mpeg-audio-frame-parser/test/mpeg_audio_frame_parser/impl_test.exs

113 lines
3.5 KiB
Elixir

defmodule MPEGAudioFrameParser.ImplTest do
use ExUnit.Case
# MP3, 128kbps, no CRC protection, 44100hz, no padding, stereo
@frame1 <<0b11111111111_11_01_0_1001_00_0_0_00_00_0_0_00::size(32), 1::size(3304)>>
@frame2 <<0b11111111111_11_01_0_1001_00_0_0_00_00_0_0_00::size(32), 0::size(3304)>>
# MP3, 256kbps, no CRC protection, 48000hz, no padding, stereo
@frame3 <<0b11111111111_11_01_0_1101_01_0_0_00_00_0_0_00::size(32), 1::size(6112)>>
describe "add_packet" do
import MPEGAudioFrameParser.Impl, only: [init: 0, add_packet: 2]
test "handles a single frame at the start of a packet" do
{:ok, state} = init()
{:ok, state} = add_packet(state, @frame1)
assert %{current_frame: nil, frames: [%{data: @frame1}]} = state
end
test "handles a single frame in the middle of a packet" do
{:ok, state} = init()
packet = <<0, 1, 2, 3, @frame1::binary>>
{:ok, state} = add_packet(state, packet)
assert %{current_frame: nil, frames: [%{data: @frame1}]} = state
end
test "ignores a packet that includes no valid frames at all" do
{:ok, state} = init()
{:ok, state} = add_packet(state, <<1::size(10240)>>)
assert %{current_frame: nil, frames: []} = state
end
test "handles two frames in consecutive packets" do
{:ok, state} = init()
{:ok, state} = add_packet(state, @frame1)
{:ok, state} = add_packet(state, @frame3)
assert %{current_frame: nil, frames: [%{data: @frame3}, %{data: @frame1}]} = state
end
test "handles a frame split unevenly across consecutive packets" do
{:ok, state} = init()
part1 = :binary.part(@frame1, {0, 256})
part2 = :binary.part(@frame1, {byte_size(@frame1), -(byte_size(@frame1) - 256)})
{:ok, state} = add_packet(state, <<0, 1, 2, 3, part1::binary>>)
{:ok, state} = add_packet(state, part2)
assert length(state.frames) == 1
assert List.first(state.frames).data == @frame1
end
test "handles three frames in a single packet" do
{:ok, state} = init()
{:ok, state} = add_packet(state, <<@frame1::binary, @frame1::binary, @frame1::binary>>)
assert length(state.frames) == 3
assert Enum.map(state.frames, & &1.data) == [@frame1, @frame1, @frame1]
end
test "handles three frames in consecutive packets" do
{:ok, state} = init()
{:ok, state} = add_packet(state, @frame3)
{:ok, state} = add_packet(state, @frame3)
{:ok, state} = add_packet(state, @frame3)
assert length(state.frames) == 3
assert Enum.map(state.frames, & &1.data) == [@frame3, @frame3, @frame3]
assert is_nil(state.current_frame)
end
end
describe "pop_frame" do
import MPEGAudioFrameParser.Impl, only: [init: 0, add_packet: 2, pop_frame: 1]
test "returns nil when there are no frames available" do
{:ok, state} = init()
assert pop_frame(state) == {:ok, nil, state}
end
test "returns a single frame" do
{:ok, state} = init()
{:ok, state} = add_packet(state, @frame1)
{:ok, frame, state} = pop_frame(state)
assert frame.data == @frame1
assert state.frames == []
end
test "returns multiple frames in the correct order" do
{:ok, state} = init()
{:ok, state} = add_packet(state, @frame1)
{:ok, state} = add_packet(state, @frame2)
{:ok, frame, state} = pop_frame(state)
assert frame.data == @frame1
{:ok, frame, _state} = pop_frame(state)
assert frame.data == @frame2
end
end
end