Common problems Those problems are related to the current version: mpeg audio version != 1 BeSweet seems to write strange mp3 headers if the bitrate is < 112. To fix this you need to use another encoder (for example, FFMPEG produce compatible streams in the full bitrate range). Those problems are related to PMP Mod v1.00 & PMP Muxer v1.00: pmp_lib_open: frame size can't be 0 This error sometimes happen when the video is encoded with MEncoder. The cause is MEncoder writing "no data" frames (when a frame is equal to the previous). -vf harddup MEncoder option will solve this problem. Thanks to JimmyZ for the detailed report and to jimparis for a quick solution. (reference to the problem and some encoding script examples can be found here) pmp_decode_open: audio_output_length != 4608 This happens when the mp3 is mono (only stereo sound is supported). This problem will be probably addressed with a check for stereo on the muxer. Thanks to wracks for helping tracking this. sync lost This usually happens using BeLight with BeSweet 1.4. The correct BeSweet version to use is v1.5b31. pmp_lib_open: scale > 0xffffff This happens with some versions of VirtualDubMod. It will be corrected in the next release. Thanks again to JimmyZ for the report. pmp_lib_open: first frame is not a keyframe Sometime MEncoder seems to write a null first frame (a frame with a length of 0 bytes, not marked as keyframe). I wasn't able to replicate this myself, seems related only to some MEncoder versions (one user experienced this on a powerpc binary).