I am a novice ffmpeg user trying to mux h.264 video with a secondary .wav commentary track, without re-encoding anything on the video side. The video's audio is in .aac.
I use Bandicam to record footage; there is a setting to record a separate .wav file (the commentary) simultaneously.
When I initially tried to figure this out, I opened a thread (link at the bottom) and was quite thrilled with the helpfulness of the user that responded. The answer seemed to satisfy my question completely. Now, however, I have a new problem and I'd thus like to ask about it openly.
Some recordings are returning the error I mentioned in the header when I try to mux the commentary back onto the video. "Input buffer exhausted before END element found" is the error. The files finish muxing, but if the error happens enough times, noticeable video/audio desync occurs in the video. I updated my FFMPEG executables to the latest builds, and the previous helpful soul pointed out I might have "malformed audio streams."
But again, (1) it's not all of them, only some, and (2) both audio streams (original recording audio and commentary) sound flawless when I load the .mp4 into Movie Studio. So I'm tempted to say ffmpeg/avanti is the culprit.
Regardless, I have no idea what the solution could be. Please help if you have any idea.