Changeset 58eb250


Ignore:
Timestamp:
Oct 26, 2018, 8:18:50 PM (13 months ago)
Author:
Paul Brossier <piem@piem.org>
Branches:
feature/autosink, feature/constantq, feature/pitchshift, feature/pydocstrings, feature/timestretch, master
Children:
d281698
Parents:
16e2bb0
Message:

[python] add docstrings for source

File:
1 edited

Legend:

Unmodified
Added
Removed
  • python/ext/py-source.c

    r16e2bb0 r58eb250  
    1717
    1818static char Py_source_doc[] = ""
    19 "   __new__(path, samplerate = 0, hop_size = 512, channels = 1)\n"
    20 "\n"
    21 "       Create a new source, opening the given path for reading.\n"
    22 "\n"
    23 "       Examples\n"
    24 "       --------\n"
    25 "\n"
    26 "       Create a new source, using the original samplerate, with hop_size = 512:\n"
    27 "\n"
    28 "       >>> source('/tmp/t.wav')\n"
    29 "\n"
    30 "       Create a new source, resampling the original to 8000Hz:\n"
    31 "\n"
    32 "       >>> source('/tmp/t.wav', samplerate = 8000)\n"
    33 "\n"
    34 "       Create a new source, resampling it at 32000Hz, hop_size = 32:\n"
    35 "\n"
    36 "       >>> source('/tmp/t.wav', samplerate = 32000, hop_size = 32)\n"
    37 "\n"
    38 "       Create a new source, using its original samplerate:\n"
    39 "\n"
    40 "       >>> source('/tmp/t.wav', samplerate = 0)\n"
    41 "\n"
    42 "   __call__()\n"
    43 "       vec, read = x() <==> vec, read = x.do()\n"
    44 "\n"
    45 "       Read vector from source.\n"
    46 "\n"
    47 "       See also\n"
    48 "       --------\n"
    49 "       aubio.source.do\n"
    50 "\n";
     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"";
    51217
    52218static char Py_source_get_samplerate_doc[] = ""
    53 "x.get_samplerate() -> source samplerate\n"
    54 "\n"
    55 "Get samplerate of source.";
     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"";
    56228
    57229static char Py_source_get_channels_doc[] = ""
    58 "x.get_channels() -> number of channels\n"
    59 "\n"
    60 "Get number of channels in source.";
     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"";
    61239
    62240static char Py_source_do_doc[] = ""
    63 "vec, read = x.do() <==> vec, read = x()\n"
    64 "\n"
    65 "Read monophonic vector from source.";
     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, shape `(hop_size,)`, dtype aubio.float_type\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"";
    66268
    67269static char Py_source_do_multi_doc[] = ""
    68 "mat, read = x.do_multi()\n"
    69 "\n"
    70 "Read polyphonic vector from source.";
     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 : np.ndarray([hop_size, channels], dtype=aubio.float_type)\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"";
    71307
    72308static char Py_source_close_doc[] = ""
    73 "x.close()\n"
    74 "\n"
    75 "Close this source now.";
     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"";
    76315
    77316static char Py_source_seek_doc[] = ""
    78 "x.seek(position)\n"
    79 "\n"
    80 "Seek to resampled frame position.";
     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"";
    81329
    82330static PyObject *
     
    218466static PyMemberDef Py_source_members[] = {
    219467  {"uri", T_STRING, offsetof (Py_source, uri), READONLY,
    220     "path at which the source was created"},
     468    "str (read-only): pathname or URL"},
    221469  {"samplerate", T_INT, offsetof (Py_source, samplerate), READONLY,
    222     "samplerate at which the source is viewed"},
     470    "int (read-only): sampling rate"},
    223471  {"channels", T_INT, offsetof (Py_source, channels), READONLY,
    224     "number of channels found in the source"},
     472    "int (read-only): number of channels"},
    225473  {"hop_size", T_INT, offsetof (Py_source, hop_size), READONLY,
    226     "number of consecutive frames that will be read at each do or do_multi call"},
     474    "int (read-only): number of samples read per iteration"},
    227475  {"duration", T_INT, offsetof (Py_source, duration), READONLY,
    228     "total number of frames in the source (estimated)"},
     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    ""},
    229491  { NULL } // sentinel
    230492};
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