Audio Dev. File

1. Try different combinations of including input and output channels and groups. Specify an input file, but not an input group. Specify an input group but not an input file ....

TODO: fix cwDsp.h: ampl_to_db(),db_to_ampl(), add pow_to_db() and db_to_pow(). Implement vectorized version in terms of the scalar versions in cwDsp.h. Decide on standard dB range. e.g. -100 to 0, 0 to 100 ....

• Flow Variables Class ** Attributes

  • type: real,int,string,audio,spectrum,enum

  • flags: attribute flags

    • src: This variable must be connected.
    • multi: This variable may be instantiated multiple times
    • fan_in: This variable allows multiple incoming connections.

  • value:

    • real,int { min,max,value,center,step }
    • enum [ list of (id,label) pairs ]

  • doc: documentation string

  • max_multi: max count of instantiations due to multiple connections

  • min_multi: min count of instantiations due to multiple connections

• Flow Proc Class ** Attributes

  • doc: documentation string
  • sub_proc:

    • sub_proc_cnt: set an absolute sub_proc_cnt

    • sub_proc_cnt_min:

    • sub_proc_cnt_max:

    • sub_proc_var

      • label
      • flags: [ audio_chs, multi_chs, fan_in_chs ]

      Calculate the sub_proc_cnt based on the count of mult's,fan_ins, and audio channels.

• Var Map:

#+BEGIN_SRC c typedef struct variable_str {

variable_str* var_link; // instance_t varL links 

} variable_t;

typedef struct proc_desc { var_desc_t* varDescA; // description of each base variable unsigned varDescN;

} proc_desc_t;

typedef struct varBase_str { char* label; // label assigned to this 'mult' unsigned multIdx; // mult index variable_t* baseVar; // all variables have a base instance (chIdx=kAnyChIdx) unsigned subProcN; // count of times this variable is replicated to specialize for a given subprocess variable_t* subProcA[ subProcN ]; // } varBase_t;

typedef struct varMap_str { unsigned multN; // count of times this variable is replicated based on multiple incoming connections to the same input variable label. varBase_t* multA[ multN ] // pointer to each base variable } varMap_t;

typedef struct instance_str { variable_t* varL; // variable linked list: list of all variable instances unsigned maxVId; // maximum application supplied vid. In general maxVId+1 == proc_desc_t.varDescN varMap_t varMap[ maxVId ]; // maps an application vid to a list of variable instances } instance_t;

#+END_SRC

• Plan

** Flow processor 'multi' processor: Add the ability for a processor to expand the number of variables based on incoming connections.

• Variables with this capability must have the 'multi' attribute in the class description.
• The new variables will be named by adding a suffix in the connection command. e.g. in:{ in.a:out.foo } connect the output out.foo to a new variable instantiated on the the local variable description 'in'.
• The new variable may then be addressed by referring to 'in.a'.
• The proc instance may then ask for a count of variable instances for a given base varaible. var_get_multi_count( ...,'in') and address them by var_get( ...,'in',multi_idx).
• Note that once a variable is given the 'multi' attribute the only way for the instance to access the variable is by supplying the 'multi' index since the variable label alone will not be adequate to select among multiple instances.

** Flow processor Fan-in capability: Add the ability for a processor variables to support multiple incoming connections.

• Fan-in capability must be enabled in the processor class description with the 'fan-in' attribute.
• The array of variables associated with fan-in connections will be addressed via ".".
• The count of inputs to a fan-in varaible instance can be accessed via: var_fan_in_count( ...,var_label)
• The variable instance associated with each fan-in connection can be accessed with var_get( ...,'in',fan_in_idx).
• Note that once a variable is given the 'fan-in' attribute a fan_in_idx must be used to access it.

** Add MIDI processors - this may be complicated by cross fading scheme.

• maybe cross-faded proc's should be all placed in a 'sub-net' and only those processes would then be cross faded.

** Add subnets. (see outline below) ** Add auto-UI (this will require a separate app).

• Functionality ** libcw:

• Remove dependency on locally built websockets library.

• Remove applications from the libcw folder and put them in their own folders. (breakout libcw from application / reorganize project) Allow ui.js to be shared by all apps.

** UI:

• Add support for custom controls
• Document the UI resource file format.
• Document the UI client/server protocol.

1. The message formats to and from the server and the javascript client.
2. When the messages are sent.

• UI: Add an option to print the UI elment information as they are created. This is a useful way to see if id maps are working. Print: ele name, uuid, appId and parent name, uuid, appId

** Flow:

• Create automatic UI for proc's.
• Create the ability to script sub-networks.
• Create true plug-in architecture - requires a C only interface.
• Add a callback function to inform the app when a variable changes. The same callback could be used to map variable labels to id's at startup. This callback may be a key part of adding an automatic UI.
• Simplify the coding of processors by having the system call the instance for each variable. This will make createing most processors a matter of responding to simple requests from the system. More complex processors could still be created using the current technique of calling explicit functions (e.g. register_and_get(), register_and_set())

*** Subnet scheme:

{
    balanced_mix: {

	doc: "This is a two channel balancer network.",

    network: {
		ain:    { class: port, source:merge.in0, doc:"Audio input."},
		ain_alt:{ class: port, source.merge.in1, doc:"Alternate audio input."},
		bal_in  { class: port, type: real,       doc:"Mix balance control." },
				    
		bal:    { class: balance,     in:{ in:bal_in.out } },	    
		merge:  { class: audio_merge, in:{ in.0:ain, in.1:ain_alt } }
		gain:   { class: audio_gain   in:{ in:merge.out, gain:bal.out } },
	    
		aout:   { class: port, type: audio, in:{ gain.out } }
	  }
    } 
}

• Create a class description by parsing the subnet and converting the 'port' instances into a variable definitions.

• Port instances are just proc's that have a single variable but do not implement any of the processing functions. The variables act as 'pass-through' variables that connect variables outside the subnet to variables inside the subnet.

• The subnet itself will be held inside an 'instance_t' and will pass on 'exec()' calls to the internal instance processor chain.

• The current flow architecture only allows static connections. This allows proc variables to be proxied to other proc variables. This doesn't scale well for processes with many variables (e.g. matrix mixer). For processes with many variables a message passing scheme works better because it allows a message to dynamically address a process (e.g. (set-in-channel-1-gain-to-42) 'set','in',1,'gain',42), 'set','out',4,'delay',15)

Note that it would be easy to form these messages on the stack and transmit them to connected processes.

• To do list:

** libcw

• Fix the time functions to make them more convenient and C++ish.
• libcw: document basic functionality: flow, UI, Audio

** Flow

• Implement MIDI processors.

• Implement flow procs for all libcm processsors.

• Create default system wide sample rate.

• Allow gain to be set on any audio input or output.

• flow metering object with resetable clip indicator and audio I/O meters

• indicate drop-outs that are detected from the audio IO system

• allow a pre/post network before and after cross fader

• allow modifiable FFT window and hop length as part of preset

• add selectable audio output file object to easily test for out of time problems

• Add attributes to proc variables:

  1. 'init' this variable is only used to initialize the proc. It cannot be changed during runtime. (e.g. audio_split.map)
  2. 'scalar' this variable may only be a scalar. It can never be placed in a list. (e.g. sine_tone.chCnt)
  3. 'multi' this src variable can be repeated and it's label is always suffixed with an integer.
  4. 'src' this variable must be connected to a source.
  5. 'min','max' for numeric variables.
  6. 'channelize' The proc should instantiate one internal process for each input channel. (e.g. spec_dist )

• Create a var args version of 'var_get()' in cwFlowTypes.h.

• add attribute list to instances: [ init_only, scalar_only, print="print values", ui ]

• why are multiple records given in the 'args:{}' attribute?

** UI:

• Notes on UI id's:

1. The appId, when set via an enum, is primarily for identifying a UI element in a callback switch statement. There is no requirement that they be unique - although it may be useful that they are guaranteed to be unique or warned when they are not. Their primary use is to identify a UI element or class of UI elements in a callback switch statement. Note that the callback also contains the uuId of the element which can then be used to send information back, or change the state of, the specific element which generated the callback. In this case there is never a need to do a appId->uuId lookup because the callback contains both items.

2. UUid's are the preferred way to interact from the app to the UI because they are unique and the fastest way to lookup the object that represents the element.

3. The 'blob' is useful for storing application information that is associated with an UI element. Using the 'blob' can avoid having to maintain a data structure which parallels the internal UI data structure for application related data. The 'blob' can be accessed efficiently via the uuId.

4. The most labor intensive GUI related accesses are changing the state of a UI element outside of a callback from that GUI element. In this case it may be advantageous to store UUID's of elements which affect one anothers state within each others blobs. Alternatively use uiElementChildCout() and uiElementChildIndexToUuid() or uiElementChildAppIdToUuid() to iterate child elements given a parent element uuid.

• Fix crash when '=' is used as a pair separator rather than ':'. cwUi is not noticing when a UI resource file fails to parse correctly. This may be a problem in cwObject or in cwUI.

• Fix bug where leaving out the ending bracket for the first 'row' div in ui.cfg causes the next row to be included in the first row, and no error to be generated, even though the resource object is invalid (i.e. there is a missing brace).

• The UI needs to be better documented. Start by giving clear names to the various parts: Browser, UI Manager, UI Server, Application. Maybe describe in Model,View,Controller terms?

• Document the meaning and way that id's and names/labels are used, and intended to be used, and found by UI. As it is they are confusing.

• The UI app id map should be validated after the UI is created. In otherwords the parent/child pairs shoud actually exists.

• Arrange the project layout so that all the UI based apps use the same ui.js. Currently changes and improvements to one version of ui.js cannot be automatically shared.

• uiSetValue() should be optionally reflected back to the app with kValueOpId messages. This way all value change messages could be handled from one place no matter if the value changes originate on the GUI or from the app.

• The ui manageer should buffer the current valid value of a given control so that the value can be accessed synchronously. This would prevent the application from having to explicitely store all UI values and handle all the 'value' and 'echo' request. It would support a model where the UI values get changed and then read by the app (e.g. getUiValue( appId, valueRef)) just prior to being used. As it is the UI values that are on the interface cannot be accessed synchronously instead the app is forced to notice all 'value' changes and store the last legal value. (12/22: Given that the cwUi.cpp _transmitTree() function appears to the current value of each control to new remote WS Sessions - the value may actually already be available. Examine how this works. Is 'value' and 'attribute' like 'order'?)

• Using the 'blob' functionality should be the default way for tying UI elements to program model. Rewrite the UI test case to reflect this.

• Add an ui::appIdToUuId() that returns the first matching appId, and then optionally looks for duplicates as an error checking scheme.

• The ui eleA[] data structure should be changed to a tree because the current expandable array allows empty slots which need to be checked for whenever the list is iterated. It is also very inefficient to delete from the eleA[] because an exhaustive search is required to find all the children of the element to be deleted.

• UI needs a special UUID (not kInvalidId) to specify the 'root' UI element. See note in cwUi._createFromObj()

** Audio:

• Should a warning be issued by audioBuf functions which return a set of values: muteFlags(),toneFlags(), gain( ... gainA) but where the size of the dest array does not match the actual number of channesl?

• cwAudioBuf.cpp - the ch->fn in update() does not have the correct memory fence.

• Replace 24 bit read/write in cwAudioFile.cpp

• Remove Audio file operations that have been superceded by 'flow' framework.

** Socket

• Any socket function which takes a IP/port address should have a version which also takes a sockaddr_in*.

** Websocket

• cwWebsock is allocating memory on send().
• cwWebsock: if the size of the recv and xmt buffer, as passed form the protocolArray[], is too small send() will fail without an error message. This is easy to reproduce by simply decreasing the size of the buffers in the protocol array.

Object

• Look at 'BUG' warnings in cwNumericConvert.h.

• cwObject must be able to parse without dynamic memory allocation into a fixed buffer

• cwObject must be able to be composed without dynamic memory allocation or from a fixed buffer.

• Clean up the cwObject namespace - add an 'object' namespace inside 'cw'

• Add underscore to the member variables of object_t.

• numeric_convert() in cwNumericConvert.h could be made more efficient using type_traits.

• numeric_convert() d_min is NOT zero, it's smallest positive number, this fails when src == 0. min value is now set to zero.

• Change file names to match object names

• Improve performance of load parser. Try parsing a big JSON file and notice how poorly it performs.

** Misc

• logDefaultFormatter() in cwLog.cpp uses stack allocated memory in a way that could easily be exploited.

• lexIntMatcher() in cwLex.cpp doesn't handle 'e' notation correctly. See note in code.

• thread needs setters and getters for internal variables

• change cwMpScNbQueue so that it does not require 'new'.

• (DONE) change all NULL's to nullptr

• (DONE) implement kTcpFl in cwTcpSocket.cpp

** Documentation

*** UI Control Creation Protocol

The UI elements have four identifiers:

uuId - An integer which is unique among all identifiers for a given cwUi object. appId - A constant (enumerated) id assigned by the application. Unique among siblings. jsId - A string id used by Javascript to identify a control. Unique among siblings. jsUuId - An integer which is unique among all identifers for the browser representation of a given cwUi object.

The 'jsId' is selected by the application when the object is created. The 'jsUuId' is generated by the JS client when the UI element is created. The 'uuId' is generated by the UI server when the JS client registers the control. The 'appId' is assigned by the UI server when the JS client regsiters the control.

Client sends 'init' message. Server sends 'create' messages. Client sends 'register' messages. Server send' 'id_assign' messages.

*** sockaddr_in reference

#include <netinet/in.h>

struct sockaddr_in {
    short            sin_family;   // e.g. AF_INET
    unsigned short   sin_port;     // e.g. htons(3490)
    struct in_addr   sin_addr;     // see struct in_addr, below
    char             sin_zero[8];  // zero this if you want to
};

struct in_addr { unsigned long s_addr; // load with inet_aton() };

*** Development Setup

  sudo dnf install g++ fftw-devel alsa-lib-devel libubsan

1. Install libwebsockets.

    sudo dnf install openssl-devel cmake
    cd sdk
    git clone https://libwebsockets.org/repo/libwebsockets
    cd libwebsockets
    mkdir build
    cd build
    cmake -DCMAKE_INSTALL_PREFIX:PATH=/home/kevin/sdk/libwebsockets/build/out ..

2. Environment setup:

   export LD_LIBRARY_PATH=~/sdk/libwebsockets/build/out/lib

Raspberry Pi Build Notes:

cd sdk
mkdir libwebsockets
cmake -DCMAKE_INSTALL_PREFIX:PATH=/home/pi/sdk/libwebsockets/build/out -DLWS_WITH_SSL=OFF ..
make
sudo make install

apt install libasound2-dev

Flow Notes:

• When a variable has a variant with a numeric channel should the 'all' channel variant be removed?

• Check for duplicate 'vid'-'chIdx' pairs in var_regster(). (The concatenation of 'vid' and 'chIdx' should be unique

• When a proc. goes into exec state there should be a guarantee that all registered variables can be successfully read. No error checking should be required.

(How about source variables? these can never be written.)

• Make an example of a repeating input port. For example a mixer than takes audio input from multiple processors.

• Make an example of a proc that has a generic port which allows any type, or a collection of specific types, to pass through. For example a 'selector' (n inputs, 1 output) or a router (1 signal to n outputs)

• Create a master cross-fader.

DONE: Add a version of var_register() that both registers and returns the value of the variable.

Flow Instance Creation:

0. Parse the 'in' list and create any 'mult' variables whose 'in-var' contains an integer or underscore suffix. See "'in' List Syntax and Semantics" below.

1. Create all vars from the class description, that were not already instantiated during 'in' list processing, and set their initial value to the default value given in the class. chIdx=kAnyChIdx.

Notes:

• All vars must be included in the class description.
• All vars have a 'kAnyChIdx' instantiation. The kAnyChIdx variable serves two purposes:
  • Setting the value of kAnyChIdx automatically broadcasts the value to all other channels.
  • kAnyChIdx acts as a template when variables are created by 'channelization'. This allows the network designer to set the value of the kAnyIdx variable and have that become the default value for all subsequent variables which are created without an explicit value. (Note that his currently works for variables created from within proc_create() (i.e. where sfx_id == kBaseSfxId, but it doesn't work for mult variables that are automatically created via var_register() because var_register() does not have a value to assign to the kAnyChIdx instance. In this case the variable get assigned the class default value. The way around this is to explicitely set the mult variable value in the 'in' stmt or the 'args' stmt.)

2. Apply the preset records from the class description according to the 'presets' list given in the instance definition.

If the variable values are given as a scalar then the existing variable is simply given a new value.

If the variable values are given as a list then new variables records will be created with explicit channels based on the index of the value in the list. This is referred to as 'channelizing' the variable because the variable will then be represented by multiple physical variable records - one for each channel. This means that all variables will have their initial record, with the chIdx set to 'any', and then they may also have further variable records for each explicit channel number. The complete list of channelized variable record is kept, in channel order, using the 'ch_link' links with the base of the list on the 'any' record.

3. Apply the variable values defined in a instance 'args' record.

The application of the args record proceeds exactly the same as applying a 'class' preset. If the variable value is presented in a list then the value is assigned to a specific channel. If the channel already exists then the value is simply replaced. If the channel does not exist then the variable is 'channelized'.

4. The varaibles listed in the 'in' list of the instance cfg. are connected to their source variables.

5. The custom class constructor is run for the instance.

Within the custom class constructor the variables to be used by the instance are 'registered' via var_register(). Registering a variable allows the variable to be assigned a constant id with which the instance can access the variable very efficiently.

If the channel associated with the registered variable does not yet exist for the variable then a channelized variable is first created before registering the variable.

6. The internal variable id map is created to implement fast access to registered variables.

Notes on 'poly' and 'mult':

The 'in' statement is formed by a list of Connect Expressions :

<input_var>:<source_inst.source_var>

There are three forms of connect expressions:

1. Simple Connect Expression: Both the input and source labels identify vars in the input and source instance.

2. Manual Mult Connect Expression: The input identifer ends with an integer. This expression indicates that an input var will be instantiated and connected to the source var. The integer indicates the suffix (sfx) id of the input var. e.g. in0:osc.out,in1:filt.out.

3. PolyMult Connect Expression: The source identifier has an underscore suffix. This form indicates that there will one instance of this var for each poly instance that the source var instances is contained by. e.g. in:osc_.out If osc is contained by an order 3 poly then statement will create and connect three instances of in - in0:osc0.out,in1:osc1.out and in2:osc2.out.

Notes:

• For an input variable to be used in either of the 'Manual' or 'PolyMult' forms the var class desc must have the 'mult' attribute.

• If any var has an integer suffix then this is converted to it's sfx id.

• If the input var of a poly mult expression has an integer suffix then this is taken to be the base sfx id for that poly connection. Other connections in the same statement will be incremented from that base value. e.g in3:osc_.out becomes in3:osc0.out,in4:osc1.out and in5:osc2.out.

• The first and last poly source instance can be indicated by specifying a begin poly index and count before and after the source index underscore: e.g. in:osc3_3.out becomes: in0:osc3.out,in1:osc4.out and in2:osc5.out.

• A similar scheme can be used to indicate particular source instance vars: in:osc.out1_2 becomes in0:osc.out1,in1:osc.out2

• It is a compile time error to have more than one input variable with the same sfx id.

'in' List Syntax and Semantics:

Syntax:

The 'in' list has the follow syntax: in: { in-stmt* } in-stmt -> in_expr":" src_expr in-expr -> in-proc-id".in-var-id src-expr -> src-proc-id"."src-var-id in-var-id -> var-id src-proc-id -> var-id src-var-id -> var-id var-id -> label { label-sfx } label-sfx -> { pri-int} {{"_"} sec-int } pri-int -> int sec-int -> int

Semantics:

in-proc-id

• The in-proc-id is only used when the in-stmt is iterating over the in-proc sfx-id. This precludes iterating over the in-var, as discussed below.

In this case the only useful option is to set the 'var-idto_` as the in-proc is taken as the the proc which the in-stmt belongs to.

The iterating source and/or var sfx-id are then set to the current proc sfx-id + source pri-int.

in-var-id

• The label part of the in-var-id must match to a var description in the input proc class description.

• If no label-sfx is given then no special action need by taken at var creation time. This var will be created by default and later connected to the source inst/var.

• (0) If the "_" is given:

  • This is an "iterating" in-stmt where multiple input vars will be created and connected.

  • If no pri-int is given then the pri-int defaults to 0.

  • If the pri-int is given then it indicates that an instance of this var should be created where the pri-int becomes the sfx-id of the var instance.

  • If sec-int is given then it gives the count of input vars which will be created. The sfx-id of each new input var begins with pri-int and increments for each new var.

  • (1) If no sec-int is given then the sec-int is implied by the count of source variables indicated in the src-expr.

• If "_" is not given:

  • No sec-int can exist without a "_".

  • If a pri-int is given then a single input var is created and the pri-int gives the sfx-id. This single input var is then connected to a single src var.

  • If no pri-int is given then the default var is created with kBaseSfxId and is connected to a single source var.

src-proc-id

• The label part of the src-proc-id must match to a previously created proc instance in the current network.

• If a label-sfx is given then the pri-int gives the sfx-id of the first proc inst to connect to. If no pri-int is given then the first sfx-id defaults to 0.

• If "_" is given:

  • This is an "iterating" src-proc and therefore the in-var must also be iterating. See (0)

  • If a sec-int is given then this gives the count of connections across multiple proc instances with sfx-id's beginnign with pri-int. Note that if sec-int is given then the in-var-id must be iterating and NOT specify an iteration count, as in (1) above.

  • If no sec-int is given then the sec-int defaults to the count of available proc instances with the given label following the source proc inst pri-int.

• If "_" is not given then this is not an iterating proc inst.

  • If the input var is iterating then it must specify the iteration count or the src-var-id must be iterating.

  • If the pri-int is given then it specifies the sfx-id of the src-proc

  • If the pri-int is not given

    • If the src-net is the same as the in-var net then the sfx-id of the in-var proc is used as the src-proc sfx-id

src-var-id

• The label part of the in-var-id must match to a var description in the source proc class descriptions.

• If a label-sfx is given then the pri-int gives the sfx-id of the first source var to connect to on the source proc instance. If no pri-int is given then the first sfx-id defaults to 0.

• If a "_" is given:

  • This is an "iterating" source var and therefore the input var must specifiy an iterating connection and the source proc inst must not specify an iterating connection. See (0) above.

  • If a sec-int is given then this gives the count of connections across multiple source vars with sfx-id's beginnign with pri-int. Note that if sec-int is given then the in-var-id must be iterating and NOT specify an iteration count, as in (1) above.

  • If sec-int is not given then the sec-int defaults to the count of available source vars with the given label following the source var pri-int.

• If "_" is not given then this is not an iterating source var. If the input var is iterating then it must specify the iteration count or the src-proc-id must be iterating.

Notes:

• If the in-var-id is iterating but neither src-proc-id or src-var-id are iterating then the in-var-id must specify the iteration count and the connection will be made to exactly one source var on the source proc inst.

• If in-var-id is iterating then the iterations count must come from exactly one place:

  • the input var sec-int
  • the source proc sec-int
  • the source var sec-int

This means that only one literal iter count can be given per in-stmt. It is a syntax error if more than one literal iter counts are given.

• Use cases
  • connect one input to one source
  • connect multiple inputs to the same var on multiple procs
  • connect multiple inputs to multiple vars on one proc
  • connect multiple inputs to one var on one proc

in-stmt Examples:

in:sproc.svar Connect the local variable in to the source variable sproc.svar.

in0:sproc.svar Create variables in0 and connect to sproc.svar.

in_2:sproc.svar Create variables in0 and in1 and connect both new variables to sproc.svar.

in_:sproc.svar0_2 Create variables in0 and in1 and connect them to sproc.svar0 and sproc.svar1.

in3_3:sproc.svar Create variables in3,in4 and in5 and connect them all to sproc.svar.

in_:sproc.svar1_2 Create variables in0,in1 and connect them to sproc.svar1 and sproc.svar2.

in1_2:sproc.svar3_ Create variables in1,in2 and connect them to sproc.svar3 and sproc.svar4.

in_:sproc.svar_ Create vars in0 ... n-1 where n is count of vars on sproc with the label svar. n is called the 'mult-count' of svar. The new variables in0 ... n-1 are also connected to sproc.svar0 ... n-1.

in_:sproc_.svar Create vars in0 ... n where n is determineed by the count of procs named sproc. n is called the 'poly-count' of sproc. The new variables in0 ... n-1 are also connected to sproc.svar0 ... n-1

If an underscore precedes the in-var then this implies that the connection is being made from a poly context.

foo : { ... in:{ _.in:sproc.svar_ } ... } This example shows an excerpt from the network definition of proc foo which is assumed to be a poly proc (there are multiple procs named 'foo' in this network). This connection iterates across the procs foo:0 ... foo:n-1 connecting the the local variable 'in' to sproc.svar0 ... n-1. Where n is the poly count of foo.

foo : { ... in:{ 1_3.in:sproc.svar_ } ... } Connect foo:1-in:0 to sproc:svar0 and foo:2-in:0 to sproc:svar1.

foo : { ... in:{ 1_3.in:sproc_.svar } ... } Connect foo:1-in:0 to sproc0:svar0 and foo:2-in:0 to sproc1:svar.

in-stmt Anti-Examples

in_:sproc_.svar_ This is illegal because there is no way to determine how many in variables should be created.

in:sproc.svar_ This is illegal because it suggests that multiple sources should be connected to a single input variable.

in:sproc_.svar This is illegal because it suggests that multiple sources should be connected to a single input variable.

_.in_:sproc.svar This is illegal because it suggests simultaneously iterating across both the local proc and var. This would be possible if there was a way to separate how the two separate iterations should be distributed to the source. To make this legal would require an additional special character to show how to apply the poly iteration and/or var iteration to the source. (e.g. _.in_:sproc*.svar_)

out-stmt Examples:

out:iproc.ivar Connect the local source variable out to the input variable iproc:ivar.

out:iproc.ivar_ Connect the local source variable out to the input variables iproc:ivar0 and iproc:ivar1.

out_:iproc.ivar_ Connect the local souce variables out0 ... out n-1 to the input variables iproc:ivar0 ... iproc:ivar n-1 where n is the mult count of the out.

out_:iproc_.ivar Connect the local souce variables out0 ... out n-1 to the input variables iproc0:ivar ... iproc n-1:ivar where n is the mult count of the out.

_.out:iproc.ivar_ Connect the local source variables foo0:out, foo n-1:out to the input variables iproc:ivar0, iproc:ivar n-1. where n is the poly count of foo.

Var Updates and Preset Application

Variable addresses are formed from the following parameters: (<proc_label><proc_label_sfx_id>)*,var_label,var_label_sfx_id, ch_idx

In the cases of poly procs (procs with public internal networks) it may not always be possible to know the <proc_label_sfx_id> without asking for it at runtime. For example for the cross-fader control the application must ask for the <proc_label_sfx_id> current or next poly channel depending on which one it is targetting.

It is notable that any proc with an internal network has to solve this problem. The problem is especially acute for proc's which change the 'current' poly channel at runtime.

The alternative is to include the concept of special values in the address (e.g. kInvalidIdx means the application isn't sure and the network should decide how to resolve the address) The problem with this is that the information to make that decision may require more information than just a simple 'special value' can encode. It also means complicating the var set/get pipeline with 'escape' routines.

There are at least two known use cases which need to address this issue:

1. The cross-fader: The application may wish to address updates to the current or next poly channel but this channel can't be determined until runtime.

• The application asks for the current or next proc_label_sfx_id at runtime depending on what its interested in doing, and sets the update address accordingly.

• Two interface objects are setup as sources for the xfade_ctl object. The address of each of these objects can be determined prior to runtime. The application then simply addresses the object corresponding to method (direct vs deferred) it requires. This solution is particularly appealing because it means that presets may be completely resolved to their potential target procs (there would be up to 'poly-count' potential targets) prior to runtime.

  As it stands now the problem with this approach is that it does not allow for the message to be resolved to its final destination. If the message is addressed to a proxy proc then that proxy must mimic all the vars on the object which it is providing an interface for. (This is actually possible and may be a viable solution???)

  One solution to this is to create a data type which is an address/value packet. The packet would then be directed to a router which would in turn use the value to forward the packet to the next destination. Each router that the packet passed through would strip off a value and pass along the message. This is sensible since the 'value' associated with a router is in fact another address.

2. The polyphonic sampler:

• How can voices be addressed once they are started?

  • A given note is started - how do we later address that note to turn it off? Answer: MIDI pitch and channel - only one note may be sounding on a given MIDI pitch and channel at any one time.

    • Extending ths idea to the xfader: There are two channels: current and deferred, but which are redirected to point to 2 of the 3 physical channels .... this would require the idea of 'redirected' networks, i.e. networks whose proc lists were really pointers to the physical procs.

      • sd_poly maintains the physical networks as it is currently implemnted.

      • xfade_ctl maintains the redirected networks - requests for proc/var addresses on the redirected networks will naturally resolve to physical networks.

      • Required modifications:

        • variable getters and setters must use a variable args scheme specify the var address: (proc-name,proc-sfx-id)*, var-name,var-sfx-id Example: xfad_ctl,0,pva,1,wnd_len,0,0 - The first 0 is known because there is only one xfad_ctl. - The 1 indicates the 'deferred' channel. - The second 0 is known because there is only one wnd_len per pva. - The third 0 indicates the channel index of the var.

        • the address resolver must then recognize how to follow internal networks

        • Networks must be maintained as lists of pointers to procs rather than a linked list of physical pointers.

        • xfade_ctl must be instantiated after sd_poly and be able to access the internal network built by sd_poly.

Generalizing the Addressing

Change the set/get interface to include a list of (proc-label,proc-sfx-id) to determine the address of the var.

Note that this still requires knowing the final address in advance. In general a router will not know how to resolve a msg to the next destination without having a final address. In otherwords setting 'proc-sfx-id' to kInvalidId is not resolvable without more information.

TODO:

• Add a 'doc' string-list to the class desc.

• When a var value is given to var_create() it does not appear to channelize the var if value is a list. Is a value ever given directly to var_create()? Look at all the places var_create() is called can the value arg. be removed?

• var_channelize() should never be called at runtime.

• DONE: Remove preset_label and type_src_label from _var_channelize() and report error locations from the point of call.

• Re-write the currawong circuit with caw.

• DONE: Move proc_dict.cfg to libcw directory.

• DONE: The proc inst 'args' should be able to create mult variables. The only way to instantiate new mult variables now is via the 'in' stmt.

• DONE: The audio_merge implementaiton is wrong. It should mimic audio_mix where all igain coeff's are instantiated even if they are not referenced.

• Finish audio feedback example - this will probably involve writing an audio_silence class.

• Issue a warning if memory is allocated during runtime.

• String assignment is allocating memory: See: rc_t _val_set( value_t* val, const char* v ) cwFlowTypes.cpp line:464.

• DONE: Add the caw examples to the test suite.

• Check for illegal variable names in class descriptions. (no periods, trailing digits, or trailing underscores)

• Check for unknown fields where the syntax clearly specifies only certain options via the 'readv()' method.

• Verify that all variables have been registered (have valid 'vid's) during post instantiation validation. (this is apparently not currently happening)

• How is the number of channels for a given variable determined? Is it the widest (max channel) preset that is encountered during preset compilation? What if a variable has a wide preset but it is not initially applied - does that mean an uninitialized channel is just sitting there? (... no i think the previous channel is duplicated in var_channelize())

• Class presets cannot address 'mult' variables. Maybe this is ok since 'mult' variables are generally connected to a source? ... although 'gain' mult variables are not necessarily connected to a source see: audio_split or audio_mix. Has this problem been addressed by allowing mult variables to be instantiated in the 'args' statement?

• Documentation w/ examples.

  • Write the rules for each implementing member function.

• value() should return a special return-code value to indicate that the value should not be updated and distinguish it from an error code - which should stop the system.

• flow classes and variable should have a consistent naming style: camelCase or snake_case.

• Variable attributes should be meaningful. e.g. src,src_opt,mult,init, .... Should we check for 'src' or 'mult' attribute on var's? (In other words: Enforce var attributes.)

• How much of the proc initialization implementation can use the preset compile/apply code?

• Reduce runtime overhead for var get/set operations.

• Implement matrix types.

• Should the object_t be used in place of value_t?

• Allow min/max limits on numeric variables.

• log:

  • should print the values for all channels - right now it is only printing the values for kAnyChIdx
  • log should print values for abuf (mean,max), fbuf (mean,max) mag, mbuf

• Audio inputs should be able to be initialized with a channel count and srate without actually connecting an input. This will allow feedback connections to be attached to them at a later stage of the network instantiation.

• Implement subnet preset application.

• Implement the var attributes and attribute checking.

• Port 'cm' and 'hum' processors.

• Implement Linux audio plugins loading

• Implement dynamic loading of procs.

• Implement a debug mode to aid in building networks and subnets (or is logging good enough)

• Implement multi-field messages.

• Implement user defined data types.

• Look more closely at the way of identify an in-stmt src-net or a out-stmt in-net. It's not clear there is a difference between specifying _ and the default behaviour. Is there a way to tell it to search the entire network from the root? Isn't that what '_' is supposed to do?

Host Environments:

• CLI, no GUI, no I/O, non-real-time only.
• CLI, no GUI, w/ I/O and real-time
• GUI, with configurable control panels

Done

• DONE: Remove the multiple 'args' thing and and 'argsLabel'. 'args' should be a simple set of arg's.

• DONE: Compile presets: at load time the presets should be resolved to the proc and vars to which they will be assigned.

• DONE: (We are not removing the kAnyChIdx) Should the var's with multiple channels remove the 'kAnyChIdx'? This may be a good idea because 'kAnyChIdx' will in general not be used if a var has been channelized - and yet it is possible for another var to connect to it as a source ... which doesn't provoke an error but would almost certainly not do what the user expects. Note that the kAnyChIdx provides an easy way to set all of the channels of a variable to the same value.

• DONE: verifiy that all proc variables values have a valid type - (i.e. (type & typeMask) != 0) when the proc instance create is complete. This checks that both the type is assigned and a valid value has been assigned - since the type is assigned the first time a value is set.

• DONE: 'poly' should be implemented as a proc-inst with an internal network - but the elements of the network should be visible outside of it.

• DONE: 'sub' should be implemented as proc-inst with an internal network, but the elements of the network should not be visible outside of it. Instead it should include the idea of input and output ports which act as proxies to the physical ports of the internal elements.

• DONE: 'poly' and 'sub' should be arbitrarily nestable.

• DONE: Allow multiple types on an input. For example 'adder' should have a single input which can by any numeric type.

• DONE: Make a standard way to turn on output printing from any port on any instance This might be a better approach to logging than having a 'printer' object. Add proc instance field: log:{ var_label_0:0, var_label_1:0 }

• Complete subnets:

  • Subnets should have presets written in terms of the subnet vars rather than the network vars or the value application needs to follow the internal variable src_var back to the proxy var.

  • DONE: write a paragraph in the flow_doc.md about overall approach taken to subnet implementation.

  • DONE: subnet var desc's should be the same as non+subnet vars but also include the 'proxy' field. In particular they should get default values. If a var desc is part of a subnet then it must have a proxy. The output variables of var desc's must have the 'out' attribute

  • DONE: improve the subnet creating code by using consistent naming + use proxy or wrap but not both

  • DONE: improve code comments on subnet creation

• DONE: Implement feedback

• DONE: Implement the ability to set backward connections - from late to early proc's. This can be done by implementing the same process as 'in_stmt' but in a separate 'out_stmt'. The difficulty is that it prevents doing some checks until the network is completely specified. For example if audio inputs can accept connections from later proc's then they will not have all of their inputs when they are instantiated. One way around this is to instantiate them with an initial set of inputs but then allow those inputs to be replaced by a later connection.

BUGS:

• DONE: The counter modulo mode is not working as expected.

• DONE: Implement 'preset' proc. This will involve implementing the 'cfg' datatype.

• DONE: Finish the 'poly' frawework. We are making 'mult' var's, but do any of the procs explicitly deal with them?

• DONE: Turn on variable 'broadcast'. Why was it turned off? ... maybe multiple updates?

• DONE: There is no way for a proc in a poly context to use it's poly channel number to select a mult variable. For example in an osc in a poly has no way to select the frequency of the osc by conneting to a non-poly proc - like a list. Consider:

1. Use a difference 'in' statememt (e.g. 'poly-in' but the same syntax used for connecting 'mult' variables.)
2. Include the proc name in the 'in' var to indicate a poly index is being iterated e.g. lfo: { class:sine_tone, in:{ osc_.dc:list.value_ } }

• DONE: Fix up the coding language - change the use of instance_t to proc_t and inst to proc, change use of ctx in cwFlowProc

DONE: After the network is fully instantiated the network and class presets are compiled. At this point all preset values must be resolvable to an actual proc variable. A warning is issued for presets with values that cannot be resolved and they are disabled. The primary reason that a preset might not be resolvable is by targetting a variable channel that does not exist.

• DONE: All cfg to value conversion should go through cfg_to_value().

Names

ixon - hoot caw, screech, warble, coo, peep, hoot, gobble, quack, honk, whistle, tweet, cheep, chirrup, trill, squawk, seet, cluck,cackle,clack cock-a-dooodle-doo song,tune,aria

Proc instantiation

Prior to executing the custom constructor the values are assigned to the variables as follows:

1. Default value as defined by the class are applied when the variable is created.
2. The proc instance 'preset' class preset is applied.
3. The proc instance 'args' values are applied.

During this stage of processing preset values may be given for variables that do not yet exist. This will commonly occur when a variable has multiple channels that will not be created until the custom constructor is run. For these cases the variable will be pre-emptively created and the preset value will be applied.

This approach has the advantage of communicating network information to the proc constructor from the network configuration - thereby allowing the network programmer to influence the configuration of the proc. instance.

caw by example:

0. DONE: Add log object. DONE: Add initial network preset selection system parameter.

1. sine->af in-stmt

2. sine->af with network preset topics:preset, class info

3. number,timer,counter,list,log topics: log, data types, system parameters

4. sine->delay->mixer->af --------> topics: mult vars, system parameters

5. topic: modulate sine with sine

6. topic: modulate sine with sine and timed preset change.

7. topic: iterating input stmt 0 - connect multiple inputs to a single source

8. topic: iterating input stmt 1 - multiple inputs to multiple sources

9. topic: iterating input stmt 2 - two ranges

10. topic: poly

11. topic: poly w/iterating input stmt

12. topic: poly w/ xfade ctl and presets

13. topic: msg feedback

14. topic: audio feedback

15. topic: subnets

16. topic: subnet with presets

17. topic: presets w/ sfx id's