==================================================================================== EVS Codec 3GPP TS26.442 Jun 30, 2015. Version CR 26.442-0010 ==================================================================================== These files represent the 3GPP EVS Codec BASOP C simulation. All code is written in ANSI-C. The system is implemented as two separate programs: EVS_cod Encoder EVS_dec Decoder For encoding using the coder program, the input is a binary audio file (*.8k, *.16k, *.32k, *.48k) and the output is a binary encoded parameter file (*.192). For decoding using the decoder program, the input is a binary parameter file (*.192) and the output is a binary synthesized audio file (*.8k, *.16k, *.32k, *.48k). FILE FORMATS: ============= The file format of the supplied binary data (*.8k, *.16k, *.32k, *.48k, *.192) is 16-bit binary data which is read and written in 16 bit words. The data is therefore platform DEPENDENT. The files contain only data, i.e., there is no header. The test files included in this package are "PC" format, meaning that the least signification byte of the 16-bit word comes first in the files. If the software is to be run on some other platform than PC, such as an HP (HP-UX) or a Sun, then binary files will need to be modified by swapping the byte order in the files. The input and output files (*.8k, 16k, 32k, 48k) are 16-bit signed binary files with 8/16/32/48 kHz sampling rate with no headers. The Encoder produces bitstream files in either ITU G.192 or EVS-MIME file storage format. Using ITU G.192 format: For every 20 ms input audio frame, the encoded bitstream using ITU G.192 format contains the following data: Word16 SyncWord Word16 DataLen Word16 1st Databit Word16 2nd DataBit . . . Word16 Nth DataBit The SyncWord from the encoder is always 0x6b21. If decoder receives SyncWord as 0x6b20 it indicates that the current frame was received in error (bad frame). The DataLen parameter gives the number of audio data bits in the frame. For example using DTX, DataLen for NO_DATA frames is zero. Each bit is presented as follows: Bit 0 = 0x007f, Bit 1 = 0x0081. Using MIME file storage format: The MIME file storage format is a byte based format which is appropriate for media file storage or as format for email/MMS attachments. Encoder: With the "-mime" option, the encoder always produces EVS-mime format specified in TS26.445 Annex.2.6. The AMRWB-mime(RFC4867) storage format is not supported by the encoder. Decoder: With the "-mime" option, the decoder can parse both EVS-mime format storage files and AMRWB-mime (RFC4867) storage format files. The decoder automatically distinguishes between the two mime storage formats by reading the initial Magic Word in the bitstream file. The EVS-mime storage format is described in TS 26.445, Annex A.2.6. The AMRWB-mime storage format is described in RFC-4867. INSTALLING THE SOFTWARE ======================= Installing the software on the PC: First unpack the compressed folder into your directory. After that you should have the following structure: . `-- c-code |-- Makefile |-- Workspace_msvc |-- basic_math |-- basic_op |-- lib_com |-- lib_dec |-- lib_enc `-- readme.txt The package includes a Makefile for gcc, which has been verified on 32-bit Linux systems. The code can be compiled by entering the directory "c-code" and typing the command: make. The resulting encoder/decoder executables are named "EVS_cod" and "EVS_dec". Both reside in the c-code directory. The package also includes solution-file for Microsoft Visual Studio 2008 (x86). To compile the code, please open "Workspace_msvc\Workspace_msvc.sln", and build "evs_enc" for the encoder and "evs_dec" for the decoder executable. The resulting encoder/decoder executables are named "EVS_cod.exe" and "EVS_dec.exe". Both reside in the c-code directory. RUNNING THE SOFTWARE ==================== The usage of the "EVS_cod" program is as follows: Usage: EVS_cod [Options] R Fs input_file bitstream_file Mandatory parameters: --------------------- R : Bitrate in bps, for EVS native modes R = (5900*, 7200, 8000, 9600, 13200, 16400, 24400, 32000, 48000, 64000, 96000, 128000) *VBR mode (average bitrate), for AMR-WB IO modes R = (6600, 8850, 12650, 14250, 15850, 18250, 19850, 23050, 23850) Alternatively, R can be a bitrate switching file which consits of R values indicating the bitrate for each frame in bit/s. These values are stored in binary format using 4 bytes per value Fs : Input sampling rate in kHz, Fs = (8, 16, 32 or 48) input_file : Input signal filename bitstream_file : Output bitstream filename Options: -------- -q : Quiet mode, no frame counters : default is deactivated -dtx D : Activate DTX mode, D = (0, 3-100) is the SID update rate where 0 = adaptive, 3-100 = fixed in number of frames, default is deactivated -dtx : Activate DTX mode with a SID update rate of 8 frames -rf p o : Activate channel-aware mode for WB and SWB signal at 13.2kbps, where FEC indicator, p: LO or HI, and FEC offset, o: 2, 3, 5, or 7 in number of frames. Alternatively p and o can be replaced by a rf configuration file with each line contains the values of p and o separated by a space, default is deactivated -max_band B : Activate bandwidth limitation, B = (NB, WB, SWB or FB) alternatively, B can be a text file where each line contains "nb_frames B" -no_delay_cmp : Turn off delay compensation -mime : Mime output bitstream file format The encoder produces TS26.445 Annex.2.6 Mime Storage Format, (not RFC4867 Format) default output bitstream file format is G.192 The usage of the "EVS_dec" program is as follows: Usage: EVS_dec [Options] Fs bitstream_file output_file Mandatory parameters: --------------------- Fs : Output sampling rate in kHz (8, 16, 32 or 48) bitstream_file : Input bitstream filename or RTP packet filename (in VOIP mode) output_file : Output speech filename Options: -------- -VOIP : VOIP mode, -Tracefile TF : Generate trace file named TF, -no_delay_cmp : Turn off delay compensation -fec_cfg_file : Output of the channel aware configuration. The outptut is written into a .txt file. Each line contains the FER indicator (HI|LO) and optimum FEC offset. -mime : Mime input bitstream file format The decoder reads both TS26.445 Annex.2.6 and RFC4867 Mime Storage Format, the magic word in the mime input file is used to determine the format. default input bitstream file format is G.192 -q : Quiet mode, no frame counter default is OFF