python - 使用`django-storages`上传时如何获取mp4的缩略图？

Question

我的工作是local.py我可以获得instance.video.path并且能够获得thumbnail. 这是我的函数、测试用例和模型

utils.py

def save_screen_shot(instance: Video) -> Video:
    try:
        filename = instance.video.path
    except ValueError as err:
        logger.info(f"The 'video' attribute has no file associated with it.")
    else:
        video_length = clean_duration(get_length(filename))
        instance.video_length = video_length

        img_output_path = f"/tmp/{str(uuid.uuid4())}.jpg"
        subprocess.call(['ffmpeg', '-i', filename, '-ss', '00:00:00.000', '-vframes', '1', img_output_path])
        # save screen_shot
        with open(img_output_path, 'rb') as ss_file:
            instance.screen_shot.save(str(uuid.uuid4()) + '.jpg', ss_file)
        instance.save()
    finally:
        instance.refresh_from_db()
        return instance

tests.py

    def test_screen_shot(self):
        client = APIClient()
        client.force_authenticate(user=self.user_a)
        with open('media/SampleVideo_1280x720_1mb.mp4', 'rb') as mp4_file:
            data = {
                'text': "Big Bug Bunny",
                'multipart_tags': 'Tri Uncle featuring',
                'video': mp4_file,
            }
            url = reverse('api:tweet-list')
            res = client.post(url, data=data, format='multipart')
            video = Video.objects.first()
            mp4_file.seek(0)  # set head to first position before do an `assertion`

            assert status.HTTP_201_CREATED == res.status_code
            assert mp4_file.read() == video.video.read()
            assert video.screen_shot  # Not None
            assert 1 == Video.objects.count()

models.py

class Video(models.Model):
    video = models.FileField(upload_to='./videos/', null=True, blank=True)

我把调试，发现在我的生产INSTALLED_APPS中有'storages'它。它让我犯了错误

ipdb> instance.video.path
*** NotImplementedError: This backend doesn't support absolute paths.
ipdb> dir(instance.video)
['DEFAULT_CHUNK_SIZE', '__bool__', '__class__', '__delattr__', '__dict__', '__dir__', '__doc__', '__enter__', '__eq__', '__exit__', '__format__', '__ge__', '__getattribute__', '__getstate__', '__gt__', '__hash__', '__init__', '__init_subclass__', '__iter__', '__le__', '__len__', '__lt__', '__module__', '__ne__', '__new__', '__reduce__', '__reduce_ex__', '__repr__', '__setattr__', '__sizeof__', '__str__', '__subclasshook__', '__weakref__', '_committed', '_del_file', '_file', '_get_file', '_require_file', '_set_file', 'chunks', 'close', 'closed', 'delete', 'encoding', 'field', 'file', 'fileno', 'flush', 'instance', 'isatty', 'multiple_chunks', 'name', 'newlines', 'open', 'path', 'read', 'readable', 'readinto', 'readline', 'readlines', 'save', 'seek', 'seekable', 'size', 'storage', 'tell', 'truncate', 'url', 'writable', 'write', 'writelines']

尝试
因为我的最终目标是

1. video_length
2. screenshot

我尝试直接访问file，但它提高了我TypeError

ipdb> instance.video.file
<S3Boto3StorageFile: videos/Marschiert_in_Feindesland_.flv_360p_j5GJ19m.mp4>
ipdb> video_length = clean_duration(get_length(instance.video.file))
*** TypeError: expected str, bytes or os.PathLike object, not S3Boto3StorageFile

问题：
我在使用时如何获取屏幕截图django-storage？

标签： pythondjangoamazon-s3video