trng-client/main.py

import asyncio
from concurrent.futures import ProcessPoolExecutor
from itertools import groupby

import bitstring
from linuxpy.video.device import Device
from Crypto.Hash import BLAKE2b

from loguru import logger

logger.level("INFO")


def chunks(lst, n):
    for i in range(0, len(lst), n):
        yield lst[i: i + n]


def extract_lsbs(data):
    logger.info("Extract LSBs.")

    buffer = []

    data = [k for k, _ in groupby(data)]
    data = chunks(data, 8)

    for chunk in data:
        if len(chunk) != 8:
            break

        ba = bitstring.BitArray(8)
        for i, byte in zip(range(len(chunk)), chunk):
            ba[i] = byte & 1

        buffer.append(ba.u)

    return bytes(buffer)


def whiten(data: bytes) -> bytes:
    logger.info("Whitening.")

    buffer = b""
    for chunk in chunks(data, 32):
        if len(chunk) < 32:
            break

        buffer += BLAKE2b.new(data=chunk, digest_bits=256).digest()

    return buffer


def video2_extractor(frame_bytes: bytes):
    logger.debug(f"frames_in {len(frame_bytes)}")
    chunked_bytes = chunks(frame_bytes, 8)
    newdata = b""

    for chunk in chunked_bytes:
        newdata += bytes(a ^ b for a, b in zip(chunk[:4], chunk[4:]))

    logger.debug(f"newdata {len(newdata)}")
    out_bytes = extract_lsbs(newdata)
    out_bytes = whiten(out_bytes)

    logger.info(f"Sample ready: {len(out_bytes)}b.")
    return out_bytes


class FrameTakeWorker:
    def __init__(self, device_id=0, processes=3):
        self.processes = processes
        self.executor_pool = ProcessPoolExecutor(max_workers=3)
        logger.info(self.executor_pool)
        self.video_source = Device.from_id(device_id)
        self.video_source.open()

        self.video_source.set_format(
            1,
            self.video_source.info.frame_sizes[0].width,
            self.video_source.info.frame_sizes[0].height,
            pixel_format="YUYV",
        )

        self.frame_gen = self.video_source.__iter__()

    async def get_frame(self):
        return next(self.frame_gen)

    async def frame_extractor(self, frame_bytes: bytes):
        loop = asyncio.get_event_loop()
        logger.info(f"Input bytes: {len(frame_bytes)}")
        output = await loop.run_in_executor(self.executor_pool, video2_extractor, frame_bytes)
        return output

    async def generator_worker(self):
        while True:
            logger.info("get frame")
            frame = await self.get_frame()
            logger.info(f"{frame}")
            data = await self.frame_extractor(bytes(frame))
            logger.info(f"{len(data)}")

    async def run_workers(self):
        tasks = [self.generator_worker() for _ in range(self.processes)]
        await asyncio.gather(*tasks)
        pass


if __name__ == "__main__":
    ftw = FrameTakeWorker(1)
    asyncio.run(ftw.run_workers())