Hello ffmpeg team, I am transcoding one .wmv file to .mp4 file, it gets successfully transcode into h264/aac encoder. But, my problem is that Converted file size is twice than Source file size. Here is my command. ffmpeg -i CCC2009Sampler.wmv -acodec aac -vcodec libx264 -fpre "libx264-lossless_ultrafast.ffpreset" -crf 18 -strict experimental -y CCC2009Sampler.mp4 Details of source file: FileFormat :: asf AvgBitRate :: 2289 kb/s Duration :: 3020(Sec) AudioCodec :: wmav2 AudioBitRate:: 128 kb/s Channel :: Stereo SamplingRate :: 44100(Hz) VideoCodec :: wmv3 (Main) VideoBitRate :: 2200 kb/s FrameRate :: -1.0(fps) VideoSize :: 640*480 FileSize :: 864231560(bytes) Details of target file :: FileFormat :: mov AvgBitRate :: 3420 kb/s Duration :: 3020 AudioDetails :: aac VideoCodec :: h264 VideoBitRate :: 3368 kb/s FrameRate :: 29.97(fps) VideoSize ::640*480 FileSize :: 1291278946(bytes) Please consider my issue. I am waiting for your reply. Thanks, Vishal T. Nikam