RTP Byte/Bitmapping for SIREN and G722.1 from Windows Messanger (searched)

[telefonie]

Hello,

Iliketo useIntel IPP G722.1 demo decoder to decode SIRENand G722.1.

My problem: Mircosoft Windows Messanger sends (SIP-Info: SIREN/16000) but the decoder722dont decode this siren data.

Because the decoder722 itselve workson SIREN data (Ive checked it with other siren data), the Byte or/and Bitmapping in the RTP-Payload must differ from the Decoder input.

Ive checkedthe length. after stripping rtp headerlength of raw-data per packet is ok with 40 octeds (bytes) = one frame.

I changed Bytes (toggle even with uneven Bytes). I changed bits in each Byte (most significant first, least significant first). I changed Byte and Bits. Nothing works.

Any idea?

Message Edited by telefonie on 10-13-2005 02:27 AM

Message Edited by telefonie on 10-13-2005 02:39 AM

Message Edited by telefonie on 10-18-2005 12:18 AM

[Vyacheslav_Baranniko]

Hello telefonie

actually, IPP G722.1 decoder input differs from RTP payload. IPP G722.1encoder composes a bitstreamof16bit wordso the input of IPP G722.1 decoder is,while RTP G722.1 payload is composed of octets. On a little endian machineleast significant byte of a word stored first in memory,whileRTP transmit most significant bytefirst, so RTPbytes to beswapped proir to passing them to IPP G722.1 decoder.

[telefonie]

Hello,

as metioned i changed byteorder already:

received:
byte1, byte2, byte3, byte4, byte5 ....

decoder input:
byte2, byte1, byte4, byte3, byte 6, ...

It didnt work anyway.

Greetings

telefonie

[raprap]

Telefonie, did you resolve this issue? I have the same exact problem,

[telefonie]

It didnt work with Microsoft rtp-data, till now. Microsoft is the only client who uses siren. Data Demo-Encoder from Patentholder id decodable after stripping of the header.

Microsoft often modify standards without documentation. At MS-GSM6.10 they modified also the packetization of RTP-Data. There I resolved it, but on Siren and G722.1 no documentation from Microsoft is available. Maybe we ask MS, but unfortunally my MS Univeral subscriptionwas running out at May.

We should keep in contact, to solve the Problem.

Regards

telefonie

[denis_birukov]

Have someone succseed with decoding Microsoft Siren (G722.1 on bitrate=16000?) I only can decode G722.1 from Messenger on bitrate=24000.