Video format convert

I use Ultra Flash Video Flv Converter convert some .mkv files to .flv format,but the sound is not the same as the original files,the sound quality is very bad.the flv files can’t be used.I convert some rm files,they working fine.How to solve the problem?

Has this tool worked for you before? I’ve never used it.

I usually go with WinFF.

44100Hz sample rate, and use either 96kbps for just someone talking or 128kbps for music.

yah,there is.but there’re several options,which one should I use?Try it one by one?

I use 44100Hz sample rate,96kbps,get the same result.Any solution?

Is there an option to change the sample rate and bitrate?