Multiple audio options on a single disc - Possible problem?

[Beholder]

Blu-ray discs have varying storage capabilities depending on the number of layers on the disc (I think typically 25, 50 or 100 GB). Apparently some films are closer to this limit than others, depending on film duration, number of extras and various other factors.

Since some discs contain multiple audio options, I wonder if this is sometimes achieved at the expense of audio- or video bit rate? For example, could a single layer 25GB disc realistically contain an average 2 hour film, some extras and multiple lossless audio options, or should one assume that in such case, some compromises have been made along the way?

Is it even possible to make a rough estimate of how much storage space each individual audio track requires?

[bhampton]

I'll start from the last question.

It is possible to know exactly how big the audio track is in any case. No rough estimate needed.

The size of the audio and video tracks is known when a disc is authored.

A lossless audio track which represents all of the audio is still much smaller in size than the video track and the video is ALWAYS compressed.

So,... you can rest assured that compromises were made every time because there is not lossless video compression.

Now, streaming compresses both the Video and the Audio to the very maximum resulting in compromises that tend to be notice-able. Streaming media needs to be very small for bandwidth concerns. Basically streaming is awful but sometimes awful is popular (see fast food for an example.)

[Beholder]

Thanks. What's the size of an average dts-hd 5.1 audio track? Is there a way to check this on a normal blu-ray player?

[bhampton]

I found a thread on AVSForum that details the audio file sizes on disc. Looks like Audio tracks are about 4GB generally.


https://www.avsforum.com/threads/new...hread.1155731/