From 27738b6b1987862bad62b27e49954481b3db246e Mon Sep 17 00:00:00 2001
From: Reiner Herrmann <reiner@reiner-h.de>
Date: Mon, 28 Aug 2017 19:26:17 +0200
Subject: Add wav header to output

---
 loopertrx.py | 102 +++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 102 insertions(+)
 create mode 100755 loopertrx.py

(limited to 'loopertrx.py')

diff --git a/loopertrx.py b/loopertrx.py
new file mode 100755
index 0000000..ec1d8a8
--- /dev/null
+++ b/loopertrx.py
@@ -0,0 +1,102 @@
+#!/usr/bin/env python3
+
+import random
+import struct
+import sys
+import usb.core
+import usb.util
+
+LOOPER_VID = 0x0483
+LOOPER_PID = 0x572a
+
+ENDPOINT_IN  = 0x81
+ENDPOINT_OUT = 0x01
+
+COMMAND_SIZE = 0xfe
+COMMAND_DATA = 0xff
+
+def mass_storage_header(data_len, cdb_len):
+    header = "USBC".encode('ascii')
+    tag = random.randint(0, 1<<32 - 1)
+    flags = 0x80
+    target = 0x00
+    header += struct.pack('<iiBBB', tag, data_len, flags, target, cdb_len)
+    return header
+
+def command_header(command, data_len, flag1, flag2):
+    cdb = bytes([0xcb, command, flag1, 0x00, flag2, 0x00, 0x00, 0x00, 0x00, 0x00])
+    header = mass_storage_header(data_len, len(cdb)) + cdb
+    header += bytes([0x00 for padding in range(31-len(header))])
+    return header
+
+def ack_data(dev):
+    dev.read(ENDPOINT_IN, 32)
+
+def get_size(dev):
+    header = command_header(COMMAND_SIZE, 5, 0x00, 0x01)
+    dev.write(ENDPOINT_OUT, header)
+    length = dev.read(ENDPOINT_IN, 100)
+    ack_data(dev)
+    if length[0] == 1:
+        return 0
+    return length[1] + (length[2] << 8) + (length[3] << 16) + (length[4] << 24)
+
+def get_data(dev, nbytes):
+    header = command_header(COMMAND_DATA, nbytes, 0x01, 0x01)
+    dev.write(ENDPOINT_OUT, header)
+    buf = dev.read(ENDPOINT_IN, nbytes)
+    ack_data(dev)
+    print('.', end='', flush=True),
+    return buf
+
+def send_data(dev, data):
+    header = command_header(COMMAND_DATA, len(data), 0x01, 0x00)
+    dev.write(ENDPOINT_OUT, header)
+    #dev.read(ENDPOINT_IN, 100)
+    dev.write(ENDPOINT_OUT, data)
+
+def send_stop(dev):
+    header = command_header(COMMAND_SIZE, 5, 0x00, 0x00)
+
+def write_wav_header(outfile, data_size):
+    header_size = 44
+    header = "RIFF".encode('ascii')
+    header += struct.pack('<i', data_size + header_size - 8)
+    header += "WAVE".encode('ascii')
+    header += "fmt ".encode('ascii')
+    fmt = 0x01 # PCM
+    nchan = 1
+    rate = 48000
+    fsize = 3
+    bps = rate * fsize
+    bits = 24
+    header += struct.pack('<ihhiihh', 16, fmt, nchan, rate, bps, fsize, bits)
+    header += "data".encode('ascii')
+    header += struct.pack('<i', data_size)
+    outfile.write(header)
+
+dev = usb.core.find(idVendor=LOOPER_VID, idProduct=LOOPER_PID)
+if not dev:
+    print("Device not found.")
+    sys.exit(1)
+if dev.is_kernel_driver_active(0):
+    dev.detach_kernel_driver(0)
+dev.set_configuration()
+
+size = get_size(dev)
+if size == 0:
+    print("No data available.")
+    sys.exit(0)
+
+with open("/tmp/dump.wav", 'wb') as outfile:
+    write_wav_header(outfile, size)
+    print("Receiving ", end='', flush=True)
+    while size > 0:
+        bufsize = (size >= 65536) and 65536 or size
+        # data needs to be transferred in multiples of 1k blocks
+        padding = (1024 - (bufsize % 1024)) % 1024
+
+        buf = get_data(dev, bufsize + padding)
+        outfile.write(buf[:bufsize])
+        size -= bufsize
+    print(" Done.")
-- 
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