ari-party
commented
2 weeks ago I tried to replicate the described issue but I was unable to.
I downloaded 3 of the latest Fireship videos and the same for @homedesign369.
All videos showed the correct duration from ffprobe's input.duration.
And I was able to play all videos with the playback bar correctly showing the duration with Windows Media Player.
Could you possibly expand on what platforms (e.g. YouTube) this issue occurs on? And possibly link the videos for future contributors? (I won't be contributing to this issue.)
why does this happen?
to preserve privacy and maintain efficiency, cobalt merges & streams videos with ffmpeg right away, without ever storing or caching anything on disk.
as result, final file length cannot be predicted, so it's missing from headers of some downloaded files.
what's affected?
this happens only when live rendering is used, most often with youtube videos. older software (vegas pro, windows media player, default players on lower end android devices) cannot generate file length, so it's either missing or shows up as some obnoxious number like 4294967295.
what can be done about it?
at the moment, this is not something that can be fixed, as it's the nature of live rendering process.
however, in most cases, the issue can be worked around by using modern software instead. for playback, vlc media player can be used instead. other (and most accessible) playback option is the built-in media player in any modern web browser.
you can also "fix" files with missing timestamp by remuxing them with ffmpeg:
if you know how to solve this issue in cobalt's rendering pipeline, feel free to make a pull request!
previous related issues
these issues were closed in favor of this one, as they all describe the same problem, but in different apps:
94
204
255
345
348
374
420
483
564