How do I using av.open to open a ByteIO object?

[fake-warrior8]

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Overview

I want to use av.open to open a ByteIO object. However, video_byte=av.open(buff) (where buff=ByteIO(some_bytes)) will output some errors. For example, video_byte.streams.video[0].time_base is None while video_mp4=av.open(some_mp4), video_mp4.streams.video[0].time_base will give a right number.

Expected behavior

video_byte = av.open(buff) (where buff=ByteIO(some_bytes)) and video_mp4=av.open(some_mp4) will work the same, which means their attributes are the same.

Actual behavior

video_byte.streams.video[0].time_base is None

Traceback:

No exceptions.

Investigation

buff=ByteIO(some_bytes)
buff.seek(0) # found in Google
video_byte = av.open(buff) 

Research

I have done the following:

• [* ] Checked the PyAV documentation
• [*] Searched on Google
• [*] Searched on Stack Overflow
• [* ] Looked through old GitHub issues
• Asked on PyAV Gitter
• ... and waited 72 hours for a response.

Additional context

{{ Add any other context about the problem here. }}