MPEG-2 Decoding: XDCAM / Sony-IMX format

holgerstrauss · ‎01-23-2006

Hi,

I'd like to decode MPEG-2 video recorded with a Sony XDCAM in IMX50 format. It is claimed that this format is MPEG-2 compliant. It uses I-frames only, with constant byte per GOP (CBG) and 30, 40 or 50 mbits per second.

The free GPL MPEG-1/2 Direct Show Decoder Filter (http://sourceforge.net/projects/gplmpgdec) can successfully decode this format. Also the DScaler MPEG-2 Video Decoder does not show any problems.

However, the MPEG-2 decoder example that comes with the Performance Primitives Library fails to decode the video. Decoding works "in principle". However, during playback, there are many small "solid subblocks" scattered all over the video which are not decoded correctly. These subblocks change their position rapidly.

Has anyone already solved this problem? Any hints?

Many thanks,

Holger

Vladimir_Dudnik · ‎01-25-2006

Hi Holger,

could you share some stream which demonstrates the problem to let us possibility to analize this issue?

Regards,
Vladimir

holgerstrauss · ‎01-31-2006

Hi Vladimir,

there is a short (2 seconds) file here:

http://media.vcs.de/Downloads/video.m2v

Many thanks
Holger

Vladimir_Dudnik · ‎02-10-2006

Hi Holger,

our experts investigated this issue, there is their comment:

Thank you for pointing this out. The problem is in ColorConverter initialization code in the case of YUV422 color format. Unfortunately, there is no workaroundavailable but we will fix this issue in the next release.

FYI:

IMX50 is 422, each sequence contains the single I-frame, each slice contains the single macroblock, quantizer scale is always 1 (minimal possible value). There is a black strip on the top of frames with line of white squares which change position from frame to frame. It seems to be some additional information, like timing or synchronization info.

Regards,
Vladimir