ios - high performance buffers in objective-c -


i'm wondering applicable kind of buffer implementation audio data in objective-c. i'm working audio data on iphone, direct data manipulation/dsp of audio data while recording or playing, performance matters. iphone development since months now. i'm dealing c-arrays of element type sint16 or float32, i'm looking better.

afaik, performance of pointer-iterated c-arrays unbeatable in objective-c environment. however, pointer arithmetic , c-arrays error prone. have make sure not access arrays out of bounds. not runtime error if do. , have make sure manually alloc , dealloc arrays correctly.

thus, i'm looking alternatives. high performance alternatives there? there in objective-c similar c++ style std::vector?

with similar mean:

  • good performance
    • iteratable pointer-/iterator-based loop
    • no overhead of boxing/unboxing basic data types float32 or sint16 objective-c objects (btw, what's correct word 'basic data types' in objective-c?)
  • bounds-checking
  • possibility copy/read/write chunks of other lists or arrays , out of searched-for list implementation
  • memory management included

i've searched , read quite bit , of course nsdata , nsmutablearray among mentioned solutions. don't double processing cost because of overhead boxing/unboxing of basic data types? code looks outright ugly simple 'set'-operation becoming dinosaur named replaceobjectatindex:withobject: isn't of concern, still subtly makes me think class not made me.

the containers provided in foundation framework have little offer audio processing, being on whole rather heavy-weight, nor providing extrinsic iterators.

furthermore, none of audio apis in ios or macosx interact buffers of samples objective-c - based, or take parameters of foundation framework containers.

most likely, want make use of accelerate framework dsp operations, , apis work on arrays of floats or int16s.

whilst of apis c-style, c++ , stl obvious weapon of choice requirements, , interworks cleanly rest of application in guise of objective-c++. stl compiles down code efficient hand-crafted c.

to memory-manage buffers, perhaps use std::array - if want bounds checking or std::shared_ptr or std::unique_ptr custom deleter if you're not worried.

places iterator expected - instance algorithm functions in <algorithm> - can take pointers basic types - such sample buffers.


Comments

Post a Comment

Popular posts from this blog

php - Why I am getting the Error "Commands out of sync; you can't run this command now" -

the documentation of error mentioned in title says if commands out of sync; can't run command now in client code, calling client functions in wrong order. this can happen, example, if using mysql_use_result() , try execute new query before have called mysql_free_result(). can happen if try execute 2 queries return data without calling mysql_use_result() or mysql_store_result() in between. from here: http://dev.mysql.com/doc/refman/5.0/en/commands-out-of-sync.html but in first query not fetching data mysql database, inserting. , in second query getting data database. here code $connection = mysqli_connect("localhost","username","password","tbl_msgs"); if(mysqli_connect_errno($connection)) { die("failed connect mysql: " . mysqli_connect_error()); } $query = "insert users (total_comments, total_views) values ({$total_comments}, {$total_views});"; $query .= "insert msgs (no...
Read more

linux - Does gcc have any options to add version info in ELF binary file? -

i mean whether gcc can insert source code version infor elf binary section or similar. not want change source file, add info gcc option in makefile. you can emit version info text file, turn text file object file statically link executable. the first step simple have write code: script or write version info in format plain text file. write makefile rule produce version.o version.txt, using objcopy . you'll have object file 2 useful symbols defined in it: beginning , end of textual version info. add generated object executable, , you'll able access version 2 ways: running strings on binary, or writing code in application print version string (you'll need declare start , end symbols variables in header file).
Read more

java - Are there any classes that implement javax.persistence.Parameter<T>? -

i'm using named queries fetch entities database using jpa , hibernate , came across puzzling me: how come there no default implementations of javax.persistence.parameter interface? i rather impressed how @staticmetamodel used criteriabuilder in jpa2 meaning type safety , don't have mess around setting string names. wanted apply similar of jpa1 ejb's i'm working on: dealergroup_.class: public dealergroup_ { public parameter<integer> id = new parameterimpl<integer>("id"); /// etc... } dealergroupfacade.class: // ... public dealergroup fetch(integer id) { typedquery<dealergroup> query = em.createnamedquery("dealergroup.fetchbyid", dealergroup.class); query.setparameter(dealergroup_.id, query); return query.getsingleresult(); } // ... i surprised find there no implementations of parameter interface - of course, implement myself absence makes me suspicious may mistake using in way? should implementing parameter...
Read more