[pulseaudio-discuss] [RFC v0 5/5] bluetooth: Dynamically change outgoing MTU

[Mikel Astiz]

Hi Tanu,

On Sun, Dec 16, 2012 at 10:08 AM, Tanu Kaskinen <tanuk at iki.fi> wrote:
> On Wed, 2012-04-11 at 09:00 +0200, Mikel Astiz wrote:
>> From: Mikel Astiz <mikel.astiz at bmw-carit.de>
>>
>> Dynamically change the size of the outgoing SCO packets according to
>> the size of the received ones.
>> ---
>>  src/modules/bluetooth/module-bluetooth-device.c |    4 ++++
>>  1 files changed, 4 insertions(+), 0 deletions(-)
>>
>> diff --git a/src/modules/bluetooth/module-bluetooth-device.c b/src/modules/bluetooth/module-bluetooth-device.c
>> index 6ab2c81..9f6d288 100644
>> --- a/src/modules/bluetooth/module-bluetooth-device.c
>> +++ b/src/modules/bluetooth/module-bluetooth-device.c
>> @@ -600,6 +600,10 @@ static int hsp_process_push(struct userdata *u) {
>>
>>          pa_assert((size_t) l <= pa_memblock_get_length(memchunk.memblock));
>>
>> +        /* Adapt size of outgoing blocks accordign to the size we just got */
>> +        if (u->write_block_size != (size_t) l)
>> +            u->write_block_size = (size_t) l;
>> +
>>          memchunk.length = (size_t) l;
>>          u->read_index += (uint64_t) l;
>>
>
> Is this still something that you'd like to have in pulseaudio? Luiz
> said[1] that there's need for more investigation, has any such
> investigation been done?
>
> [1] http://thread.gmane.org/gmane.comp.audio.pulseaudio.general/12982/focus=13309

There's some pending work so we don't have any conclusion yet.

This patch seemed to be required to have multiple simultaneous SCOs
(i.e. two headsets or phones connected and streaming audio) but we
don't understand exactly why, and depending on the Bluetooth chip it
doesn't seem necessary at all. In other words, we still have to do
more research.

We will probably reopen this topic early next year.

Cheers,
Mikel