[Live-devel] live555 is great, but I need help for recording WMV streams.

[luwei at tju.edu.cn]

Hi,

I have an urgent task that I should download and record the WMV files from Windows
Media Server via RTSP.

I have reported in the mailing-list that when using openRTSP to get a WMV stream
from windows media server, I would get a file that is different with the original
one on the server and cannot be decoded. (I settled up the server and put a wmv
file on it for comparison.)
I did further experiments and found out that the reason lied in the server side:
Experiment procedures: 
I used a windows software named HiDownload to save a WMV file, meanwhile, I
captured the ethernet packets with Ethereal. I also captured packets when playing
the RTSP stream with VLC, as well as receiving the stream with openRTSP. (I have
not tested windows media player yet.)
Results: 
1. Although the wmv file saved by HiDownload can be decoded correctly, it is not
the same as the original file.
2. The captured packets of VLC, openRTSP and HiDownload are IDENTICAL, but
HiDownload adds some stuff bytes when saving the packets. In other words,
HiDownload does more than justing receiving the stream. (For VLC, it will demux
and decode the received packets with no problem.)
Conclusion:
1. live555 library and openRTSP are great and fully compliant to RTSP protocol.
Thanks, Ross.
2. It is ugly and difficult to deal with the received RTSP packets according to
its format, especially that Microsoft's specification for WMV file format is not
clear enough. If anyone could offer help, I will quite appreciate it.