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      1 /*
      2  * Copyright (C) 2017 The Android Open Source Project
      3  *
      4  * Licensed under the Apache License, Version 2.0 (the "License");
      5  * you may not use this file except in compliance with the License.
      6  * You may obtain a copy of the License at
      7  *
      8  *      http://www.apache.org/licenses/LICENSE-2.0
      9  *
     10  * Unless required by applicable law or agreed to in writing, software
     11  * distributed under the License is distributed on an "AS IS" BASIS,
     12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
     13  * See the License for the specific language governing permissions and
     14  * limitations under the License.
     15  */
     16 package com.android.server.usb.descriptors;
     17 
     18 import com.android.server.usb.descriptors.report.ReportCanvas;
     19 import com.android.server.usb.descriptors.report.UsbStrings;
     20 
     21 /**
     22  * @hide
     23  * An audio class-specific Format Interface.
     24  *   Subclasses: UsbACFormatI and UsbACFormatII.
     25  * see audio10.pdf section 4.5.3 & & Frmts10.pdf
     26  */
     27 public class UsbASFormat extends UsbACInterface {
     28     private static final String TAG = "UsbASFormat";
     29 
     30     private final byte mFormatType;   // 3:1 FORMAT_TYPE_*
     31 
     32     public static final byte FORMAT_TYPE_I      = 1;
     33     public static final byte FORMAT_TYPE_II     = 2;
     34     // these showed up in USB 2.0
     35     public static final byte FORMAT_TYPE_III    = 3;
     36     public static final byte FORMAT_TYPE_IV     = 4;
     37 
     38     // "extended" formats
     39     public static final byte EXT_FORMAT_TYPE_I      = (byte) 0x81;
     40     public static final byte EXT_FORMAT_TYPE_II     = (byte) 0x82;
     41     public static final byte EXT_FORMAT_TYPE_III    = (byte) 0x83;
     42 
     43     public UsbASFormat(int length, byte type, byte subtype, byte formatType, int mSubclass) {
     44         super(length, type, subtype, mSubclass);
     45         mFormatType = formatType;
     46     }
     47 
     48     public byte getFormatType() {
     49         return mFormatType;
     50     }
     51 
     52     public int[] getSampleRates() {
     53         return null;
     54     }
     55 
     56     public int[] getBitDepths() {
     57         return null;
     58     }
     59 
     60     public int[] getChannelCounts() {
     61         return null;
     62     }
     63 
     64     /**
     65      * Allocates the audio-class format subtype associated with the format type read from the
     66      * stream.
     67      */
     68     public static UsbDescriptor allocDescriptor(UsbDescriptorParser parser,
     69             ByteStream stream, int length, byte type,
     70             byte subtype, int subclass) {
     71 
     72         byte formatType = stream.getByte();
     73         int acInterfaceSpec = parser.getACInterfaceSpec();
     74 
     75         switch (formatType) {
     76             case FORMAT_TYPE_I:
     77                 if (acInterfaceSpec == UsbDeviceDescriptor.USBSPEC_2_0) {
     78                     return new Usb20ASFormatI(length, type, subtype, formatType, subclass);
     79                 } else {
     80                     return new Usb10ASFormatI(length, type, subtype, formatType, subclass);
     81                 }
     82 
     83             case FORMAT_TYPE_II:
     84                 if (acInterfaceSpec == UsbDeviceDescriptor.USBSPEC_2_0) {
     85                     return new Usb20ASFormatII(length, type, subtype, formatType, subclass);
     86                 } else {
     87                     return new Usb10ASFormatII(length, type, subtype, formatType, subclass);
     88                 }
     89 
     90             // USB 2.0 Exclusive Format Types
     91             case FORMAT_TYPE_III:
     92                 return new Usb20ASFormatIII(length, type, subtype, formatType, subclass);
     93 
     94             case FORMAT_TYPE_IV:
     95                 //TODO - implement this type.
     96             default:
     97                 return new UsbASFormat(length, type, subtype, formatType, subclass);
     98         }
     99     }
    100 
    101     @Override
    102     public void report(ReportCanvas canvas) {
    103         super.report(canvas);
    104 
    105         canvas.writeParagraph(UsbStrings.getFormatName(getFormatType()), /*emphasis*/false);
    106     }
    107 }
    108