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Commit 7fb5b865 by Oliver Woodman
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Merge branch 'dev' of git://github.com/tresvecesseis/ExoPlayer into dev

parents faff8578 dd3a4a91
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Showing with 335 additions and 7 deletions
library/src/main/java/com/google/android/exoplayer/extractor/ts/MpaReader.java 0 → 100644
/*
* Copyright (C) 2014 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.google.android.exoplayer.extractor.ts;
import com.google.android.exoplayer.C;
import com.google.android.exoplayer.MediaFormat;
import com.google.android.exoplayer.extractor.TrackOutput;
import com.google.android.exoplayer.util.CodecSpecificDataUtil;
import com.google.android.exoplayer.util.MimeTypes;
import com.google.android.exoplayer.util.ParsableBitArray;
import com.google.android.exoplayer.util.ParsableByteArray;
import android.util.Pair;
import java.util.Collections;
/**
* Parses a continuous MPEG Audio byte stream and extracts individual
* frames.
*/
/* package */ public class MpaReader extends ElementaryStreamReader {
private static final int STATE_FINDING_SYNC = 0;
private static final int STATE_READING_HEADER = 1;
private static final int STATE_READING_SAMPLE = 2;
private static final int HEADER_SIZE = 4;
private static final int CRC_SIZE = 2;
private final ParsableBitArray mpaScratch;
private int state;
private int bytesRead;
// Used to find the header.
private boolean hasCrc;
// Used when parsing the header.
private boolean hasOutputFormat;
private long frameDurationUs;
private int sampleSize;
// Used when reading the samples.
private long timeUs;
//
/**
* sampling rates in hertz:
*
* @index MPEG Version ID
* @index sampling rate index
*/
private static final int[][] MPA_SAMPLING_RATES = new int[][] {
{11025, 12000, 8000}, // MPEG 2.5
{ 0, 0, 0}, // reserved
{22050, 24000, 16000}, // MPEG 2
{44100, 48000, 32000} // MPEG 1
};
/**
* bitrates:
*
* @index LSF
* @index Layer
* @index bitrate index
*/
private static final int[][][] MPA_BITRATES = new int[][][] {
{ // MPEG 1
// Layer1
{ 0, 32, 64, 96, 128, 160, 192, 224, 256, 288, 320, 352, 384, 416, 448},
// Layer2
{ 0, 32, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320, 384},
// Layer3
{ 0, 32, 40, 48, 56, 64, 80, 96, 112, 128, 160, 192, 224, 256, 320}
},
{ // MPEG 2, 2.5
// Layer1
{ 0, 32, 48, 56, 64, 80, 96, 112, 128, 144, 160, 176, 192, 224, 256},
// Layer2
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160},
// Layer3
{ 0, 8, 16, 24, 32, 40, 48, 56, 64, 80, 96, 112, 128, 144, 160}
}
};
/**
* Samples per Frame:
*
* @index LSF
* @index Layer
*/
private static final int[][] MPA_SAMPLES_PER_FRAME = new int[][] {
{ // MPEG 1
384, // Layer1
1152, // Layer2
1152 // Layer3
},
{ // MPEG 2, 2.5
384, // Layer1
1152, // Layer2
576 // Layer3
}
};
/**
* Coefficients (samples per frame / 8):
*
* @index = LSF
* @index = Layer
*/
private static final int[][] MPA_COEFFICIENTS = new int[][] {
{ // MPEG 1
12, // Layer1
144, // Layer2
144 // Layer3
},
{ // MPEG 2, 2.5
12, // Layer1
144, // Layer2
72 // Layer3
}
};
/**
* slot size per layer:
*
* @index = Layer
*/
private static final int[] MPA_SLOT_SIZE = new int[] {
4, // Layer1
1, // Layer2
1 // Layer3
};
public MpaReader(TrackOutput output) {
super(output);
mpaScratch = new ParsableBitArray(new byte[HEADER_SIZE + CRC_SIZE]);
state = STATE_FINDING_SYNC;
}
@Override
public void consume(ParsableByteArray data, long pesTimeUs, boolean startOfPacket) {
if (startOfPacket) {
timeUs = pesTimeUs;
}
while (data.bytesLeft() > 0) {
switch (state) {
case STATE_FINDING_SYNC:
if (skipToNextSync(data)) {
bytesRead = 0;
state = STATE_READING_HEADER;
}
break;
case STATE_READING_HEADER:
int targetLength = hasCrc ? HEADER_SIZE + CRC_SIZE : HEADER_SIZE;
if (continueRead(data, mpaScratch.getData(), targetLength)) {
parseHeader();
bytesRead = targetLength;
state = STATE_READING_SAMPLE;
}
break;
case STATE_READING_SAMPLE:
int bytesToRead = Math.min(data.bytesLeft(), sampleSize - bytesRead);
output.sampleData(data, bytesToRead);
bytesRead += bytesToRead;
if (bytesRead == sampleSize) {
output.sampleMetadata(timeUs, C.SAMPLE_FLAG_SYNC, sampleSize, 0, null);
timeUs += frameDurationUs;
bytesRead = 0;
state = STATE_FINDING_SYNC;
}
break;
}
}
}
@Override
public void packetFinished() {
// Do nothing.
}
/**
* Continues a read from the provided {@code source} into a given {@code target}. It's assumed
* that the data should be written into {@code target} starting from an offset of zero.
*
* @param source The source from which to read.
* @param target The target into which data is to be read.
* @param targetLength The target length of the read.
* @return Whether the target length was reached.
*/
private boolean continueRead(ParsableByteArray source, byte[] target, int targetLength) {
int bytesToRead = Math.min(source.bytesLeft(), targetLength - bytesRead);
source.readBytes(target, bytesRead, bytesToRead);
bytesRead += bytesToRead;
return bytesRead == targetLength;
}
/**
* Locates the next sync word, advancing the position to the byte that immediately follows it.
* If a sync word was not located, the position is advanced to the limit.
*
* @param pesBuffer The buffer whose position should be advanced.
* @return True if a sync word position was found. False otherwise.
*/
private boolean skipToNextSync(ParsableByteArray pesBuffer) {
byte[] mpaData = pesBuffer.data;
int startOffset = pesBuffer.getPosition();
int endOffset = pesBuffer.limit();
for (int i = startOffset; i < endOffset - 1; i++) {
int syncBits = ((mpaData[i] & 0xFF) << 8 ) | (mpaData[i + 1] & 0xFF);
if ((syncBits & 0xFFF0) == 0xFFF0) {
hasCrc = (mpaData[i + 1] & 0x1) == 0;
pesBuffer.setPosition(i);
return true;
}
}
pesBuffer.setPosition(endOffset);
return false;
}
/**
* Calculates MPEG Audio frame size
*
* @param layer The MPEG layer
* @param LSF Low Sample rate Format (MPEG 2)
* @param bitrate The bitrate in bits per second
* @param samplesPerSec The sampling rate in hertz
* @param -paddingSize
* @return Frame size in bytes
*/
private static int CalcMpaFrameSize (int layer, int LSF, int bitrate, int samplesPerSec, int paddingSize) {
return (int)(Math.floor(MPA_COEFFICIENTS[LSF][layer] * bitrate / samplesPerSec) + paddingSize) * MPA_SLOT_SIZE[layer];
}
/**
* Parses the sample header.
*/
private void parseHeader() {
int headerLength = hasCrc ? HEADER_SIZE + CRC_SIZE : HEADER_SIZE;
if (!hasOutputFormat) {
mpaScratch.setPosition(0);
mpaScratch.skipBits(12);
int isLSF = (!mpaScratch.readBit()) ? 1 : 0;
int layer = mpaScratch.readBits(2) ^ 3;
mpaScratch.skipBits(1);
int audioObjectType = 32 + layer;
int bitRate = MPA_BITRATES[isLSF][layer][mpaScratch.readBits(4)];
int sampleRate = MPA_SAMPLING_RATES[3 - isLSF][mpaScratch.readBits(2)];
int sampleRateIndex = CodecSpecificDataUtil.getSampleRateIndex(sampleRate);
int paddingBit = (mpaScratch.readBit()) ? 1 : 0;
mpaScratch.skipBits(1);
int channelConfig = mpaScratch.readBits(2) == 3 ? 1 : 2;
byte[] audioSpecificConfig = CodecSpecificDataUtil.buildAudioSpecificConfig(
audioObjectType, sampleRateIndex, channelConfig);
Pair<Integer, Integer> audioParams = CodecSpecificDataUtil.parseAudioSpecificConfig(
audioSpecificConfig);
// need to investigate how to detect if the mpeg decoder supports Layers other than Layer III
MediaFormat mediaFormat = MediaFormat.createAudioFormat(/*isLSF == 1 ?*/ MimeTypes.AUDIO_MPEG/* : MimeTypes.AUDIO_MP1L2*/,
MediaFormat.NO_VALUE, audioParams.second, audioParams.first,
Collections.singletonList(audioSpecificConfig));
output.format(mediaFormat);
hasOutputFormat = true;
frameDurationUs = (C.MICROS_PER_SECOND * MPA_SAMPLES_PER_FRAME[isLSF][layer]) / mediaFormat.sampleRate;
sampleSize = CalcMpaFrameSize(layer, isLSF, bitRate * 1000, sampleRate, paddingBit);
}
mpaScratch.setPosition(0);
ParsableByteArray header = new ParsableByteArray(mpaScratch.getData(),headerLength);
output.sampleData(header, headerLength);
}
}
library/src/main/java/com/google/android/exoplayer/extractor/ts/TsExtractor.java
......@@ -42,6 +42,8 @@ public final class TsExtractor implements Extractor, SeekMap {
private static final int TS_SYNC_BYTE = 0x47; // First byte of each TS packet.
private static final int TS_PAT_PID = 0;
private static final int TS_STREAM_TYPE_MPA = 0x03;
private static final int TS_STREAM_TYPE_MPA_LSF = 0x04;
private static final int TS_STREAM_TYPE_AAC = 0x0F;
private static final int TS_STREAM_TYPE_ATSC_AC3 = 0x81;
private static final int TS_STREAM_TYPE_ATSC_E_AC3 = 0x87;
......@@ -351,6 +353,12 @@ public final class TsExtractor implements Extractor, SeekMap {
// TODO: Detect and read DVB AC-3 streams with Ac3Reader.
ElementaryStreamReader pesPayloadReader = null;
switch (streamType) {
case TS_STREAM_TYPE_MPA:
pesPayloadReader = new MpaReader(output.track(TS_STREAM_TYPE_MPA));
break;
case TS_STREAM_TYPE_MPA_LSF:
pesPayloadReader = new MpaReader(output.track(TS_STREAM_TYPE_MPA_LSF));
break;
case TS_STREAM_TYPE_AAC:
pesPayloadReader = new AdtsReader(output.track(TS_STREAM_TYPE_AAC));
break;
......
library/src/main/java/com/google/android/exoplayer/util/CodecSpecificDataUtil.java
......@@ -41,6 +41,22 @@ public final class CodecSpecificDataUtil {
private CodecSpecificDataUtil() {}
/**
* Gets the sample rate index.
*
* @param sampleRate The sample rate in Hz.
* @return The sample rate index.
*/
public static int getSampleRateIndex(int sampleRate) {
int sampleRateIndex = 0;
for (; sampleRateIndex < AUDIO_SPECIFIC_CONFIG_SAMPLING_RATE_TABLE.length; sampleRateIndex++) {
if (AUDIO_SPECIFIC_CONFIG_SAMPLING_RATE_TABLE[sampleRateIndex] == sampleRate) {
return sampleRateIndex;
}
}
return -1;
}
/**
* Parses an AudioSpecificConfig, as defined in ISO 14496-3 1.6.2.1
*
......@@ -49,13 +65,24 @@ public final class CodecSpecificDataUtil {
*/
public static Pair<Integer, Integer> parseAacAudioSpecificConfig(byte[] audioSpecificConfig) {
int audioObjectType = (audioSpecificConfig[0] >> 3) & 0x1F;
int byteOffset = audioObjectType == 5 || audioObjectType == 29 ? 1 : 0;
int frequencyIndex = (audioSpecificConfig[byteOffset] & 0x7) << 1
| ((audioSpecificConfig[byteOffset + 1] >> 7) & 0x1);
Assertions.checkState(frequencyIndex < 13);
int sampleRate = AUDIO_SPECIFIC_CONFIG_SAMPLING_RATE_TABLE[frequencyIndex];
int channelCount = (audioSpecificConfig[byteOffset + 1] >> 3) & 0xF;
return Pair.create(sampleRate, channelCount);
if (audioObjectType < 31) {
int byteOffset = audioObjectType == 5 || audioObjectType == 29 ? 1 : 0;
int frequencyIndex = (audioSpecificConfig[byteOffset] & 0x7) << 1 |
((audioSpecificConfig[byteOffset + 1] >> 7) & 0x1);
Assertions.checkState(frequencyIndex < 13);
int sampleRate = AUDIO_SPECIFIC_CONFIG_SAMPLING_RATE_TABLE[frequencyIndex];
int channelCount = AUDIO_SPECIFIC_CONFIG_CHANNEL_COUNT_TABLE[
(audioSpecificConfig[byteOffset + 1] >> 3) & 0xF];
return Pair.create(sampleRate, channelCount);
} else {
int frequencyIndex = (audioSpecificConfig[1] & 0x1E) >> 1;
Assertions.checkState(frequencyIndex < 13);
int sampleRate = AUDIO_SPECIFIC_CONFIG_SAMPLING_RATE_TABLE[frequencyIndex];
int channelCount = AUDIO_SPECIFIC_CONFIG_CHANNEL_COUNT_TABLE[
(audioSpecificConfig[1] & 0x01) << 3 |
((audioSpecificConfig[2] >> 5) & 0x07)];
return Pair.create(sampleRate, channelCount);
}
}
/**
......
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