[x264-devel] Re: psp specific code?

[Paul Canavan]

First off....Thanks for the replies.


> The standard way to add options is a field in x264_param_t.



Nice one. Thanks.


>
> > But before you continue, is such a patch even needed anymore? iirc
> > recent PSP firmwares don't have gratuitous format restrictions. I
> > won't accept a workaround for something that Sony has already fixed.



I should have been more specific. I am looking to create 480x272 (i.e.
native res) video streams for playback with PMPMod AVC on the PSP. This is
the encoding / playback method of choice for anyone who uses the PSP for
regular video watching. It's the /only/ thing I use my PSP for. :)
(approximately 80 minutes a day commute time)

The difference compared to 320 x 240 is nothing short of astouding,
especially at high resolutions.

I checked the differences again today. For the first pass, FPS in mencoder
were 140 on average v's 68 in the source tree that I patched. This is with 5
threads v's 3 (above 3 caused stability problems for me before) on a quad
core processor.

2nd pass encodes were also limited to 1 thread. I'm unsure if this is still
the case.


> And even aside from that, did PSP compatibility require any changes
> > to the video stream, or only to the MP4 muxing? If it's just
> > muxing, then having support in x264 won't help, because x264
> > doesn't do audio, so you'll have to remux anyway.



The changes I made were to the video stream. It was some time ago though and
my memory is rusty. I basically took the patch that magick released and
applied it to an svn checkout at the time.


As far as I'm aware, PSP firmwares _used_ to require some specific
> MP4 atom, much like the iPod 640x480 'profile' does now though not as
> deeply hidden away. In current times (and I've had this tested by a
> PSP owner running a recent official firmware) this atom is no longer
> required and the only things needed are resolution, profile, level
> etc restrictions that should all be handled outside of x264.



If there's some way that I can get 480x272 using the standard x264 svn code,
I'm all ears. :)

I did hear talk some time ago that Sony would unlock 480x272 because their
film sales for the PSP were terrible, but with a 2 month old baby, I confess
that I haven't kept track of developments in the PSP world.


Before anyone jumps in to say 'could iPod 640x480 compatibility be
> added?' there's no real need for that either as it's just a case of
> adding the required atom for iTunes to accept the file for
> synchronisation to the iPod. This can be done with other tools
> (Atomic Parsley). Otherwise just stick to the restrictions and the
> file will be fine. You can even not bother with the atom and use some
> third party software to transfer the files if you like. I've been
> told the iPods themselves are less picky than iTunes.
>
> Rob
>
> PS - <shameless website plug> If you want info on the restrictions
> (and how to encode working files from FFmpeg) you can take a look at:
> http://rob.opendot.cl/index.php/useful-stuff/psp-video-guide/ and
> http://rob.opendot.cl/index.php/useful-stuff/ipod-video-guide/ .
> Feedback is welcome. </shameless website plug>



Thanks for the link. I checked it out, but like I said I want full native
res. :) I watch enough video on the PSP to warrant it.

Cheers,

Paul.
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