-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi Sara,
RTP is a complex networking protocol, so you will have to write a decoder for this, and also for the numerous audio formats that may be contained within, if you want GNU Radio to actually do something with the speech within. If you only want to look at the packets as bytes of payload, as Marcus said, just use a UDP source. GNU Radio is about signal processing much more than about application-specific protocol decoding; both problems are fundamentally different. Given the "modern" PDU capabilities, decoding network protocol data is not entirely impossible, but it's still cumbersome. Allow me a comparison: decoding an RTP stream including the numerous audio payloads that might be contained using GNU Radio is comparably elegant as demodulating FM radio with a webserver. But: there are numerous open source RTP decoder libraries available, and that's what twinklephone uses to decode the packets. I think the right thing to do is use a library which decodes RTP and the contained compressed audio and gives you PCM samples, and feed this sample stream into GNU Radio. This could be done inside a GNU Radio block, but I think it would be easier to just use an external executable and let that stream audio into your flowgraph, for example using a UDP or TCP socket, or a named pipe. Considering that, with some ALSA hackery, you can have a loopback audio device, you could even just use the soft phone of your choice to generate audio samples that you capture using the GNU Radio audio source. Greetings, Marcus On 19.06.2014 14:11, Marcus D. Leech wrote: > On 06/19/2014 07:54 AM, Sara Chérif wrote: >> Hi, I want to capture packets coming from Twinkle Soft phone in >> gnuradio, these packet are RTP packets . But in gnuradio , there >> is only UDP or TCP source ! I can't find Raw source to correspond >> to the RTP packets. Is there an alternative to RAW source in >> GNUradio ? Thanks. >> >> >> _______________________________________________ Discuss-gnuradio >> mailing list Discuss-gnuradio@gnu.org >> https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > RTP is usually carried over UDP > > > > > _______________________________________________ Discuss-gnuradio > mailing list Discuss-gnuradio@gnu.org > https://lists.gnu.org/mailman/listinfo/discuss-gnuradio > -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBAgAGBQJToth9AAoJEBQ6EdjyzlHtlkYH/3L15S8wnBoq4rtE4woyhiGB 6GebGSmhb2co2I2yy3eFil0FITdDgamZDhv2S1TAe2Hk5O0hNUAQ6MJ1XO8p5G4X zwMdmJ4RwV3owaG59Cf3wWl9gWilOY65blk3DVcek0Q6/fMg42peNrHheEDZmZAo Zk3QbWmkRImgiYM3od1Jg4+Ho5S4LLGJVUzCIIEHC5qWTHt25Pq8803cvscaRvVE LLmtXj1GFofatOPbR6520zNMhObpknWvqfVyvFlUWSOlpTN0FR3nO/KJeXxsGVq+ 3UMVcZpU9tk2RRj/UoYDqppK2eDp3VvV4HCsbVt5zJq8xxbuVGEotn1P8XTsHOo= =4etW -----END PGP SIGNATURE----- _______________________________________________ Discuss-gnuradio mailing list Discuss-gnuradio@gnu.org https://lists.gnu.org/mailman/listinfo/discuss-gnuradio
