How to merge AAC audio stream and H.264 video, with increasing delay on audio?

Question

I have an H.264 video stream and an AAC audio stream that are to be multiplexed into an MKV file. I've got this going mostly fine using mkvmerge on Linux, however for each set of streams I find that the audio stream is too fast, by 1 second per hour. These videos are 2.5 hours end to end so by the end the audio is 2.5 seconds ahead.

I know that the audio is fast, as opposed to the video being slow, but for that comparatively tiny offset, I don't really care which of the two streams is changed, but can anyone suggest a method under Linux that can force these two streams to be exactly the same length?

Answer 1

I suspect the easiest way to achieve that would be to just mux in the video with a slightly higher frame rate. That should have the effect of slightly increasing the speed of the video.