Determining lost frames in MPEG-1

Giganews Newsgroups
Subject: Determining lost frames in MPEG-1
Posted by:  pra‚Ķ (Pradipta De)
Date: 15 Nov 2003

Hello All,

I am trying to measure the PSNR of a video clip when it is sent over a
lossy link. I am using MPEG-1 system stream. The way I am trying to
calculate the PSNR is by converting the original and the received
MPEG-1 stream to YUV formats, and then trying to compare
frame-by-frame. For converting to YUV frames, I am using the ffmpeg
decoder from I have the following question:

Does anybody know how I can get a mapping between the part of the MPEG
file that generates a YUV frame, ie. frame to file offset mapping
betwen YUV and the MPEG file. I dont have the MPEG header formats,
hence I cannot parse the MPEG file directly. Any pointers to the
fields in the MPEG header will also be very helpful.


-- pradipta.