Topic: Does YEM reference keyboard built-in samples

[hechuan]

YEM can reference the built-in samples of Genos keyboards, can we reference the SX series keyboards, or can we not use YEM to reference the built-in samples of SX series keyboards.
I would like to know what sample format is used when creating packages using YEM, wav 44100 16bit? Do you know about Yamaha's WXC audio data format.

[DerekA]

Only tyros 5 and both genos have the option to use yem with the built in samples. And even then, not all of the samples are available to use

[BogdanH]

YEM accepts 44100Hz 16bit wav samples for stereo (22050Hz 16bit for mono).
I have never heard about WXC audio data format. I think I've seen somewhere WXC chip being mentioned, but it was not in audio format context.

Correction: Replaced kHz with Hz

Bogdan

[hechuan]

YEM accepts 44100kHz 16bit wav samples for stereo (22050kHz 16bit for mono).
I have never heard about WXC audio data format. I think I've seen somewhere WXC chip being mentioned, but it was not in audio format context.

Bogdan

I saw this information from the official package of Yamaha. It seems that Yamaha's package has compressed the samples, but I am not very sure how they are compressed。
  <keybank number="5">
      <noteLimitHi>G8</noteLimitHi>
      <noteLimitLo>G#7</noteLimitLo>
      <velocityLimitHi>127</velocityLimitHi>
      <velocityLimitLo>1</velocityLimitLo>
      <volume>-0.800000</volume>
      <pan>0.000000</pan>
      <centerNote>D7</centerNote>
      <tuneCoarse>0</tuneCoarse>
      <tuneFine>0.000000</tuneFine>
      <tuneLoop>0</tuneLoop>
      <samplingFrequency>32000.000000</samplingFrequency>
      <fixedPitch>OFF</fixedPitch>
      <oneShot>OFF</oneShot>
      <sample position="MONO">
        <waveFilePath>6b5164ee6e433a5733525cc4b18b5ede1ac92a03</waveFilePath>
        <waveType>WXC</waveType>
        <waveStartAddress>1c000</waveStartAddress>
        <sampleSize>352</sampleSize>
        <startPoint>0</startPoint>
        <loopStartPoint>0</loopStartPoint>
        <loopEndPoint>0</loopEndPoint>
        <wavePlacement>ABSOLUTE_ADDRESS</wavePlacement>
        <waveStartFrame>7168</waveStartFrame>
        <startFrame>0</startFrame>
        <loopStartFrame>15</loopStartFrame>
        <loopEndFrame>21</loopEndFrame>
        <lpcCoef>0</lpcCoef>
        <pitchUpLimit>0</pitchUpLimit>
        <beginLoopIndex>0</beginLoopIndex>
        <beginLoopAddress>3</beginLoopAddress>

[BogdanH]

hello hechuan,
It's hard to say what WXC means in this case. For example, if we import wav samples into YEM, then sample header will contain:
<WaveType>LINEAR16</waveType>

Of course we can speculate that WXC means something like "WaveXCompressed". But if codec is not available (or at least file structure specification), then it will remain only a guess.
On the other hand, it can also be some special wav format, similar to rex (which is actually wav, but customized for handling looped samples).

Bogdan

[pjd]

WXC is Yamaha's proprietary waveform compression format. Yamaha have not published the WXC format and it is treated like a trade secret.

Why a trade secret?

The factory waveforms are stored in WXC format within the memory feeding the Yamaha tone generators. The tone generators know how to decompress WXC waveforms on the fly.

If Yamaha published the WXC format, every software pirate on planet Earth would copy the flash ROMs and use Yamaha's waveforms. Yamaha have invested a lot of effort and money on sound development. Those sounds are important to Yamaha's competitiveness. Thus, WXC compression is a security technique as well as a compression technique.

No one outside of Yamaha knows if WXC is an acronym or what the acronym means. I'm with Bogdan -- don't worry about what "WXC" means because you can't use it anyway! 

Hope this explanation helps -- pj

P.S. A related acronym is "UTG" where "U" is the Greek micro and "TG" is "tone generator".

P.P.S. Yamaha will sue pirates. They sued Medeli for stealing Yamaha factory styles.

[hechuan]

So Yamaha does not accept other compression formats, such as Wavpack or other compression formats, right

[BogdanH]

@pj
Thank you for clarifying. I think that maybe also explains how Yamaha manages to put that many voices into relative small memory space.

@hechuan
You're right: YEM only accepts uncompressed wav files.

Bogdan

[overover]

YEM accepts 44100kHz 16bit wav samples for stereo (22050kHz 16bit for mono).
I have never heard about WXC audio data format. I think I've seen somewhere WXC chip being mentioned, but it was not in audio format context.

Bogdan

Just a small correction: the sampling frequency (also called "sampling rate" has nothing to do with "stereo" or "mono". The sample format used by Yamaha is basically "44.1 kHz (= 44100 Hz) sampling frequency / 16-bit resolution / Stereo" (YEM also supports Mono wave files).


Best regards,
Chris

[BogdanH]

Hmmm... maybe it's misunderstanding, but sampling frequency has everything to do with mono or stereo. 44100Hz means 44100 samples for both channels (stereo), which is 22050 samples for each channel. If we only have one channel (mono) then we obviously need only 22050 samples to keep the same quality as before in stereo.

Bogdan

[pjd]

Maybe it's just having to write everything out in English... 

"44,100" is being used in too different ways, here.

A sampling rate is expressed as a frequency: 44,100 Hertz (Hz).

Then, there is the amount of data being moved per second (bytes or words per second). Assume 16-bit samples and a 44,100Hz sampling rate. Mono moves 44,100 samples per second and stereo moves 88,200 samples per second.

herzliche Grüße -- pj 

[BogdanH]

You are right Chris and pj.
For whatever reason (senior moment?) I had transfer rate in mind when I wrote about sampling rate.

I apologize for confusion

Bogdan