Documenting Problems That Were Difficult To Find The Answer To

Past Duration 0.999992 Too Large

While encoding a video in ffmpeg I encountered the message:

Past duration 0.999992 too large
Last message repeated 11 times

The problem magically disappeared when I changed audio codec and bitrate for the output stream.

My input stream reported itself as:

Stream #0:2: Audio: ac3, 48000 Hz, 5.1(side), 448 kb/s

But the settings I used to encode the stream to give me the error were:

-c:a:1 aac -b:a:1 160k -metadata:s:a:1 title="5.1 channel"

Note that the input stream was ac3 but I was converting it to aac on the output. Not necessarily a bad thing for stereo output, but for 5.1 maybe not the best target codec. The ffmpeg wiki high quality audio guide states the ac3 codec is for Dolby Digital.

When I changed to the following settings the error message disappeared:

-c:a:1 ac3 -b:a:1 320k -metadata:s:a:1 title="5.1 channel"

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