IETF RFC4867 defines the RTP payload formats and storage formats for AMR and AMR_WB codecs. Iu Framing is not supported for the EVS codec.Header-full format (section A.2.2 of 3GPP TS26.445) is not supported. For EVS codec, only the compact payload format is supported (section A.2.1 of 3GPP TS26.445).Supports only 1 codec frame per packet.Supports only single channel for all codecs suppoted.This version has the following limitations: The raw file can be imported by Audacity with import -> raw data.
To generate a raw file with the 3GPP decoder use the following command on a console:ĮVS_dec.exe -mime 48 my_evs_mime_file.evs-mime out_raw_file.raw * Note: 3GPP specifications are freely available at the 3GPP site.
The source code can easily be compiled for Windows and Linux. The C source code and a windows executable of this decoder can be found inside 3GPP TS26.442 (fixed-point) and TS26.443 (floating-point). evs-mime files is to convert them to raw PCM using the decoder provided by 3GPP. Your best chance to play the content of the generated. I have not found any media player that can play files with the EVS content format specified in section A.2.6 of 3GPP TS26.445. The following command, for example, converts AMR to PCM:įfmpeg.exe -i amrwbencodedfile.amr pcmencodedfile.wav EVS If you want to play the output file in a media player that does not support AMR / AMR-WB, then use ffmpeg to convert AMR / AMR-WB to MP3, PCM or any other format. Note: Iu framing is not supported for EVS codec yet. framing can take values 'ietf' (RFC4867 bandwidth efficient) or 'iu' (3GPP TS25.415).If no value is specified, then the script will try to guess the codec and exit with a message if the codec could not be guessed. codec can take values 'amr', 'amr-wb' or 'evs'.outputamrwbencodedaudio is the name of the output file with the extracted AMR / AMR-WB audio.In principle, it should contain only the RTP flow that you want to extract into an audio file for listening on your PC. rtpfilteredpcap must be a pcap or pcapng file filtered to include only RTP data.
This script requires python3 and its modules scapy and bitarray. Extracts AMR, AMR-WB or EVS frames from RTP inside PCAP files and builds a.
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