Frequently Asked Questions (FAQ)

1. What is ComeXos?

2. What is CDP?

3. What format of audio file can be processed by CDP?

4. How do I process a stereo sound file when some of the CDP modules only allow mono sound file input?

5. Can CDP process sound files bigger than 1400 KB?

6. I have used CDP before, and I've noticed that the optional parameters for some of the modules provided here are missing. Why?

7. What is the future development of ComeXos?

ComeXos (Composers Experimental Online Suite) is a project within GEMISIS, a European Comission Initiative, to investigate the use of the Internet and which aims to serve and benefit society, mainly in the north-west of England.

ComeXos is a music project aiming to develop an Internet resource in order to investigate the mechanism of sharing musical ideas, applications and works using the net. The goal is to bring mutual benefits to our users, especially those from educational institues as well as our business partner CDP.

[Back] [Top]

CDP (Composers' Desktop Project, a.k.a. Composition Development Performance) was formed in 1987. The intention was to create an organisation through which composers could work together to bring to their own desktops a broad range of computer music facilities, particularly those relating to sound design and electro-acoustic music composition.

The sound manipulation package produced by the CDP team is also called CDP. In ComeXos, a customised version of CDP is being used as a set of examples to introduce CDP to a wider audience. It is also intended to provide a user-friendly interface to make access to this professional package as easy as possible.

[Back] [Top]

CDP can process both WAV and AIFF formats. However, in the customised version here, we have limited the file format to be WAV only. Below is a list of file formats we accept and the corresponding file size per second.

	8-bit 11025 Hz	8-bit 22050 Hz	8-bit 44100 Hz	16-bit 11025 Hz	16-bit 22050 Hz	16-bit 44100 Hz
Mono	11.28 KB	22.56 KB	45.12 KB	22.56 KB	45.12 KB	90.24 KB
Stereo	22.56 KB	45.12 KB	90.24 KB	45.12 KB	90.24 KB	180.46 KB

** An 8-bit, 11025 Hz mono wave file has a size of 11551 bytes; approx. 11.28 KB.

For more general information on sound and audio formats, check out the link here.

[Back] [Top]

In the near future, we will allow both stereo and mono files to be processed by all CDP modules. But for the moment, to process stereo files, you can first convert your original stereo sound file into 2 separate mono sound files, e.g. monoL.wav and monoR.wav, using a utility like CoolEdit. You can then process the individual mono sound files by uploading them to the server one after the other. Once both mono sound files are processed, you can then create a stereo sound file by placing the processed monoL.wav in the left channel and the processed monoR.wav in the right channel.

Please check the page on audio editing tools to find the right utilities to accomplish this task.

[Back] [Top]

Yes! CDP does not limit the file size to be processed but ComeXos does. We limit the sound file to be uploaded to maximum 1400 KB simply because our server has limited space and it is impossible to allow everyone to upload huge files. If we did so, ComeXos would be out of service very quickly.

[Back] [Top]

In order to make the CDP modules provided here as simple to use as possible, and more importantly, as close to fool-proof as possible, some of the optional parameters for individual modules are omitted. However, in future we will implement some tailor-made modules for expert-users if there is a demand for it.

[Back] [Top]

- Allow both stereo and mono files to be processed by all CDP modules provided by ComeXos.

- For the moment, when accessing the CDP section, users are pointed to the resultant wave file after each process is finished. It can be quite inefficient to download a processed wave file only to find out that it is not to the user's liking, so we will also point the user to their resultant file in real-audio format which is a compressed format. This will be done once Real Audio have produced their real audio encoder on the SGI platform (UNIX platform for Silicon Graphics computers).

- Users will be given temporary space per session, so that users can apply sucessive effects on sound files without the need to download then upload the processed file - the server keeping a temporary copy.

- More CDP modules will continue be added to ComeXos. Please keep an eye on this space.

[Back] [Top]