I’ve been hearing it ever since last August:
Google owns On2. They are going to open source all of On2’s codecs.
Continue reading
I’ve been hearing it ever since last August:
Google owns On2. They are going to open source all of On2’s codecs.
Continue reading
Thanks to all of the advice in the comments of the last post about filling in gaps in the FATE test coverage, I have staged 11 new FATE test specs:
Regarding that group of 6 Sun raster files, it’s interesting to note that the 24-bit raw Sun raster file sample is smaller than the 24-bit RLE version.
I encountered a few problems with the suggestions from the last post. Among them:
I think FFmpeg’s -map option may hold the key. But I’m a little too tired and annoyed to read the source code which I’m certain is the only true documentation for how it works.
In my last post regarding recently-staged FATE tests, a number of Amiga sentimentalists expressed willingness to help me track down multimedia formats that were prevalent on that platform. To that end, I ask: Where do I find Fibonacci-encoded 8svx files? 8svx files can contain several audio codecs, but I have been unable to find ones with the Fibonacci format.
While we’re on the subject, I may as well put out a general call for samples that have eluded me:
There are plenty of formats not covered yet according to the FATE test coverage page. For formats which have both an encoder and decoder in FFmpeg, I plan to have a better system in place in the next FATE version for testing those (which will also obviate the need for the {MAKETEST} test spec). Then there are the non-bitexact formats that require more advanced testing features which are in development.
Meanwhile, I learned that MPEG-4 ALS actually does have a formal conformance suite available (you can usually count on that for MPEG standards; take that, Xiph). So I will be disabling the current ad-hoc test spec and have staged 6 of the conformance vectors known to be correct (based on features that have been implemented thus far): 00, 01, 02, 03, 04, and 05. Further, 2 more new specs: iff-byterun1 and frwu are ready to go.
Ronald Bultje has been a long-time contributor to a variety of open source multimedia projects. He was keen to try his hand at reverse engineering and implementing an undiscovered codec. Most people start simple, but Ronald went for a vocoder (significantly more complex than the piddly little ADPCM codecs I started with). He has completed his reverse engineering of the Windows Media Audio 9 Voice algorithm and committed a decoder for FFmpeg. If you’re interested in the technical details, check out Ronald’s blog posts on the matter: Codec Woes and WMA Voice Codec Dissection.
Here is a WMA Voice file being played in FFplay using Michael’s spectrum visualization (now the default audio visualization):
