AAC Audio Encoder Plugin for DaVinci Resolve Studio (Linux)

A high-quality AAC audio encoder plugin for DaVinci Resolve Studio on Linux, using the Fraunhofer FDK-AAC library. Thanks to 'toxblh' for the the original concept.

Please don't ask for AAC or other input plugins. BlackMagic have disabled the option of making input plugins for commercial and licensing reasons and I respect their decision to do that. If you are looking for a quick way to import mp4 with AAC I recommend a small script I created which adds a right click in file explorer Nemo which does a quick transcode of the AAC to FLAC and remuxes with the pass-through AVC video, it is the only option at this point. I will put that in another repo.

Features

• ✅ High-quality AAC encoding using Fraunhofer FDK-AAC
• ✅ MP4 and MOV container support
• ✅ Selectable bitrate (96/128/160/192/224/256/320 kbps, default 192)
• ✅ Multiple sample rates (44.1 kHz, 48 kHz)
• ✅ 16-bit PCM input
• ✅ Native DaVinci Resolve integration

Screenshots

AAC codec available in audio settings

Requirements

Essential

• DaVinci Resolve Studio (version 18.0 or later)
  • ⚠️ Note: The free version does NOT support plugins
• Linux x86-64 (Ubuntu, Debian, Arch, Fedora, etc.)
• Root/sudo access for installation

Build Dependencies

• clang++ or g++ (C++11 support)
• pkg-config
• libfdk-aac-dev (Fraunhofer FDK-AAC library)
• DaVinci Resolve Developer SDK (included with Studio)

Installation

Quick Install (Recommended)

# 1. Clone the repository
git clone https://github.com/hexitnz/Resolve-Linux-Studio-AAC-FDK-Encoder-plugin.git
cd Resolve-Linux-Studio-AAC-FDK-Encoder-plugin

# 2. Run the automated installer
chmod +x install.sh
./install.sh

The installer will:

• Check for all dependencies
• Install missing packages (with your permission)
• Build the plugin
• Install to DaVinci Resolve
• Verify the installation

Manual Installation

sudo apt update
sudo apt install build-essential pkg-config libfdk-aac-dev clang

sudo pacman -S base-devel clang libfdk-aac

sudo dnf install clang make pkgconfig libfdk-aac-devel

cd src
make clean
make

sudo make install

sudo cp -r aac_fdk_plugin.dvcp.bundle /opt/resolve/IOPlugins/
sudo chmod -R 755 /opt/resolve/IOPlugins/aac_fdk_plugin.dvcp.bundle

Post-Installation

Restart DaVinci Resolve completely:

killall resolve
/opt/resolve/bin/resolve

Usage

1. Open DaVinci Resolve Studio
2. Go to the Deliver page
3. Select your export settings:
   • Format: MP4 (or MOV)
   • Codec (Video): Your choice (H.264, H.265, etc.)
   • Codec (Audio): AAC (FDK-AAC) ← This is the plugin!
   • Audio Bitrate: 96-320 kbps (dropdown, default 192)
4. Add to render queue and export

Troubleshooting

Plugin doesn't appear in codec list

Check installation:

ls -la /opt/resolve/IOPlugins/aac_fdk_plugin.dvcp.bundle/Contents/Linux-x86-64/

Verify DaVinci Resolve Studio:

• The free version does NOT support plugins
• Make sure you have the Studio version installed

Restart Resolve completely:

killall -9 resolve
/opt/resolve/bin/resolve

Build fails with "fdk-aac not found"

Install libfdk-aac:

# Ubuntu/Debian
sudo apt install libfdk-aac-dev

# Arch
sudo pacman -S libfdk-aac

# Fedora (may need RPM Fusion repositories)
sudo dnf install libfdk-aac-devel

Verify installation:

pkg-config --modversion fdk-aac

Audio is choppy or distorted

This usually indicates a mismatch between input format and plugin expectations.

Try these settings in Resolve:

• Set your Project Settings → Fairlight audio output to Stereo (this plugin only supports 2.0 stereo output)
• Set timeline audio format to 48 kHz (44.1 kHz is also supported)
• Use 16-bit audio (24-bit/float PCM input is converted internally, but the plugin currently only accepts a 16-bit pIOPropBitDepth negotiation)
• Restart the export

Check logs:

tail -f ~/.local/share/DaVinciResolve/logs/davinci_resolve.log | grep "AAC"

Permission denied errors

Fix permissions:

sudo chown -R root:root /opt/resolve/IOPlugins/aac_fdk_plugin.dvcp.bundle
sudo chmod -R 755 /opt/resolve/IOPlugins/aac_fdk_plugin.dvcp.bundle

No audio in exported file

Verify the plugin is being used:

# Start Resolve from terminal
/opt/resolve/bin/resolve 2>&1 | grep "AAC Plugin"

You should see messages like:

AAC Encoder :: Constructor
AAC Plugin :: Init - 48000 Hz, 2 ch, 16-bit, 192 kbps
AAC Plugin :: Time base declared as 1/48000 (sample-accurate PTS/Duration)
AAC Plugin :: AudioSpecificConfig forwarded to muxer (2 bytes)
AAC Plugin :: Opened - 192 kbps CBR, 2.0 stereo, frame size: 1024, inputChannels confirmed: 2

If you don't see these messages, the plugin isn't loading.

File plays fine streamed (e.g. Nextcloud, VLC) but not in some local players (e.g. QuickTime on macOS)

Exported files play correctly in VLC and via web-based players (e.g. a Nextcloud share), and report correct stream properties with ffprobe, but fail to play (often silently, with picture but no audio) in certain local players -- QuickTime Player on macOS is the most commonly reported case so far.

This is a known issue and appears to sit outside what the codec plugin can control. The actual AAC audio data is correct -- ffprobe reads the codec configuration directly from the bitstream and confirms valid AAC-LC at the expected sample rate/channels, and VLC plays it back correctly in sync. The most likely explanation is that Resolve's own internal MP4 muxer (which assembles the final moov/esds/stsd boxes from what the plugin provides) writes container metadata that's complete enough for VLC's, ffprobe's, and most streaming/web players' more lenient parsing, but not strict enough for some stricter local demuxers (QuickTime's AVFoundation-based demuxer being the most commonly reported example), which are historically pickier about MP4 box structure. This is not something the IPluginCodecRef plugin interface gives this codec direct control over.

If a client or colleague reports a file "won't play" -- but it played fine when you (or they) streamed/previewed it elsewhere (Nextcloud, Google Drive's preview, a browser, VLC) -- the file itself is very likely fine. The difference is almost always which local player/app they used to open the downloaded file, not a problem with the export. Ask what app they used to open it before assuming the export is broken.

Workaround: remux (or remux+re-encode) the exported file with ffmpeg, which rewrites the container cleanly:

# Re-encode audio and rewrite the container (known to work):
ffmpeg -i "input.mp4" -c:v copy -c:a aac -b:a 320k -movflags +faststart "output.mp4"

# Or, lossless remux only (no audio re-encode, try this first):
ffmpeg -i "input.mp4" -c copy -movflags +faststart "output.mp4"

-movflags +faststart relocates and rewrites the moov atom via ffmpeg's own muxer, which appears to resolve compatibility with stricter players.

If you can compare mp4box -info (or ffprobe -show_streams -show_format -print_format json) output between a Resolve-exported file and an ffmpeg-remuxed one and spot the specific field that differs, please open an issue with the diff -- that would help pin down exactly what Resolve's muxer is doing differently.

Exported MKV file has no audio in some players

As of v1.1.3, this codec actively rejects MKV exports and won't appear as a selectable audio codec option when MKV is the chosen container -- Resolve's deliver page will hide/gray it out. If you're on an older version and exporting to .mkv, upgrade and switch to MP4 or MOV instead.

(Note for anyone tracking versions closely: v1.1.2 first attempted this by removing mkv from the codec's declared container list at registration, but that alone didn't actually stop Resolve from allowing the combination -- it still let the export proceed and produced a broken file. v1.1.3 added a hard runtime check in the plugin's init step that reads the actual target container for each export and refuses outright if it's MKV, which is what's actually effective.)

Root cause (for anyone curious or maintaining a fork): this was confirmed, not assumed. The plugin sends correct per-frame pIOPropPTS and pIOPropDuration values with an explicit pIOPropTimeBase of 1/sampleRate -- the exact same logic, byte for byte, that produces correct timing metadata in MP4/MOV exports. Despite that, files exported to MKV consistently showed Duration: 00:00:00.000000000 on the audio track (visible via ffprobe -show_entries stream_tags=DURATION), even though the audio data itself was valid AAC and the computed/observed duration (from packet count) was correct. A zero-duration track is commonly treated as empty/silent by players, explaining the no-audio symptom. The SDK doesn't expose any separate "total track duration" hint a codec plugin could supply to correct this -- Resolve's own Matroska muxer appears to not derive the Duration element correctly from the per-block timing it's given, in a way its MP4 muxer does correctly from the equivalent data. This isn't fixable on the encoding side; it would need a fix in Resolve's MKV muxer itself, so the plugin now blocks the combination instead.

If you need an MKV deliverable, export to MP4 or MOV from Resolve and remux losslessly with ffmpeg:

ffmpeg -i "input.mp4" -c copy "output.mkv"

Uninstallation

sudo rm -rf /opt/resolve/IOPlugins/aac_fdk_plugin.dvcp.bundle

Then restart DaVinci Resolve.

Technical Details

Architecture

The plugin uses:

• FDK-AAC: Fraunhofer's high-quality AAC encoder
• DaVinci Resolve CodecPlugin API: Official plugin interface
• Ring buffer: Accumulates samples to match encoder frame size (1024 samples)
• Format conversion: Converts 16-bit PCM to float planar, then to int16 for FDK-AAC

Audio Pipeline

Resolve (16-bit PCM, stereo)
    ↓
Plugin (convert to float planar)
    ↓
Ring Buffer (accumulate 1024 samples)
    ↓
FDK-AAC (encode to AAC)
    ↓
MP4 Muxer (write to file)

Supported Formats

Development

Building for Development

# Build with debug symbols
cd src
make clean
make CXXFLAGS="-std=c++11 -fPIC -g -Wall -I. -Iinclude"

Project Structure

davinci-aac-fdk-plugin/
├── src/
│   ├── aac_encoder.cpp      # Main encoder implementation
│   ├── aac_encoder.h        # Header file
│   ├── plugin.cpp           # Plugin registration
│   ├── plugin.h             # Plugin header
│   ├── wrapper/             # SDK wrapper files
│   ├── include/             # SDK include files
│   └── Makefile            # Build configuration
├── install.sh               # Automated installer
├── README.md               # This file
├── LICENSE                 # GPL v3 license
└── docs/
    ├── BUILDING.md         # Detailed build instructions
    ├── TROUBLESHOOTING.md  # Common issues and solutions
    └── images/             # Screenshots

Contributing

Contributions are welcome! Please:

1. Fork the repository
2. Create a feature branch (git checkout -b feature/improvement)
3. Commit your changes (git commit -am 'Add new feature')
4. Push to the branch (git push origin feature/improvement)
5. Create a Pull Request

Areas for contribution:

• Support for more Linux distributions
• Additional audio formats (surround sound)
• Improved error handling
• Better documentation
• Testing on different DaVinci Resolve versions

Known Limitations

• Studio only: Free version of DaVinci Resolve does not support plugins
• Audio only: This is an audio encoder plugin (video must use built-in codecs)
• Stereo only: Currently supports 2.0 stereo only (no mono, no 5.1/7.1)
• MP4 and MOV only, no MKV: Resolve's Matroska (MKV) muxer writes a zero-duration audio track regardless of what this plugin sends it (confirmed via correct, verified PTS/Duration/timebase values that work correctly for MP4/MOV), and many players treat a zero-duration track as silent. This is outside what the codec plugin interface can control. As of v1.1.3, this codec is no longer selectable at all when MKV is the chosen container (Resolve's deliver page will gray it out / hide it from the audio codec dropdown) -- export to MP4 or MOV instead. See Troubleshooting for details.
• Linux only: This plugin is for Linux; Windows/macOS would need separate implementations
• Strict local players: Exported files may have no audio in some strict local players (QuickTime Player on macOS is the most commonly reported case), despite playing correctly in VLC/ffprobe and via streaming/web players. See Troubleshooting for a remux workaround.

FAQ

Q: Why FDK-AAC instead of FFmpeg's native AAC encoder?
A: FDK-AAC produces significantly higher quality audio, especially at lower bitrates. It's considered one of the best AAC encoders available.

Q: Does this work with DaVinci Resolve Free?
A: No. The free version does not support third-party plugins.

Q: What bitrate should I use?
A: For most purposes:

• 128 kbps: Acceptable quality
• 192 kbps: Good quality (recommended)
• 256 kbps: High quality
• 320 kbps: Maximum quality

Q: Can I use this for commercial projects?
A: Yes. The plugin is GPL v3, and FDK-AAC is available for use. Check your local laws regarding AAC patents.

Q: Why is the audio stream showing as "AAC LTP" / "64.0 kHz" (or even the wrong channel count/layout, e.g. "4 channels" / "C L R Cb") in MediaInfo instead of "AAC LC" / "48.0 kHz" / "L R" stereo?
A: This is a known MediaInfo display quirk, not an encoding defect, and it's been confirmed reproducible across multiple machines. The plugin always encodes correct AAC-LC stereo audio at the sample rate you set (44.1/48 kHz) -- MediaInfo's parsing of certain fields in the MP4 container metadata Resolve's muxer writes is unreliable, and it can misreport profile, sample rate, and channel count/layout, sometimes all at once on the same file.

You can confirm the real stream properties independently. Two options, no terminal required if you'd rather not use the command line:

• VLC: open the file, then Tools → Codec Information (or Window → Media Information → Codec Details on macOS). It reads the stream directly and will show the correct codec, channels, and sample rate.
• A right-click "Media Info" action using ffprobe -- see the example Nemo action under examples/ if you're on Linux Mint/Cinnamon.

Or from a terminal:

ffprobe -v error -show_entries stream=codec_name,sample_rate,channels,channel_layout,bit_rate -of default=noprint_wrappers=1 yourfile.mp4

Both read the codec configuration directly from the bitstream rather than relying on MediaInfo's heuristics, and will correctly report the AAC codec, your real sample rate, and stereo channel layout.

If a client reports a file "won't play" but it played fine through a streaming/web preview (Nextcloud, Google Drive, a browser), see the playback troubleshooting entry above -- that's very likely a local-player compatibility issue, not a broken export.

Acknowledgments

• Fraunhofer IIS for the FDK-AAC library
• Blackmagic Design for DaVinci Resolve and the plugin SDK
• toxblh for the davinci-linux-aac-codec project that demonstrated the plugin architecture
• The open-source community for testing and feedback

License

This project is licensed under the GNU General Public License v3.0 - see the LICENSE file for details.

Support

• Issues: GitHub Issues
• Discussions: GitHub Discussions

Changelog

See CHANGELOG.md for full details.

Version 1.1.3 (2026-06-22)

• Fixed: MKV was still selectable and still produced broken output after the 1.1.2 fix (registering it as unsupported wasn't enough to stop Resolve from allowing it). Added a runtime guard that actively blocks MKV export for this codec. Confirmed on real hardware: MKV no longer selectable, MP4/MOV unaffected.

Version 1.1.2 (2026-06-22)

• Removed MKV from supported containers -- Resolve's Matroska muxer writes a zero-duration audio track regardless of correct plugin output, causing silent audio in some players. Use MP4 or MOV instead.
• Documentation: broadened guidance on strict-player playback issues, added examples/ffprobe-info.nemo_action

Version 1.1.1 (2026-06-21)

• Fixed build failure (cannot find -lc++) by removing an unnecessary -stdlib=libc++ link flag

Version 1.1.0 (2026-06-20)

• Fixed channel negotiation bug that could produce 4-channel (LCRS) output instead of stereo
• Fixed MP4 track timing/esds metadata (correct time base + AudioSpecificConfig forwarding)
• Fixed selected bitrate not reliably reaching the exported file
• Bitrate is now a combobox (96-320 kbps, default 192)
• Locked to 16-bit PCM input, 2.0 stereo only
• install.sh now builds from src/ instead of an embedded copy

Version 1.0.0 (2025-10-27)

• Initial release
• AAC-LC encoding with FDK-AAC
• Support for MP4, MOV, MKV containers
• Configurable bitrate (96-320 kbps)
• 16-bit and 24-bit audio support

Made with ❤️ for the DaVinci Resolve Linux community