>> Out of curiosity, does the noise of the uncompressed recording look >> worse in black frames than regular ones, or is it only after mpeg >> compression that things look bad? If the latter, than perhaps you want > > The latter. I see the blocks/splotches all the time in dark scenes. > Also during fades in from black and then fades to black. > > It's only after mpeg compression that it looks bad (sometimes very > much so). Using various filters (such as yuvmedianfilter and -D 10 to > the encoder helps a little bit but it's not enough.
Ok, so this is an artifact introduced by MPEG compression, right? Maybe something can be done to the compression algorithm itself to help.... (For example, maybe it is possible to donate bits from the chroma channels to the luma channel on dark frames?) > For example here's what a few Y entries from a black frame look like > (values are decimal): > >0000200 030 026 022 023 030 026 024 026 027 025 025 027 027 030 026 023 >0000220 023 025 025 026 032 030 024 024 027 026 023 024 031 023 022 027 >0000240 030 021 022 030 030 025 026 027 026 025 026 030 031 024 030 027 >0000260 024 025 030 024 025 027 030 027 023 026 027 024 026 031 024 025 >0000300 027 025 024 024 032 026 024 024 027 024 024 027 026 023 030 025 >0000320 024 026 025 026 027 031 022 022 026 030 024 025 027 026 020 026 >0000340 031 025 025 026 027 024 024 027 026 025 027 025 024 023 030 026 >0000360 021 025 030 026 022 022 031 031 025 023 025 027 023 023 030 027 > > To the eye that looks black, but the encoder sees the constantly > changing (by small, usually +/- 2) values. Comes out looking like > alternating blocks of darkgrey/black. What do those numbers look like after it is squeezed through MPEG? Could you post example before/after frames (on the web, pref.)? It would help stimulate our brainstorming. :) -matt m. ------------------------------------------------------- This SF.Net email is sponsored by: Oracle 10g Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE. http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click _______________________________________________ Mjpeg-users mailing list [EMAIL PROTECTED] https://lists.sourceforge.net/lists/listinfo/mjpeg-users
