High-level audio software architecture
The following are the major audio software architecture components:
**Application 1**
A generic multimedia app that produces or consumes audio and sends it through higher-level frameworks (like GStreamer or PipeWire) instead of directly interacting with hardware.
**Application 2**
Another app sharing the same audio stack, demonstrating that multiple applications can simultaneously use and route audio streams.
**GStreamer**
A multimedia framework that processes audio/video (e.g., decoding, encoding) before passing audio streams to the system audio layer.
**PipeWire**
A user-space audio server that manages audio routing, mixing, and connections between applications and hardware devices.
**ALSA + ASoC FWK**
This layer bridges user space and hardware drivers, with ALSA handling sound subsystem functions and ASoC managing embedded audio hardware interactions.
**Q6 APM Driver**
A Qualcomm-specific driver that communicates with the DSP's Audio Processing Manager to control audio routing and processing.
**PCM driver**
Handles the transfer of raw digital audio (PCM data) between memory and the audio subsystem for playback or recording.
**DAI driver**
Manages the digital audio interface (like I2S/TDM), configuring how audio data is transferred between processor and codec.
**CODEC driver**
Controls the audio codec hardware, configuring it to convert digital audio signals to analog output and vice versa.
**PipeWire**
PipeWire is a multimedia server for Linux that routes audio between Apps and hardware. It replaces PulseAudio, offering low-latency, secure, and flexible media handling for applications.
**Platform Abstraction Layer (PAL)**
Provides higher-level audio-specific APIs to access the audio hardware and drivers to enable audio features.
**Audio Graph Manager (AGM)**
Provides interfaces to allow TinyALSA-based mixer controls and PCM/compressed plug-ins to interact and enable audio features.
**AudioReach Graph Service (ARGS)**
Consists of the Graph Service Layer (GSL), Generic Packet Router (GPR), and acdb Management Layer (AML) modules. Handles initialization and creation of graphs, and creation of packets for sending a series of commands to the AudioReach Engine (ARE).
**Audio calibration database (acdb)**
Includes information about various audio use cases such as graphs, module calibration data, etc. The Apps processor parses acdb files to get the graph information used by ARE to enable the use case.
**AudioReach Engine (ARE)**
Modular framework that runs on the LPAI DSP. It helps set up, configure, and run signal processing modules for audio features.
**Qualcomm Audio Calibration Tool (QACT™ Platform)**
PC-based software that provides a GUI to visualize, configure, and store audio graphs in the acdb for audio use cases.
## **Config 1 vs Config 2**
QLI 2.0 introduces an overlay model that allows customers to start with a clean open-source base build and optionally layer in Qualcomm's proprietary, DSP-accelerated audio stack — without requiring a full reflash. This is referred to as the Config 1 → Config 2 transition.
| **Attribute** | **Config 1 (Base Build)** | **Config 2 (Overlay)** |
| :- | :- | :- |
| Image recipe | `qcom-multimedia-image` | `qcom-multimedia-proprietary-image` |
| Audio stack | ASoC (upstream) | AudioReach (downstream) |
### **Config 1 — Upstream ASoC**
Config 1 uses the ALSA System-on-Chip (ASoC) framework. Audio runs entirely on the application processor using upstream kernel drivers, with no dependency on Qualcomm proprietary components.
#### **Key characteristics**
* Standard ALSA sound card exposed to userspace
* Audio pipeline components: Codec Driver, Platform Driver, Machine Driver
* UCM profiles (`ucm.conf`) used for routing
* ASoC topology binary (`.tplg`) for mixer paths and routing
* Compatible with `aplay`, `arecord`, GStreamer, and PipeWire via ALSA sinks/sources
#### **Kernel modules**
The following kernel modules are loaded in a Config 1 build:
* `q6apm_dai`
* `q6apm_lpass_dais`
* `q6prm`
* `q6prm_clocks`
* `snd-soc-sc8280xp`
* `snd_q6apm`
* `snd_q6dsp_common`
#### **When to choose Config 1**
* Full open-source, upstream kernel-only requirement
* No requirement for DSP-accelerated audio features (SVA, Fluence, Haptics)
* Targeting mainline Linux distributions or AOSP with upstream drivers
* No-touch or low-touch integration
#### **Build**
Config 1 builds the `qcom-multimedia-image`.
```bash theme={null}
git clone https://github.com/qualcomm-linux/meta-qcom.git -b master
kas shell meta-qcom/ci/
