tests/codecs_test.py

# Copyright 2021-2023 Google LLC
#
# 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
#
#      https://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.

# -----------------------------------------------------------------------------
# Imports
# -----------------------------------------------------------------------------
import random
import pytest
from bumble.codecs import AacAudioRtpPacket, BitReader, BitWriter


# -----------------------------------------------------------------------------
def test_reader():
    reader = BitReader(b'')
    with pytest.raises(ValueError):
        reader.read(1)

    reader = BitReader(b'hello')
    with pytest.raises(ValueError):
        reader.read(40)

    reader = BitReader(bytes([0xFF]))
    assert reader.read(1) == 1
    with pytest.raises(ValueError):
        reader.read(10)

    reader = BitReader(bytes([0x78]))
    value = 0
    for _ in range(8):
        value = (value << 1) | reader.read(1)
    assert value == 0x78

    data = bytes([x & 0xFF for x in range(66 * 100)])
    reader = BitReader(data)
    value = 0
    for _ in range(100):
        for bits in range(1, 33):
            value = value << bits | reader.read(bits)
    assert value == int.from_bytes(data, byteorder='big')


def test_writer():
    writer = BitWriter()
    assert bytes(writer) == b''

    for i in range(100):
        for j in range(1, 10):
            writer = BitWriter()
            chunks = []
            for k in range(j):
                n_bits = random.randint(1, 32)
                random_bits = random.getrandbits(n_bits)
                chunks.append((n_bits, random_bits))
                writer.write(random_bits, n_bits)

            written_data = bytes(writer)
            reader = BitReader(written_data)
            for n_bits, written_bits in chunks:
                read_bits = reader.read(n_bits)
                assert read_bits == written_bits


def test_aac_rtp():
    # pylint: disable=line-too-long
    packet_data = bytes.fromhex(
        '47fc0000b090800300202066000198000de120000000000000000000000000000000000000000000001c'
    )
    packet = AacAudioRtpPacket.from_bytes(packet_data)
    adts = packet.to_adts()
    assert adts == bytes.fromhex(
        'fff1508004fffc2066000198000de120000000000000000000000000000000000000000000001c'
    )

    payload = bytes(list(range(1, 200)))
    rtp = AacAudioRtpPacket.for_simple_aac(44100, 2, payload)
    assert rtp.audio_mux_element.payload == payload
    assert (
        rtp.audio_mux_element.stream_mux_config.audio_specific_config.sampling_frequency
        == 44100
    )
    assert (
        rtp.audio_mux_element.stream_mux_config.audio_specific_config.channel_configuration
        == 2
    )
    rtp2 = AacAudioRtpPacket.from_bytes(bytes(rtp))
    assert str(rtp2.audio_mux_element.stream_mux_config) == str(
        rtp.audio_mux_element.stream_mux_config
    )
    assert rtp2.audio_mux_element.payload == rtp.audio_mux_element.payload


# -----------------------------------------------------------------------------
if __name__ == '__main__':
    test_reader()
    test_writer()
    test_aac_rtp()