What is the level of control in USB HUs?

[DerAlte]

Originally Posted by panky12345

Vebmetal, as far as i know & experienced with CDs, the HU should look only for recognizable music files, process them for a moment (Sony HU) and then start playing. Some of the discs (full Mp3) in my system take longer intervals (more than 30 sec) to play.

This is where "feature" (no, not "future") developers cause havoc for end-users.

The initial read/scan is supposed to build a list of folders (MP3; also list of files in the first folder) or tracks (ACD) that can be immediately displayed, and is supposed to be balanced for scan time and reaction time for "next folder/file/track".

This "Initial read/scan time" is configurable in some HUs. For MP3 CDs with a LOT of files, this is an advantage. The read/scan delay comes once again only when you are going past the last entry of the first scan.

One school of thought is that the complete content tree should be built before allowing further processing, resulting in a looooong wait, excruciatingly slow for DVDs. With this method, the access time is reduced for subsequent directory / file accesses. Bad UI design! If you have many sub-directories & files, GHY.

It also depends on which microcontroller is used - speed directly proportional to unit cost!

Unfortunately publicity of the above information is strategically avoided by manufacturers (geek-speak for normal users), in contrast with the world of cellphones.

[radek]

Originally Posted by panky12345

Vebmetal, as far as i know & experienced with CDs, the HU should look only for recognizable music files, process them for a moment (Sony HU) and then start playing. Some of the discs (full Mp3) in my system take longer intervals (more than 30 sec) to play.

I recently got Blau Hamburg which is USB compatible. When I connected my USB drive that contains lot of other files and MP3 songs, it started playing MP3 songs in no time. There was no processing time, atleast you dont notice any delay.

[rocksterraghu]

The level of control depends on the connected drive/player too.

Some HUs which are iPod ready, can read the metadata (more like indexing, data about data) already generated in the iPod, making it easier to use and enabling faster access. This would also mean that you can search by Artist, Album, Playlist etc.

Some players tend to generate metadata and save it on the same drive (like thumbs.db in your windows, that stores metadata about image files). This procedure may take sometime during the first read, but speeds up the process thereafter (unless you add a lot more files the next time). I read somewhere that some Kenwood USB HUs do it. It starts playing the first track and indexes in the background. There are certain drawbacks, such as maximum number of folders/files accessible by the unit (Yuck! ) and the HU does not necessarily play the tracks in alphabetical order, but in the order in which it is written on the disk (first accessible first). *How boring!*

Flash drives come with the advantage that they don't have boring things like seek time or latency or even fragmentation. Technically, they should be faster than these drives. However, the limitation is size.

[panky12345]

true said raghu, it depends a lot on the connecting driver. my situation is cassette HU attached to 10 Mp3 changer.