[Scilab-users] 3 byte integers

[Federico Miyara]

Stéphane,

Sorry for having explained myself so poorly. The problem with the macros 
already available is that in order to save a wavfile in a single 
operation, I need to have the whole signal loaded in a variable. I'm not 
sure whether it is possible to handle a variable with about 2 
gigasamples (the maximum 16 bit mono file that Windows allows --a total 
file size of 4 GB--). This would demand 16 GB just for a single variable.

I'm pretty sure that problems would arise even with an audio variable 
much smaller than that.

This is the reason why I need to be able to append new audio data to an 
existing wave file, so that much less information is handled at a time. 
Of course this requires to edit the header to update the file size after 
the append, but this is quite easy.

The tough part is to save three byte numbers, since the existing mput 
command supports 1, 2, 4 and 8 byte formats, but not the 3 byte used for 
24 bit audio. If there were a native macro or primitive capable of 
formatting numbers as 3 byte, it would be helpful.

Thanks,

Federico Miyara



On 17/12/2019 18:37, Federico Miyara wrote:
>
> Stéphane,
>
> wavewrite also supports 3 bytes, but as I commented, I cannot save, 
> not evem generate huge files, so i must create them by successive 
> appending, so i needto be able to save 3 byte numbers directly.
>
> Thanks anyway.
>
> Regards,
>
> Federico Miyara
>
> On 17/12/2019 17:15, Stéphane Mottelet wrote:
>> Hello
>>
>> I think it is supported in savewave and loadwave. There was a pb with 
>> savewave but fixed by
>>
>> https://codereview.scilab.org/#/c/19947/
>>
>> in 6.0.2
>>
>> S.
>>
>>> Le 17 déc. 2019 à 20:09, Federico Miyara <fmiyara at fceia.unr.edu.ar> 
>>> a écrit :
>>>
>>> 
>>> Dear All,
>>>
>>> While it is possible to create directly a wav file of reasonable 
>>> size from Scilab, if the size is very large, say, 1 Gb,we willmost 
>>> likely have memory problems. That's why I'm trying to program a 
>>> script allowing to append new audio data to an existing wav file.
>>>
>>> It is simple to save 8 bit, 16 bit and 32 bit samples to a file. 
>>> However, 24 bit is also a popular format and Scilab doesn't seem to 
>>> support 3 byte integer format, either for variables and read/write 
>>> file operations.
>>>
>>> Is there some way to save 3 byte integers other than creating a 
>>> specialized routine from scratch?
>>>
>>> Regards,
>>>
>>> Federico Miyara
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