Convert HEVC to AC3 — Free Online Tool
Extract and convert the audio track from an HEVC/H.265 video file into AC3 (Dolby Digital) format using the ac3 encoder at 192k bitrate. This is the go-to conversion for pulling Dolby Digital-compatible audio from H.265 encoded content for use in DVD authoring, Blu-ray workflows, or home theater systems.
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FFmpeg Command
Copy this command to run the same conversion locally with FFmpeg on your desktop. Download FFmpeg
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Note: Browser-based encoding uses approximate quality targets. For precise CRF compression, copy the FFmpeg command above and run it on your desktop.
Estimated output:
Conversion Complete!
DownloadHow It Works
HEVC (.hevc) files contain a raw H.265 video stream, but this conversion targets only the audio track embedded within — the video is discarded entirely and only the audio channel is processed. FFmpeg decodes the audio stream from the HEVC container and re-encodes it using the ac3 codec (Dolby Digital), a lossy compression format developed by Dolby Laboratories. Because AC3 is a pure audio format, the output .ac3 file contains no video data — just a Dolby Digital audio stream ready for muxing into DVD, Blu-ray, or broadcast containers. The default 192k bitrate is appropriate for stereo content; surround sound (5.1) content typically benefits from higher bitrates like 384k or 640k to preserve spatial audio fidelity.
What Each Flag Does
| Flag | What it does |
|---|---|
ffmpeg
|
Invokes the FFmpeg multimedia processing tool. In this browser-based tool, FFmpeg runs locally via WebAssembly (ffmpeg.wasm) — no data leaves your machine. |
-i input.hevc
|
Specifies the input file — an HEVC/H.265 raw video bitstream file. FFmpeg will probe this file for available streams; in this conversion, only the audio stream will be used in the output. |
-c:a ac3
|
Sets the audio codec to ac3, which encodes the output using Dolby Digital compression. This is the codec required for standard AC3 output compatible with DVD players, Blu-ray systems, AV receivers, and broadcast equipment. |
-b:a 192k
|
Sets the audio bitrate to 192 kilobits per second, the default for stereo Dolby Digital content. For 5.1 surround sound sources extracted from HEVC content, increasing this to 384k or 640k is strongly recommended to avoid audible quality loss across all channels. |
output.ac3
|
Defines the output filename with the .ac3 extension, producing a raw Dolby Digital audio bitstream. This file contains only the re-encoded audio — no video, subtitles, or container metadata from the original HEVC source are included. |
Common Use Cases
- Extracting Dolby Digital audio from an HEVC-encoded film or TV episode for authoring onto a DVD or Blu-ray disc that requires AC3 audio tracks
- Preparing audio from H.265 surveillance or broadcast footage for integration into a broadcast television workflow that mandates Dolby Digital compliance
- Pulling the audio from an HEVC home video and converting it to AC3 for playback on a home theater receiver or AV amplifier that decodes Dolby Digital but not raw H.265 audio
- Stripping and transcoding the audio component of an H.265 file for use as a standalone AC3 track to be muxed into an MKV or VOB container separately from the video
- Converting commentary or secondary audio tracks from HEVC source material into AC3 for compatibility with DVD authoring software like Adobe Encore or DVDStyler
Frequently Asked Questions
No. AC3 is a pure audio format — it cannot contain video data. When you convert an HEVC file to AC3, FFmpeg extracts and re-encodes only the audio stream; the H.265 video stream is completely discarded. If you need to keep the video, you would instead mux the AC3 audio into a container like MKV or MP4 alongside the video stream.
Yes. AC3 (Dolby Digital) is a lossy codec, so some audio quality is lost during encoding regardless of the source. If the HEVC file's audio was already lossy (e.g., AAC or MP3), you are performing a lossy-to-lossy transcode, which compounds the quality degradation. For best results, use the highest bitrate the AC3 format supports (640k) when quality preservation is critical, and avoid transcoding from lossy sources more than once.
For 5.1 surround sound, the default 192k bitrate is too low and will result in noticeably degraded audio. Dolby Digital 5.1 typically requires at least 384k for acceptable quality, and the Blu-ray standard uses 640k for lossless-like fidelity. In the FFmpeg command, change '-b:a 192k' to '-b:a 384k' or '-b:a 640k' to accommodate surround channels properly.
Raw HEVC files (with the .hevc extension) often contain only the H.265 video bitstream and no audio track at all, since .hevc is typically used for raw video data. If your file has no audio stream, FFmpeg will produce an empty or errored output. You may need to work with a containerized version of the file (such as an .mkv or .mp4 containing H.265 video) if you expect an audio track to be present.
To increase the output bitrate, change the '-b:a 192k' flag to a higher value supported by the AC3 codec. For example, use '-b:a 384k' for 5.1 surround content or '-b:a 640k' for maximum Dolby Digital quality. The full modified command would look like: ffmpeg -i input.hevc -c:a ac3 -b:a 384k output.ac3. Note that AC3 has a maximum bitrate of 640k.
Yes. On Linux or macOS you can loop over files in the terminal: 'for f in *.hevc; do ffmpeg -i "$f" -c:a ac3 -b:a 192k "${f%.hevc}.ac3"; done'. On Windows Command Prompt, use: 'for %f in (*.hevc) do ffmpeg -i "%f" -c:a ac3 -b:a 192k "%~nf.ac3"'. This is particularly useful for the desktop FFmpeg command shown on this page, which is ideal for batch jobs or files larger than 1GB that exceed the browser tool's limit.
Technical Notes
The AC3 (Dolby Digital) format supports a fixed set of bitrates ranging from 96k to 640k, and the encoder will reject values outside this range. Channel layout matters significantly: AC3 supports up to 5.1 channels, and if the source HEVC audio is stereo, the output AC3 will be stereo at the specified bitrate. Metadata such as chapter markers, subtitle tracks, and multiple audio streams are not preserved in this conversion — AC3 is a raw audio bitstream format with no container-level metadata support of that kind. If the HEVC source audio is encoded in a format with a very different sample rate or channel count, FFmpeg will automatically resample and remix to match AC3's requirements, which can introduce subtle quality changes. AC3 is natively supported by most DVD and Blu-ray players, AV receivers, and broadcast decoders, making it an excellent interchange format for professional video post-production pipelines. However, for modern streaming or archival use cases, more efficient codecs like EAC3 (Dolby Digital Plus) or AAC may be preferable.