How to convert Flash Video files (FLV) to MP3

When you install and run the program, the main window will appear.

To convert FLV files, you must first add them to the processing list. To do this, click the Add files button and specify the desired FLV files. They appear on the list. Files can also be added using drag and drop.

The program includes a number of conversion profiles designed for the typical conversion tasks. They are available on the Profile drop-down list. To use one of profiles, simply select it on this list.

If you do not have experience in converting audio files, select the profile named Default encoder settings and click the Convert button to start the conversion.

At default settings, the application converts audio tracks from FLV files to MP3 using constant bitrate encoding (CBR), and automatically selects all the encoding parameters so as to preserve the original audio quality.

If you want to set manually parameters of the FLV to MP3 conversion, you can do it in the Audio section.

First, at the Output format list select MP3 – MPEG-1 Layer 3.

Then in the audio settings, select the desired bitrate, which will be used to encode the audio stream from FLV file to MP3 – this parameter determines the sound quality of the resulting MP3 file.
Bitrate is best set to a value close to the bitrate of the audio stream in the source FLV file. If you use a lower value, you should expect to lose sound quality. However, if you set the bitrate much higher than in the source file, the generated MP3 file will be very large, and the sound quality will be the same as using a lower bitrate.
If you set audio Bitrate in the Auto position, the program will automatically adjust the bitrate to a value close to the audio bitrate in the source file.

At default settings will be applied encoding at a constant bitrate (CBR). On the Bitrate mode list you can also set the variable bitrate encoding: ABR or VBR – Lame preset. You must remember that some older MP3 players support only MP3 files encoded at a constant bitrate, so if you want to use variable bitrate encoding, first check the documentation of your player.

Parameters Sampling frequency and Channels (the number of audio channels in the output file) is best left in the positions Auto, then the program automatically selects the appropriate values.

Using the Volume slider you can adjust the sound level in the resulting MP3 file. When set to 1x, the volume will not change.

In FLV files very often audio tracks are encoded using MP3 codec. In this case, you only need to extract the original audio stream and save it to an MP3 file. When extracting audio tracks, the sound does not change – the sound in the generated MP3 file will be the same as in the source file.

To obtain information which codec was used to encode the audio in FLV file, make sure that the column Audio codec is shown – right-click the table header and in the context menu with a list of columns, select the Audio codec.

On the picture above you can see that the sound in the files 2, 4 and 5 has been encoded by MP3 encoder. To extract the original MP3 audio tracks from these files, on the list Output format select Try extract original audio stream.

When you add FLV files to the processing list and set all the necessary parameters, you can already start the conversion by clicking the Convert button. The Conversion window will appear, where you can track the progress of the operation.

With default settings, the converted files will appear in the same directory that contains the source files. You can change output folder in the Output section. Generated MP3 files will have the same name as FLV files, only the extension is changed to .mp3.