While messing with the reverse playback in MPEG-2 files I was tracing mpegvideoparse and mpeg2dec plugins.
My application builds playbin2 pipeline.

I've put a breakpoint at the line 1040 of the file gstmpeg2dec.c
http://cgit.freedesktop.org/gstreamer/gst-plugins-ugly/tree/ext/mpeg2dec/gstmpeg2dec.c#n1040
where the mpeg2dec plugin pushes the decoded frame downstream.

Then I've discovered an address of the pushed buffer's data and have given this address  to the Bitmap Memory Debugger ( http://www.theycamefromhollywood.com/bmd/ ). The buffer contained a decoded frame in YUV format, and BMD has visualized Y component of it.

Then I've opened the same file in the Elecard Stream Eye and AVIdemux applications and have found the same frame.
Both applications gave another timestamp for it, much earlier.

For example, the first movie frame (I frame) with the timestamp 0:00:00, according to the AVIdemux and the StreamEye, has the timestamp 0:00:01.02, when mpeg2dec pushes it downstream.