greetings all, i'm looking for some free ways to record my voice along with the voiceover screenreader on mac to produce some helpful tutorials/ podcasts. was using OBS for this when i was using windows, but, i'm not sure how to do this on mac. would be glad if someone help me in this regards. thanks in advance.
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Just press record
Just Press Record is free, I think, and it's very simple. Hence the name.
Garage Band is free but complicated.
Voice memo is free but I've never used it.
Blackhole
I checked out the Just Press Record app mentioned above hoping that it would simplify my setup, but it comes with a caveat which probably makes it less appealing to you as well:
For that reason I am posting my setup even though it's rather complex.
To record both the microphone and system audio at the same time I use Blackhole, which is available on MacPorts. Blackhole creates a virtual audio device with an input and output, and routes whatever is sent through its output end back into the system through its input end.
To start off you will need to install a variant of Blackhole compiled to provide more than two channels unless you want the output to be in mono with the microphone on one side and the system output on the other side. MacPorts offers a variant of BlackHole with 8 channels which you can install by typing:
Once Blackhole is installed you will need to open Audio MIDI Setup, create an aggregate device, and add both a microphone and Blackhole to it, then create an multi-output device and add your headphones and Blackhole to it. I suggest using headphones because otherwise the video will end up with echo produced by recording both the system audio stream routed through Blackhole and the audio captured from the speakers. Beware that you might need to disable VoiceOver's cursor tracking (VO+Fn+Shift+3) to use Audio MIDI Setup properly, and remember to re-enable it once you're done.
After creating the aggregate device and multi-output device as I mentioned above, go to system settings and route the system audio through blackhole (you can also do this in Audio MIDI Setup but it doesn't ask for confirmation so you might end up with no audio if you mess things up without an accessible way to recover). Once the setup is complete, the newly created aggregate device will be available as an input device to any application that can record audio including Screenshot Utility.
VoiceOver's audio ducking is known to make system audio recorded through Blackhole much quieter, so if you want to record VoiceOver at full volume, I suggest disabling it in VoiceOver Utility for recording.
Another problem with this setup is that if you install a version of Blackhole compiled for, say, 64 channels, your video will end up with 64 channels of audio, but since those videos tend to be huge, you can take advantage of the fact that you'll need to compress them anyway to also mix all the channels into one or two channels.
To compress the video and mix the audio channels I use ffmpeg from the command-line. Ffmpeg is a kind of a Swiss army knife of audio and video conversion and re-encoding which can do compression, resizing, resampling, and mixing altogether in one go, which is precisely what's needed in this step.
Ffmpeg can also be installed from MacPorts as follows:
After ffmpeg is installed you can use it to re-encode your video, such as in the following example which resamples a video named Input.mov to 30 frames per second, rescales it to 960x540, remixes 4 channels of audio into 2, and finally compresses it to an output video named Output.mp4.
Feel free to ask questions if you need further assistance. I will subscribe to this thread so that I can reply to you without having to periodically check the forum.