDRV_PCM_FMTBIT_S24_3LE Zhang wei
2013-04-11 9:00 ` Clemens Ladisch
[not found] ` <6B947C8AC4195040A8C6876A496C644A082F1EEE@BJ-MAIL-04.vimicro.com>
2013-04-11 9:35 ` Clemens Ladisch [this message]
2013-04-11 15:27 ` Gabriel M. Beddingfield
2013-04-30 13:24 ` Mark Brown
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