Phonon used in Qt Project - Custom QIODevice to support encrypted files
kohlhaas at lyth.de
Tue Nov 27 08:44:09 GMT 2012
I want to integrate Audio and Video support in my Qt-application using
the Phonon framework. I'm handling protected data (mp3, avi etc.).
Therefore I'm writing those files encrypted to the filesystem.
To avoid loading a whole video in the buffer I subclassed QIODevice and
provided a custom IODevice which decrypts the encrypted content
'on-the-fly' when Phonon asks for more bytes. (function readData)
I'm initializing the MediaSource using this custom IODevice.
Encryption/Decryption works fine, no problems. Now I tried to play
different video types (Audio: mp3 is working) with my Phonon-Player.
WMV: not working
noticed the following sentence:
"Warning: On Windows, we only support QIODevices containing the avi,
mp3, or mpg formats. Use the constructor that takes a file name to open
files (the Qt backend does not use a QFile internally)."
Is there any way to avoid this restrictions and to extend this
functionality? Unfortunalety I definitely have to use encrypted files.
And perhaps can tell me somebody what's the reason behind this? Using
usual (not encrypted) files without the custom IODevice there is no
problem playing video files containing other formats like WMV or (with
the right codecs) MP4.
Thanks in advance :)
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