On Thu, Oct 12, 2006 at 07:57:51PM +0900, Jihee Kim wrote: > I. Please let me know the libmpeg2 decoder passed the conformance test > (ISO/IEC 13818-4) for main profile of MPEG2. > > I got the result that the pixel values from libmpeg2 and w6737 (mpeg2 > reference code) have than +-2 term.
Hmmm, I've been comparing with mpeg2 reference code in the past and at that time things were fine as far as I could see. The test scripts I used should be in svn as the mpeg2dec-streams module. It's fairly large as this will include the test streams as well. One thing you want to look for in the test scripts is an annotated list of test streams - I believe a small number of them have been commented out with an explanation of why they differ. If I remember right, one reason with some mpeg1 test streams was that they had been artificially generated and had IDCT output exceeding the +-384 range before truncation - the standard (either mpeg2 or ieee1180, dont remember) does not specify IDCT behavior in that case. If I remember right, the reference decoder was wrapping around IDCT results before the libmpeg2 one, but I could be wrong about this. > 2. I knew mpeg2 involved mpeg1 and I guessed if passed the conformance test > for the main profile of MPEG2, then MPEG1 should pass the test. > > According to above words, however, MPEG1 passed only for the bitstream > with "constrained parameters", is it right? Peter gave you a good answer to that (heh, I did not even remember the thing about the VBV buffer size). It'd be nice to dynamically allocate the VBV buffer, but we never got around to doing that. -- Michel "Walken" Lespinasse "Bill Gates is a monocle and a Persian cat away from being the villain in a James Bond movie." -- Dennis Miller ------------------------------------------------------------------------- Using Tomcat but need to do more? Need to support web services, security? Get stuff done quickly with pre-integrated technology to make your job easier Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642 _______________________________________________ Libmpeg2-devel mailing list Libmpeg2-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/libmpeg2-devel
