Supported Formats
Dubby can play virtually any media format. Files that aren’t natively supported by your device are automatically transcoded.
Video codecs
Section titled “Video codecs”| Codec | Web | Apple TV | Android TV | Shield Pro |
|---|---|---|---|---|
| H.264 (AVC) | Direct | Direct | Direct | Direct |
| H.265 (HEVC) | Transcode | Direct | Direct | Direct |
| VP9 | Direct | Transcode | Direct | Direct |
| AV1 | Direct | Transcode | Transcode | Transcode |
When transcoding is needed, the server converts to H.264 (broadest compatibility) using hardware acceleration if available.
Audio codecs
Section titled “Audio codecs”| Codec | Web | Apple TV | Android TV | Shield Pro |
|---|---|---|---|---|
| AAC | Direct | Direct | Direct | Direct |
| AC3 (Dolby Digital) | Transcode | Direct | Passthrough | Passthrough |
| EAC3 (DD+) | Transcode | Direct | Passthrough | Passthrough |
| DTS | Transcode | Transcode | Passthrough | Passthrough |
| TrueHD | Transcode | Transcode | Transcode | Passthrough |
| Opus | Direct | Transcode | Direct | Direct |
| FLAC | Direct | Direct | Direct | Direct |
| MP3 | Direct | Direct | Direct | Direct |
Default transcode targets by platform:
- Web — AAC stereo (browsers don’t support surround via MSE)
- Apple TV — AC3 5.1
- Android TV — AC3 5.1 (AAC via HDMI passthrough causes silence)
- Shield Pro — EAC3 (supports Atmos; lossless formats passthrough natively)
Audio bitrate defaults: 384 kbps for 5.1+, 192 kbps for stereo.
Container formats
Section titled “Container formats”For direct play (HTTP Range):
| Container | Web | Apple TV | Android TV | Shield Pro |
|---|---|---|---|---|
| MP4 / M4V / MOV | Direct | Direct | HLS | Direct |
| MKV | HLS | HLS | HLS | Direct |
| WebM | Direct | HLS | HLS | Direct |
| AVI | HLS | HLS | HLS | HLS |
Files in unsupported containers are remuxed (repackaged without re-encoding) into HLS, which adds minimal overhead.
HDR formats
Section titled “HDR formats”| Format | Web | Apple TV | Android TV | Shield Pro |
|---|---|---|---|---|
| HDR10 | Not supported | Passthrough | Passthrough | Passthrough |
| HLG | Not supported | Passthrough | Passthrough | Passthrough |
| Dolby Vision P5 | Not supported | Passthrough | HDR10 fallback | Native decode |
| Dolby Vision P7/P8 | Not supported | HDR10 fallback | HDR10 fallback | Native decode |
When a device doesn’t support the source HDR format, the server tonemaps to SDR automatically.
Subtitle formats
Section titled “Subtitle formats”| Format | Type | Support |
|---|---|---|
| SRT | Text | Extracted and delivered as WebVTT |
| ASS / SSA | Text | Converted to WebVTT (styling simplified) |
| WebVTT | Text | Native support |
| PGS / SUP | Image-based | Burned into video (requires full transcode) |
- External subtitles (files next to the video) are auto-detected during library scan
- Embedded subtitles (inside the container) are extracted and delivered separately
- Image-based subtitles (PGS) must be burned into the video stream, which triggers a full transcode
What plays where — quick reference
Section titled “What plays where — quick reference”| Source format | Web | Apple TV | Android TV | Shield Pro |
|---|---|---|---|---|
| H.264 + AAC (MP4) | Direct | Direct | HLS | Direct |
| HEVC + AAC (MKV) | Transcode | HLS | HLS | Direct |
| H.264 + AC3 (MKV) | Transcode audio | HLS | HLS | Direct |
| HEVC + TrueHD (MKV) | Full transcode | Transcode audio | Transcode audio | Direct |
| HEVC + HDR10 | Transcode to SDR | Passthrough | Passthrough | Passthrough |
| HEVC + Dolby Vision | Transcode to SDR | Passthrough (P5) | HDR10 fallback | Native DV |