[MEncoder-users] "requested bitrate is too low." in 2-pass x264 encoding

[Stroller]

On 10 Apr 2010, at 17:03, Grozdan wrote:
>> ...
>> Pardon me, I think I was mistaken.
>>
>> I think that MP4Box is supported by my distro (Gentoo), but that  
>> undvd used
>> mpeg4ip or mp4creator, and it is the remuxer that undvd used that was
>> depreciated.
>
> Yeah, undvd uses mp4creator which is officially dead for some time.
> There is a fork of it somewhere, but I don't know much about it. I
> don't know why he chose to use it instead of mp4box, as the latter not
> only is active but also supports much more options than mp4creator

I had some discussions with the author, and he wasn't really  
interested in .mp4.

When I initially used it it outputted only .avi files (IIRC) and these  
play file on mplayer, which the author used and was perfectly happy  
with. But IIRC they were an invalid format due to the audio codec  
used, and wouldn't play on my Mac.

Additionally, I use a PS3 to play back .mp4 files, so I was quite   
happy when he added mp4 support. However with the death of mp4creator  
undvd's author wasn't interested in fixing mp4 support again, which  
made it useless to me.

I compiled a local copy of mp4creator, but it's obviously something I  
don't want to continue supporting - I would rather take on a whole  
wrapper-script project from scratch, than be using an old mp4creator  
and constantly in fear that mplayer would break the old version of  
undvd I would be reliant upon.

> Also, the x264 options in undvd are pretty bad, last time I looked  
> at it.

Would you care to clarify?

ISTM that this is something that can be fixed.

The things I really appreciate about undvd are scandvd (shows length  
of titles, subtitles & audio tracks), coloured output, and it's auto- 
cropping of the  black bars (which is a little clever, I think; I  
think it always ensures the frame size is divisible by 16, or whatever  
is appropriate). Also: that it's simple, and doesn't push too many  
options upon me.

It annoys me that I have to set quality in undvd by choosing a target  
file size (instead of just settings a BPS, which would be more  
useful), and that I must tell it not to rescale the video to a smaller  
frame size. But again, these faults are easily fixed / overcome.

Whatever commands one passes to mplayer / mencoder, I notice that I'm  
not alone in appreciating scandvd (mentioned by Laine Lee in his post  
of 10 April 2010 05:12:52 BST).

> I can probably patch undvd at some point, but if you're willing to do
> it, have a go.

I don't know whether the answer is just to make minor patches or start  
again from the ground up. I have a much better ability to read perl  
now, which I really didn't have at the time mp4creator was removed  
from my distro's repository, so I can perhaps asses this. I do want to  
make the time to do some programming this year, but that may be  
difficult, as I am better at procrastinating.

> I'm not really interested in undvd, though. It's a very
> simplistic tool as an interface, but also a dumb one.

On the other hand, your h264enc just makes me go "WTF!?! all these  
options! what do they do?" With undvd I set it to crop, not to down- 
scale, and I set a target file size, and I would get a rip that was  
almost indistinguishable from the original DVD (and which would play  
on my PS3).

After some experimentation I determined that my optimal file size for  
ripping the 170 minute movie Heat was 2gig, and made target sizes  
relative to this. Clearly it would be better simply to choose a BPS to  
rip to.

Unfortunately, h264enc's presets are little use to me, because they're  
already too complicated for me to choose one in the first place (or  
were, at least, last time I tried it - perhaps 1 year ago).

> It can't handle anything but PAL content, last time I checked.

Interesting, I'm not sure that I checked this. I live in the UK and  
have a mixed collection of PAL & NTSC DVDs, but I have a US PS3 - that  
is region-locked to NTSC playback. My main use for undvd was to rip my  
PAL disks, therefore, so the .mp4 rips could be played on the PS3  
(streamed using MediaTomb). In many ways it would be easier for my  
just to buy a £20 PAL DVD player, but that would be an admission of  
defeat. ;)

> There's a similar
> script called abdvde (on doom9 forum) which is much better than undvd,
> but it only outputs to MKV container (afaik)

Thanks, I'll bear that in mind. It will be some weeks (at least)  
before I have the time to investigate this.

Stroller.