v1.14.5
Some songs looked like they were playing but made no sound. One URL was quietly returning two different files.
Reported as "gana play ho raha par sound nahi ara" — the track appeared to be playing normally, the progress bar moved, and nothing came out of the speakers. Nothing was reporting an error, which is exactly why it was hard to see.
Playing, but silent
A browser does not fetch a song in one go. It asks for the beginning, works out what kind of file it is and how long it is, then asks for the rest in pieces. Those requests have to be answered from the same file, and they were not. Measured on one track: the opening request came back as one format about thirteen megabytes long, and the follow-up requests came back as a completely different format about six megabytes long. The player had already worked out the song from the first answer, so the later pieces meant nothing to it — it could not decode them, but nothing had actually failed either, so it just carried on showing a playing track and produced silence. The cause was that two different sources were being used for the same song, and which one answered depended on the shape of the request. Songs are now matched to one source and stay on it.
YouTube tracks failed roughly a fifth of the time
The streaming helper is refused by YouTube at random — measured at twenty percent of requests, and never twice for the same reason. It was being asked once and taken at its word. Of twelve refusals observed, all twelve succeeded when simply asked again, so it is now retried before anything is given up on.
Tracks that stopped partway now say so
YouTube limits how much of a track can be read from one link — measured at about one megabyte, which is roughly thirty seconds to a minute of music, and the limit does not move no matter how many times a fresh link is fetched. That length is now stated up front, so a track that can only be partly played is a short track that finishes cleanly instead of one that appears full length and stalls in silence. Songs available in the main catalogue are played from there instead, where no such limit exists.