python - Python文件中的FFmpeg已经存在错误

Question

我正在使用 python(3.6) 和 Django(2.0) 开发一个项目，如果它是任何其他格式，我正在将视频转换为 mp4。

这是我的代码:

来自views.py:

def generate_thumbnail(filename, thumb_name):
    print('func called')
    print(filename)
    video_input_path = os.path.join(filename)
    img_output_path = os.path.join(thumb_name)
    subprocess.call(['ffmpeg', '-i', video_input_path, '-ss', '00:00:00.000', 'vframes', '1', img_output_path])


def convert_to_mp4(video_name, only_name):
    os.popen(
        "ffmpeg -i '{input}' -ac 2 -b:v 2000k -c:a aac -c:v libx264 -b:a 160k -vprofile high -bf 0 -strict experimental -f mp4 '{output}.mp4'".format(
            input=video_name, output=only_name))
    return True


def perform_upload(video, thumbnail):
    print('vdieo name is: {}'.format(video))
    servise = discovery.build('storage', 'v1', credentials=credentials)
    bucket_name = 'test_bucket004'
    print('Uploading the video...')
    media = MediaFileUpload(video, chunksize=4149304, mimetype='video/mp4',
                            resumable=True)
    req = servise.objects().insert(
        bucket=bucket_name,
        name=str(video),
        media_body=media,
        body={"cacheControl": "public,max-age=31536000"},
        predefinedAcl='publicRead'
    )
    resp = None
    while resp is None:
        status, resp = req.next_chunk()
    print(resp)
    video_url = 'http://storage.googleapis.com/' + bucket_name + '/' + str(video)

    print('Uploading your thumbnail...')
    media = MediaFileUpload(thumbnail, chunksize=4149304, mimetype='image/jpeg',
                            resumable=True)
    req = servise.objects().insert(
        bucket=bucket_name,
        name=str(thumbnail),
        media_body=media,
        body={"cacheControl": "public,max-age=31536000"},
        predefinedAcl='publicRead'
    )
    resp = None
    while resp is None:
        status, resp = req.next_chunk()
    print(resp)
    thumb_url = 'https://storage.googleapis.com/' + bucket_name + '/' + str(thumbnail)

    return video_url, thumb_url


class VideoConverter(generics.ListCreateAPIView):
    def get(self, request, *args, **kwargs):
        return HttpResponse('Get request', status=200)

    def post(self, request, *args, **kwargs):
        serializer = VideoConverterSerializer(data=self.request.data)
        validation = serializer.is_valid()
        print(serializer.errors)
        if validation is True:
            url = request.POST.get('video_url')
            filename = url.split('/')
            filename = filename[-1]
            print(filename)
            ext = filename.split('.')
            print(ext[-1])
            only_name = ext[0]
            urllib.request.urlretrieve(url, filename)
            generate_thumbnail(filename, only_name + '_thumbnail.jpg')
            if ext == 'mp4':
                videourl, thumb_url = perform_upload(filename, only_name + '_thumbnail.jpg')
            else:
                conversion = convert_to_mp4(filename, only_name)
                if conversion is True:
                    videourl, thumb_url = perform_upload(only_name + '.mp4', only_name + '_thumbnail.jpg')

            return HttpResponse('Video url is: {}\n \nThumbnail url is: {}'.format(videourl, thumb_url))
        else:
            return HttpResponse('Not a valid request')

但是，当我将 Mp4 格式的视频传递给它时，它会在 IDE 控制台中返回一个错误，如下所示:

ffmpeg version 4.0.2 Copyright (c) 2000-2018 the FFmpeg developers built with Apple LLVM version 10.0.0 (clang-1000.10.43.1) configuration: --prefix=/usr/local/Cellar/ffmpeg/4.0.2 --enable-shared --enable-pthreads --enable-version3 --enable-hardcoded-tables --enable-avresample --cc=clang --host-cflags= --host-ldflags= --enable-gpl --enable-libmp3lame --enable-libx264 --enable-libxvid --enable-opencl --enable-videotoolbox --disable-lzma libavutil 56. 14.100 / 56. 14.100 libavcodec 58. 18.100 / 58. 18.100 libavformat 58. 12.100 / 58. 12.100 libavdevice 58. 3.100 / 58. 3.100 libavfilter 7. 16.100 / 7. 16.100 libavresample 4. 0. 0 / 4. 0. 0 libswscale 5. 1.100 / 5. 1.100 libswresample 3. 1.100 / 3. 1.100 libpostproc 55. 1.100 / 55. 1.100 Input #0, mov,mp4,m4a,3gp,3g2,mj2, from 'PHP_GCS.mp4': Metadata: major_brand : mp42 minor_version : 1 compatible_brands: mp41mp42isom creation_time : 2018-08-03T13:08:04.000000Z Duration: 00:01:21.40, start: 0.000000, bitrate: 1584 kb/s Stream #0:0(und): Video: h264 (Main) (avc1 / 0x31637661), yuv420p, 1918x1078 [SAR 1:1 DAR 137:77], 1581 kb/s, 30 fps, 30 tbr, 600 tbn, 1200 tbc (default) Metadata: creation_time : 2018-08-03T13:08:04.000000Z handler_name : Core Media Video

File 'PHP_GCS.mp4' already exists. Overwrite ? [y/N]

并在这里停止执行，直到我按下回车按钮。我真的很困惑为什么会这样，因为当视频已经是 mp4 时，我没有使用 ffmpeg但仅用于缩略图生成。

这里有什么问题？

提前致谢!

Answer 1

我认为您错过了代码中的某些内容。

您在视频转换器中的 Post 处理程序具有以下代码:

        ext = filename.split('.')
        print(ext[-1])
        only_name = ext[0]
        urllib.request.urlretrieve(url, filename)
        generate_thumbnail(filename, only_name + '_thumbnail.jpg')
        if ext == 'mp4': # mistake here

但是您没有检查 if 语句中的正确部分。

你应该写if ext[-1] == 'mp4'因为现在你正在将一个列表与一个总是返回 false 的字符串进行比较!

这可能会解决您的问题，如果没有，请告诉我，我会相应地更新我的答案。