Sorry it took so long to review your project more carefully.
Your animation has 1080 frames, as shown in the dopesheet or graph views. Your timeline FPS is 60 (the default is 30).
When you export, you can choose a different frame rate:
- If you choose 60 when exporting, you'll get the same number of frames as the dopesheet or graph: 1080. This will show as 0 to 1079. 1080 frames / 60 FPS = 18 seconds.
- If you choose 30 you'll get 540 frames, shown as 0 to 539. 540 frames / 30 FPS = 18 seconds.
- If you choose 20 you'll get 360 frames, shown as 0 to 359. 360 frames / 20 FPS = 18 seconds.
In all cases the duration in seconds of the animation is correct. How many frames your export has depends on the frame rate you choose. I think this is why when you choose other export types you see a different number of frames -- the frame rate setting is different for the other export types.
I see this all working correctly in 4.2.09-beta. When I open your project and go to export, I see:
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Look at the "Range" part:
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This shows 0-1079 possible frames. The values that have been typed are 0-359 frames, meaning your export will only have the first 360 frames of the possible 1080. To export all frames, uncheck that box:
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While I see it working correctly in 4.2.09-beta, your screenshot looks odd. This part:
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Where is the "Range" checkbox?! The only reason it should not appear is if your animation has only 1 frame.
