objective c - AUHAL with USB audio device -

-

i've got usb audio device (presonus audiobox) , want able switch audio output of program between usb device , default output device (the internal speakers). apple documentation tells me have use auhal:

if need connect [..] hardware device other default output device, need use auhal.

source

normally, make device description , if exists. wrote function test this:

-(osstatus) showauhaldevices {     //show available auhal devices     // create description     audiocomponentdescription test_desc;     test_desc.componenttype = kaudiounittype_output;     test_desc.componentsubtype = kaudiounitsubtype_haloutput;     test_desc.componentmanufacturer = kaudiounitmanufacturer_apple;     test_desc.componentflags = 0;     test_desc.componentflagsmask = 0;      // determine number of available components     uint32 count = audiocomponentcount(&test_desc);      // print result     osstatus err = noerr;     cfstringref compname;     audiocomponent test_comp;      (uint32 = 0; < count; i++)     {         test_comp = audiocomponentfindnext(nil, &test_desc);         err = audiocomponentcopyname(test_comp, &compname);         nslog(@"audio component number %u/%u: %@", (i+1), count, compname);     }      return err; }

the problem here cannot set test_desc.componentmanufacturer = kaudiounitmanufacturer_apple; manufacturer apple, usb device doesn't show in list printed in log.

what missing? , far know, not driver issue.

thanks in advance.

edit

i've set properties zero, usb device still doesn't show between 98 different components. can find [avcapturedevice deviceswithmediatype:avmediatypeaudio] though, can set input, not output..

componentmanufacture can set 0 treat wildcard (as can componenttype , componentsubtype).

//show available auhal devices // create description audiocomponentdescription test_desc; test_desc.componenttype = kaudiounittype_output; test_desc.componentsubtype = kaudiounitsubtype_haloutput; test_desc.componentmanufacturer = 0; test_desc.componentflags = 0; test_desc.componentflagsmask = 0;

additionally, usage of audiocomponentfindnext wrong in how pass nil first parameter. first parameter should component wish begin search from. pass nil first time , result of first call second time , on.

audiocomponent test_comp = nullptr;  (uint32 = 0; < count; i++) {     test_comp = audiocomponentfindnext(test_comp, &test_desc);     ... }

Comments

Post a Comment

Popular posts from this blog

html - Firefox flex bug applied to buttons? -

-
i'm trying apply flex button on firefox i'm having problem on chrome doesn't happens. this css: .button { display: inline-flex; align-items: center; } as can see in fiddle, "caret" word moved new line, happens if element <button> tag, <div> works expected. http://codepen.io/anon/pen/xblmgx is firefox bug or there css i'm missing? nevermind, looks "mr firefox" doesn't idea... <button> not implementable (by browsers) in pure css, bit of black box, perspective of css. means don't react in same way e.g. <div> would. this isn't specific flexbox -- e.g. don't render scrollbars if put "overflow:scroll" on button, , don't render table if put "display:table" on it. stepping further, isn't specific <button> . consider <fieldset> , <table> have special rendering behavior: data:text/html,<fieldset style="d
Read more

html - Missing border-right in select on Firefox -

-
Image
when put select div width , padding-left, options have no border on right. more, happend if select have width 118px , parent have 15px of padding left! have idea, going on? my code: <!doctype html> <html> <head lang="en"> </head> <body> <div style="width: 1000px; padding-left: 15px;"> <select style="width: 118px;"> <option>a</option> <option>b</option> <option>c</option> </select> </div> </body> </html> and result: here plunker: click it happend on firefox on windows. tested on 40.0.2 version -webkit-box-sizing: border-box; -moz-box-sizing: border-box; -ms-box-sizing: border-box; box-sizing: border-box; source: https://stackoverflow.com/a/11390432/4431269 source of problem: https://bugzilla.mozilla.org/show_bug.cgi?id=924068 and use of google ! edit: (source of problem, explained) after rea
Read more

c# - two queries in same method -

-
i trying execute 2 queries in same method gives me exception. can red of exception declaring new command there way use same command? string id="hi"; connection.open(); oledbcommand command1 = new oledbcommand(); command1.connection = connection; string query1 = "select * products category='" + combobox1.text + "' , subcategory = '" + combobox2.text + "' , sizes='" + combobox3.text + "'"; command1.commandtext = query1; oledbdatareader reader = command1.executereader(); while (reader.read()) { id = reader[0].tostring(); } textbox1.text = id; string query = "insert category_in (category_id,amount,amount_in) values ('"+ id+"' ,500,300)"; command1.commandtext = query; command1.executenonquery(); messagebox.show("saved"); connection.close();
Read more