[Solved] Can anyone confirm the strange behavior on convert videos with wildcard.media

I use wildcard.video. I use it with symlink

ln -s /usr/bin/ffprobe /usr/local/bin/avprobe

, because ubuntu has changed the package. If i upload a video or press the convert button in action menu then the convert process fails. I investigated the problem a little bit and i found the following situation.

# https://github.com/collective/wildcard.media/blob/master/wildcard/media/convert.py#L49

def _run_command(self, cmd, or_error=False):
        if isinstance(cmd, six.string_types):
            cmd = cmd.split()
        cmdformatted = ' '.join(cmd)
        logger.info("Running command %s" % cmdformatted)
        process = subprocess.Popen(cmd, stdout=subprocess.PIPE,
                                   stderr=subprocess.PIPE,
                                   close_fds=self.close_fds)
        output, error = process.communicate()
        
        print("###Output###")
        print(output)
        print("###ReturnCode###")
        print(process.returncode)
        print("###Command###")
        print(cmd)
        print("###Command Formatted###")
        print(cmdformatted)
        print("###Error###")
        print(output)
        
        process.stdout.close()
        process.stderr.close()

        if process.returncode != 0:
            error = """Command
%s
finished with return code
%i
and output:
%s
%s""" % (cmdformatted, process.returncode, output, error)
            logger.info(error)
            raise Exception(error)
        logger.info("Finished Running Command %s" % cmdformatted)
        if not output:
            if or_error:
                return error
        return output

Here is the output of print statements:

###Output###
b''
###ReturnCode###
0
###Command###
['/usr/bin/avprobe', '/tmp/tmp4p3bo3ph/testvideo.mp4']
###Command Formatted###
/usr/bin/avprobe /tmp/tmp4p3bo3ph/testvideo.mp4

###Error###
b"ffprobe version 4.2.4-1ubuntu0.1 Copyright (c) 2007-2020 the FFmpeg developers
  built with gcc 9 (Ubuntu 9.3.0-10ubuntu2)
  configuration: --prefix=/usr --extra-version=1ubuntu0.1 --toolchain=hardened --libdir=/usr/lib/x86_64-linux-gnu --incdir=/usr/include/x86_64-linux-gnu --arch=amd64 --enable-gpl --disable-stripping --enable-avresample --disable-filter=resample --enable-avisynth --enable-gnutls --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libbs2b --enable-libcaca --enable-libcdio --enable-libcodec2 --enable-libflite --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libgme --enable-libgsm --enable-libjack --enable-libmp3lame --enable-libmysofa --enable-libopenjpeg --enable-libopenmpt --enable-libopus --enable-libpulse --enable-librsvg --enable-librubberband --enable-libshine --enable-libsnappy --enable-libsoxr --enable-libspeex --enable-libssh --enable-libtheora --enable-libtwolame --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwavpack --enable-libwebp --enable-libx265 --enable-libxml2 --enable-libxvid --enable-libzmq --enable-libzvbi --enable-lv2 --enable-omx --enable-openal --enable-opencl --enable-opengl --enable-sdl2 --enable-libdc1394 --enable-libdrm --enable-libiec61883 --enable-nvenc --enable-chromaprint --enable-frei0r --enable-libx264 --enable-shared
  libavutil      56. 31.100 / 56. 31.100
  libavcodec     58. 54.100 / 58. 54.100
  libavformat    58. 29.100 / 58. 29.100
  libavdevice    58.  8.100 / 58.  8.100
  libavfilter     7. 57.100 /  7. 57.100
  libavresample   4.  0.  0 /  4.  0.  0
  libswscale      5.  5.100 /  5.  5.100
libswresample   3.  5.100 /  3.  5.100
  libpostproc    55.  5.100 / 55.  5.100
Input #0, mov,mp4,m4a,3gp,3g2,mj2, from '/tmp/tmp4p3bo3ph/testvideo.mp4':
  Metadata:
    major_brand     : isom
    minor_version   : 512
    compatible_brands: isomiso2avc1mp41
    encoder         : Lavf58.29.100
  Duration: 00:01:55.03, start: 0.000000, bitrate: 1731 kb/s
    Stream #0:0(eng): Video: h264 (High) (avc1 / 0x31637661), yuv420p, 1920x1080 [SAR 1:1 DAR 16:9], 1601 kb/s, 25 fps, 25 tbr, 12800 tbn, 50 tbc (default)
    Metadata:
      handler_name    : ?Mainconcept Video Media Handler
    Stream #0:1(eng): Audio: aac (LC) (mp4a / 0x6134706D), 48000 Hz, stereo, fltp, 123 kb/s (default)
    Metadata:
      handler_name    : #Mainconcept MP4 Sound Media Handler"

From my point of view error and output are twisted. But the documentation of subprocess says that the returned value is a tuple of output, error. I'm a little bit confused.

Update:
I found the issue. It's a missing string decode from bytes to str and the afterwards string operations in the _convertFormat method.

class AVProbeProcess(BaseSubProcess):
    """
    """
    if os.name == 'nt':
        bin_name = 'avprobe.exe'
    else:
        bin_name = 'avprobe'

    def info(self, filepath):
        cmd = [self.binary, filepath]
        result = {}
        for line in self._run_command(cmd, or_error=True).splitlines():
            line = line.decode() # -> that was misssing
            if ':' not in line:
                continue
            name, data = line.split(':', 1)
            data = data.strip()
            if not data:
                continue
            name = name.strip().lower()
            if ' ' in name:
                continue
            result[name] = data
        return result

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