i recently encounted this .m4c file type video clip,
i couldnt find a support codec, who would do me a favor of inform me which encoder to use? or specific video player operations.
tried to use splitter + ffdshow +MPC; none of the three actually support this file type. 
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I suggest that you download a “Vistacodece”.It has a very full decoder, with the use of MPC.
Hope can solve the problem.
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