protected override bool BuildFrames()
{
var binaryHeaders = new List<MediaFrame>();
//1. Go to the beginning of the file
if (!MediaFile.SeekBegin())
{
Logger.FATAL("Unable to seek in file");
return false;
}
//2. Ignore the flv header
if (!MediaFile.SeekAhead(9))
{
Logger.FATAL("Unable to seek in file");
return false;
}
//3. We are not interested in the previous tag size
if (!MediaFile.SeekAhead(4))
{
Logger.FATAL("Unable to seek in file");
return false;
}
//4. Build the frames
while (MediaFile.Position != MediaFile.Length)
{
//5. Read the tag type
byte tagType;
if (!MediaFile.ReadUInt8(out tagType))
{
Logger.WARN("Unable to read data");
break;
}
//6. Set the frame type based on the tag type
//Also set the iskeyFrame property here
var mustBreak = false;
var frame = new MediaFrame();
switch (tagType)
{
case 8: //audio data
_audioSamplesCount++;
frame.Type = MediaFrameType.Audio;
break;
case 9: //video data
_videoSamplesCount++;
frame.Type = MediaFrameType.Video;
break;
case 15://message data
frame.Type = MediaFrameType.Message;
break;
case 18: //info data
frame.Type = MediaFrameType.Data;
break;
default:
Logger.WARN("Invalid tag type: {0} at cursor {1}", tagType, MediaFile.Position);
mustBreak = true;
break;
}
if (mustBreak) break;
//7. Read the frame length
uint tempLength = MediaFile.Br.ReadU24();
//if (!MediaFile.ReadUInt24(out tempLength))
//{
// Logger.WARN("Unable to read data");
// break;
//}
frame.Length = tempLength;
//8. read the timestamp and set the timing on the frame
var timestamp = MediaFile.Br.ReadSU32();
//if (!MediaFile.ReadSUI32(out timestamp))
//{
// Logger.WARN("Unable to read data");
// break;
//}
//TODO: correctly compute delta time
frame.DeltaTime = 0;
frame.AbsoluteTime = timestamp;
//9. Ignore the stream ID
if (!MediaFile.SeekAhead(3))
{
Logger.WARN("Unable to seek in file");
break;
}
//10. Save the start of the data
frame.Start = (uint)MediaFile.Position;
//11. Set the isKeyFrame flag and the isBinary flag
byte _byte;
switch (frame.Type)
{
case MediaFrameType.Video:
if (!MediaFile.PeekByte(out _byte))
{
Logger.FATAL("Unable to peek byte");
return false;
}
frame.IsKeyFrame = ((_byte >> 4) == 1);
if (frame.IsKeyFrame)
{
frame.IsBinaryHeader = ((_byte & 0x0f) == 7);
if (frame.IsBinaryHeader)
{
ulong dword;
if (!MediaFile.PeekUInt64(out dword))
{
Logger.FATAL("Unable to peek byte");
return false;
}
frame.IsBinaryHeader = (((dword >> 48) & 0xff) == 0);
}
}
else
{
frame.IsBinaryHeader = false;
}
break;
case MediaFrameType.Audio:
frame.IsKeyFrame = true;
if (!MediaFile.PeekByte(out _byte))
{
Logger.FATAL("Unable to peek byte");
return false;
}
frame.IsBinaryHeader = ((_byte >> 4) == 10);
if (frame.IsBinaryHeader)
{
ushort word;
if (!MediaFile.PeekUInt16(out word))
{
Logger.FATAL("Unable to peek byte");
return false;
}
frame.IsBinaryHeader = ((word & 0x00ff) == 0);
}
break;
}
if (frame.IsBinaryHeader)
Logger.WARN("frame: {0}", frame);
if (!MediaFile.SeekAhead(frame.Length))
{
Logger.WARN("Unable to seek in file");
break;
}
//13. We are not interested in the previous tag size
//if (!MediaFile.SeekAhead(4))
//{
// Logger.WARN("Unable to seek in file");
// break;
//}
var preTagSize = MediaFile.Br.ReadInt32();
//14. Store it in the proper location and adjust the timestamp accordingly
//if (frame.IsBinaryHeader)
//{
//frame.AbsoluteTime = 0;
binaryHeaders.Insert(0, frame);
//binaryHeaders.Add(frame);
//}
//else
// {
_frames.Add(frame);
// }
}
//_frames.Sort(CompareFrames);
//15. Add the binary headers
//_frames.InsertRange(0, binaryHeaders);
//for (var i = 0; i < binaryHeaders.Count; i++) {
// _frames.Insert(0, binaryHeaders[i]);
//}
return true;
}
