eac3to

eac3to is a command-line tool for Windows, originally written by madshi, for working with Blu-ray (and HD DVD) content and its audio. It lists the titles on an unencrypted disc folder, demuxes the video, audio, subtitle and chapter tracks of a chosen title, and converts audio between formats: decoding DTS-HD MA, TrueHD and LPCM to FLAC or WAV, extracting the DTS core from a DTS-HD track, applying delays and gain, and fixing frame-rate (speed-up/slow-down) conversions.

For most remuxing work, FFmpeg and MKVToolNix are simpler and run on every platform; MKVToolNix opens Blu-ray playlists directly. eac3to is still used when you want its title listing for a disc folder or its audio handling in one step.

Get it

madshi stopped development at version 3.36. The code was handed over to the DG tools developers (DGDecNV), who publish new builds at rationalqm.us/eac3to and support it on their forum. It is a portable archive: extract it to a folder and add that folder to PATH. Some conversions (for example AAC or DTS encoding) depend on external encoders that are not bundled; eac3to -test reports which are found.

Usage

The general form is:

eac3to source [title)] [track: destination ...] [options]

List the titles of a disc folder, then the tracks of one title:

eac3to "D:\Movie\BDMV"
eac3to "D:\Movie\BDMV" 1)

A number followed by ) selects a title (playlist); a number followed by : selects a track in it. Extract several tracks of title 1 in one pass:

eac3to "D:\Movie\BDMV" 1) 1: chapters.txt 2: video.mkv 3: audio.flac 4: subs.sup

The output extension decides what happens to each track: .flac or .wav decodes audio losslessly, while a matching extension (.dts, .thd, .ac3) copies the stream. -demux extracts the main video track and all audio tracks in their original formats.

Other common jobs:

eac3to input.dts output.dts -core          # keep only the DTS core of a DTS-HD track
eac3to input.ac3 output.ac3 +200ms         # delay audio by 200 ms
eac3to input.dts output.flac -slowdown     # 25 fps PAL audio to 23.976 fps

Option	Effect
-core	Extract the DTS core of a DTS-HD track, or the AC3 core of a TrueHD track.
+100ms, -100ms	Delay or advance audio.
+3dB, -3dB	Change the gain.
-slowdown, -speedup	Undo PAL speed-up (25 to 23.976 fps), or apply it (23.976 to 25 fps).
-down16	Reduce decoded audio to 16-bit.
-downStereo, -downDpl	Downmix to plain stereo or Dolby Pro Logic II.
-keepDialnorm	Keep dialogue normalisation, which eac3to otherwise removes when decoding.
-demux	Extract the main video track and all audio tracks in their original formats.
-log=file.txt	Write the log to a specific file.

Read eac3to’s output before trusting the result: it reports problems such as gaps or overlaps in the source and what it did about them.

Related pages

• Handle audio and subtitles
• MKVToolNix and FFmpeg
• FLAC and Dolby audio formats