[MEncoder-users] converting and subtitle questions

[Erik Slagter]

RC wrote:
> "Jorge Peixoto de Morais Neto" <please.no.spam.here at gmail.com> wrote:
> 
>> And this is good, because in my experience, H.264 absolutely kicks the
>> butt of MPEG-4 part 2. I was told that the difference was not very
>> big, but they were wrong. The difference is huge.

Agree.

[ ... ]

> In my testing, x264 (encoding DVD with the recomended x264 options) has
> a nasty habit of strongly smoothing and removing lots of detail in
> certain parts of the picture, while at the same time leaving other parts
> of the same frame very noisy.  What's worse, x264 makes odd choices of
> the noise to preserve, which looks completely unlike the original
> (where the noise does a good job helping to mask blockiness), and very
> different from the noise Xvid encodes (which I don't happen to like, but
> is at least non-irritating).  This heavy, seemingly non-random, noise
> actually makes the picture look worse instead of better.
> 
> In addition, many parts of the picture appear to have had their contrast
> lowered, and this makes the video look washed out in areas.  This
> effect is all the worse when contrasted with neighboring extremely noisy
> blocks. All strange effects, that make the lower-bitrate x264 encodes
> actually look better than somewhat higher bitrate versions.  Though,
> then the medium bitrate FMP4 encodes look generally better than either.
> 
> Even if you don't have very good eyes, you should be able to see this
> effect very clearly just by turning up the contrast and saturation.

Also agree.

I exactly recognize the artifacts you mention. But I'd like to add:
  - on a phone you won't see the difference anyway ;-)
  - I assume the artifacts are a result of a suboptimal implementation, 
not per se h264 itself, I am convinced we will see improvement here, 
over time.
  - at least with ffmpeg's mpeg4-2 implementation I never managed to get 
an acceptable picture quality, using bit rates lower than a comparable 
mpeg2 encoding (so what's the point then...)
  - I've noticed that h264's artifacts are far worse on my computer 
monitors (various TFT) than on my television (CRT). Actually I have that 
with mpeg4-2 as well.
  - encoding with the crf option seems to be the wisest choice, but that 
won't impose any vbv requirements the device might impose.

The last video I encoded for my Playstation 3 (also h264+aac in mp4) 
tends to stutter, I am afraid we have a vbv-problem here :-/

Interesting stuff...