1 /* 2 * Copyright (C) 2015 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 17 package com.android.tv.tuner; 18 19 import android.util.Log; 20 21 import com.android.tv.tuner.data.nano.Channel; 22 23 import java.io.BufferedReader; 24 import java.io.IOException; 25 import java.io.InputStream; 26 import java.io.InputStreamReader; 27 import java.util.ArrayList; 28 import java.util.List; 29 30 /** 31 * Parses plain text formatted scan files, which contain the list of channels. 32 */ 33 public class ChannelScanFileParser { 34 private static final String TAG = "ChannelScanFileParser"; 35 36 public static final class ScanChannel { 37 public final int type; 38 public final int frequency; 39 public final String modulation; 40 public final String filename; 41 /** 42 * Radio frequency (channel) number specified at 43 * https://en.wikipedia.org/wiki/North_American_television_frequencies 44 * This can be {@code null} for cases like cable signal. 45 */ 46 public final Integer radioFrequencyNumber; 47 forTuner(int frequency, String modulation, Integer radioFrequencyNumber)48 public static ScanChannel forTuner(int frequency, String modulation, 49 Integer radioFrequencyNumber) { 50 return new ScanChannel(Channel.TYPE_TUNER, frequency, modulation, null, 51 radioFrequencyNumber); 52 } 53 forFile(int frequency, String filename)54 public static ScanChannel forFile(int frequency, String filename) { 55 return new ScanChannel(Channel.TYPE_FILE, frequency, "file:", filename, null); 56 } 57 ScanChannel(int type, int frequency, String modulation, String filename, Integer radioFrequencyNumber)58 private ScanChannel(int type, int frequency, String modulation, String filename, 59 Integer radioFrequencyNumber) { 60 this.type = type; 61 this.frequency = frequency; 62 this.modulation = modulation; 63 this.filename = filename; 64 this.radioFrequencyNumber = radioFrequencyNumber; 65 } 66 } 67 68 /** 69 * Parses a given scan file and returns the list of {@link ScanChannel} objects. 70 * 71 * @param is {@link InputStream} of a scan file. Each line matches one channel. 72 * The line format of the scan file is as follows:<br> 73 * "A <frequency> <modulation>". 74 * @return a list of {@link ScanChannel} objects parsed 75 */ parseScanFile(InputStream is)76 public static List<ScanChannel> parseScanFile(InputStream is) { 77 BufferedReader in = new BufferedReader(new InputStreamReader(is)); 78 String line; 79 List<ScanChannel> scanChannelList = new ArrayList<>(); 80 try { 81 while ((line = in.readLine()) != null) { 82 if (line.isEmpty()) { 83 continue; 84 } 85 if (line.charAt(0) == '#') { 86 // Skip comment line 87 continue; 88 } 89 String[] tokens = line.split("\\s+"); 90 if (tokens.length != 3 && tokens.length != 4) { 91 continue; 92 } 93 if (!tokens[0].equals("A")) { 94 // Only support ATSC 95 continue; 96 } 97 scanChannelList.add(ScanChannel.forTuner(Integer.parseInt(tokens[1]), tokens[2], 98 tokens.length == 4 ? Integer.parseInt(tokens[3]) : null)); 99 } 100 } catch (IOException e) { 101 Log.e(TAG, "error on parseScanFile()", e); 102 } 103 return scanChannelList; 104 } 105 } 106