Byte Offset of FLV keyframes for netStream.appendBytes()

Question

Short Version:

I am looking for a library or sample code in either C or Actionscript which allows me to find the byte offset in a FLV file for each keyframe. I am aware that the spec is published at http://download.macromedia.com/f4v/video_file_format_spec_v10_1.pdf but wading through it and writing reliable code would, hopefully, be reinventing the wheel ;)

Longer version:

In Actionscript- I am successfully using netStream.appendBytes() to play a flv file. However, now I want to enable seeking.

It seems that I must change the stream offset to the beginning of a keyframe in the file, simply seeking to any position in the file does not work (neither when using NetStreamAppendBytesAction.RESET_SEEK nor NetStreamAppendBytesAction.RESET_BEGIN)

However, I'm not sure how to determine where that is. Even if the file were encoded with CBR and I knew the timecode for a keyframe, it would still need to be after the header which could be any length.

So I am looking for a library or solution in either C or Actionscript which allows me to find the byte offset in the file of each keyframe- that way I'll have the precise value and can even use VBR

(C will be used either to find this information beforehand, or possibly at runtime via alchemy)

Answer 1

Use netStream onSeekPoint event : http://help.adobe.com/en_US/FlashPlatform/reference/actionscript/3/flash/net/NetStream.html#event:onSeekPoint