Fragmented MP4 creation

[pmuvva]

Hi,
I am able to create Normal MP4 file by passing "mp4"string to avFormatContextForOutputPath() in ffmpegwrapper.c file. It works fine but when I am setting fragmented MP4 by setting av_opt_set(outputFormatContext, "movflags", "empty_moov+default_base_moof+frag_keyframe+dash", 0);
I am getting below error
E/FFmpegWrapper: av_interleaved_write_frame video: 1 pkt: 1 size: 25945 error: Operation not permitted.
E/FFmpegWrapper: av_interleaved_write_frame video: 0 pkt: 1 size: 565 error: Operation not permitted .

Any help will be appreciated...