But I didn’t find how toĬonfigure this mode when establishing the connection. So I also want to try to work in ‘transparent’ mode, as you previously had explained. Is it any correlation between slot’s data and the mentioned packed size on SCO layer?ģ) Another my thought is the voice compression on the radio layer (I chose CVSD) may insert additional packet size/data alignments problems. HV3 High quality Voice(no error correction)30 data bytes transmitted every 6 slots HV2 High quality Voice(2/3 rate FEC) 20 data bytes transmitted every 4 slots HV1 High quality Voice(1/3 rate FEC) 10 data bytes transmitted every 2 slots These are my thoughts:ġ) In the case “the data in the request is not a multiple of the packet size used by the SCO layer” – is there any way to know this packet size? So I will pass to the SCO layer the expected data size.Ģ) In the case the answer 1) is negative, can you give a hint about approximate size of this SCO packet? Is it 10-30 bytes or 500, or may be 4-5 Kbytes?Īccording to the standard, the translated SCO data are placed in PHY slots, and its data and rate depend on the packet type: I would like to get some clarifications of this matter. I have set PacketType = SCO_PKT_ALL, supposing the SCO layer will select the best one.Ĭoncerning the incomplete send, it is a real problem. Following is my BRB:īrb->TransmitBandwidth = brb->ReceiveBandwidth = 8000 // 64Kb/sīrb->ContentFormat = SCO_VS_IN_CODING_LINEAR | SCO_VS_IN_SAMPLE_SIZE_8BIT | SCO_VS_AIR_CODING_FORMAT_CVSD īrb->RetransmissionEffort= SCO_RETRANSMISSION_NONE īrb->ChannelFlags = SCO_CF_LINK_SUPPRESS_PIN īrb->CallbackFlags = SCO_CALLBACK_DISCONNECT // Get notification about remote disconnectīrb->ReferenceObject = (PVOID) WdfDeviceWdmGetDeviceObject(DevCtx->Header.Device) Įgidio, thanks for the answers. What is possible problem? Is it some incorrect settings I pass to the connection BRB. Is not called! As result the application has stuck. But the following data sending fails as follows: WdfRequestSend() returns Ok, but the completion callback (passed to WdfRequestSetCompletionRoutine) I have tried also PacketType= SCO_HV2, SCO_HV3, SCO_EV3 (BTW what does it mean - SCO_EVx?) - the connection establishment completes Ok. When setting PacketType=SCO_HV1 value the result callback receives IoStatus.Status = C000000D (STATUS_INVALID_PARAMETER)!!!
#BLUETOOTH SCO AUDIO APP BLUETOOTH#
For voice compression, you need to follow the Bluetooth specifications of the profile you are implementing. If you are doing this just for fun and you are writing both side (sender and receiver), well, in this case you can define what you wantĪs long as you are consistent, play around and see what it works.
![bluetooth sco audio app bluetooth sco audio app](https://i.imgur.com/SfHjIA3.png)
#BLUETOOTH SCO AUDIO APP FREE#
When you are done with SCO, send a BRB_SCO_FLUSH_CHANNEL to free the last request, just in case there was any residual data in there.
![bluetooth sco audio app bluetooth sco audio app](https://ars.els-cdn.com/content/image/3-s2.0-B9781928994428500124-f09-07-9781928994428.jpg)
If latency is not an issue, send more data in the request, the more the better For example low latency: send at least 10msec data in each request. The amount of data in the request depends on the latency you want, more data you have, higher is the latency.
![bluetooth sco audio app bluetooth sco audio app](https://http2.mlstatic.com/soporte-base-para-audifonos-headsets-gamer-escritorio-D_NQ_NP_734715-MLM31373372889_072019-F.jpg)
the size of these fragments depend on the packet type used by the underline infrastructure. You should not depend on how the SCO layer fragments the data. About the packet types, use the BRB_SCO_GET_SYSTEM_INFO to find out the supported packet types.