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 20 /** 21 * @hide 22 * An audio class-specific Format II interface. 23 * see Frmts10.pdf section 2.3 24 */ 25 public final class Usb10ASFormatII extends UsbASFormat { 26 private static final String TAG = "Usb10ASFormatII"; 27 28 private int mMaxBitRate; // 4:2 Indicates the maximum number of bits per second this 29 // interface can handle. Expressed in kbits/s. 30 private int mSamplesPerFrame; // 6:2 Indicates the number of PCM audio samples contained 31 // in one encoded audio frame. 32 private byte mSamFreqType; // Indicates how the sampling frequency can be programmed: 33 // 0: Continuous sampling frequency 34 // 1..255: The number of discrete sampling frequencies supported 35 // by the isochronous data endpoint of the AudioStreaming 36 // interface (ns) 37 private int[] mSampleRates; // if mSamFreqType == 0, there will be 2 values: 38 // the min & max rates. otherwise mSamFreqType rates. 39 // All 3-byte values. All rates in Hz 40 41 public Usb10ASFormatII(int length, byte type, byte subtype, byte formatType, int subclass) { 42 super(length, type, subtype, formatType, subclass); 43 } 44 45 public int getMaxBitRate() { 46 return mMaxBitRate; 47 } 48 49 public int getSamplesPerFrame() { 50 return mSamplesPerFrame; 51 } 52 53 public byte getSamFreqType() { 54 return mSamFreqType; 55 } 56 57 public int[] getSampleRates() { 58 return mSampleRates; 59 } 60 61 @Override 62 public int parseRawDescriptors(ByteStream stream) { 63 mMaxBitRate = stream.unpackUsbShort(); 64 mSamplesPerFrame = stream.unpackUsbShort(); 65 mSamFreqType = stream.getByte(); 66 int numFreqs = mSamFreqType == 0 ? 2 : mSamFreqType; 67 mSampleRates = new int[numFreqs]; 68 for (int index = 0; index < numFreqs; index++) { 69 mSampleRates[index] = stream.unpackUsbTriple(); 70 } 71 72 return mLength; 73 } 74 75 @Override 76 public void report(ReportCanvas canvas) { 77 super.report(canvas); 78 79 canvas.openList(); 80 canvas.writeListItem("Max Bit Rate: " + getMaxBitRate()); 81 canvas.writeListItem("Samples Per Frame: " + getMaxBitRate()); 82 byte sampleFreqType = getSamFreqType(); 83 int[] sampleRates = getSampleRates(); 84 canvas.writeListItem("Sample Freq Type: " + sampleFreqType); 85 canvas.openList(); 86 if (sampleFreqType == 0) { 87 canvas.writeListItem("min: " + sampleRates[0]); 88 canvas.writeListItem("max: " + sampleRates[1]); 89 } else { 90 for (int index = 0; index < sampleFreqType; index++) { 91 canvas.writeListItem("" + sampleRates[index]); 92 } 93 } 94 canvas.closeList(); 95 96 canvas.closeList(); 97 } 98 99 } 100
