/**
* Modifies current position.
*
* @param pos Current position in file
*/
private void setCurrentPosition(long pos) {
if (pos == Long.MAX_VALUE) {
pos = file.length();
}
if (!useLoadBuf) {
in.position((int) pos);
return;
}
try {
if (pos >= (channel.position() - in.limit()) && pos < channel.position()) {
in.position((int) (pos - (channel.position() - in.limit())));
} else {
channel.position(pos);
fillBuffer(bufferSize, true);
}
} catch (Exception e) {
log.error("Error setCurrentPosition", e);
}
}
/** {@inheritDoc} */
public synchronized ITag readTag() {
long oldPos = getCurrentPosition();
ITag tag = readTagHeader();
if (tagPosition == 0 && tag.getDataType() != TYPE_METADATA && generateMetadata) {
// Generate initial metadata automatically
setCurrentPosition(oldPos);
KeyFrameMeta meta = analyzeKeyFrames();
tagPosition++;
if (meta != null) {
return createFileMeta();
}
}
ByteBuffer body = ByteBuffer.allocate(tag.getBodySize(), false);
// XXX Paul: this assists in 'properly' handling damaged FLV files
long newPosition = getCurrentPosition() + tag.getBodySize();
if (newPosition <= getTotalBytes()) {
int limit;
while (getCurrentPosition() < newPosition) {
fillBuffer(newPosition - getCurrentPosition());
if (getCurrentPosition() + in.remaining() > newPosition) {
limit = in.limit();
in.limit((int) (newPosition - getCurrentPosition()) + in.position());
body.put(in);
in.limit(limit);
} else {
body.put(in);
}
}
body.flip();
tag.setBody(body);
tagPosition++;
}
return tag;
}
/**
* Create tag for metadata event.
*
* @return Metadata event tag
*/
private ITag createFileMeta() {
// Create tag for onMetaData event
ByteBuffer buf = ByteBuffer.allocate(1024);
buf.setAutoExpand(true);
Output out = new Output(buf);
// Duration property
out.writeString("onMetaData");
Map<Object, Object> props = new HashMap<Object, Object>();
props.put("duration", duration / 1000.0);
if (firstVideoTag != -1) {
long old = getCurrentPosition();
setCurrentPosition(firstVideoTag);
readTagHeader();
fillBuffer(1);
byte frametype = in.get();
// Video codec id
props.put("videocodecid", frametype & MASK_VIDEO_CODEC);
setCurrentPosition(old);
}
if (firstAudioTag != -1) {
long old = getCurrentPosition();
setCurrentPosition(firstAudioTag);
readTagHeader();
fillBuffer(1);
byte frametype = in.get();
// Audio codec id
props.put("audiocodecid", (frametype & MASK_SOUND_FORMAT) >> 4);
setCurrentPosition(old);
}
props.put("canSeekToEnd", true);
out.writeMap(props, new Serializer());
buf.flip();
ITag result = new Tag(IoConstants.TYPE_METADATA, 0, buf.limit(), null, 0);
result.setBody(buf);
return result;
}
