nl.vpro.domain.subtitles.EBU Maven / Gradle / Ivy
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Subtitles are related to media, but are implemented completely parallel. Classes to contain, parse, and assemble subtitle objects are here.
package nl.vpro.domain.subtitles;
import lombok.extern.slf4j.Slf4j;
import java.io.IOException;
import java.io.InputStream;
import java.time.Duration;
import java.util.Iterator;
import java.util.NoSuchElementException;
import java.util.Spliterator;
import java.util.Spliterators;
import java.util.function.Function;
import java.util.stream.Stream;
import java.util.stream.StreamSupport;
/**
* Code borrowed from https://github.com/JDaren/subtitleConverter
*
* Adapted so it returns a stream of our {@link Cue} objects
* @author Michiel Meeuwissen
* @since 5.3
*/
@Slf4j
public class EBU {
private EBU() {
}
public static Stream parse(String parent, Duration offset, Function offsetGuesser, InputStream is) {
return StreamSupport.stream(Spliterators.spliteratorUnknownSize(parseToIterator(parent, offset, offsetGuesser, is), Spliterator.ORDERED), false);
}
protected static Iterator parseToIterator(final String parent, final Duration offsetArgument, Function offsetGuesser, final InputStream is) {
if (is == null) {
throw new IllegalArgumentException("Inputstream cannot be null");
}
return new Iterator() {
protected Cue next;
protected Boolean hasNext = null;
private int i = 0;
final byte[] ttiBlock = new byte[128];
final int numberOfTTIBlocks;
final int fps;
final int numberOfSubtitles;
int subtitleNumber = 1;
Duration offset = offsetArgument;
{
byte[] gsiBlock = new byte[1024];
try {
//we read the file
//but first we create the possible styles
int bytesRead = is.read(gsiBlock);
//the GSI block is loaded
if (bytesRead < 1024) {
//the file must contain at least a GSI block and a TTI block
//this is a fatal parsing error.
throw new IllegalArgumentException("The file must contain at least a GSI block, but read only " + bytesRead + " (< 1024)");
}
//CPC : code page number 0..2
//DFC : disk format code 3..10
//save the number of frames per second
byte[] dfc = {gsiBlock[6], gsiBlock[7]};
fps = Integer.parseInt(new String(dfc));
//DSC : Display Standard Code 11
//CCT : Character Code Table number 12..13
byte[] cct = {gsiBlock[12], gsiBlock[13]};
int table = Integer.parseInt(new String(cct));
//LC : Language Code 14..15
//OPT : Original Programme Title 16..47
byte[] opt = new byte[32];
System.arraycopy(gsiBlock, 16, opt, 0, 32);
String title = new String(opt);
//OEP : Original Episode Title 48..79
byte[] oet = new byte[32];
System.arraycopy(gsiBlock, 48, oet, 0, 32);
String episodeTitle = new String(oet);
//TPT : Translated Programme Title 80..111
//TEP : Translated Episode Title 112..143
//TN : Translator's Name 144..175
//TCD : Translators Contact Details 176..207
//SLR : Subtitle List Reference code 208..223
//CD : Creation Date 224..229
//RD : Revision Date 230..235
//RN : Revision Number 236..237
//TNB : Total Number of TTI Blocks 238..242
byte[] tnb = {gsiBlock[238], gsiBlock[239], gsiBlock[240], gsiBlock[241], gsiBlock[242]};
numberOfTTIBlocks = Integer.parseInt(new String(tnb).trim());
//TNS : Total Number of Subtitles 243..247
byte[] tns = {gsiBlock[243], gsiBlock[244], gsiBlock[245], gsiBlock[246], gsiBlock[247]};
numberOfSubtitles = Integer.parseInt(new String(tns).trim());
//TNG : Total Number of Subtitle Groups 248..250
//MNC : Max Number of characters in row 251..252
//MNR : Max number of rows 253..254
//TCS : Time Code: Status 255
//TCP : Time Code: Start-of-Programme 256..263
//TCF : Time Code: First In-Cue 264..271
//TND : Total Number of Disks 272
//DSN : Disk Sequence Number 273
//CO : Country of Origin 274..276
//PUB : Publisher 277..308
//EN : Editor's Name 309..340
//ECD : Editor's Contact Details 341..372
// Spare bytes 373..447
//UDA : User-Defined Area 448..1023
//we add the title
//this checks the reference to the characters coding employed.
if (table > 4 || table < 0) {
log.error("Invalid Character Code table number, corrupt data? will try to parse anyways assuming it is latin.");
} else if (table != 0) {
log.error("Only latin alphabet supported for import from STL, other languages may produce unexpected results.");
}
int subtitleNumber = 1;
} catch (IOException e) {
log.error(e.getMessage(), e);
throw new RuntimeException(e);
}
}
@Override
public boolean hasNext() {
findNext();
return hasNext;
}
@Override
public Cue next() {
findNext();
if (!hasNext()) {
throw new NoSuchElementException();
}
hasNext = null;
return next;
}
protected void findNext() {
if (hasNext == null) {
next = null;
try {
Cue toFill = new Cue();
toFill.parent = parent;
boolean additionalText = false;
StringBuilder currentContent = new StringBuilder();
//the TTI blocks are read
while (i < numberOfTTIBlocks && next == null) {
i++;
//the TTI block is loaded
int bytesRead = is.read(ttiBlock);
if (bytesRead < 128) {
//unexpected end of file
log.error("Unexpected end of file, {} blocks read, expecting {} blocks in total.", i, numberOfTTIBlocks);
break;
}
//SGN : Subtitle group number 0
//SN : Subtitle Number 1..2
int currentSubNumber = Math.abs(ttiBlock[1] + 256 * ttiBlock[2]);
if (currentSubNumber != subtitleNumber) {
//missing subtitle number?
log.debug("Unexpected subtitle number {} (expected {}) at TTI block {} Parsing proceeds...", subtitleNumber, currentSubNumber, i);
}
toFill.sequence = subtitleNumber;
toFill.identifier = "" + subtitleNumber;
//EBN : Extension Block Number 3
int ebn = ttiBlock[3];
if (ebn != -1 && ebn != -2) {
additionalText = true;
} else if (ebn == -2) {
//EBN is UserData so Jump it.
additionalText = false;
continue;
} else {
additionalText = false;
}
//CS : Cumulative Status 4
//TCI : Time Code In 5..8
String startTime = "" + ttiBlock[5] + ":" + ttiBlock[6] + ":" + ttiBlock[7] + ":" + ttiBlock[8];
//TCO : Time Code Out 9..12
String endTime = "" + ttiBlock[9] + ":" + ttiBlock[10] + ":" + ttiBlock[11] + ":" + ttiBlock[12];
//VP : Vertical Position 13
//JC : Justification Code 14
int justification = ttiBlock[14];
//0:none, 1:left, 2:centered, 3:right
//CF : Comment Flag 15
if (ttiBlock[15] == 0) {
//comments are ignored
//TF : Text Field 16..112
byte[] textField = new byte[112];
System.arraycopy(ttiBlock, 16, textField, 0, 112);
if (additionalText)
//if it is just additional text for the caption
parseTextForSTL(currentContent, textField, justification);
else {
TimeLine timeLine = parseTime(startTime, endTime, fps);
if (offset == null) {
offset = offsetGuesser.apply(timeLine);
}
toFill.start = parseTime(startTime + "/" + fps).minus(offset);
toFill.end = parseTime(endTime + "/" + fps).minus(offset);
parseTextForSTL(currentContent, textField, justification);
}
}
//we increase the subtitle number
if (!additionalText) {
subtitleNumber++;
next = toFill;
break;
}
}
if (next != null) {
hasNext = true;
next.content = currentContent.toString().trim();
} else {
hasNext = false;
//we close the reader
is.close();
if (subtitleNumber != numberOfSubtitles) {
log.debug("Number of parsed subtitles ({}) different from expected number of subtitles ({})", subtitleNumber, numberOfSubtitles);
}
}
} catch (Exception e) {
hasNext = false;
//format error
throw new IllegalArgumentException("Format error in the file, might be due to corrupt data." + e.getMessage(), e);
}
}
}
};
}
private static TimeLine parseTime(String startTime, String endTime, int fps) {
return new TimeLine(null, parseTime(startTime + "/" + fps), parseTime(endTime + "/" + fps));
}
/**
* This method parses the text field taking into account STL control codes
*/
private static void parseTextForSTL(StringBuilder currentCaption, byte[] textField, int justification) {
boolean italics = false;
boolean underline = false;
int diacritical_mark = 0;
String color = "white";
String text = "";
//we go around the field in pair of bytes to decode them
for (int i = 0; i < textField.length; i++) {
if (textField[i] < 0) {
//first byte > 8 (4 bits)
if (textField[i] <= -113) {
//we might be with a control code
if (i + 1 < textField.length && textField[i] == textField[i + 1])
i++; //if repeated skip one
switch (textField[i]) {
case -128:
italics = true;
break;
case -127:
italics = false;
break;
case -126:
underline = true;
break;
case -125:
underline = false;
break;
case -124:
//Boxing not supported
break;
case -123:
//Boxing not supported
break;
case -118:
//line break
currentCaption.append(text.trim()).append("\n");
text = "";
break;
case -113:
//end of caption
currentCaption.append(text.trim());
text = "";
//we check the style
if (underline)
color += "U";
if (italics)
color += "I";
//style = tto.styling.get(color);
if (justification == 1) {
color += "L";
} else if (justification == 3) {
color += "R";
}
//we end the loop
i = textField.length;
break;
default:
//non valid code...
}
} else if (textField[i] >= -64 && textField[i] <= -49) {
// diacritical characters
diacritical_mark = textField[i];
} else {
//other codes and non supported characters...
//corresponds to the upper half of the character code table
}
} else if (textField[i] < 32) {
//it is a teletext control code, only colors are supported
if (i + 1 < textField.length && textField[i] == textField[i + 1])
i++; //if repeated skip one
switch (textField[i]) {
case 7:
color = "white";
break;
case 2:
color = "green";
break;
case 4:
color = "blue";
break;
case 6:
color = "cyan";
break;
case 1:
color = "red";
break;
case 3:
color = "yellow";
break;
case 5:
color = "magenta";
break;
case 0:
color = "black";
break;
default:
//non supported
}
} else {
//we have a supported character coded in the two bytes, range is from 0x20 to 0x7F
byte[] x = {textField[i]};
String raw_string = new String(x);
if (diacritical_mark != 0) {
if ((diacritical_mark == -62) && (textField[i] == 101)) raw_string = "é";
else if ((diacritical_mark == -56) && (textField[i] == 105)) raw_string = "ï";
else if ((diacritical_mark == -63) && (textField[i] == 97)) raw_string = "à";
else if ((diacritical_mark == -56) && (textField[i] == 101)) raw_string = "ë";
else if ((diacritical_mark == -61) && (textField[i] == 101)) raw_string = "ê";
else if ((diacritical_mark == -63) && (textField[i] == 117)) raw_string = "ù";
else if ((diacritical_mark == -61) && (textField[i] == 105)) raw_string = "î";
else if ((diacritical_mark == -63) && (textField[i] == 101)) raw_string = "è";
else if ((diacritical_mark == -61) && (textField[i] == 97)) raw_string = "â";
else if ((diacritical_mark == -61) && (textField[i] == 111)) raw_string = "ô";
else if ((diacritical_mark == -61) && (textField[i] == 117)) raw_string = "û";
else if ((diacritical_mark == -53) && (textField[i] == 99)) raw_string = "ç";
else if ((diacritical_mark == -56) && (textField[i] == 97)) raw_string = "ä";
else if ((diacritical_mark == -56) && (textField[i] == 111)) raw_string = "ö";
else if ((diacritical_mark == -56) && (textField[i] == 117)) raw_string = "ü";
diacritical_mark = 0;
}
text += raw_string;
}
}
}
/**
* @param value string in the correct format
*/
private static Duration parseTime(String value) {
int h, m, s, f;
String[] args = value.split("/");
float fps = Float.parseFloat(args[1]);
args = args[0].split(":");
h = Integer.parseInt(args[0]);
m = Integer.parseInt(args[1]);
s = Integer.parseInt(args[2]);
f = Integer.parseInt(args[3]);
return Duration.ofMillis((long) (f * 1000L / fps) + s * 1000L + m * 60000L + h * 3600000L);
}
}
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