[MPlayer-users] streamed and stored pictures offset

[Michael Hess]

Hi there,

I am doing research on the video quality over IP networks, and I have set
up a Darwin streaming server to serve me some streams. So fare, so good,
this works. When I now go, and save the streamed pictures as jpg, I have
an difference in the numbers between the streamed file
rtsp://andsoon/test.mp4
and the file from the harddisk mplayer test.mp4.
I thougt, that my pc is dropping some jpegs, so I have modified the source
and now use the sh_video->pts (play time seconds i think) to generate the
filenames instead of the simplet interger which was decreased each time a
picture was stored. This had the problem, that if some frames where lost
(what I want to do in the end) i had an offset between the pictures. And
now the strange thing appears. They names are still not simelar, and after
about 47 seconds I have an offset of 20% of a frame (in seconds: 0.008103
seconds). (23.98 Frames / seconds => 0.0417s) This is in my eyes very
strange because I thought, that a pictures is stored every time when the
player calles the function to display this frame... I am now wondering,
where this offset comes from... Anybody an idea ?

Best regards, and merry Chrismas to everybody..

Michael Hess