[Csnd-dev] [Csound API] Using csoundListChannels in C#
| Date | 2021-11-05 10:53 |
| From | Giovanni Bedetti |
| Subject | [Csnd-dev] [Csound API] Using csoundListChannels in C# |
Hi all,
this is my first post on this list so forgive me if I'm doing something wrong.
I'm helping Rory to develop and maintain CsoundUnity, which you can find here: https://github.com/rorywalsh/CsoundUnity.
We would like to retrieve the list of the Csound channels using csoundListChannels (https://csound.com/docs/api/group__CONTROLEVENTS.html#ga5fa6839d0f6bae9a3c5a0e82e4d83a5f), but something is wrong with the current implementation, and this causes Unity to crash.
The GetChannelList method C# implementation can be found here:
https://github.com/rorywalsh/CsoundUnity/blob/7600d63988de5d9c810dc0697da9ad52d555afe5/Runtime/CsoundUnityBridge.cs#L682
The ChannelInfoProxy structure, that represents controlChannelInfo_s (https://csound.com/docs/api/structcontrolChannelInfo__s.html), can be found here: https://github.com/rorywalsh/CsoundUnity/blob/7600d63988de5d9c810dc0697da9ad52d555afe5/Runtime/CsoundUnityBridge.cs#L775
The ChannelHintsProxy structure, that represents controlChannelHints_s (https://csound.com/docs/api/structcontrolChannelHints__s.html), can be found here: https://github.com/rorywalsh/CsoundUnity/blob/7600d63988de5d9c810dc0697da9ad52d555afe5/Runtime/CsoundUnityBridge.cs#L788
The crash occurs when Marshalling a channel name, possibly because the size of the whole structure is wrong. The size of the structure is now 68.
The name is Marshalled with this line: string chanName = CharPtr2String(proxy.name);
and the CharPtr2String method is defined as:
internal static String CharPtr2String(IntPtr pString)
{
return ((pString != null) && (pString != IntPtr.Zero)) ? Marshal.PtrToStringAnsi(pString) : string.Empty;
}
Before the crash happens, the address to be Marshalled as a string is something like: 0xa1bc8a7400000000, which looks wrong.
This happens after correctly Marshalling one channel with an empty name (that I assume it's the Cabbage form), from this simple csd:
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| Date | 2021-11-08 11:37 |
| From | Giovanni Bedetti |
| Subject | Re: [Csnd-dev] [Csound API] Using csoundListChannels in C# |
Hi all, just to confirm that this was fixed on the C# side. The
ChannelHintsProxy implementation was missing an attribute to correctly Marshal the attributes char*. I noticed a little issue with audio channels that have names created with sprintf, for example: Sfile sprintf "file_%d", itab ;where itab is 900 chnset ain, Sfile When calling csoundListChannels, this returns an audio channel named "file_900" but also an audio channel named "Sfile". Interestingly, if I multiply the value by something (in this order), an audio channel "Sfile" is not returned: chnset kgain * ain, Sfile Instead this returns a "Sfile" audio channel again: chnset ain * kgain, Sfile This is not a big issue right now, but maybe it's worth having a look. This is the opcode that triggers this behaviour: opcode analyze, 0, iikiiik itab, iupdt, kgain, ilo, ihi, itrsh, klp xin ilen = ftlen(itab) aphs phasor (sr/ilen) kphs = k(aphs) Sprgrs sprintf "progress_%d", itab chnset kphs, Sprgrs ain table aphs, itab, 1 Sfile sprintf "file_%d", itab chnset ain, Sfile iupdte chnget "update" ;number of divisons of an octave. Default is 12 and is limited to 120. ifrqs = 12 ;the number of conformations needed for an octave jump. Default is 10. iconf = 20 ;starting pitch for tracker. Default value is (ilo + ihi)/2. istrt = (ilo + ihi) / 2.0 ilo = octmidinn(ilo) ihi = octmidinn(ihi) istrt = octmidinn(istrt) ain tone ain, klp koct, kamp pitch ain, iupdt, ilo, ihi, itrsh, ifrqs, iconf, istrt krms rms ain Soct sprintf "oct_%d", itab Shz sprintf "hz_%d", itab Samp sprintf "amp_%d", itab Srms sprintf "rms_%d", itab chnset koct, Soct chnset koct, Shz chnset kamp, Samp chnset krms, Srms endop Cheers! Il giorno ven 5 nov 2021 alle ore 10:53 Giovanni Bedetti <giovanni.bedetti@gmail.com> ha scritto: Hi all, |