Cadence/src/jacklib_helpers.py

#!/usr/bin/env python3
# -*- coding: utf-8 -*-

# Helper functions for extra jacklib functionality
# Copyright (C) 2012 Filipe Coelho <falktx@falktx.com>
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# For a full copy of the GNU General Public License see the COPYING file

# ------------------------------------------------------------------------------------------------------------
# Try Import jacklib

try:
    import jacklib
except ImportError:
    jacklib = None

# ------------------------------------------------------------------------------------------------------------
# Get JACK error status as string

def get_jack_status_error_string(cStatus):
    errorString = ""
    status      = cStatus.value

    if status & jacklib.JackFailure:
        errorString += "Overall operation failed;\n"
    if status & jacklib.JackInvalidOption:
        errorString += "The operation contained an invalid or unsupported option;\n"
    if status & jacklib.JackNameNotUnique:
        errorString += "The desired client name was not unique;\n"
    if status & jacklib.JackServerStarted:
        errorString += "The JACK server was started as a result of this operation;\n"
    if status & jacklib.JackServerFailed:
        errorString += "Unable to connect to the JACK server;\n"
    if status & jacklib.JackServerError:
        errorString += "Communication error with the JACK server;\n"
    if status & jacklib.JackNoSuchClient:
        errorString += "Requested client does not exist;\n"
    if status & jacklib.JackLoadFailure:
        errorString += "Unable to load internal client;\n"
    if status & jacklib.JackInitFailure:
        errorString += "Unable to initialize client;\n"
    if status & jacklib.JackShmFailure:
        errorString += "Unable to access shared memory;\n"
    if status & jacklib.JackVersionError:
        errorString += "Client's protocol version does not match;\n"
    if status & jacklib.JackBackendError:
        errorString += "Backend Error;\n"
    if status & jacklib.JackClientZombie:
        errorString += "Client is being shutdown against its will;\n"

    if errorString:
        errorString = errorString.strip().rsplit(";", 1)[0] + "."

    return errorString

# ------------------------------------------------------------------------------------------------------------
# Convert C char** -> Python list

def c_char_p_p_to_list(c_char_p_p):
    i = 0
    retList = []

    if not c_char_p_p:
        return retList

    while True:
        new_char_p = c_char_p_p[i]
        if new_char_p:
            retList.append(str(new_char_p, encoding="utf-8"))
            i += 1
        else:
            break

    jacklib.free(c_char_p_p)
    return retList

# ------------------------------------------------------------------------------------------------------------
# Convert C void* -> jack_default_audio_sample_t*

def translate_audio_port_buffer(void_p):
    return jacklib.cast(void_p, jacklib.POINTER(jacklib.jack_default_audio_sample_t))

# ------------------------------------------------------------------------------------------------------------
# Convert a JACK midi buffer into a python variable-size list

def translate_midi_event_buffer(void_p, size):
    if not void_p:
        return ()
    elif size == 1:
        return (void_p[0],)
    elif size == 2:
        return (void_p[0], void_p[1])
    elif size == 3:
        return (void_p[0], void_p[1], void_p[2])
    elif size == 4:
        return (void_p[0], void_p[1], void_p[2], void_p[3])
    else:
        return ()