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Clean up WebvttParser somewhat.

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This commit is contained in:
Oliver Woodman 2015-11-25 16:47:52 +00:00
parent 7e2fffe74d
commit 042bd2ff82
1 changed files with 23 additions and 48 deletions
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71
library/src/main/java/com/google/android/exoplayer/text/webvtt/WebvttParser.java
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@ -45,9 +45,8 @@ public final class WebvttParser implements SubtitleParser {
private static final Pattern HEADER = Pattern.compile("^\uFEFF?WEBVTT((\u0020|\u0009).*)?$");
private static final Pattern COMMENT_BLOCK = Pattern.compile("^NOTE((\u0020|\u0009).*)?$");
private static final Pattern METADATA_HEADER = Pattern.compile("\\S*[:=]\\S*");
private static final Pattern CUE_IDENTIFIER = Pattern.compile("^(?!.*(-->)).*$");
private static final Pattern TIMESTAMP = Pattern.compile("(\\d+:)?[0-5]\\d:[0-5]\\d\\.\\d{3}");
private static final Pattern CUE_SETTING = Pattern.compile("\\S*:\\S*");
private static final Pattern CUE_HEADER = Pattern.compile("^(\\S+)\\s+-->\\s+(\\S+)(.*)?$");
private static final Pattern CUE_SETTING = Pattern.compile("\\S+?:\\S+");
private final PositionHolder positionHolder;
private final StringBuilder textBuilder;
@ -79,20 +78,20 @@ public final class WebvttParser implements SubtitleParser {
BufferedReader webvttData = new BufferedReader(new InputStreamReader(inputStream, C.UTF8_NAME));
String line;
// file should start with "WEBVTT"
// File should start with "WEBVTT".
line = webvttData.readLine();
if (line == null || !HEADER.matcher(line).matches()) {
throw new ParserException("Expected WEBVTT. Got " + line);
}
// parse the remainder of the header
// Parse the remainder of the header.
while (true) {
line = webvttData.readLine();
if (line == null) {
// we reached EOF before finishing the header
// We reached EOF before finishing the header.
throw new ParserException("Expected an empty line after webvtt header");
} else if (line.isEmpty()) {
// we've read the newline that separates the header from the body
// We read the newline that separates the header from the body.
break;
}
@ -104,32 +103,29 @@ public final class WebvttParser implements SubtitleParser {
}
}
// process the cues and text
// Process the cues and text.
while ((line = webvttData.readLine()) != null) {
// parse webvtt comment block in case it is present
// Skip a comment block, if present.
Matcher matcher = COMMENT_BLOCK.matcher(line);
if (matcher.find()) {
// read lines until finding an empty one (webvtt line terminator: CRLF, or LF or CR)
// Skip until the end of the comment block.
while ((line = webvttData.readLine()) != null && !line.isEmpty()) {
// ignore comment text
// Ignore comment text.
}
continue;
}
// parse the cue identifier (if present) {
matcher = CUE_IDENTIFIER.matcher(line);
if (matcher.find()) {
// ignore the identifier (we currently don't use it) and read the next line
line = webvttData.readLine();
if (line == null) {
// end of file
break;
}
// Skip anything other than a cue header.
matcher = CUE_HEADER.matcher(line);
if (!matcher.matches()) {
continue;
}
long cueStartTime;
long cueEndTime;
CharSequence cueText;
// Parse the cue start and end times.
long cueStartTime = parseTimestampUs(matcher.group(1));
long cueEndTime = parseTimestampUs(matcher.group(2));
// Default cue settings.
Alignment cueTextAlignment = null;
float cueLine = Cue.DIMEN_UNSET;
int cueLineType = Cue.TYPE_UNSET;
@ -138,34 +134,13 @@ public final class WebvttParser implements SubtitleParser {
int cuePositionAnchor = Cue.TYPE_UNSET;
float cueWidth = Cue.DIMEN_UNSET;
// parse the cue timestamps
matcher = TIMESTAMP.matcher(line);
// parse start timestamp
if (!matcher.find()) {
throw new ParserException("Expected cue start time: " + line);
} else {
cueStartTime = parseTimestampUs(matcher.group());
}
// parse end timestamp
String endTimeString;
if (!matcher.find()) {
throw new ParserException("Expected cue end time: " + line);
} else {
endTimeString = matcher.group();
cueEndTime = parseTimestampUs(endTimeString);
}
// parse the (optional) cue setting list
line = line.substring(line.indexOf(endTimeString) + endTimeString.length());
matcher = CUE_SETTING.matcher(line);
// Parse the cue settings list.
matcher = CUE_SETTING.matcher(matcher.group(3));
while (matcher.find()) {
String match = matcher.group();
String[] parts = match.split(":", 2);
String name = parts[0];
String value = parts[1];
try {
if ("line".equals(name)) {
parseLineAttribute(value, positionHolder);
@ -194,7 +169,7 @@ public final class WebvttParser implements SubtitleParser {
cuePositionAnchor = alignmentToAnchor(cueTextAlignment);
}
// parse text
// Parse the cue text.
textBuilder.setLength(0);
while ((line = webvttData.readLine()) != null && !line.isEmpty()) {
if (textBuilder.length() > 0) {
@ -202,7 +177,7 @@ public final class WebvttParser implements SubtitleParser {
}
textBuilder.append(line.trim());
}
cueText = Html.fromHtml(textBuilder.toString());
CharSequence cueText = Html.fromHtml(textBuilder.toString());
WebvttCue cue = new WebvttCue(cueStartTime, cueEndTime, cueText, cueTextAlignment, cueLine,
cueLineType, cueLineAnchor, cuePosition, cuePositionAnchor, cueWidth);