[pulseaudio-discuss] Timing interval for Bluetooth Wideband speech
nsathish41 at gmail.com
Tue Mar 27 06:39:55 UTC 2018
On Sat, Mar 17, 2018 at 1:26 AM, Tanu Kaskinen <tanuk at iki.fi> wrote:
> On Thu, 2018-03-15 at 14:49 +0530, Sathish Narasimman wrote:
> > Hi,
> > I would like to know the PulseAudio module that is responsible for
> > the audio for every 1 millisecond.
> > For NBS the packets are pushed with 48bytes and 1milli sec interval.
> Where does this 1 ms interval come from? The audio that pulseaudio
> writes with SCO is mono, 16-bit, 8000 Hz. With that specification 48
> bytes means 3 ms packets, not 1 ms.
> > But for WBS the timing between 2 SCO packets needs to be *7.5 Milli Sec.*
> > *May I know how to change the packet interval between the 2 SCO packets.*
> The write_block_size variable in src/modules/bluetooth/module-bluez5-
> device.c controls how big packets pulseaudio writes. That in turn is
> calculated based on write_link_mtu, and that comes from the transport
> acquire() callback. The ofono backend always returns 48 bytes. The
> native backend returns 48 bytes by default, but it can also be
> configured to ask the kernel what the real MTU is.
I am able to set the MTU to 60 bytes in the and able to make the SCO
But still, the data rate is maintained as 1 msec.
Do we need to introduce any latency in the PA?
As per core spec 5 , Vol 4 Part B of USB transaction the HCI
packet interval need to be 7.5msec.
Do we need to maintain the rate in PA?
> pulseaudio-discuss mailing list
> pulseaudio-discuss at lists.freedesktop.org
-------------- next part --------------
An HTML attachment was scrubbed...
More information about the pulseaudio-discuss