Hi Andreas,

Can you say a bit more about the Codec, like: What is the average compression ratio? Does it use a fixed or variable bit rate? How CPU intensive is compression/decompression?

You can choose compression ratio using "quality factor". Now I set the default number as vorbis= 0.0 (you can choose -0.1 to 1.0), speex= 4 (0 to 10). In this condition:

- vorbis 35kbps - speex 19kbps - GSM 36kbps - original data 352kbps (22050 Hz mono: see below)

It uses variable bit rate. I haven't masure CPU factor seriously though, I didn't feel any problem on OLPC B2. I will test it later.

-- test code

src := FMSound majorChord asSampledSound. src duration. "2.0" src samples asByteArray size * 8 / src duration. "352800.0"

gsm _ src compressWith: GSMCodec. gsm channels first size * 8 / src duration. "36432.0" gsm asSound play.

vorbis _ src compressWith: OggVorbisCodec. vorbis channels first size * 8 / src duration. "35252.0" vorbis asSound play.

speex _ src compressWith: OggSpeexCodec. speex channels first size * 8 / src duration. "18952.0" speex asSound play.

Cheers, - Takashi

Hi Bert,

I'll take another look next week, but maybe you could provide something that works cleanly in the latest VM? I started an OLPC branch at

    http://squeakvm.org/svn/squeak/branches/olpc

which contains the latest additions (cursor support, video plugin, etc).

Maybe the most simple way would be just I commit my code to the repository. Only tricky part of the OggPlugin source code was it needs external libraries (libogg, libvorbis, and libspeex). It should be compiled if it was placed properly and Makefile was good. I'll take a look later.

One thing. I'm a little bit vaguely. What was the purpose of this repository? Is it for providing a stable source tree, or experimental space for OLPC? Can I commit directly?

Hi Bert,

I have just uploaded OggVorbis plugin into http://squeakvm.org/svn/squeak/branches/olpc/.

So you can compile it as:

1) Make sure you have installed ogg / vorbis / speex headers (libogg-devel, libvorbis-devel, and speex-devel in rpm) 2) Go sugar-jhbuild directory and type $ ./sugar-jhbuild buildone squeak

For some reason, jhbuild might complain as "configuration changed", but please just choose [1] rerun stage build. Makefile should be recreated again in this case. If you don't have necessary ogg headers (libogg, libvorbos, and speex), OggPlugin would be just ignored.

However, I wanted to show a diagnosis message and stop jhbuild process if you don't have speex.h before starting make, like "This module needs speex package with headers!". Because you might not be aware the new vm won't include OggPlugin. Do you know proper way to some test before make?

Thanks, - Takashi

...

One thing. I'm a little bit vaguely. What was the purpose of this repository? Is it for providing a stable source tree, or experimental space for OLPC?

It's "stable" only in so far as we want to make sure that sugar-jhbuild does not break. Otherwise this is a way to put out stuff without waiting for Ian.

...

Can I commit directly?

Sure, but you need to ask Ian for an account.

• Bert -

Bert,

you need to make sure the VM compiles even without the headers and libraries present. We need to have configure-time checks for all needed headers and libraries, and disable the plugin if those are not present. I see you check for the headers, but not for the libraries. There is an AC_PLUGIN_CHECK_LIB macro for this, see doc/HowToBuildFromSource.txt

OK. I added a couple of AC_CHECK_LIBs because using both AC_TRY_COMPILE and AC_PLUGIN_CHECK_LIB caused an error in disablePlugin.c. This is somewhat ugly though, it seems to work well. I'm completely novice about the syntax of acinclude.m4, so please check it.

The proper way to make sure ogg or speex is installed would be in sugar-jhbuild sanitycheck.

I'll take a look at that.

cheers, - Takashi

On Apr 4, 2007, at 15:28 , Bert Freudenberg wrote:

...

...

The proper way to make sure ogg or speex is installed would be in sugar-jhbuild sanitycheck.

I'll take a look at that.

I discussed this with Marco P. G. on IRC. He had an issue with adding this as a prerequisite for each Sugar developer. To which I replied that IMO every Sugar developer should be able to rely on certain media libraries. Which he found okay for ogg vorbis, but maybe not for speex. Speex already is on the OLPC, but that may be by accident. There is no definitive list of what the platform will support. Worse, there is no such list at all. Maybe a post to Sugar list would be in order ...

Anyway, I published a new Squeak VM RPM. It will install ogg/vorbis/ speex automatically if needed, so we should be fine for now.

- Bert -