Ever since 300 update. Everything I get from Riverside plays back slo-mo audio. They're wavs play fine. The mp4s playback fine in VLC Player. The RS MP4s encoded in Shutter Encoder still play back with slo-mo audio. Older MP4s from Riverside also NOW slo-mo. MP4s rendered in Vegas are playing fine on the timeline. (Mp4 to Mp4)
This is a known issue with all mono audio in video files. Either separate the audio and convert to wav or check "enable legacy AVC decoding" in preferences/video if they are in AVC files.
This is suddenly happening with files that played fine before. I will try the other suggestions, but this has to have something to do with the latest update.
Yes, this is a known issue with the new decoder in build 300 and mono audio. There are many threads here about it and replies from VEGAS engineers who are fixing it.
Enable legacy AVC to perform like build 208 with the so4compound decoder.