Naive question about digital encoding

I have what it likely a very naive question about the digital input to my DAC, but its puzzled me for a while and I'd like to understand what's happening.

I have an older DAC that I have connected to my DVD player which acts as a transport. Regardless of whether I play CD's or DVD's, the whole thing works and the system sounds fine. The DAC is designed to accept a 16 bit/44 khz signal, and I assume that the DVD audio is encoded at 24/96. What's happening with the DAC when I play DVD audio through it? I would expect to hear nothing intelligible since the formats presumably aren't the same, but this doesn't seem to be the case. Can anyone explain what's being output by the DVD player in both cases, and how the DAC is able to interpret both types of input?

Thanks, Ken
Not all DVDs are recorded with 24/96 sampling rate. If your dac is a 16/44.1 unit it will pass 16/44.1 and that's it. The 24/96 will play through it at 16/44.1 and the additional resolution bits/samples are "thrown on the floor" meaning they are discarded and not played. Nothing really wrong with this setup, except that you won't get the additional resolution available on the 24/96 discs.
You won't get anything in the DVD-A format per se through your DAC, as the player will not pass the DVD-A signal through its digital outputs. To hear the DVD-A, you need to use the player's analog outputs.

What you're getting from the DVD player's digital output is (probably) already 16/44.1 stereo, regardless of whether you're playing a CD, DVD-A or DVD-V. At least some DVD players can be setup to output 96kHz, however, for those DACs (and sources) which support it.
Hate to burst your bubble, but you're not listening to "DVDs" at all. There's a separate 16/44.1 recording on each DVD disk, and that's what's being sent to your DAC. In all likelihood, this is exactly the same thing you'd find on a CD of the same recording. If you want to hear something better than 16/44.1, you've got to bypass the DAC and hook the analog outs of the DVD player directly into your preamp.
Thanks for all of the responses. As always, when all else fails, RTFM. The DVD player has an option buried deep in the setup menu for specifying the format of the digital output, which in my case is set as "incompatible with 96khz". I'll have to assume this means that it outputs 16/44.1.

I should do my homework before posting :-}.

Thanks again. Ken