Add Python/NumPy bindings to ctcdecode

native_client/ctcdecode/COPYING

@@ -0,0 +1,5 @@
+Decoder sources originally imported from https://github.com/parlance/ctcdecode, commit 140b45860cec6671fb0bf6dbb675073241c0f9b0
+Decoder sources are under the MIT license (LICENSE.parlance).
+
+Binding code adapted from https://github.com/PaddlePaddle/DeepSpeech/tree/develop/decoders/swig, commit 3ea19973c66a6a10320888ba47a8857bebf5abfa
+Binding code are under the Apache License (LICENSE.paddlepaddle).

native_client/ctcdecode/LICENSE.paddlepaddle

@@ -0,0 +1,202 @@
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native_client/ctcdecode/LICENSE.parlance

@@ -1,6 +1,7 @@
 MIT License
 
-Copyright (c) 2017 Ryan Leary
+Copyright (c) 2017-2018 Ryan Leary
+Copyright (c) 2018 Mozilla Corporation
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

native_client/ctcdecode/Makefile

@@ -0,0 +1,18 @@
+.PHONY: bindings clean
+
+include ../definitions.mk
+
+NUM_PROCESSES ?= 1
+
+all: bindings
+
+clean:
+	rm -rf dist temp_build ds_ctcdecoder.egg-info
+	rm -f swigwrapper_wrap.cpp swigwrapper.py
+
+bindings:
+	pip install --quiet $(PYTHON_PACKAGES) wheel==0.31.0 setuptools==39.1.0
+	AS=$(AS) CC=$(CC) CXX=$(CXX) LD=$(LD) CFLAGS="$(CFLAGS) $(CXXFLAGS)" LDFLAGS="$(LDFLAGS_NEEDED)" $(PYTHON_PATH) $(NUMPY_INCLUDE) python ./setup.py build --num_processes $(NUM_PROCESSES) $(PYTHON_PLATFORM_NAME) $(SETUP_FLAGS)
+	find temp_build -type f -name "*.o" -delete
+	AS=$(AS) CC=$(CC) CXX=$(CXX) LD=$(LD) CFLAGS="$(CFLAGS) $(CXXFLAGS)" LDFLAGS="$(LDFLAGS_NEEDED)" $(PYTHON_PATH) $(NUMPY_INCLUDE) python ./setup.py bdist_wheel --num_processes $(NUM_PROCESSES) $(PYTHON_PLATFORM_NAME) $(SETUP_FLAGS)
+	rm -rf temp_build

native_client/ctcdecode/README.mozilla

@@ -1,2 +0,0 @@
-Originally imported from https://github.com/parlance/ctcdecode, commit 140b45860cec6671fb0bf6dbb675073241c0f9b0
-

native_client/ctcdecode/__init__.py

@@ -0,0 +1,106 @@
+from __future__ import absolute_import, division, print_function
+
+from . import swigwrapper
+
+
+class Scorer(swigwrapper.Scorer):
+    """Wrapper for Scorer.
+
+    :param alpha: Parameter associated with language model. Don't use
+                  language model when alpha = 0.
+    :type alpha: float
+    :param beta: Parameter associated with word count. Don't use word
+                 count when beta = 0.
+    :type beta: float
+    :model_path: Path to load language model.
+    :trie_path: Path to trie file (optional).
+    :alphabet: Alphabet
+    :type model_path: basestring
+    """
+
+    def __init__(self, alpha, beta, model_path, trie_path, alphabet):
+        swigwrapper.Scorer.__init__(self, alpha, beta, model_path, trie_path, alphabet.config_file())
+
+
+def ctc_beam_search_decoder(probs_seq,
+                            alphabet,
+                            beam_size,
+                            cutoff_prob=1.0,
+                            cutoff_top_n=40,
+                            ext_scoring_func=None):
+    """Wrapper for the CTC Beam Search Decoder.
+
+    :param probs_seq: 2-D list of probability distributions over each time
+                      step, with each element being a list of normalized
+                      probabilities over alphabet and blank.
+    :type probs_seq: 2-D list
+    :param alphabet: alphabet list.
+    :alphabet: Alphabet
+    :param beam_size: Width for beam search.
+    :type beam_size: int
+    :param cutoff_prob: Cutoff probability in pruning,
+                        default 1.0, no pruning.
+    :type cutoff_prob: float
+    :param cutoff_top_n: Cutoff number in pruning, only top cutoff_top_n
+                         characters with highest probs in alphabet will be
+                         used in beam search, default 40.
+    :type cutoff_top_n: int
+    :param ext_scoring_func: External scoring function for
+                             partially decoded sentence, e.g. word count
+                             or language model.
+    :type external_scoring_func: callable
+    :return: List of tuples of log probability and sentence as decoding
+             results, in descending order of the probability.
+    :rtype: list
+    """
+    beam_results = swigwrapper.ctc_beam_search_decoder(
+        probs_seq, alphabet.config_file(), beam_size, cutoff_prob, cutoff_top_n,
+        ext_scoring_func)
+    beam_results = [(res.probability, alphabet.decode(res.tokens)) for res in beam_results]
+    return beam_results
+
+
+def ctc_beam_search_decoder_batch(probs_seq,
+                                  seq_lengths,
+                                  alphabet,
+                                  beam_size,
+                                  num_processes,
+                                  cutoff_prob=1.0,
+                                  cutoff_top_n=40,
+                                  ext_scoring_func=None):
+    """Wrapper for the batched CTC beam search decoder.
+
+    :param probs_seq: 3-D list with each element as an instance of 2-D list
+                      of probabilities used by ctc_beam_search_decoder().
+    :type probs_seq: 3-D list
+    :param alphabet: alphabet list.
+    :alphabet: Alphabet
+    :param beam_size: Width for beam search.
+    :type beam_size: int
+    :param num_processes: Number of parallel processes.
+    :type num_processes: int
+    :param cutoff_prob: Cutoff probability in alphabet pruning,
+                        default 1.0, no pruning.
+    :type cutoff_prob: float
+    :param cutoff_top_n: Cutoff number in pruning, only top cutoff_top_n
+                         characters with highest probs in alphabet will be
+                         used in beam search, default 40.
+    :type cutoff_top_n: int
+    :param num_processes: Number of parallel processes.
+    :type num_processes: int
+    :param ext_scoring_func: External scoring function for
+                             partially decoded sentence, e.g. word count
+                             or language model.
+    :type external_scoring_function: callable
+    :return: List of tuples of log probability and sentence as decoding
+             results, in descending order of the probability.
+    :rtype: list
+    """
+    batch_beam_results = swigwrapper.ctc_beam_search_decoder_batch(
+        probs_seq, seq_lengths, alphabet.config_file(), beam_size, num_processes,
+        cutoff_prob, cutoff_top_n, ext_scoring_func)
+    batch_beam_results = [
+        [(res.probability, alphabet.decode(res.tokens)) for res in beam_results]
+        for beam_results in batch_beam_results
+    ]
+    return batch_beam_results

native_client/ctcdecode/setup.cfg

@@ -0,0 +1,16 @@
+# temp_build is two deep because SWIG does not clean relative paths when
+# building, so ../kenlm pollutes the source directory.
+
+[build_ext]
+build-lib=temp_build/temp_build
+build-temp=temp_build/temp_build
+
+[build_py]
+build-lib=temp_build/temp_build
+
+[bdist_wheel]
+bdist-dir=temp_build/temp_build
+
+[install_lib]
+build-dir=temp_build/temp_build
+

native_client/ctcdecode/setup.py

@@ -0,0 +1,147 @@
+#!/usr/bin/env python
+from __future__ import absolute_import, division, print_function
+
+from distutils.command.build import build
+from setuptools import setup, Extension, distutils
+
+import argparse
+import glob
+import multiprocessing.pool
+import os
+import platform
+import sys
+
+try:
+    import numpy
+    try:
+        numpy_include = numpy.get_include()
+    except AttributeError:
+        numpy_include = numpy.get_numpy_include()
+except ImportError:
+    numpy_include = ''
+    assert 'NUMPY_INCLUDE' in os.environ
+
+numpy_include = os.getenv('NUMPY_INCLUDE', numpy_include)
+numpy_min_ver = os.getenv('NUMPY_DEP_VERSION', '')
+
+parser = argparse.ArgumentParser(description=__doc__)
+parser.add_argument(
+    "--num_processes",
+    default=1,
+    type=int,
+    help="Number of cpu processes to build package. (default: %(default)d)")
+args = parser.parse_known_args()
+
+# reconstruct sys.argv to pass to setup below
+sys.argv = [sys.argv[0]] + args[1]
+
+def read(fname):
+    return open(os.path.join(os.path.dirname(__file__), fname)).read()
+
+project_version = read('../../VERSION').strip()
+
+# monkey-patch for parallel compilation
+# See: https://stackoverflow.com/a/13176803
+def parallelCCompile(self,
+                     sources,
+                     output_dir=None,
+                     macros=None,
+                     include_dirs=None,
+                     debug=0,
+                     extra_preargs=None,
+                     extra_postargs=None,
+                     depends=None):
+    # those lines are copied from distutils.ccompiler.CCompiler directly
+    macros, objects, extra_postargs, pp_opts, build = self._setup_compile(
+        output_dir, macros, include_dirs, sources, depends, extra_postargs)
+    cc_args = self._get_cc_args(pp_opts, debug, extra_preargs)
+
+    # parallel code
+    def _single_compile(obj):
+        try:
+            src, ext = build[obj]
+        except KeyError:
+            return
+        self._compile(obj, src, ext, cc_args, extra_postargs, pp_opts)
+
+    # convert to list, imap is evaluated on-demand
+    thread_pool = multiprocessing.pool.ThreadPool(args[0].num_processes)
+    list(thread_pool.imap(_single_compile, objects))
+    return objects
+
+
+def compile_test(header, library):
+    dummy_path = os.path.join(os.path.dirname(__file__), "dummy")
+    command = "bash -c \"g++ -include " + header \
+                + " -l" + library + " -x c++ - <<<'int main() {}' -o " \
+                + dummy_path + " >/dev/null 2>/dev/null && rm " \
+                + dummy_path + " 2>/dev/null\""
+    return os.system(command) == 0
+
+
+# hack compile to support parallel compiling
+distutils.ccompiler.CCompiler.compile = parallelCCompile
+
+FILES = glob.glob('../kenlm/util/*.cc') \
+        + glob.glob('../kenlm/lm/*.cc') \
+        + glob.glob('../kenlm/util/double-conversion/*.cc')
+
+FILES += glob.glob('third_party/openfst-1.6.7/src/lib/*.cc')
+
+FILES = [
+    fn for fn in FILES
+    if not (fn.endswith('main.cc') or fn.endswith('test.cc') or fn.endswith(
+        'unittest.cc'))
+]
+
+LIBS = ['stdc++']
+if platform.system() != 'Darwin':
+    LIBS.append('rt')
+
+ARGS = ['-O3', '-DNDEBUG', '-DKENLM_MAX_ORDER=6', '-std=c++11',
+        '-Wno-unused-local-typedef', '-Wno-sign-compare']
+
+if compile_test('zlib.h', 'z'):
+    ARGS.append('-DHAVE_ZLIB')
+    LIBS.append('z')
+
+if compile_test('bzlib.h', 'bz2'):
+    ARGS.append('-DHAVE_BZLIB')
+    LIBS.append('bz2')
+
+if compile_test('lzma.h', 'lzma'):
+    ARGS.append('-DHAVE_XZLIB')
+    LIBS.append('lzma')
+
+decoder_module = Extension(
+    name='ds_ctcdecoder._swigwrapper',
+    sources=['swigwrapper.i'] + FILES + glob.glob('*.cpp'),
+    swig_opts=['-c++', '-extranative'],
+    language='c++',
+    include_dirs=[
+        numpy_include,
+        '..',
+        '../kenlm',
+        'third_party/openfst-1.6.7/src/include',
+        'third_party/ThreadPool',
+    ],
+    libraries=LIBS,
+    extra_compile_args=ARGS
+)
+
+class BuildExtFirst(build):
+    sub_commands = [('build_ext', build.has_ext_modules),
+                    ('build_py', build.has_pure_modules),
+                    ('build_clib', build.has_c_libraries),
+                    ('build_scripts', build.has_scripts)]
+
+setup(
+    name='ds_ctcdecoder',
+    version=project_version,
+    description="""DS CTC decoder""",
+    cmdclass = {'build': BuildExtFirst},
+    ext_modules=[decoder_module],
+    package_dir = {'ds_ctcdecoder': '.'},
+    py_modules=['ds_ctcdecoder', 'ds_ctcdecoder.swigwrapper'],
+    install_requires = ['numpy%s' % numpy_min_ver],
+)

native_client/ctcdecode/swigwrapper.i

@@ -0,0 +1,70 @@
+%module swigwrapper
+
+%{
+#include "ctc_beam_search_decoder.h"
+#define SWIG_FILE_WITH_INIT
+%}
+
+%include "pyabc.i"
+%include "std_vector.i"
+%include "numpy.i"
+
+%init %{
+import_array();
+%}
+
+// Convert NumPy arrays to pointer+lengths
+%apply (double* IN_ARRAY2, int DIM1, int DIM2) {(const double *probs, int time_dim, int class_dim)};
+%apply (double* IN_ARRAY3, int DIM1, int DIM2, int DIM3) {(const double *probs, int batch_dim, int time_dim, int class_dim)};
+%apply (int* IN_ARRAY1, int DIM1) {(const int *seq_lengths, int seq_lengths_size)};
+
+// Convert char* to Alphabet
+%rename (ctc_beam_search_decoder) mod_decoder;
+%inline %{
+std::vector<Output>
+mod_decoder(const double *probs,
+            int time_dim,
+            int class_dim,
+            char* alphabet_config_path,
+            size_t beam_size,
+            double cutoff_prob,
+            size_t cutoff_top_n,
+            Scorer *ext_scorer)
+{
+    Alphabet a(alphabet_config_path);
+    return ctc_beam_search_decoder(probs, time_dim, class_dim, a, beam_size,
+                                   cutoff_prob, cutoff_top_n, ext_scorer);
+}
+%}
+
+%rename (ctc_beam_search_decoder_batch) mod_decoder_batch;
+%inline %{
+std::vector<std::vector<Output>>
+mod_decoder_batch(const double *probs,
+                  int batch_dim,
+                  int time_dim,
+                  int class_dim,
+                  const int *seq_lengths,
+                  int seq_lengths_size,
+                  char* alphabet_config_path,
+                  size_t beam_size,
+                  size_t num_processes,
+                  double cutoff_prob,
+                  size_t cutoff_top_n,
+                  Scorer *ext_scorer)
+{
+    Alphabet a(alphabet_config_path);
+    return ctc_beam_search_decoder_batch(probs, batch_dim, time_dim, class_dim,
+                                         seq_lengths, seq_lengths_size, a, beam_size,
+                                         num_processes, cutoff_prob, cutoff_top_n,
+                                         ext_scorer);
+}
+%}
+
+%include "output.h"
+%include "scorer.h"
+%include "ctc_beam_search_decoder.h"
+
+%template(IntVector) std::vector<int>;
+%template(OutputVector) std::vector<Output>;
+%template(OutputVectorVector) std::vector<std::vector<Output>>;