[ghost-dev] Current state of Ghost?

[Ishaan Dalal]

Hi,

I'm considering applying to the GSoC to assist in Ghost development. I
had a couple of questions, which I'll ask before talking a little bit
about my background.

1) Based on the ghost-dev archives and the CVS, it looks like no new
code has been developed since last July. Apparently, Anup KC attempted
to implement some techniques for sinusoidal analysis, but then
switched to quantizing the sinusoids extracted by Jean-Marc's "old"
code. Are these impressions accurate (more or less)?

2) The ghost trunk has both C and MATLAB code. Is there a preference,
one way or another? Personally, I've found MATLAB (with MEX-speedups
for things like bit-twiddling) much more productive when developing
proof-of-concept DSP algorithms from theory (i.e., scratch), as
opposed to modifying/optimizing existing C-code.

3) The Ghost wiki doesn't really explain what *purpose* it is supposed
to eventually have; presumably, a general, better-quality replacement
for contemporary MDCT-based codecs (OGG/AAC)? Would an initial
milestone be something focusing on the classical strengths of
sinusoidal modeling, e.g. musical instruments? What about low-bitrate
techniques for general audio, a la SBR (which I know is patented, but
sinusoidal analysis and the mention of "interpolation" in the archives
naturally suggested that link to me)?

4) What does the orphaned reference to a Phase-locked Loop in the wiki refer to?

About me: I'm a Master's student in Electrical Engineering at the
Cooper Union for the Advancement of Science and Art in New York, NY.
My primary experience with perceptual audio coding was when I designed
and implemented a real-time MDCT-based decoder in assembly for a
16-bit RISC microcontroller, as part of a junior-level embedded
systems course. The other hands-on experience with DSP techniques,
specifically multirate/fixed-point, has been my senior project. This
was essentially software-defined radio and image processing,
implemented on an FPGA for a biomedical application and resulted in
two publications (http://i.zdom.org/pubs).

Thanks,
-Ishaan Dalal