用NLTK库，在所给的代码框架上，代写一个语言合成器的程序。
Introduction - Speech Synthesiser
For this assignment you will be required to create a Speech Synthesiser Python program. This will be a very basic waveform concatenation system, whereby the acoustic units are recordings of monophones. You will be provided with several files that you must use to do this:
SimpleAudio.py
This is a version of the SimpleAudio.py module that we have used in the lab sessions. The Audio class will allow you to save, load and play .wav files as well as perform some simple audio processing functions. You should not modify this file.
synth.py
This is a skeleton structure of the program. Your task is to fill in the missing components to make it work. You are free to add any classes, methods or functions that you wish but you must not change the existing argparse arguments.
monophones/
A folder containing .wav files of monophones.
examples/
A folder containing example .wav files of how the synthesiser should sound.
Task 1 - Basic Synthesis
The primary task for this assignment is to design a program that takes an input phrase and synthesises it. The main steps in the procedure are as follows:
- normalise the text (convert to lower/upper case, remove punctuation, etc.)
- convert the word sequence to a phone sequence - you should make use of nltk.corpus.cmudict to do this.
- concatenate the monophone wav files together in the right order to produce synthesised audio.
Your program should work by executing the synth.py script from the command line with arguments, e.g. the following should play “hello”:-
python synth.py -p "hello"
If a word is not in the cmudict then you should print a warning to the user and exit the program. You can also listen to the examples hello.wav and rose.wav which were created as follows:
python synth.py -o hello.wav "hello nice to meet you"
python synth.py -o rose.wav "A rose by any other name would smell as sweet"
If you execute the same commands with your program and the output sounds the same then it is likely you have a functioning basic synthesiser.
Task 2 - Extending the Functionality
Implement at least two of the following extensions:-
Extension A - Volume Control
Allow the user to set the volume argument (–volume, -v) to a value between 0.0 and 1.0.
You should use the rescale method from the Audio class to do this.
Extension B - Punctuation
If the input phrase contains a comma - insert 250ms of silence.
If it contains a period, question mark or exclamation mark - insert 500ms of silence.
Strip all other punctuation.
Extension C - Spelling
Allow the user to set the spell argument (–spell, -s) that will synthesise spelling instead of pronunciation. Do this by converting a string into a sequence of letters, then to an appropriate phone sequence to pronounce for each letter in its alphabetic form.
Extension D - Text Normalisation for Numbers
If the input phrase contains numbers in numerical form, convert them to word sequences, e.g.
"The meaning of life is 42"
-> "the meaning of life is forty two"
You should include the ability to normalise numbers from 0 up to at least 999 (“nine hundred and ninety nine”).
Decimal points can be handled by reciting “point” and then reading the numbers after the point as individual digits, e.g.
"Pi is about 3.14159"
-> "pi is about three point one four one five nine"
Take care not to treat decimal points as periods (see Punctuation).
Extension E - Text Normalisation for Dates
If the string contains dates in the form DD/MM, DD/MM/YY or DD/MM/YYYY, then convert them to word sequences, e.g.
"Burns Night is 25/01"
-> "burns night is the twenty fifth of january"
"John Lennon died on 1/12/80"
-> "john lennon died on the first of december nineteen eighty"
You may wish to make use of the built-in datetime and/or re packages to do this.
Rules and Assessment
Your submission should abide by the following rules:-
- you are encouraged to discuss the assignment together but all submissions must be written individually and be your own work.
- you may only use numpy, nltk, the provided files, and any packages that are built-in to Python.
- you may not change any of the existing arguments provided in synth.py.