Small simplification of finding the last sound to be created by pagePlayer
Use transcoded media during transcript playback, for more accurate seeking and audio length prediction.

When certain VBR-encoded files are played, they sync with the transcript correctly until a seek is performed. After a seek, the sync is off by several seconds, which is useless when trying to read along with a podcast.
Accurately jump to sentences upon clicking a timecode; wait for audio to buffer if not yet available.