| /* |
| * Copyright (C) 2015 The Android Open Source Project |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| package com.android.usbtuner; |
| |
| import android.media.MediaDataSource; |
| import android.os.Environment; |
| import android.util.Log; |
| import android.util.SparseBooleanArray; |
| |
| import com.android.usbtuner.ChannelScanFileParser.ScanChannel; |
| import com.android.usbtuner.data.Channel; |
| import com.android.usbtuner.data.TunerChannel; |
| import com.android.usbtuner.ts.TsParser; |
| import com.android.usbtuner.tvinput.EventDetector; |
| import com.android.usbtuner.tvinput.FileSourceEventDetector; |
| |
| import java.io.BufferedInputStream; |
| import java.io.File; |
| import java.io.FileInputStream; |
| import java.io.IOException; |
| import java.util.List; |
| |
| /** |
| * A {@link DataSource} implementation which provides the MPEG-2 TS stream from a local file |
| * generated by capturing TV signal. |
| */ |
| public class FileDataSource extends MediaDataSource implements InputStreamSource { |
| private static final String TAG = "FileDataSource"; |
| |
| private static final int TS_PACKET_SIZE = 188; |
| private static final int TS_SYNC_BYTE = 0x47; |
| private static final int MIN_READ_UNIT = TS_PACKET_SIZE * 10; |
| private static final int READ_BUFFER_SIZE = MIN_READ_UNIT * 10; // ~20KB |
| private static final int CIRCULAR_BUFFER_SIZE = MIN_READ_UNIT * 4000; // ~ 8MB |
| private static final int PADDING_SIZE = MIN_READ_UNIT * 1000; // ~2MB |
| private static final int READ_TIMEOUT_MS = 10000; // 10 secs. |
| private static final int BUFFER_UNDERRUN_SLEEP_MS = 10; |
| private static final String FILE_DIR = |
| new File(Environment.getExternalStorageDirectory(), "Streams").getAbsolutePath(); |
| |
| // Virtual frequency base used for file-based source |
| public static final int FREQ_BASE = 100; |
| |
| private final Object mCircularBufferMonitor = new Object(); |
| private final byte[] mCircularBuffer = new byte[CIRCULAR_BUFFER_SIZE]; |
| private final FileSourceEventDetector mEventDetector; |
| |
| private long mBytesFetched; |
| private long mLastReadPosition; |
| private boolean mStreaming; |
| |
| private Thread mStreamingThread; |
| private StreamProvider mSource; |
| |
| public FileDataSource(EventDetector.EventListener eventListener) { |
| mEventDetector = new FileSourceEventDetector(eventListener); |
| } |
| |
| @Override |
| public boolean setScanChannel(ScanChannel channel) { |
| String filepath = new File(FILE_DIR, channel.filename).getAbsolutePath(); |
| mSource = new StreamProvider(filepath); |
| if (mSource.isReady()) { |
| mEventDetector.start(mSource); |
| return true; |
| } |
| return false; |
| } |
| |
| /** |
| * Sets the channel required to start streaming from this device. Afterwards, prepares |
| * the tuner device for streaming. Package retrieval can be made at any time after invoking |
| * this method and before stopping the stream. |
| * |
| * @param channel a {@link TunerChannel} instance tune to |
| * @return {@code true} if the entire operation was successful; {@code false} otherwise |
| */ |
| @Override |
| public boolean tuneToChannel(TunerChannel channel) { |
| Log.i(TAG, "tuneToChannel with: " + channel.getFilepath()); |
| mSource = new StreamProvider(channel.getFilepath()); |
| if (!mSource.isReady()) { |
| return false; |
| } |
| mEventDetector.start(mSource); |
| mSource.addPidFilter(channel.getVideoPid()); |
| mSource.addPidFilter(channel.getAudioPid()); |
| mSource.addPidFilter(channel.getPcrPid()); |
| return true; |
| } |
| |
| /** |
| * Starts streaming data. |
| */ |
| @Override |
| public void startStream() { |
| mSource.addPidFilter(TsParser.ATSC_SI_BASE_PID); |
| mSource.addPidFilter(TsParser.PAT_PID); |
| synchronized (mCircularBufferMonitor) { |
| if (mStreaming) { |
| return; |
| } |
| mStreaming = true; |
| } |
| |
| mStreamingThread = new StreamingThread(); |
| mStreamingThread.start(); |
| Log.i(TAG, "Streaming started"); |
| } |
| |
| /** |
| * Blocks the current thread until the streaming thread stops. In rare cases when the tuner |
| * device is overloaded this can take a while, but usually it returns pretty quickly. |
| */ |
| @Override |
| public void stopStream() { |
| synchronized (mCircularBufferMonitor) { |
| mStreaming = false; |
| mCircularBufferMonitor.notify(); |
| } |
| |
| try { |
| if (mStreamingThread != null) { |
| mStreamingThread.join(); |
| } |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| } |
| } |
| |
| @Override |
| public long getLimit() { |
| synchronized (mCircularBufferMonitor) { |
| return mBytesFetched; |
| } |
| } |
| |
| @Override |
| public long getPosition() { |
| synchronized (mCircularBufferMonitor) { |
| return mLastReadPosition; |
| } |
| } |
| |
| /** |
| * Provides MPEG-2 transport stream from a local file. Stream can be filtered by PID. |
| */ |
| public static class StreamProvider { |
| private final String mFilepath; |
| private final SparseBooleanArray mPids = new SparseBooleanArray(); |
| private final byte[] mPreBuffer = new byte[READ_BUFFER_SIZE]; |
| |
| private BufferedInputStream mInputStream; |
| |
| private StreamProvider(String filepath) { |
| mFilepath = filepath; |
| open(filepath); |
| } |
| |
| private void open(String filepath) { |
| try { |
| mInputStream = new BufferedInputStream(new FileInputStream(filepath)); |
| } catch (IOException e) { |
| Log.e(TAG, "Error opening input stream", e); |
| mInputStream = null; |
| } |
| } |
| |
| private boolean isReady() { |
| return mInputStream != null; |
| } |
| |
| public String getFilepath() { |
| return mFilepath; |
| } |
| |
| public void addPidFilter(int pid) { |
| mPids.put(pid, true); |
| } |
| |
| public boolean isFilterEmpty() { |
| return mPids.size() > 0; |
| } |
| |
| public void clearPidFilter() { |
| mPids.clear(); |
| } |
| |
| public boolean isInFilter(int pid) { |
| return mPids.get(pid); |
| } |
| |
| private int read(byte[] inputBuffer) { |
| int readSize = readInternal(); |
| if (readSize <= 0) { |
| // Reached the end of stream. Restart from the beginning. |
| close(); |
| open(mFilepath); |
| if (mInputStream == null) { |
| return -1; |
| } |
| readSize = readInternal(); |
| } |
| |
| if (mPreBuffer[0] != TS_SYNC_BYTE) { |
| Log.e(TAG, "Error reading input stream - no TS sync found"); |
| return -1; |
| } |
| int filteredSize = 0; |
| for (int i = 0, destPos = 0; i < readSize; i += TS_PACKET_SIZE) { |
| if (mPreBuffer[i] == TS_SYNC_BYTE) { |
| int pid = ((mPreBuffer[i + 1] & 0x1f) << 8) + (mPreBuffer[i + 2] & 0xff); |
| if (mPids.get(pid)) { |
| System.arraycopy(mPreBuffer, i, inputBuffer, destPos, TS_PACKET_SIZE); |
| destPos += TS_PACKET_SIZE; |
| filteredSize += TS_PACKET_SIZE; |
| } |
| } |
| } |
| return filteredSize; |
| } |
| |
| private int readInternal() { |
| int readSize; |
| try { |
| readSize = mInputStream.read(mPreBuffer, 0, mPreBuffer.length); |
| } catch (IOException e) { |
| Log.e(TAG, "Error reading input stream", e); |
| return -1; |
| } |
| return readSize; |
| } |
| |
| private void close() { |
| try { |
| mInputStream.close(); |
| } catch (IOException e) { |
| Log.e(TAG, "Error closing input stream:", e); |
| } |
| mInputStream = null; |
| } |
| } |
| |
| @Override |
| public int readAt(long pos, byte[] buffer, int offset, int amount) throws IOException { |
| synchronized (mCircularBufferMonitor) { |
| long initialBytesFetched = mBytesFetched; |
| while (mBytesFetched < pos + amount && mStreaming) { |
| try { |
| mCircularBufferMonitor.wait(READ_TIMEOUT_MS); |
| } catch (InterruptedException e) { |
| // Wait again. |
| Thread.currentThread().interrupt(); |
| } |
| if (initialBytesFetched == mBytesFetched) { |
| Log.w(TAG, "No data update for " + READ_TIMEOUT_MS + "ms. returning -1."); |
| |
| // Returning -1 will make demux report EOS so that the input service can retry |
| // the playback. |
| return -1; |
| } |
| } |
| if (!mStreaming) { |
| Log.w(TAG, "Stream is already stopped."); |
| return -1; |
| } |
| if (mBytesFetched - CIRCULAR_BUFFER_SIZE > pos) { |
| Log.e(TAG, "Demux is requesting the data which is already overwritten."); |
| return -1; |
| } |
| int posInBuffer = (int) (pos % CIRCULAR_BUFFER_SIZE); |
| int bytesToCopyInFirstPass = amount; |
| if (posInBuffer + bytesToCopyInFirstPass > mCircularBuffer.length) { |
| bytesToCopyInFirstPass = mCircularBuffer.length - posInBuffer; |
| } |
| System.arraycopy(mCircularBuffer, posInBuffer, buffer, offset, bytesToCopyInFirstPass); |
| if (bytesToCopyInFirstPass < amount) { |
| System.arraycopy(mCircularBuffer, 0, buffer, offset + bytesToCopyInFirstPass, |
| amount - bytesToCopyInFirstPass); |
| } |
| mLastReadPosition = pos + amount; |
| mCircularBufferMonitor.notify(); |
| return amount; |
| } |
| } |
| |
| @Override |
| public long getSize() throws IOException { |
| return -1; |
| } |
| |
| @Override |
| public void close() {} |
| |
| @Override |
| public int getType() { |
| return Channel.TYPE_FILE; |
| } |
| |
| /** |
| * Adds {@link ScanChannel} instance for local files. |
| * |
| * @param output a list of channels where the results will be placed in |
| */ |
| public static void addLocalStreamFiles(List<ScanChannel> output) { |
| File dir = new File(FILE_DIR); |
| if (!dir.exists()) return; |
| |
| File[] tsFiles = dir.listFiles(); |
| if (tsFiles == null) return; |
| int freq = FileDataSource.FREQ_BASE; |
| for (File file : tsFiles) { |
| if (!file.isFile()) continue; |
| output.add(ScanChannel.forFile(freq, file.getName())); |
| freq += 100; |
| } |
| } |
| |
| /** |
| * A thread managing a circular buffer that holds stream data to be consumed by player. |
| * Keeps reading data in from a {@link StreamProvider} to hold enough amount for buffering. |
| * Started and stopped by {@link #startStream()} and {@link #stopStream()}, respectively. |
| */ |
| private class StreamingThread extends Thread { |
| @Override |
| public void run() { |
| byte[] dataBuffer = new byte[READ_BUFFER_SIZE]; |
| |
| synchronized (mCircularBufferMonitor) { |
| mBytesFetched = 0; |
| mLastReadPosition = 0; |
| } |
| |
| while (true) { |
| synchronized (mCircularBufferMonitor) { |
| while ((mBytesFetched - mLastReadPosition + PADDING_SIZE) > CIRCULAR_BUFFER_SIZE |
| && mStreaming) { |
| try { |
| mCircularBufferMonitor.wait(); |
| } catch (InterruptedException e) { |
| // Wait again. |
| Thread.currentThread().interrupt(); |
| } |
| } |
| if (!mStreaming) { |
| break; |
| } |
| } |
| |
| int bytesWritten = mSource.read(dataBuffer); |
| if (bytesWritten <= 0) { |
| try { |
| // When buffer is underrun, we sleep for short time to prevent |
| // unnecessary CPU draining. |
| sleep(BUFFER_UNDERRUN_SLEEP_MS); |
| } catch (InterruptedException e) { |
| Thread.currentThread().interrupt(); |
| } |
| continue; |
| } |
| |
| mEventDetector.feedTSStream(dataBuffer, 0, bytesWritten); |
| |
| synchronized (mCircularBufferMonitor) { |
| int posInBuffer = (int) (mBytesFetched % CIRCULAR_BUFFER_SIZE); |
| int bytesToCopyInFirstPass = bytesWritten; |
| if (posInBuffer + bytesToCopyInFirstPass > mCircularBuffer.length) { |
| bytesToCopyInFirstPass = mCircularBuffer.length - posInBuffer; |
| } |
| System.arraycopy(dataBuffer, 0, mCircularBuffer, posInBuffer, |
| bytesToCopyInFirstPass); |
| if (bytesToCopyInFirstPass < bytesWritten) { |
| System.arraycopy(dataBuffer, bytesToCopyInFirstPass, mCircularBuffer, 0, |
| bytesWritten - bytesToCopyInFirstPass); |
| } |
| mBytesFetched += bytesWritten; |
| mCircularBufferMonitor.notify(); |
| } |
| } |
| |
| Log.i(TAG, "Streaming stopped"); |
| mSource.close(); |
| } |
| } |
| } |