[Ffmpeg-user] Encoding SWF files using audio codec CODEC_ID_ADPCM_SWF

Hello newsgroup! I want to create SWF files, therefore I am using output format "swf". I also want to add a audio stream so I am using CODEC_ID_ADPCM_SWF. But this codec cannot be opened, because of wrong codec parameters (bit rate, sample rate or something like that). No my question is: Does anyone know which codec parameters can be used for CODEC_ID_ADPCM_SWF? Or is it better to use MP3 as audio stream for SWF files? Are there any problems when using MP3 with SWF output format? Thank you lot for your suggestions! Sincerly Lars