Jean Hoderd wrote:

...

I would second that emphatically. Don't scale at all and you will get much better results.

I scaled down because I noticed block artifacts in the unscaled version. As a matter of fact, I still notice some blocks even at 640x480. Perhaps I am doing something very wrong with my lavc and xvid options, in which case your help would be appreciated.

If you are seeing encoding artifacts after doing two pass lavc backup of dvd's, you need to lose some of your options. If scaling down looks better, it's only because you are getting some statistical blur, at the cost of detail. What's wrong with: -lavcopts vcodec=mpeg4:mbd=2:v4mv:trell:vpass=$N:vbitrate=1800 -ofps 24000/1001 and maybe some hqdn3d depending on the source? And remember folks, we are talking anime here, not live action. Phil

Hi Jean Hoderd! On 2005.04.19 at 09:23:14 -0700, Jean Hoderd wrote next:

I scaled down because I noticed block artifacts in the unscaled version. As a matter of fact, I still notice some blocks even at 640x480. Perhaps I am doing something very wrong with my lavc and xvid options, in which case your help would be appreciated.

Or does scaling down introduce other kind of artifacts?

lavc likes to produce blocking artifacts a lot, it does it even with vqscale 2 on some scenes. There are some options related to masking blocks - haven't tried them, though. It all depends whether you want to watch video with postprocessing (will remove blocks, but some detail will be thrown as well) or not. If this is a first case, use lavc. However, at this bitrate you can encode video that will look better without pp, if you will do the things right. xvid is more suited for this. I generally use these parameters for encoding with xvid: pass=1:bitrate=XXX:min_iquant=1:max_iquant=4:min_pquant=1:max_pquant=6: min_bquant=2:max_bquant=9:me_quality=6:quant_type=mpeg:keyframe_boost=15: trellis:chroma_me:chroma_opt:max_bframes=2:hq_ac:vhq=1:bvhq=1 Don't forget you should always do 2-pass encoding when using xvid, first pass doesn't even takes bitrate into account. for bvhq=1, you need xvid 1.1-beta1 or later. If you use older one, upgrade (it will improve quality) or drop this option. For lavc I use something like this: vcodec=mpeg4:vbitrate=XXX:vqmin=1:lmin=1:v4mv:mbd=2:trell:subcmp=2: cmp=2:precmp=2:mv0:autoaspect:vpass=1:mpeg_quant:psnr:vqcomp=0.7: vqblur=0.3 When you get blocks even on scenes with qscale=2, vqmin=1:lmin=1 can help a lot. Sometimes, they can do wonders. However, if the picture is always good enough with qscale=2, it's better not to use these options. Don't scale to 640x480, crop black borders and colored lines (check it manually! mplayer -vo x11 and xmag are your friends - cropdetect isn't good enough, use it for a start), then downscale to nearest numbers divisible by 16 with bicubic scaler, if needed - the difference won't be noticeable at all, but this can help encoding. Use hqdn3d filter, don't forget to lower the settings, they are way too high for dvds. Something like 3:3:5 for anime and 3:2:4 for real life contents usually is the best. Use postprocessing (pp=ac or spp) if you see blocks on original material, but check if details aren't destroyed after this. But if you haven't solved problem with interlacing/ telecine/ incorrect NTSC to PAL transform/ whatever, do it first, if you will do it incorrectly, it will hurt quality really a lot. I have several PAL discs that apparently were produced of telecined NTSC-version.. they are simply awful. I can't think of any way to get something descent looking of them. Probably something like pp=lb,unsharp=l3x3:1.2:c3x3:1.2 is the best... Don't use if for encoding, though. -- Vladimir