source: python/ext/py-source.c @ fa3b1f1

feature/autosinkfeature/constantqfeature/pitchshiftfeature/pydocstringsfeature/timestretch
Last change on this file since fa3b1f1 was fa3b1f1, checked in by Paul Brossier <piem@piem.org>, 13 months ago

[py] [doc] improve source.do/do_multi descriptions

  • Property mode set to 100644
File size: 18.1 KB
Line 
1#include "aubio-types.h"
2
3typedef struct
4{
5  PyObject_HEAD
6  aubio_source_t * o;
7  char_t* uri;
8  uint_t samplerate;
9  uint_t channels;
10  uint_t hop_size;
11  uint_t duration;
12  PyObject *read_to;
13  fvec_t c_read_to;
14  PyObject *mread_to;
15  fmat_t c_mread_to;
16} Py_source;
17
18static char Py_source_doc[] = ""
19"source(path, samplerate=0, hop_size=512, channels=0)\n"
20"\n"
21"Create a new source, opening the given pathname for reading.\n"
22"\n"
23"`source` open the file specified in `path` and creates a callable\n"
24"returning `hop_size` new audio samples at each invocation.\n"
25"\n"
26"If `samplerate=0` (default), the original sampling rate of `path`\n"
27"will be used. Otherwise, the output audio samples will be\n"
28"resampled at the desired sampling-rate.\n"
29"\n"
30"If `channels=0` (default), the original number of channels\n"
31"in `path` will be used. Otherwise, the output audio samples\n"
32"will be down-mixed or up-mixed to the desired number of\n"
33"channels.\n"
34"\n"
35"If `path` is a URL, a remote connection will be attempted to\n"
36"open the resource and stream data from it.\n"
37"\n"
38"The parameter `hop_size` determines how many samples should be\n"
39"read at each consecutive calls.\n"
40"\n"
41"Parameters\n"
42"----------\n"
43"path : str\n"
44"   pathname (or URL) of the file to be opened for reading\n"
45"samplerate : int, optional\n"
46"   sampling rate of the file\n"
47"hop_size : int, optional\n"
48"   number of samples to be read per iteration\n"
49"channels : int, optional\n"
50"   number of channels of the file\n"
51"\n"
52"Examples\n"
53"--------\n"
54"By default, when only `path` is given, the file will be opened\n"
55"with its original sampling rate and channel:\n"
56"\n"
57">>> src = aubio.source('stereo.wav')\n"
58">>> src.uri, src.samplerate, src.channels, src.duration\n"
59"('stereo.wav', 48000, 2, 86833)\n"
60"\n"
61"A typical loop to read all samples from a local file could\n"
62"look like this:\n"
63"\n"
64">>> src = aubio.source('stereo.wav')\n"
65">>> total_read = 0\n"
66">>> while True:\n"
67"...     samples, read = src()\n"
68"...     # do something with samples\n"
69"...     total_read += read\n"
70"...     if read < src.hop_size:\n"
71"...         break\n"
72"...\n"
73"\n"
74"In a more Pythonic way, it can also look like this:\n"
75"\n"
76">>> total_read = 0\n"
77">>> with aubio.source('stereo.wav') as src:\n"
78"...     for frames in src:\n"
79"...         total_read += samples.shape[-1]\n"
80"...\n"
81"\n"
82".. rubric:: Basic interface\n"
83"\n"
84"`source` is a **callable**; its :meth:`__call__` method\n"
85"returns a tuple containing:\n"
86"\n"
87"- a vector of shape `(hop_size,)`, filled with the `read` next\n"
88"  samples available, zero-padded if `read < hop_size`\n"
89"- `read`, an integer indicating the number of samples read\n"
90"\n"
91"To read the first `hop_size` samples from the source, simply call\n"
92"the instance itself, with no argument:\n"
93"\n"
94">>> src = aubio.source('song.ogg')\n"
95">>> samples, read = src()\n"
96">>> samples.shape, read, src.hop_size\n"
97"((512,), 512, 512)\n"
98"\n"
99"The first call returned the slice of samples `[0 : hop_size]`.\n"
100"The next call will return samples `[hop_size: 2*hop_size]`.\n"
101"\n"
102"After several invocations of :meth:`__call__`, when reaching the end\n"
103"of the opened stream, `read` might become less than `hop_size`:\n"
104"\n"
105">>> samples, read = src()\n"
106">>> samples.shape, read\n"
107"((512,), 354)\n"
108"\n"
109"The end of the vector `samples` is filled with zeros.\n"
110"\n"
111"After the end of the stream, `read` will be `0` since no more\n"
112"samples are available:\n"
113"\n"
114">>> samples, read = src()\n"
115">>> samples.shape, read\n"
116"((512,), 0)\n"
117"\n"
118"**Note**: when the source has more than one channels, they\n"
119"are be down-mixed to mono when invoking :meth:`__call__`.\n"
120"To read from each individual channel, see :meth:`__next__`.\n"
121"\n"
122".. rubric:: ``for`` statements\n"
123"\n"
124"The `source` objects are **iterables**. This allows using them\n"
125"directly in a ``for`` loop, which calls :meth:`__next__` until\n"
126"the end of the stream is reached:\n"
127"\n"
128">>> src = aubio.source('stereo.wav')\n"
129">>> for frames in src:\n"
130">>>     print (frames.shape)\n"
131"...\n"
132"(2, 512)\n"
133"(2, 512)\n"
134"(2, 230)\n"
135"\n"
136"**Note**: When `next(self)` is called on a source with multiple\n"
137"channels, an array of shape `(channels, read)` is returned,\n"
138"unlike with :meth:`__call__` which always returns the down-mixed\n"
139"channels.\n"
140"\n"
141"If the file is opened with a single channel, `next(self)` returns\n"
142"an array of shape `(read,)`:\n"
143"\n"
144">>> src = aubio.source('stereo.wav', channels=1)\n"
145">>> next(src).shape\n"
146"(512,)\n"
147"\n"
148".. rubric:: ``with`` statements\n"
149"\n"
150"The `source` objects are **context managers**, which allows using\n"
151"them in ``with`` statements:\n"
152"\n"
153">>> with aubio.source('audiotrack.wav') as source:\n"
154"...     n_frames=0\n"
155"...     for samples in source:\n"
156"...         n_frames += len(samples)\n"
157"...     print('read', n_frames, 'samples in', samples.shape[0], 'channels',\n"
158"...         'from file \"\%s\"' \% source.uri)\n"
159"...\n"
160"read 239334 samples in 2 channels from file \"audiotrack.wav\"\n"
161"\n"
162"The file will be closed before exiting the statement.\n"
163"\n"
164"See also the methods implementing the context manager,\n"
165":meth:`__enter__` and :meth:`__exit__`.\n"
166"\n"
167".. rubric:: Seeking and closing\n"
168"\n"
169"At any time, :meth:`seek` can be used to move to any position in\n"
170"the file. For instance, to rewind to the start of the stream:\n"
171"\n"
172">>> src.seek(0)\n"
173"\n"
174"The opened file will be automatically closed when the object falls\n"
175"out of scope and is scheduled for garbage collection.\n"
176"\n"
177"In some cases, it is useful to manually :meth:`close` a given source,\n"
178"for instance to limit the number of simultaneously opened files:\n"
179"\n"
180">>> src.close()\n"
181"\n"
182".. rubric:: Input formats\n"
183"\n"
184"Depending on how aubio was compiled, :class:`source` may or may not\n"
185"open certain **files format**. Below are some examples that assume\n"
186"support for compressed files and remote urls was compiled in:\n"
187"\n"
188"- open a local file using its original sampling rate and channels,\n"
189"  and with the default hop size:\n"
190"\n"
191">>> s = aubio.source('sample.wav')\n"
192">>> s.uri, s.samplerate, s.channels, s.hop_size\n"
193"('sample.wav', 44100, 2, 512)\n"
194"\n"
195"- open a local compressed audio file, resampling to 32000Hz if needed:\n"
196"\n"
197">>> s = aubio.source('song.mp3', samplerate=32000)\n"
198">>> s.uri, s.samplerate, s.channels, s.hop_size\n"
199"('song.mp3', 32000, 2, 512)\n"
200"\n"
201"- open a local video file, down-mixing and resampling it to 16kHz:\n"
202"\n"
203">>> s = aubio.source('movie.mp4', samplerate=16000, channels=1)\n"
204">>> s.uri, s.samplerate, s.channels, s.hop_size\n"
205"('movie.mp4', 16000, 1, 512)\n"
206"\n"
207"- open a remote resource, with hop_size = 1024:\n"
208"\n"
209">>> s = aubio.source('https://aubio.org/drum.ogg', hop_size=1024)\n"
210">>> s.uri, s.samplerate, s.channels, s.hop_size\n"
211"('https://aubio.org/drum.ogg', 48000, 2, 1024)\n"
212"\n"
213"See Also\n"
214"--------\n"
215"sink: write audio samples to a file.\n"
216"";
217
218static char Py_source_get_samplerate_doc[] = ""
219"get_samplerate()\n"
220"\n"
221"Get sampling rate of source.\n"
222"\n"
223"Returns\n"
224"-------\n"
225"int\n"
226"    Sampling rate, in Hz.\n"
227"";
228
229static char Py_source_get_channels_doc[] = ""
230"get_channels()\n"
231"\n"
232"Get number of channels in source.\n"
233"\n"
234"Returns\n"
235"-------\n"
236"int\n"
237"    Number of channels.\n"
238"";
239
240static char Py_source_do_doc[] = ""
241"source.do()\n"
242"\n"
243"Read vector of audio samples.\n"
244"\n"
245"If the audio stream in the source has more than one channel,\n"
246"the channels will be down-mixed.\n"
247"\n"
248"Returns\n"
249"-------\n"
250"samples : numpy.ndarray\n"
251"    `fvec` of size `hop_size` containing the new samples.\n"
252"read : int\n"
253"    Number of samples read from the source, equals to `hop_size`\n"
254"    before the end-of-file is reached, less when it is reached,\n"
255"    and `0` after.\n"
256"\n"
257"See Also\n"
258"--------\n"
259"do_multi\n"
260"\n"
261"Examples\n"
262"--------\n"
263">>> src = aubio.source('sample.wav', hop_size=1024)\n"
264">>> src.do()\n"
265"(array([-0.00123001, -0.00036685,  0.00097106, ..., -0.2031033 ,\n"
266"       -0.2025854 , -0.20221856], dtype=" AUBIO_NPY_SMPL_STR "), 1024)\n"
267"";
268
269static char Py_source_do_multi_doc[] = ""
270"do_multi()\n"
271"\n"
272"Read multiple channels of audio samples.\n"
273"\n"
274"If the source was opened with the same number of channels\n"
275"found in the stream, each channel will be read individually.\n"
276"\n"
277"If the source was opened with less channels than the number\n"
278"of channels in the stream, only the first channels will be read.\n"
279"\n"
280"If the source was opened with more channels than the number\n"
281"of channel in the original stream, the first channels will\n"
282"be duplicated on the additional output channel.\n"
283"\n"
284"Returns\n"
285"-------\n"
286"samples : numpy.ndarray\n"
287"    NumPy array of shape `(hop_size, channels)` containing the new\n"
288"    audio samples.\n"
289"read : int\n"
290"    Number of samples read from the source, equals to `hop_size`\n"
291"    before the end-of-file is reached, less when it is reached,\n"
292"    and `0` after.\n"
293"\n"
294"See Also\n"
295"--------\n"
296"do\n"
297"\n"
298"Examples\n"
299"--------\n"
300">>> src = aubio.source('sample.wav')\n"
301">>> src.do_multi()\n"
302"(array([[ 0.00668335,  0.0067749 ,  0.00714111, ..., -0.05737305,\n"
303"        -0.05856323, -0.06018066],\n"
304"       [-0.00842285, -0.0072937 , -0.00576782, ..., -0.09405518,\n"
305"        -0.09558105, -0.09725952]], dtype=" AUBIO_NPY_SMPL_STR "), 512)\n"
306"";
307
308static char Py_source_close_doc[] = ""
309"close()\n"
310"\n"
311"Close this source now.\n"
312"\n"
313".. note:: Closing twice a source will **not** raise any exception.\n"
314"";
315
316static char Py_source_seek_doc[] = ""
317"seek(position)\n"
318"\n"
319"Seek to position in file.\n"
320"\n"
321"If the source was not opened with its original sampling-rate,\n"
322"`position` corresponds to the position in the re-sampled file.\n"
323"\n"
324"Parameters\n"
325"----------\n"
326"position : str\n"
327"   position to seek to, in samples\n"
328"";
329
330static PyObject *
331Py_source_new (PyTypeObject * pytype, PyObject * args, PyObject * kwds)
332{
333  Py_source *self;
334  char_t* uri = NULL;
335  uint_t samplerate = 0;
336  uint_t hop_size = 0;
337  uint_t channels = 0;
338  static char *kwlist[] = { "uri", "samplerate", "hop_size", "channels", NULL };
339
340  if (!PyArg_ParseTupleAndKeywords (args, kwds, "|sIII", kwlist,
341          &uri, &samplerate, &hop_size, &channels)) {
342    return NULL;
343  }
344
345  self = (Py_source *) pytype->tp_alloc (pytype, 0);
346
347  if (self == NULL) {
348    return NULL;
349  }
350
351  self->uri = NULL;
352  if (uri != NULL) {
353    self->uri = (char_t *)malloc(sizeof(char_t) * (strnlen(uri, PATH_MAX) + 1));
354    strncpy(self->uri, uri, strnlen(uri, PATH_MAX) + 1);
355  }
356
357  self->samplerate = 0;
358  if ((sint_t)samplerate > 0) {
359    self->samplerate = samplerate;
360  } else if ((sint_t)samplerate < 0) {
361    PyErr_SetString (PyExc_ValueError,
362        "can not use negative value for samplerate");
363    return NULL;
364  }
365
366  self->hop_size = Py_default_vector_length / 2;
367  if ((sint_t)hop_size > 0) {
368    self->hop_size = hop_size;
369  } else if ((sint_t)hop_size < 0) {
370    PyErr_SetString (PyExc_ValueError,
371        "can not use negative value for hop_size");
372    return NULL;
373  }
374
375  self->channels = 1;
376  if ((sint_t)channels >= 0) {
377    self->channels = channels;
378  } else if ((sint_t)channels < 0) {
379    PyErr_SetString (PyExc_ValueError,
380        "can not use negative value for channels");
381    return NULL;
382  }
383
384  return (PyObject *) self;
385}
386
387static int
388Py_source_init (Py_source * self, PyObject * args, PyObject * kwds)
389{
390  self->o = new_aubio_source ( self->uri, self->samplerate, self->hop_size );
391  if (self->o == NULL) {
392    // PyErr_Format(PyExc_RuntimeError, ...) was set above by new_ which called
393    // AUBIO_ERR when failing
394    return -1;
395  }
396  self->samplerate = aubio_source_get_samplerate ( self->o );
397  if (self->channels == 0) {
398    self->channels = aubio_source_get_channels ( self->o );
399  }
400  self->duration = aubio_source_get_duration ( self->o );
401
402  self->read_to = new_py_fvec(self->hop_size);
403  self->mread_to = new_py_fmat(self->channels, self->hop_size);
404
405  return 0;
406}
407
408static void
409Py_source_del (Py_source *self, PyObject *unused)
410{
411  if (self->o) {
412    del_aubio_source(self->o);
413    free(self->c_mread_to.data);
414  }
415  if (self->uri) {
416    free(self->uri);
417  }
418  Py_XDECREF(self->read_to);
419  Py_XDECREF(self->mread_to);
420  Py_TYPE(self)->tp_free((PyObject *) self);
421}
422
423
424/* function Py_source_do */
425static PyObject *
426Py_source_do(Py_source * self, PyObject * args)
427{
428  PyObject *outputs;
429  uint_t read;
430  read = 0;
431
432  Py_INCREF(self->read_to);
433  if (!PyAubio_ArrayToCFvec(self->read_to, &(self->c_read_to))) {
434    return NULL;
435  }
436  /* compute _do function */
437  aubio_source_do (self->o, &(self->c_read_to), &read);
438
439  outputs = PyTuple_New(2);
440  PyTuple_SetItem( outputs, 0, self->read_to );
441  PyTuple_SetItem( outputs, 1, (PyObject *)PyLong_FromLong(read));
442  return outputs;
443}
444
445/* function Py_source_do_multi */
446static PyObject *
447Py_source_do_multi(Py_source * self, PyObject * args)
448{
449  PyObject *outputs;
450  uint_t read;
451  read = 0;
452
453  Py_INCREF(self->mread_to);
454  if (!PyAubio_ArrayToCFmat(self->mread_to,  &(self->c_mread_to))) {
455    return NULL;
456  }
457  /* compute _do function */
458  aubio_source_do_multi (self->o, &(self->c_mread_to), &read);
459
460  outputs = PyTuple_New(2);
461  PyTuple_SetItem( outputs, 0, self->mread_to);
462  PyTuple_SetItem( outputs, 1, (PyObject *)PyLong_FromLong(read));
463  return outputs;
464}
465
466static PyMemberDef Py_source_members[] = {
467  {"uri", T_STRING, offsetof (Py_source, uri), READONLY,
468    "str (read-only): pathname or URL"},
469  {"samplerate", T_INT, offsetof (Py_source, samplerate), READONLY,
470    "int (read-only): sampling rate"},
471  {"channels", T_INT, offsetof (Py_source, channels), READONLY,
472    "int (read-only): number of channels"},
473  {"hop_size", T_INT, offsetof (Py_source, hop_size), READONLY,
474    "int (read-only): number of samples read per iteration"},
475  {"duration", T_INT, offsetof (Py_source, duration), READONLY,
476    "int (read-only): total number of frames in the source\n"
477    "\n"
478    "Can be estimated, for instance if the opened stream is\n"
479    "a compressed media or a remote resource.\n"
480    "\n"
481    "Example\n"
482    "-------\n"
483    ">>> n = 0\n"
484    ">>> src = aubio.source('track1.mp3')\n"
485    ">>> for samples in src:\n"
486    "...     n += samples.shape[-1]\n"
487    "...\n"
488    ">>> n, src.duration\n"
489    "(9638784, 9616561)\n"
490    ""},
491  { NULL } // sentinel
492};
493
494static PyObject *
495Pyaubio_source_get_samplerate (Py_source *self, PyObject *unused)
496{
497  uint_t tmp = aubio_source_get_samplerate (self->o);
498  return (PyObject *)PyLong_FromLong (tmp);
499}
500
501static PyObject *
502Pyaubio_source_get_channels (Py_source *self, PyObject *unused)
503{
504  uint_t tmp = aubio_source_get_channels (self->o);
505  return (PyObject *)PyLong_FromLong (tmp);
506}
507
508static PyObject *
509Pyaubio_source_close (Py_source *self, PyObject *unused)
510{
511  if (aubio_source_close(self->o) != 0) return NULL;
512  Py_RETURN_NONE;
513}
514
515static PyObject *
516Pyaubio_source_seek (Py_source *self, PyObject *args)
517{
518  uint_t err = 0;
519
520  int position;
521  if (!PyArg_ParseTuple (args, "I", &position)) {
522    return NULL;
523  }
524
525  if (position < 0) {
526    PyErr_Format(PyExc_ValueError,
527        "error when seeking in source: can not seek to negative value %d",
528        position);
529    return NULL;
530  }
531
532  err = aubio_source_seek(self->o, position);
533  if (err != 0) {
534    PyErr_SetString (PyExc_ValueError,
535        "error when seeking in source");
536    return NULL;
537  }
538  Py_RETURN_NONE;
539}
540
541static char Pyaubio_source_enter_doc[] = "";
542static PyObject* Pyaubio_source_enter(Py_source *self, PyObject *unused) {
543  Py_INCREF(self);
544  return (PyObject*)self;
545}
546
547static char Pyaubio_source_exit_doc[] = "";
548static PyObject* Pyaubio_source_exit(Py_source *self, PyObject *unused) {
549  return Pyaubio_source_close(self, unused);
550}
551
552static PyObject* Pyaubio_source_iter(PyObject *self) {
553  Py_INCREF(self);
554  return (PyObject*)self;
555}
556
557static PyObject* Pyaubio_source_iter_next(Py_source *self) {
558  PyObject *done, *size;
559  if (self->channels == 1) {
560    done = Py_source_do(self, NULL);
561  } else {
562    done = Py_source_do_multi(self, NULL);
563  }
564  if (!PyTuple_Check(done)) {
565    PyErr_Format(PyExc_ValueError,
566        "error when reading source: not opened?");
567    return NULL;
568  }
569  size = PyTuple_GetItem(done, 1);
570  if (size != NULL && PyLong_Check(size)) {
571    if (PyLong_AsLong(size) == (long)self->hop_size) {
572      PyObject *vec = PyTuple_GetItem(done, 0);
573      return vec;
574    } else if (PyLong_AsLong(size) > 0) {
575      // short read, return a shorter array
576      PyArrayObject *shortread = (PyArrayObject*)PyTuple_GetItem(done, 0);
577      PyArray_Dims newdims;
578      PyObject *reshaped;
579      newdims.len = PyArray_NDIM(shortread);
580      newdims.ptr = PyArray_DIMS(shortread);
581      // mono or multiple channels?
582      if (newdims.len == 1) {
583        newdims.ptr[0] = PyLong_AsLong(size);
584      } else {
585        newdims.ptr[1] = PyLong_AsLong(size);
586      }
587      reshaped = PyArray_Newshape(shortread, &newdims, NPY_CORDER);
588      Py_DECREF(shortread);
589      return reshaped;
590    } else {
591      PyErr_SetNone(PyExc_StopIteration);
592      return NULL;
593    }
594  } else {
595    PyErr_SetNone(PyExc_StopIteration);
596    return NULL;
597  }
598}
599
600static PyMethodDef Py_source_methods[] = {
601  {"get_samplerate", (PyCFunction) Pyaubio_source_get_samplerate,
602    METH_NOARGS, Py_source_get_samplerate_doc},
603  {"get_channels", (PyCFunction) Pyaubio_source_get_channels,
604    METH_NOARGS, Py_source_get_channels_doc},
605  {"do", (PyCFunction) Py_source_do,
606    METH_NOARGS, Py_source_do_doc},
607  {"do_multi", (PyCFunction) Py_source_do_multi,
608    METH_NOARGS, Py_source_do_multi_doc},
609  {"close", (PyCFunction) Pyaubio_source_close,
610    METH_NOARGS, Py_source_close_doc},
611  {"seek", (PyCFunction) Pyaubio_source_seek,
612    METH_VARARGS, Py_source_seek_doc},
613  {"__enter__", (PyCFunction)Pyaubio_source_enter, METH_NOARGS,
614    Pyaubio_source_enter_doc},
615  {"__exit__",  (PyCFunction)Pyaubio_source_exit, METH_VARARGS,
616    Pyaubio_source_exit_doc},
617  {NULL} /* sentinel */
618};
619
620PyTypeObject Py_sourceType = {
621  PyVarObject_HEAD_INIT (NULL, 0)
622  "aubio.source",
623  sizeof (Py_source),
624  0,
625  (destructor) Py_source_del,
626  0,
627  0,
628  0,
629  0,
630  0,
631  0,
632  0,
633  0,
634  0,
635  (ternaryfunc)Py_source_do,
636  0,
637  0,
638  0,
639  0,
640  Py_TPFLAGS_DEFAULT,
641  Py_source_doc,
642  0,
643  0,
644  0,
645  0,
646  Pyaubio_source_iter,
647  (unaryfunc)Pyaubio_source_iter_next,
648  Py_source_methods,
649  Py_source_members,
650  0,
651  0,
652  0,
653  0,
654  0,
655  0,
656  (initproc) Py_source_init,
657  0,
658  Py_source_new,
659  0,
660  0,
661  0,
662  0,
663  0,
664  0,
665  0,
666  0,
667  0,
668};
Note: See TracBrowser for help on using the repository browser.