Leonidius20
high CPU usage when recording
App version: 0.2.0 from F-Droid Phone: Fairphone 4 Android: 14 LineageOS 21-
I tried your app and I noticed high CPU usage and battery drain. I have used similar apps that run for much longer without any impact on CPU.
I connected to the phone using ADB and ran the top utility. It shows me this:
PID USER PR NI VIRT RES SHR S[%CPU] %MEM TIME+ ARGS
19846 u0_a67 20 0 14G 160M 85M S 100 2.9 9:08.48 io.github.leonidius20.recorder.lite
The app is using one core at 100% all the time while recording.
My settings:
- Audio source: unprocessed
- Container: WAV
- Codec: PCM
- Channels: mono
- Sample rate: 48000
- Bit depth: 16 bit int
As I'm using an uncompressed format I'm surprised that it places such a big demand on CPU.
I tried reducing the sample rate to 8000 and the problem is the same.
Is this a known problem for you or for any other users or am I the first person to comment on this?
I tried using MP4 / AAC and the CPU usage is only about 13%
- Audio source: unprocessed
- Container: MPEG4
- Codec: AAC-LC
- Channels: mono
- Sample rate: 48000
- Bit depth: 16 bit int
Comparing the audio quality with the WAV (high CPU) and the MPEG4/AAC-LC (low CPU), I found the WAV quality is much better.
In the latter case, it sounds like the compression, despite only using 13% of CPU, is not keeping up with the samples coming in and it is dropping some of them. I was testing at 48000. I tested various USB audio devices so it doesn't depend on the audio hardware in the phone. I test the same audio devices against a PC to compare the recording. I might make some more tests later.