Converting DTS to AC3

From NMTWiki

This tutorial will allow you to convert DTS (Digital Theater Systems) Audio Stream in MKV files which Popcorn Hour cannot play due to licensing issues into AC3 Stream.

Contents 1 Windows 1.1 Prerequisites 1.2 Converting 2 Linux/OS X 2.1 Prerequisites 2.2 Using mkvdts2ac3 2.2.1 Installation 2.2.2 Usage 2.3 Step by Step 2.3.1 Get the track information 2.3.2 Extract the DTS track 2.3.3 Converting the DTS track to AC3 2.3.4 Remux the AC3 track into MKV 2.3.5 Verify 2.3.6 Delete temporary files 2.3.6.1 Keep the DTS and the AC3 track 2.3.6.2 Remove the DTS track 2.4 Possible errors

Windows

Prerequisites

• Download and save the MKV AudioConverter
• Run it and choose to view the tutorial
• Download the various utilities required by your conversion (for DTS-to-AC3 you need MKVToolnix, eac3to and DelayCut)

Converting

• Select the source file with the Browse button
• Name the output file via the Browse button
• Click "Run"
• Sit back and wait for the finished .MKV file

Linux/OS X

Prerequisites

Download and install the following:

• mkvtoolnix - Matroska (MKV) tools
• libdca - DTS to WAV decoder
• aften - WAV to AC3 encoder

Using mkvdts2ac3

Installation

Download the latest stable version of mkvdts2ac3, a bash script for automatic DTS to AC3 conversion in matroska files, and extract the tarball.

Usage

To convert the audio simply run the script with the following command:

/path/to/mkvdts2ac3 /path/to/matroska.file.mkv

The script will automatically extract the DTS track, convert it to AC3, and merge it back into the original file.

If you would not like to retain the DTS track in the final file you can run the script with the -n argument:

/path/to/mkvdts2ac3 -n /path/to/matroska.file.mkv

Once the script has completed it will display the "Total processing time: XXX seconds" and the bash prompt will reappear. You can ensure the AC3 track has been added by running:

mkvmerge -i /path/to/matroska.file.mkv

Step by Step

Get the track information

mkvmerge -i /path/to/matroska.file.mkv

Sample output

Track ID 1: video (V_MPEG4/ISO/AVC)
Track ID 2: audio (A_DTS)

This means that the matroska.file.mkv contains two tracks, a video track with id 1 and a DTS track with id 2.

Extract the DTS track

2 is the DTS track ID from the given example.

mkvextract tracks /path/to/matroska.file.mkv 2:/tmp/dts.file.dts

Converting the DTS track to AC3

dcadec -o wavall /tmp/dts.file.dts | aften - /tmp/ac3.file.ac3

Remux the AC3 track into MKV

mkvmerge -o /tmp/matroska.file.mkv /path/to/matroska.file.mkv /tmp/ac3.file.ac3

Verify

mkvmerge -i /tmp/matroska.file.mkv

Sample output

Track ID 1: video (V_MPEG4/ISO/AVC)
Track ID 2: audio (A_DTS)
Track ID 3: audio (A_AC3)

Delete temporary files

rm /tmp/dts.file.dts
/tmp/ac3.file.ac3

Keep the DTS and the AC3 track

Move the /tmp/matroska.file.mkv to the proper directory or overwrite the original file:

mv /tmp/matroska.file.mkv /path/to/matroska.file.mkv

Remove the DTS track

3 is the AC3 Track ID from the given example (see Verify)

mkvmerge -o /tmp/matroska.file.ac3.only.mkv -a 3 /tmp/matroska.file.mkv

Move the /tmp/matroska.file.ac3.only.mkv to the proper directory or overwrite the original file:

mv /tmp/matroska.file.ac3.only.mkv /path/to/matroska.file.mkv

Possible errors

dcadec: error while loading shared libraries: libdca.so.0: cannot open shared object file: No such file or directory

Copy the libdca.so.0 to /usr/local/lib/libdca.so.0 ater you built libdca