Encoders¶
Sixteen adapters in three families. Every one is offered only when the tools it needs are present - see Required and optional tools.
The encoder reference lists every option of every adapter, generated from the source so it cannot drift.
FFmpeg built-in¶
Eight encoders that need nothing beyond a working FFmpeg build.
| Codec | FFmpeg encoder | Output |
|---|---|---|
| Opus | libopus |
Ogg Opus (.opus) |
| FLAC | flac |
FLAC (.flac) |
| AAC | aac |
M4A (.m4a) or ADTS (.aac) |
| MP3 | libmp3lame |
MP3 (.mp3) |
| AC-3 | ac3 |
Raw AC-3 (.ac3) |
| E-AC-3 | eac3 |
Raw E-AC-3 (.eac3) |
| DTS | dca |
Raw DTS (.dts) |
| ALAC | alac |
M4A (.m4a) |
Availability depends on the FFmpeg build you point at, not just on FFmpeg being installed. A distribution build without libopus or libmp3lame shows those adapters as unavailable.
Standalone encoders¶
Three third-party command-line encoders, for cases where their output is preferred to FFmpeg's.
| Adapter | Profiles / modes | Output |
|---|---|---|
| opusenc | VBR, constrained VBR, or hard CBR; music/speech tuning | Ogg Opus |
| qaac (Apple AAC) | AAC-LC or HE-AAC; TVBR, CVBR, ABR, or CBR | M4A or ADTS |
| fdkaac (Fraunhofer FDK AAC) | AAC-LC, HE-AAC, or HE-AAC v2; CBR or VBR | M4A or ADTS |
These do not read your source file directly. FFmpeg decodes the selected stream to PCM and pipes it in - 24-bit WAV for opusenc, 16-bit WAV for the two AAC encoders. The external encoder writes straight to the queue's temporary output, so cancellation, progress, and atomic publishing behave exactly as they do for the built-in adapters.
qaac additionally requires a working Apple CoreAudioToolbox installation; its startup check determines availability.
DeeZy (Dolby professional)¶
Five adapters for licensed Dolby encoding, driving DeeZy, the Dolby Encoding Engine, and - for the immersive formats - TrueHDD.
| Adapter | Target / source constraint | Output |
|---|---|---|
| DeeZy DD | Auto, mono, stereo, or 5.1; downmix only, except explicit 5.0-to-5.1 | AC-3 |
| DeeZy DDP | Auto, mono, stereo, 5.1, or 7.1; downmix only, except explicit 5.0-to-5.1 | E-AC-3 |
| DeeZy DDP-BluRay | Fixed 7.1 from an 8-channel source | E-AC-3 |
| DeeZy Atmos | Streaming 5.1 or BluRay 7.1 from a valid Atmos source | E-AC-3 with Atmos |
| DeeZy AC-4 | Immersive stereo from 6+ channels or TrueHD Atmos | AC-4 |
All five support BS.1770 and Leq(A) metering, DRC, and downmix controls; Atmos and AC-4 add TrueHDD warp and bed controls.
These adapters behave differently enough from the rest to be worth reading about separately - see DeeZy encoders.
Choosing between them¶
- For Opus,
ffmpeg.libopusandopusencuse the same underlying library. opusenc exposes a slightly different control surface and hard CBR. - For AAC, FFmpeg's native
aacis the always-available option; qaac generally sounds better at low bitrates but is Windows-only; fdkaac is the portable middle ground and the only one offering HE-AAC v2. - For AC-3 and E-AC-3, FFmpeg's encoders are fine for general use. The DeeZy adapters exist for licensed Dolby workflows where the reference encoder's output is the requirement.