| # 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 utilities for USB audio using chameleon.""" |
| |
| |
| def set_usb_playback_configs_on_chameleon(widget_link, playback_configs): |
| """Sets the playback configurations for the USB gadget driver on Chameleon. |
| |
| This method also sets the channel map of the link based on the channel |
| number specified in the configs dictionary. |
| |
| @param widget_link: The USBWidgetLink object to be handled. |
| @param playback_configs: A 4-entry dictionary with following fields: |
| 'file_type', 'sample_format', 'channel' and 'rate'. |
| For e.g., |
| format = { |
| 'file_type': 'wav', |
| 'sample_format': 'S16_LE', |
| 'channel': 2, |
| 'rate': 48000 |
| } |
| However, the 'file_type' field will be ignored |
| since file type for playback is determined by the |
| file type of the playback file passed in by user. |
| |
| """ |
| channel_number = playback_configs['channel'] |
| widget_link.channel_map = \ |
| _convert_channel_number_to_channel_map(channel_number) |
| usb_ctrl = widget_link.usb_ctrl |
| usb_ctrl.set_playback_configs(playback_configs) |
| |
| |
| def set_usb_capture_configs_on_chameleon(widget_link, capture_configs): |
| """Sets the capture configurations for the USB gadget driver on Chameleon. |
| |
| This method also sets the channel map of the link based on the channel |
| number specified in the configs dictionary. |
| |
| @param widget_link: The USBWidgetLink object to be handled. |
| @param capture_configs: A 4-entry dictionary with following fields: |
| 'file_type', 'sample_format', 'channel' and 'rate'. |
| For e.g., |
| format = { |
| 'file_type': 'wav', |
| 'sample_format': 'S16_LE', |
| 'channel': 2, |
| 'rate': 48000 |
| } |
| 'file_type' field is used to specify the file type |
| in which captured audio data should be saved. |
| |
| """ |
| channel_number = capture_configs['channel'] |
| widget_link.channel_map = \ |
| _convert_channel_number_to_channel_map(channel_number) |
| usb_ctrl = widget_link.usb_ctrl |
| usb_ctrl.set_capture_configs(capture_configs) |
| |
| |
| def _convert_channel_number_to_channel_map(channel_number): |
| """Converts the channel number passed into a list representing channel map. |
| |
| @param channel_number: A number representing the number of channels. |
| |
| @return: A list representing the corresponding channel map. |
| |
| """ |
| return range(channel_number) |
