Posts Tagged libvpx

On WebM, H264, and FFmpeg implementation

 I was recently reminded by Gregory Maxwell of Xiph about the new, non-Google implementation of VP8 done within the context of FFmpeg, and many commenters on Slashdot observed that the fact that the implementation shares lots of code with the H264 part is further demonstration that VP8 is infriging on MPEG-LA held patents.

Actually, there is nothing in the implementation that suggests this, only the fact that some underlying alogrithms are similar (but not identical). For example, the entropy coder is quite similar, and it certainly helps to reuse some of the highly optimized librarties that are within FFMPEG, this is however no indication of patent infringement. What is certain, is the fact that I suspect that libVPX (Google implementation) will remain the “official” one, because there is no guarantee that in the alternative implementation the current IPR safeguards and efforts to avoid existing patents will be done properly. In fact, some of the obvious “missing optimizations” both in the decoder and encoder are clearly done to avoid patents, and this means that Google can be reasonably sure of being safe from IPR claims for the current code drop. If a FFMPEG developer implements some optimization (especially in the encoder) that actually implements a claimed part of a current patent you can end up with a freely implemented source code that implements an IPR-covered claim, like most of FFMPEG actually.

So, to end up this brief post: the existence of a parallel implementation of libvpx is a good thing; the fact that it shares lots of code with FFMPEG is no proof of IPR infringement, but on the other hand it is probably safer to use the libvpx one from Google, as it seems that it was developed explicitly to avoid existing IPR issues.

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