I need to convert .webm files to .flv. I have used
'exec("ffmpeg -i 1.webm -acodec libfaac -ab 96k -ac 2 -vcodec libx264 -vpre hq -crf 22 -threads 0 1.flv");'.
When i use the above code, the file is converting to 1.flv with 0 bytes. No data is in 1.flv file.