.m4a - sound files are shown with wrong duration. A file is shown with duration 19:25, immediately after start of playing it the current time jumps to 9:43 and progress is shown as 50%, updated smoothly from there.The stock player on the other hand displays the duration as 09:42, starting at 00:00. This behaviour has been seen with all files which were created by youtube-dl on linux The origin from youtube-videos may be significant. I have some .mp3 files created by youtube-mp3 online converter (http://www.youtube-mp3.org/)that show another type of duration misinformation, here an example file is shown as 18:13 but runs for 4:30 (there is some whitespace at the end of it). Factor 4 this time and here the progress bar starts at 00:00 and it skipps to the next song at 25%. However, the latter error is only with some .mp3 created that way while others behave as expected.