In Feb 2011 I had a similar question: ffmpeg and libmp3lame produces bad audio quality? Now I'd like to know if it is possible to the get the original audio quality from a (flash) video? Every time I convert a video, the quality is worse than the original quality, not much worse but you can hear the difference. These are my attempts:
avconv -i ~/"$2.flv" -acodec libmp3lame -c:v libx264 -qscale 1 -aq 1 -q 1 -vol 100 -ab 196608 ~/"$2.avi"
I tried to use the best quality -qscale 1, aq 1 and so on. I even tried to use -same_quant, I already tried -codec copy, shown in this thread, but then the quality is not better but even worse and I don't see any video then. Is there a way to achieve that? By the way, I don't care about the output format.
I made some test by downloading a video from YT and listen to it both on YT and on my local machine. I didn't convert the video, I just listened to a flv file itself and determined that the local quality is even worse than the file on YT. So I'm not sure if this is really an avconv problem. I wonder where this quality difference between the stream from YT and the downloaded file from TY come from. Any ideas?