[XviD-devel] Newbie question: Debugging codecs

[suxen_drol]

On Mon, 09 Dec 2002 13:03:55 +0200 "turan yuksel" <mendoccino@hotmail.com> wrote:

> Hello,
> 
> I am adding some enhancements over the microsoft mpeg-4 code (as a part of 
> my graduate study) but things usually get slow when I make a bug. It's 
> sometimes very tiring to detect the location of the bug (encoder or decoder) 
> since (as far as I've seen)

why the microsoft reference code? why not xvid, ffmeg?

> - the simplest-looking way to detect encoder errors is tracing the bitstream 
> codeword-by-codeword, after localizing the error.
> - the simplest-looking way to detect decoder errors is firstly deciding that 
> the bitstream is error-free (*)(see above) and then tracing the 
> code+bitstream line by line.
> 
> Since I am implementing my encoder and decoder simultaneously, it's so 
> difficult to decide if my output is error-free. (since I'm adding something 
> nonstandard, there are no other players to verify my bitstreams)
> 
> I wonder if there's a better technique to debug codecs.

idea:
* modifiy your encoder to stdoutput a plain-english description of the
bitstream that's being written to the bitstream. ie. "mb[0,0] mode=0"
* modify your decoder to std-ouput a plain english description of the
bitstream being read in.

diff the resultant stdouts

> Ok, this is a bit off from the XviD development topic but I had no idea 
> about where to ask this.

if you havent dont so already, repost your query to
ffmpeg-devel@lists.sourceforge.net

-- pete; life is like a box of ammo