From: Richard Cochran <richardcochran@gmail.com>
To: Henrik Austad <henrik@austad.us>
Cc: linux-kernel@vger.kernel.org, linux-media@vger.kernel.org,
alsa-devel@vger.kernel.org, netdev@vger.kernel.org,
henrk@austad.us, Arnd Bergmann <arnd@linaro.org>
Subject: Re: [very-RFC 0/8] TSN driver for the kernel
Date: Mon, 13 Jun 2016 21:51:36 +0200 [thread overview]
Message-ID: <20160613195136.GC2441@netboy> (raw)
In-Reply-To: <20160613114713.GA9544@localhost.localdomain>
On Mon, Jun 13, 2016 at 01:47:13PM +0200, Richard Cochran wrote:
> 3. ALSA support for tunable AD/DA clocks. The rate of the Listener's
> DA clock must match that of the Talker and the other Listeners.
> Either you adjust it in HW using a VCO or similar, or you do
> adaptive sample rate conversion in the application. (And that is
> another reason for *not* having a shared kernel buffer.) For the
> Talker, either you adjust the AD clock to match the PTP time, or
> you measure the frequency offset.
Actually, we already have support for tunable clock-like HW elements,
namely the dynamic posix clock API. It is trivial to write a driver
for VCO or the like. I am just not too familiar with the latest high
end audio devices.
I have seen audio PLL/multiplier chips that will take, for example, a
10 kHz input and produce your 48 kHz media clock. With the right HW
design, you can tell your PTP Hardware Clock to produce a 10000 PPS,
and you will have a synchronized AVB endpoint. The software is all
there already. Somebody should tell the ALSA guys about it.
I don't know if ALSA has anything for sample rate conversion or not,
but haven't seen anything that addresses distributed synchronized
audio applications.
Thanks,
Richard
next prev parent reply other threads:[~2016-06-13 19:52 UTC|newest]
Thread overview: 56+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-11 23:01 [very-RFC 0/8] TSN driver for the kernel Henrik Austad
2016-06-11 23:01 ` [very-RFC 1/8] TSN: add documentation Henrik Austad
2016-06-11 23:01 ` [very-RFC 2/8] TSN: Add the standard formerly known as AVB to the kernel Henrik Austad
2016-06-11 23:01 ` [very-RFC 3/8] Adding TSN-driver to Intel I210 controller Henrik Austad
2016-06-11 23:01 ` [very-RFC 4/8] Add TSN header for the driver Henrik Austad
2016-06-11 23:01 ` [very-RFC 5/8] Add TSN machinery to drive the traffic from a shim over the network Henrik Austad
2016-06-11 23:01 ` [very-RFC 6/8] Add TSN event-tracing Henrik Austad
2016-06-12 16:58 ` Steven Rostedt
2016-06-12 21:25 ` Henrik Austad
2016-06-13 2:22 ` Steven Rostedt
2016-06-13 7:20 ` Henrik Austad
2016-06-11 23:01 ` [very-RFC 7/8] AVB ALSA - Add ALSA shim for TSN Henrik Austad
2016-06-15 11:49 ` Richard Cochran
2016-06-15 12:13 ` Henrik Austad
2016-06-15 12:43 ` Richard Cochran
2016-06-11 23:01 ` [very-RFC 8/8] MAINTAINERS: add TSN/AVB-entries Henrik Austad
2016-06-13 11:47 ` [very-RFC 0/8] TSN driver for the kernel Richard Cochran
2016-06-13 13:00 ` Henrik Austad
2016-06-13 19:32 ` Richard Cochran
2016-06-14 9:30 ` Henrik Austad
2016-06-14 18:26 ` Richard Cochran
2016-06-14 20:38 ` Henrik Austad
2016-06-15 7:04 ` Richard Cochran
2016-06-15 7:50 ` Henrik Austad
2016-06-15 11:41 ` Richard Cochran
2016-06-15 7:11 ` Richard Cochran
2016-06-13 19:37 ` Richard Cochran
2016-06-13 13:12 ` Arnd Bergmann
2016-06-13 15:56 ` John Fastabend
2016-06-14 8:35 ` Henrik Austad
2016-06-13 19:51 ` Richard Cochran [this message]
2016-06-14 11:18 ` One Thousand Gnomes
2016-06-14 17:04 ` Richard Cochran
2016-06-15 3:15 ` Takashi Sakamoto
2016-06-15 8:06 ` Richard Cochran
2016-06-18 5:22 ` Takashi Sakamoto
2016-06-18 22:45 ` Henrik Austad
2016-06-19 9:46 ` Richard Cochran
2016-06-20 8:05 ` Henrik Austad
2016-06-20 11:08 ` [alsa-devel] " Pierre-Louis Bossart
2016-06-20 11:49 ` Henrik Austad
2016-06-20 12:18 ` Richard Cochran
2016-06-20 12:31 ` Richard Cochran
2016-06-20 15:21 ` Richard Cochran
2016-06-21 5:54 ` Takashi Iwai
2016-06-21 6:38 ` Richard Cochran
2016-06-21 6:45 ` Takashi Iwai
2016-06-21 17:18 ` Pierre-Louis Bossart
2016-06-21 17:45 ` Pierre-Louis Bossart
2016-06-21 19:40 ` Richard Cochran
2016-06-22 12:36 ` Pierre-Louis Bossart
2016-06-23 10:38 ` Henrik Austad
2016-06-23 13:28 ` Richard Cochran
2016-06-15 3:27 ` Takashi Sakamoto
-- strict thread matches above, loose matches on Subject: below --
2016-06-11 22:22 Henrik Austad
2016-06-11 22:49 ` Henrik Austad
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