Does non-mod16 resolutions create less quality x264 videos???

[Kostarum Rex Persia]

Does it.I heard from one place that if I set mod 8 or mod 4 resolutions in x264 codec,I will get(at the end) less quality x264 video.

Can someone explain this to me. :thanks:

[Sirber]

x264 add black bars to get to mod16, so it's harder in those area.

[Kostarum Rex Persia]

Yes,yes,but I ask for mod 8 or mod 4 resolutions.I never use so far mod 8 oe mod 4,so I akking this because I heard that non-mod16 resolutions crete less quality video.Is it true?

[Sirber]

read my post again...

[akupenguin]

They're not black. x264 replicates edge pixels (i.e. the same padding algorithm as is defined in the standard for motion compensation). But that doesn't change the answer.

[omion]

Internally, x264 will expand the frame to a mod-16 resolution (like aku said) so the codec will see (and compress) this resolution. The result of this is that it will compress about as well as the next higher mod-16 resolution.

This means that you'll be using more bits per (visible) pixel than if you had used the mod-16 version.

I'd call it more of a compressibility loss than a quality loss, as the same settings will get you the same quality between a mod-16 and a non-mod-16 video.

[celtic_druid]

A compressibility loss is a quality loss if you are trying to hit a given bitrate.

[Kostarum Rex Persia]

Ok,thanks guys.If anyone forget to tell something about this......

[hitbit]

Regarding non-mod16 x264 movies, anyone other than me had problems playing these files with ffdshow? (mplayer plays them fine)

[Manao]

if mplayer plays them fine, a recent ffdshow one should to. There were issues with older builds, but it has been fixed in libavcodec, so it should also be fixed in ffdshow

[hitbit]

ffdshow plays them only if a resize to mod16 option (internal to ffdshow) is active. Strange, why this happens only with AVC?