Hallo > The first one is concerned with recording a video stream from a Hi8 source > using a BT878 based card (that is, software encoding). From time to time (say > in an interval of a few minutes), there appear horizontal lines in single > frames. The pictures below show a sample. Note that the jpg image is > interlaced. > > http://www.nada.kth.se/~hanke/files/pert.jpg > http://www.nada.kth.se/~hanke/files/pert.ppm > > The perturbations are clearly seen near the knees. Did anybody experience > similar defects? I think that this could be a problem of the BTTV chipset. If the card notices that the data will not make it in time to the CPU, disk or somewhere else the cards stops transmitting the current line, and starts transmitting the next line. That behavior causes less visible artefacts when you view tv. But makes mor problems when you try to encode the video.
The zoran chipset has a different approach to this. When the zoran chipset notices that the date will not make it in time it stops transmitting the whole frame or field. Because the whole frame is more important, and a missing field/frame can usally be easier replicated. > The other artifact is connected with using matteblend which amounts to > reencoding the footage. I am using always a quality factor of 80. > Nevertheless, The pictures contain broad horizontal stripes which were not > present in the original. A sample is given below: Sorry, no idea about that problem. auf hoffentlich bald, Berni the Chaos of Woodquarter Email: [EMAIL PROTECTED] www: http://www.lysator.liu.se/~gz/bernhard ------------------------------------------------------- This SF.Net email is sponsored by: IBM Linux Tutorials Free Linux tutorial presented by Daniel Robbins, President and CEO of GenToo technologies. Learn everything from fundamentals to system administration.http://ads.osdn.com/?ad_id=1470&alloc_id=3638&op=click _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
