Originally committed as revision 22403 to svn://svn.ffmpeg.org/ffmpeg/trunk

This ensures proper escaping of numerical IPv6 addresses.

The RTSP (de)muxer needs its own network initialization, since it isn't
a protocol and url_open hasn't been called yet.

Originally committed as revision 22226 to svn://svn.ffmpeg.org/ffmpeg/trunk

This way, we avoid overwriting stream_index in the user's AVPacket
with a nonsense value.

Originally committed as revision 22081 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 21974 to svn://svn.ffmpeg.org/ffmpeg/trunk

Originally committed as revision 21971 to svn://svn.ffmpeg.org/ffmpeg/trunk