Reauthoring A Blu-ray Disc

In addition to creating AVCHD or BDMV discs from scratch, MultiAVCHD can be used to remove content from existing discs. This can be used for a variety of purposes. Most commonly it is used for removing either entire titles (including menus) or specific audio or subtitle streams from backups.

In many cases this will allow you to backup a dual layer original to a single layer (BD-R) disc. If the original disc contains several episodes, instead of a single main movie file, you could also create a backup with those episodes split between two discs. And, of course, even if your blank disc is big enough, you may wish to remove unwanted extras.

If you haven't already installed MultiAVCHD, you should do so now. You can find a complete list of the required software, along with links to download it, on the first page of this guide.
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Entering Reauthor Mode

In order to reauthor a Blu-ray disc with MultiAVCHD, you must first load the disc as your source. Use the second source button from the left.


MultiAVCHD will then ask if you want to switch to Blu-ray re-author mode. Obviously you need to answer Yes. In re-author mode, most of MultiAVCHD's options won't be available, and some which are available (like disc size) won't actually do anything. The main purpose of this mode, and what we will be looking at here, is removing content while retaining the original disc structure.



Next MultiAVCHD will examine the structure of your Blu-ray disc files. Depending on a variety of factors, this can take several minutes. Once this has finished, use the Properties button to start the reauthoring process.

Title Properties Dialog

The Title Properties dialog is where you can examine each title, determine what streams it contains, and remove audio or subtitle streams, or even entire titles, from your disc.

1. Title list

Every title on your disc will be listed here. This includes both actual titles and menus. The information displayed in the rest of this window will reflect whatever title is selected here.

2. Properties

You can get additional information about the selected title here, including the video encoding used, resolution, duration, framerate, and size of the video stream.

3. Preview

Basic information about the title may not be enough to identify it. You can use the Preview button to get a selection of still images which hopefully will clear up any confusion.

4. Blank title

Use this button to remove an entire title. Blanking a title will preserve the M2TS file, but remove the video and audio.

5. Audio streams

Rather than removing an entire title, you may prefer to remove extra audio streams. There are two basic types of audio found on Blu-ray discs. If you want to save as much space as possible, it's generally best to get rid of any audio identified as SD. Just make sure to also check the number of channels. There may be multiple audio streams which appear similar, except that one has 5 or more channels, while another is only in stereo. The first step in removing an audio stream is selecting it from this list.

6. Subtitles list

You can also remove individual subtitle streams by opening the Subtitles tab. Subtitles are significantly smaller than audio streams, but it's common to see many subtitle streams for featured titles.

7. Remove or Blank streams

Once you have an audio or subtitle stream selected from their respective lists, these buttons can be used to remove them. In terms of size, there won't be any difference between removing or blanking a stream. Functionally, there is a slight difference since you can reverse a blanking operation (at least before you create your output files), but removing a stream is harder to undo.

Once you have gone through the entire list of titles, close the Title Properties dialog.

Creating Your Disc

As in the basic instructions on the first page of this guide, the final steps will be setting a destination folder to create your new files in and telling MultiAVCHD what kind of disc to make.

Destination Path

At the bottom left you will find the option to set the folder where MultiAVCHD will create your Blu-ray or AVCHD disc structure. Aside from making sure there is enough free space on the drive it resides on, you might not really care where this is if you have the burning option set. Of course that you might need to know where your files are if there are problems.

You can also enter a suffix here, which will be appended to the name of the folder. That way you can have all your MultiAVCHD output in folders which start with the same text and still customize each one for the contents.

Start

The Start button will bring you to one last dialog where you need to select the type of disc you are making.

Select destination and backup device type Dialog

In this case, you should pretty much always select Blu-ray disc. Since we haven't re-encoded any of the video from the original disc, it will almost certainly violated AVCHD specs. This may or may not be a problem for your standalone player, but selecting Blu-ray is still the safest bet. Feel free to experiment with AVCHD Disc to see if the results play in your standalone player.

Encode, Author, and Burn

Once you select the type of disc to author, MultiAVCHD will perform any necessary encoding, author the files to create the disc structure, and burn with ImgBurn if selected. You may want to go ahead and put a blank disc in your burner if you are walking away from your computer while it runs.

Discuss on the forums

We have a thread on our Blu-ray ripping forum dedicated to this guide and MultiAVCHD in general. Let us know what you think, and what else you would like to see added to the guide. Did we get something wrong? Is something important to you that's missing? Help us make this guide better for you and the next person who reads it.

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