Convert RAW iq samples to SDRAngel "sdriq" format

ConvertRawToSDRAngel.py

#! /bin/env python3
"""
Convert raw IQ samples to SDRIQ with header, suitable for batch processing

for use with RTL_SDR convert from unsigned 8 bit to signed 16 bit samples. using rtl_433 

.cu8 - RTL_SDR Raw samples (collected via rtl_tcp)
.cs16 - converted samples for this script (or raw data from a 16 bit SDR) 

Converting formats: 

rtl_433 -w output.cs16 input.cu8 

## License

Changes Copyright 2022 Andrey K. Shmakov

Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

## Changelog

V3 - Added buffered copy of 128MB for large files where file.read() fails

V2 - Changed interface to consume list of files, automatically calculate fout name
Added safety and with statements for file operations

Added filename extraction for frequency and sample rate

ala https://triq.org/pdv/ and recomendations per https://triq.org/rtl_433/IQ_FORMATS.html

V1 - https://gist.github.com/kbeckmann/6db25501ff02c46e79143c0ed1c47d88, Unknown License
"""
 

import sys
import struct
import binascii
import os

COPY_BLOCK_SIZE=128000000

def get_sr(fname):
    loc = fname.lower().find('sps')
    if loc != -1:
        prefix = fname[loc-1]
        mult = 1
        if prefix in ['k','K']:
            mult = 1000
        elif prefix in['m','M']:
            mult = 1000000           
        elif not(prefix.isnumeric()):
            print("Unknown prefix in sample rate: ", prefix)
            return False

        i =  1 if prefix.isnumeric() else  2
        while fname[loc-i].isnumeric():
            i = i+1

        num = fname[loc - i + 1: loc if prefix.isnumeric() else loc-1]
        return int(num)*mult 

    else:
        return False
        
def get_f(fname):
    loc = fname.lower().find('hz')
    if loc != -1:
        prefix = fname[loc-1]
        mult = 1
        if prefix in ['k','K']:
            mult = 1000
        elif prefix in['m','M']:
            mult = 1000000           
        elif not(prefix.isnumeric()):
            print("Unknown prefix in frequency: ", prefix)
            return False

        i =  1 if prefix.isnumeric() else  2
        while fname[loc-i].isnumeric() or fname[loc-i] == '.':
            i = i+1

        num = fname[loc - i + 1: loc if prefix.isnumeric() else loc-1]
        return int(float(num)*mult) 

    else:
        return False
    

# See https://github.com/f4exb/sdrangel/tree/master/plugins/samplesource/filesource
for ifname in sys.argv[1:]:
    ofname = os.path.splitext(ifname)[0] + ".sdriq"

    if not(os.path.exists(ifname)) or not(os.path.isfile(ifname)):
        print (ifname, " either doesn't exist or is not a file")
        continue

    with open(ifname, 'rb') as fin:
        print ("Reading: ", ifname)
        data = fin.read(COPY_BLOCK_SIZE)
        w = bytearray()
        sr = get_sr(ifname)
        if not(sr):
            print("Invalid SR for :", ifname)
            continue
        else:
            print("SR is ", sr)

        fr = get_f(ifname)
        if not(fr):
            print("Invalid frequency for:", ifname)
            continue
        else:
            print("Frequency is ", fr)
        

        w += struct.pack("<I", sr)
        w += struct.pack("<Q", fr) # Center freq Hz
        w += struct.pack("<Q", 0)         # Timestamp
        w += struct.pack("<I", 16)        # Sample size 16 or 24 ?
        w += struct.pack("<I", 0)         # Padding

        
        with open(ofname, 'wb') as fout:
            print ("Writing :", ofname) 
            fout.write(w)
            fout.write(struct.pack("<I", binascii.crc32(w)))
            cntr = len(data)
            while(data):
                fout.write(data)
                data = fin.read(COPY_BLOCK_SIZE)
                cntr = cntr + len(data)
            print("Data Bytes Copied: ", cntr)
            

            
# Original Code - Konrad Beckmann https://gist.github.com/kbeckmann/6db25501ff02c46e79143c0ed1c47d88
#data = open(sys.argv[1], "rb").read()
#out = open(sys.argv[2], "wb")

#w = bytearray()
#w += struct.pack("<I", 3200000)    # Sample rate
#w += struct.pack("<Q", 1280000000) # Center freq Hz
#w += struct.pack("<Q", 0)         # Timestamp
#w += struct.pack("<I", 16)        # Sample size 16 or 24 ?
#w += struct.pack("<I", 0)         # Padding
#out.write(w)
#out.write(struct.pack("<I", binascii.crc32(w))) # CRC32
#out.write(data)

To use with RTL SDR Samples, convert from unnsigned 8 bits to signed 16 bits using rtl_433

Script is intended to be used with rtl_433 filename based metadata(https://triq.org/rtl_433/IQ_FORMATS.html#file-name-meta-data)

rtl_433 -w output_300ksps_100MHZ.cs16 input_300ksps_100MHZ.cu8

convert with this script

./ConvertRawToSDRAngel.py output_300ksps_100MHZ.cs16

open output_300ksps_100MHZ.sdriq in SDRAngel and confirm the metadata.

for i in *.cu8; do rtl_433 -w "${i%.cu8}.cs16" $i; done