rohc

about pcap file "test\report\samples\ipv4\udp\rtp\voip"

Asked by qingbaibai

hello,

I use the pcap file "test\report\samples\ipv4\udp\rtp\voip" to test my code. I open it with wireshark. I use the "telephony\VoIP calls" to analysis the file. It shows " detected 0 VoIP calls". I want to know the VoIP codec because I want to listen it to make sure that the voice is acceptable after decompressing. Thank you.

Regards,
qingbaibai

Question information

Language:
English Edit question
Status:
Solved
For:
rohc Edit question
Assignee:
No assignee Edit question
Solved by:
qingbaibai
Solved:
Last query:
Last reply:
Revision history for this message
Didier Barvaux (didier-barvaux) said : 		#1

Hello,

The RTP frames contains data referenced as Payload Type (PT) = 114. A search on the web reports that PT=114 refers to x-msrta. This format seems to used in MSN messenger. So the capture was probably a dump of a MSN messenger audio chat. However I do not know how to listen to it. Probably dump all RTP payloads in a file then find a compatible audio player...

About your last words "to make sure that the voice is acceptable after decompressing": ROHC compression is lossless, so the decompressed packets are functionally equivalent (if not equal bit per bit) to the source packets. Except if you find bugs, the voice after decompression is as acceptable as the voice before compression.

Regards,
Didier

Revision history for this message
qingbaibai (sunqing-cztz) said : 		#2

hello,

I need to test the code under the condition of packet loss. Therefore, I want to listen to it. Thank you.

Regards,
qingbaibai