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Add minimal support of DVB AIT

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This is used by broadcast channels to provide interactive contents.
This commit is contained in:
Pierre-Hugues Husson 2020-01-28 16:07:02 +01:00
parent 8da0e27d2e
commit 1d65afdd16
6 changed files with 302 additions and 2 deletions
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1
library/common/src/main/java/com/google/android/exoplayer2/util/MimeTypes.java
View file

@ -97,6 +97,7 @@ public final class MimeTypes {
public static final String APPLICATION_DVBSUBS = BASE_TYPE_APPLICATION + "/dvbsubs";
public static final String APPLICATION_EXIF = BASE_TYPE_APPLICATION + "/x-exif";
public static final String APPLICATION_ICY = BASE_TYPE_APPLICATION + "/x-icy";
public static final String APPLICATION_AIT = BASE_TYPE_APPLICATION + "/ait";
private static final ArrayList<CustomMimeType> customMimeTypes = new ArrayList<>();

6
library/core/src/main/java/com/google/android/exoplayer2/metadata/MetadataDecoderFactory.java
View file

@ -17,6 +17,7 @@ package com.google.android.exoplayer2.metadata;
import androidx.annotation.Nullable;
import com.google.android.exoplayer2.Format;
import com.google.android.exoplayer2.metadata.dvbsi.AitDecoder;
import com.google.android.exoplayer2.metadata.emsg.EventMessageDecoder;
import com.google.android.exoplayer2.metadata.icy.IcyDecoder;
import com.google.android.exoplayer2.metadata.id3.Id3Decoder;
@ -67,7 +68,8 @@ public interface MetadataDecoderFactory {
return MimeTypes.APPLICATION_ID3.equals(mimeType)
|| MimeTypes.APPLICATION_EMSG.equals(mimeType)
|| MimeTypes.APPLICATION_SCTE35.equals(mimeType)
|| MimeTypes.APPLICATION_ICY.equals(mimeType);
|| MimeTypes.APPLICATION_ICY.equals(mimeType)
|| MimeTypes.APPLICATION_AIT.equals(mimeType);
}
@Override
@ -83,6 +85,8 @@ public interface MetadataDecoderFactory {
return new SpliceInfoDecoder();
case MimeTypes.APPLICATION_ICY:
return new IcyDecoder();
case MimeTypes.APPLICATION_AIT:
return new AitDecoder();
default:
break;
}

58
library/core/src/main/java/com/google/android/exoplayer2/metadata/dvbsi/Ait.java Normal file
View file

@ -0,0 +1,58 @@
package com.google.android.exoplayer2.metadata.dvbsi;
import android.os.Parcel;
import android.os.Parcelable;
import com.google.android.exoplayer2.metadata.Metadata;
public class Ait implements Metadata.Entry {
/*
The application shall be started when the service is selected, unless the
application is already running.
*/
public static final int CONTROL_CODE_AUTOSTART = 0x01;
/*
The application is allowed to run while the service is selected, however it
shall not start automatically when the service becomes selected.
*/
public static final int CONTROL_CODE_PRESENT = 0x02;
public final int controlCode;
public final String url;
Ait(int controlCode, String url) {
this.controlCode = controlCode;
this.url = url;
}
@Override
public String toString() {
return "Ait(controlCode = " + controlCode + ", url = " + url + ")";
}
@Override
public int describeContents() {
return 0;
}
@Override
public void writeToParcel(Parcel parcel, int i) {
parcel.writeString(url);
parcel.writeInt(controlCode);
}
public static final Parcelable.Creator<Ait> CREATOR =
new Parcelable.Creator<Ait>() {
@Override
public Ait createFromParcel(Parcel in) {
String url = in.readString();
int controlCode = in.readInt();
return new Ait(controlCode, url);
}
@Override
public Ait[] newArray(int size) {
return new Ait[size];
}
};
}

195
library/core/src/main/java/com/google/android/exoplayer2/metadata/dvbsi/AitDecoder.java Normal file
View file

@ -0,0 +1,195 @@
package com.google.android.exoplayer2.metadata.dvbsi;
import com.google.android.exoplayer2.metadata.Metadata;
import com.google.android.exoplayer2.metadata.MetadataDecoder;
import com.google.android.exoplayer2.metadata.MetadataInputBuffer;
import com.google.android.exoplayer2.util.ParsableByteArray;
import com.google.android.exoplayer2.util.TimestampAdjuster;
import java.nio.ByteBuffer;
import java.nio.charset.Charset;
import java.util.ArrayList;
public class AitDecoder implements MetadataDecoder {
// Specification of AIT can be found in 5.3.4 of TS 102 809 v1.1.1
// https://www.etsi.org/deliver/etsi_ts/102800_102899/102809/01.01.01_60/ts_102809v010101p.pdf
private final static int DESCRIPTOR_TRANSPORT_PROTOCOL = 0x02;
private final static int DESCRIPTOR_SIMPLE_APPLICATION_LOCATION = 0x15;
private final static int TRANSPORT_PROTOCOL_HTTP = 3;
private TimestampAdjuster timestampAdjuster;
private final ParsableByteArray sectionData;
public AitDecoder() {
sectionData = new ParsableByteArray();
}
@Override
public Metadata decode(MetadataInputBuffer inputBuffer) {
if (timestampAdjuster == null
|| inputBuffer.subsampleOffsetUs != timestampAdjuster.getTimestampOffsetUs()) {
timestampAdjuster = new TimestampAdjuster(inputBuffer.timeUs);
timestampAdjuster.adjustSampleTimestamp(inputBuffer.timeUs - inputBuffer.subsampleOffsetUs);
}
ByteBuffer buffer = inputBuffer.data;
byte[] data = buffer.array();
int size = buffer.limit();
sectionData.reset(data, size);
int tableId = sectionData.peekUnsignedByte();
//Only this table is allowed in AIT streams
if (tableId == 0x74) {
return parseAit(sectionData);
}
return new Metadata();
}
private Metadata parseAit(ParsableByteArray sectionData) {
int tmp;
int tableId = sectionData.readUnsignedByte();
tmp = sectionData.readUnsignedShort();
int endOfSection = sectionData.getPosition() + (tmp & 4095) - 4 /* Ignore leading CRC */;
tmp = sectionData.readUnsignedShort();
int applicationType = tmp & 0x7fff;
tmp = sectionData.readUnsignedByte();
int versionNumber = (tmp & 0x3e) >> 1;
boolean current = (tmp & 1) == 1;
int section_number = sectionData.readUnsignedByte();
int last_section_number = sectionData.readUnsignedByte();
tmp = sectionData.readUnsignedShort();
int commonDescriptorsLength = tmp & 4095;
//Since we currently only keep url and control code, which are unique per application,
//there is no useful information in common descriptor.
sectionData.skipBytes(commonDescriptorsLength);
tmp = sectionData.readUnsignedShort();
int appLoopLength = tmp & 4095;
ArrayList<Ait> aits = new ArrayList<>();
while(sectionData.getPosition() < endOfSection) {
// Values that will be stored in Ait()
String aitUrlBase = null;
String aitUrlExtension = null;
int aitControlCode = -1;
long application_identifier = sectionData.readUnsignedInt24() << 24L;
application_identifier |= sectionData.readUnsignedInt24();
int controlCode = sectionData.readUnsignedByte();
aitControlCode = controlCode;
tmp = sectionData.readUnsignedShort();
int sectionLength = tmp & 4095;
int positionOfNextSection = sectionData.getPosition() + sectionLength;
while(sectionData.getPosition() < positionOfNextSection) {
int type = sectionData.readUnsignedByte();
int l = sectionData.readUnsignedByte();
int positionOfNextSection2 = sectionData.getPosition() + l;
if(type == DESCRIPTOR_TRANSPORT_PROTOCOL) {
int protocolId = sectionData.readUnsignedShort();
int label = sectionData.readUnsignedByte();
if(protocolId == TRANSPORT_PROTOCOL_HTTP) {
while (sectionData.getPosition() < positionOfNextSection2) {
int urlBaseLength = sectionData.readUnsignedByte();
String urlBase = sectionData.readString(urlBaseLength);
int extensionCount = sectionData.readUnsignedByte();
aitUrlBase = urlBase;
for (int i = 0; i < extensionCount; i++) {
int len = sectionData.readUnsignedByte();
sectionData.skipBytes(len);
}
}
}
} else if(type == DESCRIPTOR_SIMPLE_APPLICATION_LOCATION) {
String url = sectionData.readString(l);
aitUrlExtension = url;
}
sectionData.setPosition(positionOfNextSection2);
}
sectionData.setPosition(positionOfNextSection);
if(aitControlCode != -1 && aitUrlBase != null && aitUrlExtension != null) {
aits.add(new Ait(aitControlCode, aitUrlBase + aitUrlExtension));
}
}
return new Metadata(aits);
}
static final String dvbCharset[] = {
"ISO-8859-15",
"ISO-8859-5",
"ISO-8859-6",
"ISO-8859-7",
"ISO-8859-8",
"ISO-8859-9",
null,
"ISO-8859-11",
null,
"ISO-8859-13",
null,
"ISO-8859-15",
null,
null,
null,
null,
//0x10
null,
null,
null,
null,
null,
null,
null,
null,
null,
null,
null,
null,
null,
null,
null,
null,
};
static String readDvbString(ParsableByteArray data, int length) {
if(length == 0) return null;
int charsetSelect = data.peekUnsignedByte();
if(charsetSelect >= 0x20)
return data.readString(length, Charset.forName("ISO-8859-15"));
data.skipBytes(1);
if(charsetSelect == 0x1f) {
data.skipBytes(length - 1);
return null;
}
if(charsetSelect != 0x10)
return data.readString(length-1, Charset.forName(dvbCharset[charsetSelect]));
if(length == 2) {
data.skipBytes(1);
return null;
}
charsetSelect = data.readUnsignedShort();
if(charsetSelect > 1 && charsetSelect < 0x10) {
String charsetName = "ISO-8859-" + charsetSelect;
return data.readString(length-3, Charset.forName(charsetName));
}
return null;
}
}

36
library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ts/DefaultTsPayloadReaderFactory.java
View file

@ -18,11 +18,17 @@ package com.google.android.exoplayer2.extractor.ts;
import android.util.SparseArray;
import androidx.annotation.IntDef;
import androidx.annotation.Nullable;
import com.google.android.exoplayer2.C;
import com.google.android.exoplayer2.Format;
import com.google.android.exoplayer2.extractor.ExtractorOutput;
import com.google.android.exoplayer2.extractor.TrackOutput;
import com.google.android.exoplayer2.extractor.ts.TsPayloadReader.EsInfo;
import com.google.android.exoplayer2.util.CodecSpecificDataUtil;
import com.google.android.exoplayer2.util.MimeTypes;
import com.google.android.exoplayer2.util.ParsableByteArray;
import com.google.android.exoplayer2.util.TimestampAdjuster;
import java.lang.annotation.Documented;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
@ -176,11 +182,41 @@ public final class DefaultTsPayloadReaderFactory implements TsPayloadReader.Fact
case TsExtractor.TS_STREAM_TYPE_DVBSUBS:
return new PesReader(
new DvbSubtitleReader(esInfo.dvbSubtitleInfos));
case TsExtractor.TS_STREAM_TYPE_AIT:
return new SectionReader(new SectionPassthrough(MimeTypes.APPLICATION_AIT));
default:
return null;
}
}
public class SectionPassthrough implements SectionPayloadReader {
private TimestampAdjuster timestampAdjuster = null;
private final String mimeType;
private TrackOutput output;
SectionPassthrough(String mimeType) {
this.mimeType = mimeType;
}
@Override
public void init(TimestampAdjuster timestampAdjuster, ExtractorOutput extractorOutput, TsPayloadReader.TrackIdGenerator idGenerator) {
this.timestampAdjuster = timestampAdjuster;
idGenerator.generateNewId();
output = extractorOutput.track(idGenerator.getTrackId(), C.TRACK_TYPE_METADATA);
output.format(Format.createSampleFormat(null, mimeType,
timestampAdjuster.getTimestampOffsetUs()));
}
@Override
public void consume(ParsableByteArray sectionData) {
int sampleSize = sectionData.bytesLeft();
output.sampleData(sectionData, sampleSize);
output.sampleMetadata(timestampAdjuster.getLastAdjustedTimestampUs(), C.BUFFER_FLAG_KEY_FRAME,
sampleSize, 0, null);
}
}
/**
* If {@link #FLAG_OVERRIDE_CAPTION_DESCRIPTORS} is set, returns a {@link SeiReader} for
* {@link #closedCaptionFormats}. If unset, parses the PMT descriptor information and returns a

8
library/extractor/src/main/java/com/google/android/exoplayer2/extractor/ts/TsExtractor.java
View file

@ -96,6 +96,9 @@ public final class TsExtractor implements Extractor {
public static final int TS_STREAM_TYPE_SPLICE_INFO = 0x86;
public static final int TS_STREAM_TYPE_DVBSUBS = 0x59;
//Those are special IDs, which don't have actual TS definitions
public static final int TS_STREAM_TYPE_AIT = 0x101;
public static final int TS_PACKET_SIZE = 188;
public static final int TS_SYNC_BYTE = 0x47; // First byte of each TS packet.
@ -494,6 +497,7 @@ public final class TsExtractor implements Extractor {
private static final int TS_PMT_DESC_REGISTRATION = 0x05;
private static final int TS_PMT_DESC_ISO639_LANG = 0x0A;
private static final int TS_PMT_DESC_AC3 = 0x6A;
private static final int TS_PMT_DESC_AIT = 0x6F;
private static final int TS_PMT_DESC_EAC3 = 0x7A;
private static final int TS_PMT_DESC_DTS = 0x7B;
private static final int TS_PMT_DESC_DVB_EXT = 0x7F;
@ -578,7 +582,7 @@ public final class TsExtractor implements Extractor {
pmtScratch.skipBits(4); // reserved
int esInfoLength = pmtScratch.readBits(12); // ES_info_length.
EsInfo esInfo = readEsInfo(sectionData, esInfoLength);
if (streamType == 0x06) {
if (streamType == 0x06 || streamType == 0x05) {
streamType = esInfo.streamType;
}
remainingEntriesLength -= esInfoLength + 5;
@ -688,6 +692,8 @@ public final class TsExtractor implements Extractor {
dvbSubtitleInfos.add(new DvbSubtitleInfo(dvbLanguage, dvbSubtitlingType,
initializationData));
}
} else if (descriptorTag == TS_PMT_DESC_AIT) {
streamType = TS_STREAM_TYPE_AIT;
}
// Skip unused bytes of current descriptor.
data.skipBytes(positionOfNextDescriptor - data.getPosition());