docstr: Can apply additional effect with filter graph
docstr_tok: ["Can","apply","additional","effect","with","filter","graph"]
code: def test_filter_graph_video(self):
      """Can apply additional effect with filter graph"""
      src_rate = 30
      num_frames, width, height = 400, 160, 90
      filter_desc = "framestep=2"
      enc_rate = 15
      ext = "mp4"
      filename = f"test.{ext}"
  
      original = torch.zeros(
          (num_frames, 3, height, width), dtype=torch.uint8
      )
  
      dst = self.get_temp_path(filename)
      w = StreamWriter(dst, format=ext)
      w.add_video_stream(
          frame_rate=src_rate,
          format="rgb24",
          height=height,
          width=width,
          filter_desc=filter_desc,
          encoder_format="yuv420p",
          encoder_frame_rate=enc_rate,
      )
  
      with w.open():
          w.write_video_chunk(0, original)
  
      reader = torchaudio.io.StreamReader(
          src=self.get_temp_path(filename)
      )
      reader.add_video_stream(-1)
      reader.process_all_packets()
      (output,) = reader.pop_chunks()
  
      self.assertEqual(
          output.shape, [num_frames // 2, 3, height, width]
      )
  
imports: import io
  import math
  import torch
  import torchaudio
  from parameterized import parameterized, parameterized_class
  from torchaudio.io import CodecConfig, StreamReader, StreamWriter
  from torchaudio_unittest.common_utils import get_asset_path, get_sinusoid, nested_params, rgb_to_yuv_ccir, skipIfNoFFmpeg, skipIfNoModule, TempDirMixin, TorchaudioTestCase
  from .common import lt42
label_desc: Use image node_id 15 for calling the StreamWriterCorrectnessTest obj's underlying member method code with example usage: obj.test_filter_graph_video() without return types