AV composition: Using only 3 audio & 3 images

Hey all,

Today we cover how to create an electroacoustic composition using minimal input sounds and images, and transform them to form a new piece. Software that we're gonna use is Audacity and Ardour to compose the soundtrack, and then Blender for the video. Openshot to finish the video editing off ;)

Audio workflow is as follows:
-Open the samples you've got in Audacity
-Modify them (check out the "change pitch / tempo / speed" options)
-Repeat bits (select audio, effects->repeat) to get noises @ a certain pitch
-Export each resulting soundfile that you think is useful

-Open Ardour, create a new session
-Import the created file to the region list
-Start arranging sounds in time
-Add a reverb bus, some sends to it
-Don't be afraid to have lots of little regions

Screeny of Ardour session:

Next export to wav, then load up blender:
-Open a "Video Sequence Editor" pane, and hit "add->Sound"
-"Alt-A" should now play back the audio you've created
-Use markers to identify critical points in the soundtrack
-Open a "Node editor" view, and add lots of fun effects
-Using the "IPO curve editor" and keyframes, animate the effects
-Hit render once in a while to ensure you're getting what you expect

Screeny of Blender session:

Then choose your (video) render / export settings, and let Blender do the grunt work. Now to finish you video, and export it to a usable quality and size, load up Openshot:
-Import your audio & video
-Align them in the timeline
-Add fades / titles / whatever
-Hit export, and choose your target format (web, DVD, youtube, phone)

That should be it :)

CSound: Global variables create helper instruments

Quick tutorial on how to make "helper" instruments in csound. Basically rather than running multiple "reverb" opcodes in various instruments, you create a "send" (like in your DAW software), and put a reverb on the send. Later you mix in whatever amount of that send you want into the "master" output.

The screenshot shows some code in QuteCSound, the comments should explain the rest of the theory of the send.

Cross synthesis & time stretching in CSound

The goals:
1. Cross-synthesise the two sounds using Csound’s pvcross opcode.
2. Time-stretch and pitch-shift one of the sounds using Csound’s pvoc opcode

To use any of CSounds phase vocoding opcodes we need to first analyse the files we want to use: its not hard, but you need to know to do it. Open the "Utilites" tab:

Then select your analysis type "PVANAL" is the one we want, after that set your input & output filenames, samplerate, num channels, and a frame size of perhaps 1024.. or there abouts.

Now hit "Run PVANAL" and it should print out the following in the console.
PV analysis output:

util pvanal:
audio sr = 44100, monaural
opening WAV infile adrien.wav
analysing 119879 sample frames (2.7 secs)
1024 infrsize, 256 infrInc
466 output frames estimated
pvanal: creating pvocex file
20
40
[snip]
460
480

484 1-chan blocks written to adrien.pvx

Ok so we've analysed the files needed, now to use them in the .csd file:
Helpful docs online: http://www.csounds.com/manual/html/pvcross.html

Some code like beside here generated some inresting results, but I don't know what the end goal should sound like...

Probably not really like this :(

Time stretching is a bit easier:

see http://www.csounds.com/manual/html/pvoc.html

 

 Not sayin its fantastic but it works :)

DnB production: Mastering EQ

Ever listened to some drum and bass? Wondered how they got that sound? A fraction of that sound is what I'm going to explain today. Apart from a whole lot of drum programming, compression, reverb and filtering there's some other "last" steps to take. One of the interesting things I've noticed is quite a lot of "old school" dnb tracks have some hefty master EQing going on.

Check out "Terrorist" by Renegade: Its a DnB classic. First just listen, and estimate what EQing could have been applied. Then listen to the track routing the audio into JAAA (Jack/ALSA Audio Analyser) and checkout this:

You see that?? Wow. Bout -20dB cut all around 10kHz, and another starting around 15kHz all the way up to 17kHz. Sure you ear's response to highs isn't linear: but that's still a hell of an EQing going on. Its all about the brightness of the track right there: that crispy snare snap and ringing hats.

Now check Helicopter by Deep Blue Jungle: its got quite an even response. Note the heavy bass, and that its a sound that is quite transient: it appears, rings and then dims away until the next downbeats. Inbetween those downbeats there's substantial congas, hats, shakers etc going on. Has some high cut applied (possibly shelving) applied starting at just over 15kHz:

Then checkout Dj Hypes "The Chopper", and note that the song is all about the bassline. To make the bass more obvious, there's a -40dB high shelf applied at just over 11kHz, dimming all bright attention grabbing overtones of the fast drums. As the drums are never a very prominent part of the sound, they're just cut out constantly.

Finally we'll look at Badman's "War in '94": It features some quite low bass lines, some saxophone and drums. Also some pad sounds are prominent at certain stages during the song:

All in all what I'm going to do when producing some DnB track, is load up Fons & Nedko's fantastic 4 band parametric EQ with LV2 gui: http://nedko.arnaudov.name/soft/lv2fil/trac/

It provides a new way to listen to the same songs, but without that mastering EQ applied: just reverse it using the above filter (yes the 4th section is disabled in the screeny: turn it on / off to notice the huge difference in brightness in the track!

 Conclusion: Don't be afraid of some hefty EQing, it can really add that final shape to the song: either adding dramatic effect to a certain element of the mix, or reducing its impact to highlight the other parts of the song.

Why another blog?

This blog is dedicated to production techniques, tips & tricks using open source audio software, and the linux platform. More specifically, I'm using Arch linux, with the ArchAudio repos, and some custom compiled software. Its a little techy, but well worth the new and fancy features that are available when using the latest & greatest :)

Hopefully you'll enjoy all resources to be posted on the blog, and have some fun browsing around. Comment & sharing opinions welcome! -Harry