Directshowsource of Avisynth 2.6 lost first 50 frame for a MP4 file.

[trasit]

I met a strange problem.
I downloaded a 1 min 720 P film from the Youtube.
http://www.youtube.com/watch?v=qaOvHKG0Tio

I found that when I put it into avisynth, the first 50 frames were lost, it means first 2 secs of video disappeared.
I use the following:
DirectshowSource("Microsoft 2014 Super Bowl Commercial_ Empowering.mp4",fps=23.976,convertfps=true)

I can not find any clue that what the problem is.

If anybody have met the same problem?

[jagabo]

What you get with DirectShowSource() will depend on what DirectShow filters you have installed. I have no problem with that video and DirectShowSource() here. But try using ffms2 instead.

A=ffAudioSource("Microsoft 2014 Super Bowl Commercial_ Empowering.mp4")
V=ffVideoSource("Microsoft 2014 Super Bowl Commercial_ Empowering.mp4") 
AudioDub(V, A)

https://code.google.com/p/ffmpegsource/

[trasit]

What you get with DirectShowSource() will depend on what DirectShow filters you have installed. I have no problem with that video and DirectShowSource() here. But try using ffms2 instead.

A=ffAudioSource("Microsoft 2014 Super Bowl Commercial_ Empowering.mp4")
V=ffVideoSource("Microsoft 2014 Super Bowl Commercial_ Empowering.mp4") 
AudioDub(V, A)

https://code.google.com/p/ffmpegsource/

Many thanks for the tip, now I installed K-lite codec, the problem solved.