# Copyright 2016 The TensorFlow Authors. All Rights Reserved.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
# =============================================================================
"""Tests for third_party.tensorflow.contrib.ffmpeg.encode_audio_op."""

from __future__ import absolute_import
from __future__ import division
from __future__ import print_function

import os.path

import six

from tensorflow.contrib import ffmpeg
from tensorflow.python.framework import dtypes
from tensorflow.python.ops import array_ops
from tensorflow.python.platform import resource_loader
from tensorflow.python.platform import test


class EncodeAudioOpTest(test.TestCase):

  def setUp(self):
    super(EncodeAudioOpTest, self).setUp()
    path = os.path.join(resource_loader.get_data_files_path(),
                        'testdata/mono_10khz.wav')
    with open(path, 'rb') as f:
      self._contents = f.read()

  def _compareWavFiles(self, original, encoded):
    """Compares the important bits of two WAV files.

    Some encoders will create a slightly different header to the WAV file.
    This compares only the important bits of the header as well as the contents.

    Args:
      original: Contents of the original .wav file.
      encoded: Contents of the new, encoded .wav file.
    """
    self.assertLess(44, len(original))
    self.assertLess(44, len(encoded))
    self.assertEqual(original[:4], encoded[:4])
    # Skip file size
    self.assertEqual(original[8:16], encoded[8:16])
    # Skip header size
    self.assertEqual(original[20:36], encoded[20:36])
    # Skip extra bits inserted by ffmpeg.
    self.assertEqual(original[original.find(b'data'):],
                     encoded[encoded.find(b'data'):])

  def testRoundTrip(self):
    """Reads a wav file, writes it, and compares them."""
    with self.cached_session():
      audio_op = ffmpeg.decode_audio(
          self._contents,
          file_format='wav',
          samples_per_second=10000,
          channel_count=1)
      encode_op = ffmpeg.encode_audio(
          audio_op, file_format='wav', samples_per_second=10000)
      encoded_contents = encode_op.eval()
      self._compareWavFiles(self._contents, encoded_contents)

  def testRoundTripWithPlaceholderSampleRate(self):
    with self.cached_session():
      placeholder = array_ops.placeholder(dtypes.int32)
      audio_op = ffmpeg.decode_audio(
          self._contents,
          file_format='wav',
          samples_per_second=placeholder,
          channel_count=1)
      encode_op = ffmpeg.encode_audio(
          audio_op, file_format='wav', samples_per_second=placeholder)
      encoded_contents = encode_op.eval(feed_dict={placeholder: 10000})
      self._compareWavFiles(self._contents, encoded_contents)

  def testFloatingPointSampleRateInvalid(self):
    with self.cached_session():
      with self.assertRaises(TypeError):
        ffmpeg.encode_audio(
            [[0.0], [1.0]],
            file_format='wav',
            samples_per_second=12345.678)

  def testZeroSampleRateInvalid(self):
    with self.cached_session() as sess:
      encode_op = ffmpeg.encode_audio(
          [[0.0], [1.0]],
          file_format='wav',
          samples_per_second=0)
      with six.assertRaisesRegex(self, Exception, 'must be positive'):
        sess.run(encode_op)

  def testNegativeSampleRateInvalid(self):
    with self.cached_session() as sess:
      encode_op = ffmpeg.encode_audio(
          [[0.0], [1.0]],
          file_format='wav',
          samples_per_second=-2)
      with six.assertRaisesRegex(self, Exception, 'must be positive'):
        sess.run(encode_op)


if __name__ == '__main__':
  test.main()