Cheapest, simplest method to record Binaural sounds using 2 recorders, phones etc.

 

Binaural sounds are almost like what we hear with natural source. If someone says hi behind us and we record audio in mono, stereo and binaural the best output with realism is recorded in binaural. This article makes a basic quality binaural recorder. The quality is not great because of limitations and manual steps required causing further inaccuracies. You can check the sample quality at end of article to check what it feels like.

As picture above shows we need 2 audio recorders. I used 2 Samsung devices with same official recorder app. Phone acts as left ear and tab acts as right ear. MIC are at top of the devices and therefore top is kept at middle of a box. Box acts are head reducing audio from both sides. Recording on both devices should begin at the same time!. If recording time is not same on both we have to shift the playback timing of one track to match both tracks.

IMPORTANT:

2 recorders must be of same hardware/model, same software and same settings to get same audio data. Different devices can work but many times volume levels & dominating frequency can differ e.g. high frequency/volume on left, lower on right etc.

When recording is done below steps are to be done to create final sound.

- Start Audacity app.

- Import Left audio recording from whatever device acted as left. If imported file is stereo it has to be converted into mono. Audacity can do that easily. Now this mono track should be set to Left Only track. There is a slider to set panning between Left and Right. Slide it to leftmost.

- Same as above right track is imported. Slider is shifted rightmost.

- Now Check the waveforms and using this the shifting of track can be done to match the timing issues happened during starting of recorders. Suppose started recording with a clap. Using the clap as reference we can do shifting of Left or right track until the timing error caused during recording is diminished.

- NOTE: Lets assume both track have been set to perfect time match i.e. a sound is heard at both ears at same time. This is actual wrong setup for binaural!. When sound comes from right it reaches right ear first and then left. The time travelled between right left ear MUST EXIST between the tracks. This is important for accuracy of audio source positions. Below is technical information and can be avoided if you cannot understand the topic but it tells the importance of time difference between Left and Right.

https://en.wikipedia.org/wiki/Interaural_time_difference

https://en.wikipedia.org/wiki/Sound_localization

After shifting of tracks sound can be tested and it will surely sound like binaural. The above method is very cheap and prone to lots of errors. This article is for giving understanding of binaural and some experimentations for advance work. Below is the recording I created.

Sample recording file:

https://drive.google.com/file/d/140yaOUVX4ptCyBduURUFXzGjx3Nrwl7o/view?usp=sharing

I hope this article has helped you in binaural recording. I also made an Android app in 2016 with automated process and create binaural recording easily. However I could not keep developing the app. Below are some links to the app -

https://forum.xda-developers.com/t/binaural-3d-sound-recorder-app-using-2-devices-as-mic.3361953/

backup apks for old android devices only. -

https://drive.google.com/file/d/1PP1N1HsOfLVqaMEMj77g0giLON9ecNuV/view?usp=sharing

Sample i recorded using my android app

https://drive.google.com/file/d/1PftsM9XHOUJB8vzL4cB4vUV5mGZ-28v3/view?usp=sharing

Useful Collection of Public Domain, Creative Commons, Free sounds and graphics for commercial use

As an Indie developer i required lot of free sound, music and game art for commercial use. Internet is huge but it still lacks resources with permissible license. Looking for free stuff is not bad but also not great because every work has value and in real life there is no free meal. There are very helping people who offer their work for free to ease development work of indie workers. Below are links to such useful assets.



opengameart.org

http://www.opengameart.org

A website with lots of free multimedia resources. Contains 2D, 3D, music, sound etc stuff with search and page wise browsing. It includes resources with multiple types of open licenses.



Kenney Vleugels website:

http://kenney.nl/


"We've created over 35,000 images, audio files and 3D models for you to use in your projects. Thanks to our public domain license you're even allowed to use them in commercial projects!"

220+MB of arts and sounds.




Glitch Game Art

https://www.glitchthegame.com/public-domain-game-art/

"The collaborative, web-based, massively multiplayer game Glitch began its initial private testing in 2009, opened to the public in 2010, and was shut down in 2012. It was played by more than 150,000 people and was widely hailed for its original and highly creative visual style.

The entire library of art assets from the game, has been made freely available, dedicated to the public domain. Code from the game client is included to help developers work with the assets. All of it can be downloaded and used by anyone, for any purpose. (But: use it for good.)"


Huge collection of arts. Don't miss it!



The Last Door Game Assets

http://thelastdoor.com
http://opengameart.org/content/the-last-door-season-one-complete-assets-pack

"Hey pals! We have a special gift for you! Today, in commemoration of Alan Turing, father of modern computing, all of Season One's assets will become open source! Also, we want to commemorate you, as the great community we proudly have. Thank you so much! Now you can create your own 'The Last Door' content by using the original graphics and sounds! Create videos, animate gifs or develop your won 'The Last Door' game! The assets are under Creative Commons Attribution 4.0 license, so you can spread your passion in all formats and ways."



https://kronbits.itch.io/matriax-free-assets

"Hi! I'm Davit Masia, I create a lot of graphics for fun, mockups,etc... that usually ends lost on my folders. So i decided upload and share with everybody all that stuff so people can use in their projects. Assets are free but any donation will be welcomed and motivate me to add more and more"

Around 30MB of free arts.



https://github.com/sparklinlabs/superpowers-asset-packs

https://sparklinlabs.itch.io/superpowers

"The assets in this repository are created at Sparklin Labs by Pixel-boy.
They are released under the Creative Commons Zero (CC0) license.
You can use the assets found in this repository in your own games, even commercial ones. Attribution is not required but appreciated. Placing a link to http://superpowers-html5.com/ somewhere would be awesome :)"



http://www.gameart2d.com/

"GameArt2D.com is a place to buy royalty free 2D game art assets. It contains more than 50 items, from platformer & top down tileset, side scrolling & top down character spritesheet, game GUI, space shooter asset, and many more.

Who's the guy behind this site?
I'm Zuhria Alfitra a.k.a pzUH. A lone wolf indie-gamedev-wannabe from Yogyakarta, Indonesia."



http://www.wpclipart.com/downloads.html

Huge collection of cliparts, images of animals, plants, education, shapes etc. It can be very helpful to make a derivative art. Get a simple shape and enhance it to something more beautiful. ~1GB of images. Public Domain.



https://openclipart.org/

"Unlimited Commercial Use

We try to make it clear that you may use all clipart from Openclipart even for unlimited commercial use. ... We use the Creative Commons Zero 1.0 Public Domain License every time an artist uploads a piece of clipart to Openclipart to make it clear the artist is releasing the creative work for anyone to use for any reason, even commercially."



https://github.com/saniv/free-game-art

Very good collection of collections!. This is a MUST visit page. However the repository is big and sometimes you might want to download only few folders from github. For example we want to download a CC0 or non GPL licensed assets. If you know how to use command line then a single folder can be exported from github. GUI based software can also do that.

For example you want to download https://github.com/saniv/free-game-art-unsorted/tree/master/oblique/DCGames_stuff folder but there is no option on that page. Start command shell like bash on Linux or cmd.exe on Windows. Install SVN subversion software and run this command -


Firstly copy the link

https://github.com/saniv/free-game-art-unsorted/tree/master/oblique/DCGames_stuff

Then replace tree/master by trunk. It becomes like this -

https://github.com/saniv/free-game-art-unsorted/trunk/oblique/DCGames_stuff


Now run

svn export https://github.com/saniv/free-game-art-unsorted/trunk/oblique/DCGames_stuff

This will download only the DCGames_stuff folder. If you don't like command line then try a GUI software like TortoiseSVN and export the url above as example.




https://craftpix.net/freebies/


Freebies license:

"You are permitted to use the resources in any number of personal and commercial projects for yourself or a client.
You can modify the resources according to your requirements and include them into works such as websites, applications, printed materials and others."








Textures:



Blender Texture Disc

Public domain textures pack in a CD.


Sweet home 3D texture packs

https://sourceforge.net/projects/sweethome3d/files/SweetHome3D-textures/Textures-1.1/

Contains some useful texture packs.



http://unluckystudio.com/

Owned by Sujit Yadav. He has shared some useful vector arts.



NOTE:
To get more images and textures one can use public domain or CC0 like licensed photos or videos.





3D models:


http://telias.free.fr/

"Hi there. 'Free the models' is a site dedicated to provide free content for 3d applications and 3d/game engines. The license of the content is that what you download from here is one step away from public domain. So, everything you download from here is free for any use EXCEPT it cannot be included in another free web or cd collection and it cannot be sold separately. Otherwise you can use it in your commercial game, 3d application or render work. You don't have to provide credit but It would be nice if you do. Thank you. Elias Tsiantas /Herakleion/Greece."




https://sourceforge.net/projects/sweethome3d/files/SweetHome3D-models/3DModels-1.5.1/

Lots of 3D models in sh3f format. Its like zip file and can be extracted.






Free Sounds:



http://www.99sounds.org

A very useful and huge collection of high quality audios. Below are some sound files i downloaded from this website.

[99Sounds] 99 Drum Samples
[99Sounds] Atmospherik Mekanisms
[99Sounds] Cinematic Sound Effects
99Sounds Drones
[99Sounds] InterSpace
[99Sounds] Magnetic Fields
[99Sounds]_Massamolla
[99Sounds] Percussa Toolbox by Richard Gould
[99Sounds] Project Exodus
[99Sounds] Project Pegasus
[99Sounds] Punching Percussion
99Sounds Radiophonic Atmospheres by Red Sky Lullaby
[99Sounds] Rain And Thunder
[99Sounds] Sound Design Tools
[99Sounds] The Warehouse


The files are very big and i have compressed them to very low size still maintaining quality. Due to their license restriction i cannot share those compressed ogg files. Please visit their site and download them all. Many of these audio have 96KHz sample rate. Do read the download resume technique at end of this article to download from this site because the big files many times stop resuming.



https://www.freesound.org/

Various licenses and huge collection of user submitted sounds.


www.pacdv.com/sounds/

Another good site i used.
Search "free sounds" on Google. There are many sites like this.





Get sound samples from sound pack formats

One best way to get sounds is packed, synth sound formats. Sound formats like SoundFont SF2, Downloadable Sound DLS, Patch (pat files). There are many sites which offer these files. Below are some valuable sound collections or packs.


cybernetik_mayhem_samplepack_-_by_cybernetika

Big collection of sound sample. Uncompressed size 844 MB



DrumKits from Hydrogen DrumMachine app

The drumkit files are zip files with sample configuration. Extract audio files from them and use in any DAW. Drumkits names:

3355606kit, ColomboAcousticDrumkit, HardElectro1, Synthie-1, BJA_Pacific, DeathMetal, HipHop-1, TD-7kit, Boss_DR-110, EasternHop-1, HipHop-2, Techno-1, circAfrique v4, ElectricEmpireKit, K-27_Trash_Kit, TR808909, Classic-626, ErnysPercussion, Millo-Drums_v.1, VariBreaks, Classic-808, ForzeeStereo, Millo_MultiLayered2, YamahaVintageKit




http://www.rhythm-lab.com

Many free sound samples.




Download some free Digital Audio making software and many of them offer free sound packs inside them. Linux Multimedia Studio is among them. Download tracker music software and their XI instruments which can be converted to wav or flac.






List of CC0 websites for images, wallpapers, photos

https://www.pexels.com/
https://freeimages.red/
https://stocksnap.io/
http://skitterphoto.com/
https://pixabay.com/



https://blog.wikimedia.org/2017/02/07/the-met-public-art-creative-commons/


"The Metropolitan Museum of Art makes 375,000 images of public domain art freely available under Creative Commons Zero"

As it says huge collection of museum art can be used for even commercial purpose. Deriving these arts to make new things can be very useful.




How to get more multimedia assets with lesser effort?


I spent lot time in learning programming, music, sound effects, digital arts and some more skills. Now i can make games alone. However i realized one must rather invest time in one skill they love most and Master that skill ( I love all but music is at top :) ). What about those technologies where skill is not enough to complete a work faster? There are many ways to do it. You can pay to a freelancer and get your work done. What if you don't have much money?. This is where free stuff comes to help. Some very useful links have been shared above. But now i will share techniques to get free stuff with little effort.

A video is a sequence of pictures. Therefore an open licensed movie is also bundle of same license image assets. With this idea i downloaded open source videos like BigBuckBunny. ElephantsDream, Sintel etc. There are lots of effects, textures, sounds etc in these videos. Extract data from these videos and use them wherever needed. But don't forget to follow the license honestly!.


Here are links of some public domain, Creative Commons videos:


Blender Movies:

https://www.blender.org/features/projects/


Other:

https://en.wikipedia.org/wiki/List_of_animated_films_in_the_public_domain_in_the_United_States

http://tvtropes.org/pmwiki/pmwiki.php/Main/PublicDomainAnimation

https://en.wikipedia.org/wiki/List_of_open-source_films


WARNING:


There are many resources which are public domain but can still cause copyright issues. For example old SuperMan cartoons are public domain but the SuperMan himself is not!. Please be careful for these type of things.






How to resume downloads which expires if stopped?

Many websites generate download links which expire after some time or fail if multiple connections are created. I use UGET on linux. Windows version of this software is also available. Simply add a URL and start downloading. When a new url is created go to properties of the download item and replace the old url by new url. Another way is to use KGET. Its also a Linux app. It can add mirror links. Add whenever a new link is created.


Download link:
http://ugetdm.com/ 




The links shared here can be very helpful to many indie and non-indie developers. Please submit links in comments i will add here.

BVHUtil - A multi-platform BVH MoCap utility (Like BVH Hacker)

Update 28-Feb-2017:

Due to lack of fund, time and reason i quit gaming this project was suspended. However even after ~1.5yrs no BVH viewer on android exists. I thought someone might make one. So may be i will try to re-build a simple bvh viewer to keep an option for some users. The download link to PlayStore is dead because i disabled the BVH Viewer app but many apk sites maintain a copy of it. Please download from these sites. I will update link if i could.




I am working on 3d games like Tekken 3, Dear Or Alive using unity3d and some other engines/libraries. Soon i started working got stuck in making models and their animations. While making 2d games i could make graphics alone but in this case its way more harder and time consuming. I make human models using OpenSource software MakeHuman and then import them into Blender 3D to do rest of work. However there is a method called Animation Re-targeting which can use external animation to be applied to acompatible model. A compatible model means they must have same skeletal architecture no matter what design of mesh they have. Fortunately one can use BVH MoCap files. Many of them are freely downloadable. Carnegie-Mellon Graphics Lab Motion Capture Database offers lots of free BVH files.



There is already an editor called BVH Hacker which can do most of tasks anyone needs. However i tried to find, as much as i can, a software which can edit REST POSE of BVH file without affecting the motion data. I could not find any & there were methods which were time consuming and not for anyone who doesn't know how to use Blender3D. So i made Rest Pose editor* myself and it works well.


Details:
However i am using it for personal use and willing to release it on stores. At present BVHUtil works on its own format which is nothing but extension of BVH replacing Euler rotations channels by Quaternion.


Features:
- BVH viewer with interpolation of animation.


WIP features for updates to come:
- Frame control for viewing. View any frame like seeking a video frame.
- Remove frames
- Edit Frame animation data i.e. rotation of joints/bones.
- Export* interpolated frames to enhance animation smoothness within file.
- Export* any part of skeleton. E.g. export right hand as bvh.
- Edit rest pose* without affecting a single animation frame. This feature is rare and i will take some time to make it available. This feature is complete and ready but is not exposed in UI. More info at bottom.
- Animation re-targeting to embed animation in a model? I myself need this and will make it anyhow.


* mark is for features which are available in my own BVH2 format. This is extension of bvh format where Euler rotations are replaced by Quaternions. Once i make precise port of these features to bvh format i will update this app. * features will be available once i finish BVH2 to BVH export. BVH2 format name can probably be changed with something else.


Download:
I have only released Android version yet. PC version will be released after i am done with mobile builds.


https://play.google.com/store/apps/details?id=org.greh.bvhutil


Key words:
Edit Mocap BVH rest pose, rest pose editor, android bvh viewer, android mocap viewer