QMediaResource::dataSize() returns zero byte size for online video

redstoneleo

I am trying to use QMediaResource::dataSize() to get an online video byte size. However, it just returns zero - which is hard to believe in this case:

This may be zero if the size is unknown.

especially for the first url.

I just want to know: (1) if it is a bug with PyQt5 or Qt5, (2) does the equivalent code in Qt5 return a nonzero result, and (3) is there any way to get the video byte size of the m3u8 url referred to?

>>> from PyQt5.QtMultimedia import *
>>> from PyQt5.QtCore import *
>>> QMediaResource(QUrl('http://downdb.51voa.com/201610/will-philippines-cut-ties-with-us-and-grow-closer-to-china.mp3')).dataSize()
0
>>> QMediaResource(QUrl('https://www.the5fire.com/static/demos/diaosi.m3u8'),"application/vnd.apple.mpegurl").dataSize()
0
>>>

>>> QMediaResource(QNetworkRequest(QUrl('https://www.the5fire.com/static/demos/diaosi.m3u8')),"application/vnd.apple.mpegurl").dataSize()
0
>>> QMediaResource(QNetworkRequest(QUrl('https://www.the5fire.com/static/demos/diaosi.m3u8'))).dataSize()
0
>>> QMediaResource(QNetworkRequest(QUrl('http://downdb.51voa.com/201610/will-philippines-cut-ties-with-us-and-grow-closer-to-china.mp3'))).dataSize()
0
>>>

raven-worx

@redstoneleo
m3u is a playlist format. And playlist may contain multiple media urls.
Also note that the byte size isn't guaranteed to be known, depending on the webserver implementation.