Re: [Kaldi-developers] python wrappers for Kaldi

[Jan C. <jan...@gm...>]

Hi All,

the wrapper is built during Kaldi compilation. I build it using provided 
Makefile. The build depends on:
1. Python and numpy (by default it queries the python interpreter found 
on the path for header file location)
2. Boost with Boost::Python library. It is quite heavy to build, but 
most Linux distributions ship it. Boost python doesn't require any code 
generation steps, the wrapper is defined in a normal c++ code file.

During build Python and Boost libraries and Kaldi object files are 
linked into a CPython extention module, 
kaldi/src/python/kaldi_io_internal.so. It works with both static and 
shared Kaldi builds. Further usage requires that python finds 
kaldi_io.py and kaldi_io_internal.so on the PYTHONPATH - it can be for 
example added to the PYTHONPATH variable in the path.sh script of a recipe.

Jan

On 12/13/2014 3:33 PM, Daniel Povey wrote:
> Also, Jan- could you send us an email explaining how this works-
>    How does Python "see" the C++ headers?  Do you have to invoke some
> special program, like swig?  Do you have to write some special kind of
> header that shows how the C++ objects are to be interpreted by python?
>   A brief example would be helpful, if so.
>    How is the resulting program linked, if at all?  If you require
> functions C++ libraries, are these obtained from the .a or .so files
> at runtime, or compiled into some kind of executable-like blob at
> compile time?  Does your framework require that Kaldi be compiled
> using dynamic (.so) libraries?
>
> Dan
>
>
> On Sat, Dec 13, 2014 at 12:04 PM, Jan Chorowski <jan...@gm...> wrote:
>> Hello Dan,
>>
>> thank you for the comments. I tried to make it in the Kaldi spirit,
>> consistency is important. Of course, the scripts can be removed and replaced
>> with some more useful examples. I don't have too much experience with
>> bridging Python to C++, so any critique on the wrappers and the approach
>> taken is welcome.
>>
>> Jan
>>
>>
>> On 12/13/2014 2:55 PM, Daniel Povey wrote:
>>> Hi all.
>>>   From a first look, it does look very impressive, and nicely documented.
>>> I would appreciate it if people on the list who have Python experience
>>> would comment on this- you can either reply to this thread, or to me.
>>> I don't know if this has been done in the "natural" way, or if there
>>> is some reason why people in the future will say, "why did you do it
>>> this way, you should have done XXX".
>>>
>>> Jan:
>>> in the scripts/ directory you seem to have some examples of how you
>>> can create python programs that behave very much like Kaldi
>>> command-line programs, using your framework.  This is very useful.
>>> However, the programs
>>>    apply-global-cmvn.py
>>>    compute-global-cmvn-stats.py
>>> are perhaps a little confusing because they provide the same
>>> functionality that you could get with "compute-cmvn-stats ->
>>> matrix-sum" and "apply-cmvn" on the output of that command; and they
>>> do so using different formats for the CMVN information.  I know the
>>> format of storing the CMVN stats in a two-row matrix is perhaps not
>>> perfectly ideal, but it's a standard within Kaldi and it would be
>>> confusing to deviate from that standard.
>>> Of course, this is a very minor issue that doesn't affect the validity
>>> of the framework as a whole.  I am just pointing this out; the main
>>> discussion should be about the framework and whether people feel it's
>>> the "right" way to do this.
>>>
>>> Dan
>>>
>>> On Sat, Dec 13, 2014 at 6:28 AM, Jan Chorowski <jan...@gm...>
>>> wrote:
>>>> Hi all!
>>>>
>>>> I've written wrappers to access Kaldi data files from within Python
>>>> using boost::python (the code is on github
>>>> https://github.com/janchorowski/kaldi-git/tree/python/src/python). If
>>>> you think this would be an interesting addition please instruct me how
>>>> to contribute.
>>>>
>>>> Best Regards,
>>>> Jan Chorowski
>>>>
>>>>
>>>>
>>>> ------------------------------------------------------------------------------
>>>> Download BIRT iHub F-Type - The Free Enterprise-Grade BIRT Server
>>>> from Actuate! Instantly Supercharge Your Business Reports and Dashboards
>>>> with Interactivity, Sharing, Native Excel Exports, App Integration & more
>>>> Get technology previously reserved for billion-dollar corporations, FREE
>>>>
>>>> http://pubads.g.doubleclick.net/gampad/clk?id=164703151&iu=/4140/ostg.clktrk
>>>> _______________________________________________
>>>> Kaldi-developers mailing list
>>>> Kal...@li...
>>>> https://lists.sourceforge.net/lists/listinfo/kaldi-developers
>>