client/cros/audio/cras_utils.py

# Copyright (c) 2013 The Chromium Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""This module provides cras audio utilities."""

import logging
import re

from autotest_lib.client.cros.audio import cmd_utils

_CRAS_TEST_CLIENT = '/usr/bin/cras_test_client'

def playback(*args, **kargs):
    """A helper function to execute the playback_cmd."""
    cmd_utils.execute(playback_cmd(*args, **kargs))


def capture(*args, **kargs):
    """A helper function to execute the capture_cmd."""
    cmd_utils.execute(capture_cmd(*args, **kargs))


def playback_cmd(playback_file, block_size=None, duration=None,
                 channels=2, rate=48000):
    """Gets a command to playback a file with given settings.

    @param playback_file: the name of the file to play. '-' indicates to
                          playback raw audio from the stdin.
    @param block_size: the number of frames per callback(dictates latency).
    @param duration: seconds to playback
    @param rate: the sampling rate

    """
    args = [_CRAS_TEST_CLIENT]
    args += ['--playback_file', playback_file]
    if block_size is not None:
        args += ['--block_size', str(block_size)]
    if duration is not None:
        args += ['--duration', str(duration)]
    args += ['--num_channels', str(channels)]
    args += ['--rate', str(rate)]
    return args


def capture_cmd(
        capture_file, block_size=None, duration=10, channels=1, rate=48000):
    """Gets a command to capture the audio into the file with given settings.

    @param capture_file: the name of file the audio to be stored in.
    @param block_size: the number of frames per callback(dictates latency).
    @param duration: seconds to record. If it is None, duration is not set,
                     and command will keep capturing audio until it is
                     terminated.
    @param rate: the sampling rate.

    """
    args = [_CRAS_TEST_CLIENT]
    args += ['--capture_file', capture_file]
    if block_size is not None:
        args += ['--block_size', str(block_size)]
    if duration is not None:
        args += ['--duration', str(duration)]
    args += ['--num_channels', str(channels)]
    args += ['--rate', str(rate)]
    return args


def loopback(*args, **kargs):
    """A helper function to execute loopback_cmd."""
    cmd_utils.execute(loopback_cmd(*args, **kargs))


def loopback_cmd(output_file, duration=10, channels=2, rate=48000):
    """Gets a command to record the loopback.

    @param output_file: The name of the file the loopback to be stored in.
    @param channels: The number of channels of the recorded audio.
    @param duration: seconds to record.
    @param rate: the sampling rate.

    """
    args = [_CRAS_TEST_CLIENT]
    args += ['--loopback_file', output_file]
    args += ['--duration_seconds', str(duration)]
    args += ['--num_channels', str(channels)]
    args += ['--rate', str(rate)]
    return args


def get_cras_nodes_cmd():
    """Gets a command to query the nodes from Cras.

    @returns: The command to query nodes information from Cras using dbus-send.

    """
    return ('dbus-send --system --type=method_call --print-reply '
            '--dest=org.chromium.cras /org/chromium/cras '
            'org.chromium.cras.Control.GetNodes')


def set_system_volume(volume):
    """Set the system volume.

    @param volume: the system output vlume to be set(0 - 100).

    """
    get_cras_control_interface().SetOutputVolume(volume)


def set_node_volume(node_id, volume):
    """Set the volume of the given output node.

    @param node_id: the id of the output node to be set the volume.
    @param volume: the volume to be set(0-100).

    """
    get_cras_control_interface().SetOutputNodeVolume(node_id, volume)


def set_capture_gain(gain):
    """Set the system capture gain.

    @param gain the capture gain in db*100 (100 = 1dB)

    """
    get_cras_control_interface().SetInputGain(gain)


def get_cras_control_interface():
    """Gets Cras DBus control interface.

    @returns: A dBus.Interface object with Cras Control interface.

    @raises: ImportError if this is not called on Cros device.

    """
    try:
        import dbus
    except ImportError, e:
        logging.exception(
                'Can not import dbus: %s. This method should only be '
                'called on Cros device.', e)
        raise
    bus = dbus.SystemBus()
    cras_object = bus.get_object('org.chromium.cras', '/org/chromium/cras')
    return dbus.Interface(cras_object, 'org.chromium.cras.Control')


def get_cras_nodes():
    """Gets nodes information from Cras.

    @returns: A dict containing information of each node.

    """
    return get_cras_control_interface().GetNodes()


def get_selected_nodes():
    """Gets selected output nodes and input nodes.

    @returns: A tuple (output_nodes, input_nodes) where each
              field is a list of selected node IDs returned from Cras DBus API.
              Note that there may be multiple output/input nodes being selected
              at the same time.

    """
    output_nodes = []
    input_nodes = []
    nodes = get_cras_nodes()
    for node in nodes:
        if node['Active']:
            if node['IsInput']:
                input_nodes.append(node['Id'])
            else:
                output_nodes.append(node['Id'])
    return (output_nodes, input_nodes)


def set_selected_output_node_volume(volume):
    """Sets the selected output node volume.

    @param volume: the volume to be set (0-100).

    """
    selected_output_node_ids, _ = get_selected_nodes()
    for node_id in selected_output_node_ids:
        set_node_volume(node_id, volume)


def get_active_stream_count():
    """Gets the number of active streams.

    @returns: The number of active streams.

    """
    return int(get_cras_control_interface().GetNumberOfActiveStreams())


def set_system_mute(is_mute):
    """Sets the system mute switch.

    @param is_mute: Set True to mute the system playback.

    """
    get_cras_control_interface().SetOutputMute(is_mute)


def set_capture_mute(is_mute):
    """Sets the capture mute switch.

    @param is_mute: Set True to mute the capture.

    """
    get_cras_control_interface().SetInputMute(is_mute)


def node_type_is_plugged(node_type, nodes_info):
    """Determine if there is any node of node_type plugged.

    This method is used in has_loopback_dongle in cros_host, where
    the call is executed on autotest server. Use get_cras_nodes instead if
    the call can be executed on Cros device.

    Since Cras only reports the plugged node in GetNodes, we can
    parse the return value to see if there is any node with the given type.
    For example, if INTERNAL_MIC is of intereset, the pattern we are
    looking for is:

    dict entry(
       string "Type"
       variant             string "INTERNAL_MIC"
    )

    @param node_type: A str representing node type defined in CRAS_NODE_TYPES.
    @param nodes_info: A str containing output of command get_nodes_cmd.

    @returns: True if there is any node of node_type plugged. False otherwise.

    """
    match = re.search(r'string "Type"\s+variant\s+string "%s"' % node_type,
                      nodes_info)
    return True if match else False


# Cras node types reported from Cras DBus control API.
CRAS_OUTPUT_NODE_TYPES = ['HEADPHONE', 'INTERNAL_SPEAKER', 'HDMI', 'USB',
                          'BLUETOOTH']
CRAS_INPUT_NODE_TYPES = ['MIC', 'INTERNAL_MIC', 'USB', 'BLUETOOTH']
CRAS_NODE_TYPES = CRAS_OUTPUT_NODE_TYPES + CRAS_INPUT_NODE_TYPES


def get_selected_node_types():
    """Returns the pair of active output node types and input node types.

    @returns: A tuple (output_node_types, input_node_types) where each
              field is a list of selected node types defined in CRAS_NODE_TYPES.

    """
    output_node_types = []
    input_node_types = []
    nodes = get_cras_nodes()
    for node in nodes:
        if node['Active']:
            node_type = str(node['Type'])
            if node_type not in CRAS_NODE_TYPES:
                raise RuntimeError(
                        'node type %s is not valid' % node_type)
            if node['IsInput']:
                input_node_types.append(node_type)
            else:
                output_node_types.append(node_type)
    return (output_node_types, input_node_types)