import av
import av.datasets

input_container = av.open(av.datasets.curated("pexels/time-lapse-video-of-night-sky-857195.mp4"))
output_container = av.open("hevc_qsv_encoded.mp4", "w", options={})

input_stream = input_container.streams.video[0]
output_stream = output_container.add_stream('hevc_qsv', input_stream.average_rate)
output_stream.width = input_stream.width
output_stream.height = input_stream.height

output_stream.pix_fmt = "nv12"
output_stream.codec_context.global_quality = 20
output_stream.codec_context.qscale = True

for frame in input_container.decode(video=0):
    packet = output_stream.encode(frame)
    if packet: output_container.mux(packet)

input_container.close()
output_container.close()