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# Copyright 2015 The Chromium OS 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 the level control for audio widgets."""
from autotest_lib.client.cros.chameleon import chameleon_audio_ids as ids
class _AudioLevel(object):
"""Audio signal level on audio widgets."""
# Line level signal on consumer equipment is typically -10 dBV, or
# 0.316 Volt RMS.
LINE_LEVEL = 'Line level'
# Mic level signal on microphone is typically -60 dBV, or
# 1 mV RMS.
MIC_LEVEL = 'Mic level'
# Digital signal, e.g., USB, HDMI. is not subjected to bias level or
# full swing constraints. The signal is guranteed to be transmitted to the
# other end without noise introduced on the path.
# Signal level is relative to full swing of data width.
# E.g. 2^12 is 1/8 of maximum amplitude, that is, 2^15 - 1, of signed
# 16 bit data format.
# TODO(cychiang) Check if we need to do level scaling for digital signal.
DIGITAL = 'Digital'
# The signal level of input of bluetooth module on the audio board is
# slightly higher than mic level.
BLUETOOTH_SIGNAL_INPUT_LEVEL = 'Bluetooth signal input level'
# The relative level of audio levels. This is used to compute scale between
# two levels.
_AudioLevel.LINE_LEVEL: 1.0,
_AudioLevel.MIC_LEVEL: 0.033,
ids.ChameleonIds.LINEOUT: _AudioLevel.LINE_LEVEL,
ids.ChameleonIds.USBOUT: _AudioLevel.DIGITAL,
ids.CrosIds.HDMI: _AudioLevel.DIGITAL,
ids.CrosIds.HEADPHONE: _AudioLevel.LINE_LEVEL,
ids.CrosIds.SPEAKER: _AudioLevel.LINE_LEVEL,
ids.CrosIds.USBOUT: _AudioLevel.DIGITAL,
ids.PeripheralIds.MIC: _AudioLevel.MIC_LEVEL,
ids.PeripheralIds.BLUETOOTH_DATA_RX: _AudioLevel.LINE_LEVEL,
ids.PeripheralIds.BLUETOOTH_DATA_TX: _AudioLevel.DIGITAL,
ids.ChameleonIds.HDMI: _AudioLevel.DIGITAL,
ids.ChameleonIds.LINEIN: _AudioLevel.LINE_LEVEL,
ids.ChameleonIds.USBIN: _AudioLevel.DIGITAL,
ids.CrosIds.EXTERNAL_MIC: _AudioLevel.MIC_LEVEL,
ids.CrosIds.INTERNAL_MIC: _AudioLevel.MIC_LEVEL,
ids.CrosIds.BLUETOOTH_MIC: _AudioLevel.DIGITAL,
ids.CrosIds.USBIN: _AudioLevel.DIGITAL,
ids.PeripheralIds.SPEAKER: _AudioLevel.LINE_LEVEL,
ids.PeripheralIds.BLUETOOTH_DATA_RX: _AudioLevel.DIGITAL,
class LevelController(object):
"""The controller which sets scale between widgets of different levels."""
def __init__(self, source, sink):
"""Initializes a LevelController.
@param source: An AudioWidget for source.
@param sink: An AudioWidget for sink.
self._source = source
self._sink = sink
def _get_needed_scale(self):
"""Gets the needed scale for _source and _sink to balance the level.
@returns: A number for scaling on source widget.
source_level = _SOURCE_LEVEL_TABLE[self._source.port_id]
sink_level = _SINK_LEVEL_TABLE[self._sink.port_id]
if source_level == sink_level:
return 1
return _RELATIVE_LEVEL[sink_level] / _RELATIVE_LEVEL[source_level]
def reset(self):
"""Resets scale of _source."""
self._source.handler.scale = 1
def set_scale(self):
"""Sets scale of _source to balance the level."""
self._source.handler.scale = self._get_needed_scale()
self._sink.handler.scale = 1