public FlvReader(FileInfo file, bool generateMetadata)
{
_file = file;
FileStream fs = new FileStream(file.FullName, FileMode.Open, FileAccess.Read, FileShare.Read, 65536);
//_reader = new AMFReader(file.Open(FileMode.Open));
_reader = new AMFReader(fs);
_generateMetadata = generateMetadata;
if (GetRemainingBytes() >= 9)
DecodeHeader();
_keyframeMeta = AnalyzeKeyFrames();
}
public int Seek(int ts)
{
lock (_syncLock)
{
if (_keyFrameMeta == null)
{
if (!(_reader is IKeyFrameDataAnalyzer))
{
// Seeking not supported
return ts;
}
_keyFrameMeta = (_reader as IKeyFrameDataAnalyzer).AnalyzeKeyFrames();
}
if (_keyFrameMeta.Positions.Length == 0)
{
// no video keyframe metainfo, it's an audio-only FLV
// we skip the seek for now.
// TODO add audio-seek capability
return ts;
}
if (ts >= _keyFrameMeta.Duration)
{
// Seek at or beyond EOF
_reader.Position = long.MaxValue;
return (int) _keyFrameMeta.Duration;
}
int frame = 0;
for (int i = 0; i < _keyFrameMeta.Positions.Length; i++)
{
if (_keyFrameMeta.Timestamps[i] > ts) {
break;
}
frame = i;
}
_reader.Position = _keyFrameMeta.Positions[frame];
return _keyFrameMeta.Timestamps[frame];
}
}
/// <summary>
/// Key frames analysis may be used as a utility method so synchronize it.
/// </summary>
/// <returns></returns>
public KeyFrameMeta AnalyzeKeyFrames()
{
lock (this.SyncRoot)
{
if (_keyframeMeta != null)
return _keyframeMeta;
// Lists of video positions and timestamps
List<long> positionList = new List<long>();
List<int> timestampList = new List<int>();
// Lists of audio positions and timestamps
List<long> audioPositionList = new List<long>();
List<int> audioTimestampList = new List<int>();
long origPos = GetCurrentPosition();
// point to the first tag
SetCurrentPosition(9);
// Maps positions to tags
_posTagMap = new Dictionary<long,int>();
int idx = 0;
bool audioOnly = true;
while (this.HasMoreTags())
{
long pos = GetCurrentPosition();
_posTagMap.Add(pos, idx++);
// Read tag header and duration
ITag tmpTag = this.ReadTagHeader();
_duration = tmpTag.Timestamp;
if (tmpTag.DataType == IOConstants.TYPE_VIDEO)
{
if (audioOnly)
{
audioOnly = false;
audioPositionList.Clear();
audioTimestampList.Clear();
}
if (_firstVideoTag == -1)
{
_firstVideoTag = pos;
}
// Grab Frame type
byte frametype = _reader.ReadByte();
if (((frametype & IOConstants.MASK_VIDEO_FRAMETYPE) >> 4) == IOConstants.FLAG_FRAMETYPE_KEYFRAME)
{
positionList.Add(pos);
timestampList.Add(tmpTag.Timestamp);
}
}
else if (tmpTag.DataType == IOConstants.TYPE_AUDIO)
{
if (_firstAudioTag == -1)
{
_firstAudioTag = pos;
}
if (audioOnly)
{
audioPositionList.Add(pos);
audioTimestampList.Add(tmpTag.Timestamp);
}
}
// This properly handles damaged FLV files - as far as duration/size is concerned
long newPosition = pos + tmpTag.BodySize + 15;
if (newPosition >= GetTotalBytes())
{
#if !SILVERLIGHT
log.Info("New position exceeds limit");
if (log.IsDebugEnabled)
{
log.Debug("Keyframe analysis");
log.Debug(" data type=" + tmpTag.DataType + " bodysize=" + tmpTag.BodySize);
log.Debug(" remaining=" + GetRemainingBytes() + " limit=" + GetTotalBytes() + " new pos=" + newPosition + " pos=" + pos);
}
#endif
break;
}
else
{
SetCurrentPosition(newPosition);
}
}
// restore the pos
SetCurrentPosition(origPos);
_keyframeMeta = new KeyFrameMeta();
_keyframeMeta.Duration = _duration;
_posTimeMap = new Dictionary<long,long>();
if (audioOnly)
{
// The flv only contains audio tags, use their lists to support pause and seeking
positionList = audioPositionList;
timestampList = audioTimestampList;
}
_keyframeMeta.AudioOnly = audioOnly;
_keyframeMeta.Positions = new long[positionList.Count];
_keyframeMeta.Timestamps = new int[timestampList.Count];
for (int i = 0; i < _keyframeMeta.Positions.Length; i++)
{
_keyframeMeta.Positions[i] = (long)positionList[i];
_keyframeMeta.Timestamps[i] = (int)timestampList[i];
_posTimeMap.Add((long)positionList[i], (long)((int)timestampList[i]));
}
return _keyframeMeta;
}
}
