#!/usr/bin/env python3

# Note: this utility can run under python2.7 or python3

program = 'vdifd'
author  = 'Walter Brisken'
version = '0.8'
verdate = '20211004'

from os import system
from sys import exit, argv

def printVersion():
	print('%s ver. %s  %s  %s' % (program, version, author, verdate))

def usage():
	print('')
	printVersion()
	print('')
	print('A VDIF decoder for multi-thread, single channel VDIF data.  Uses vmux')
	print('and m5d to do the heavy lifting.\n')
	print('Usage : %s <infile> <frame size> <data rate> <threadlist> <n> [<offset> [<nbit>] ]\n' % program)
	print('  <infile> is the name of the VDIF file\n')
	print('  <frame size> is the size of each input VDIF frame, inc. header (e.g., 5032)\n')
	print('  <data rate> is the stream data rate (Mbps)\n')
	print('  <n> is the number of samples per channel to decode\n')
	print('  <offset> optionally jump into input file by this many bytes\n')
	print('  <nbit> is number of bits per sample (default is 2)\n')

if '--version' in argv:
	printVersion()
	exit()

if len(argv) < 6:
	usage()
	exit()

infile = argv[1]
framesize = int(argv[2])
datarate = int(argv[3])
threadlist = argv[4]
nt = len(threadlist.split(','))
n = int(argv[5])
if len(argv) > 6:
	offset = int(argv[6])
else:
	offset = 0
if len(argv) > 7:
	nbit = int(argv[7])
else:
	nbit = 2

nc = 1
while(nc < nt):
	nc *= 2

outputpayload = nc*(framesize-32)
framespersecond = (datarate*1000000)//(nt*(framesize-32)*8)
outputdatarate = outputpayload*framespersecond*8//1000000

cmd = 'vmux %s %d %d %s - %d | m5d - VDIF_%d-%d-%d-%d %d' % (infile, framesize, framespersecond, threadlist, offset, outputpayload, outputdatarate, nc, nbit, n) 

print('Executing: %s' % cmd)
system(cmd)