FlacExtractor can detect spurious/garbage FLAC frame headers within encoded FLAC data

[Tolriq]

Version

Media3 1.1.0

More version details

No response

Devices that reproduce the issue

All

Devices that do not reproduce the issue

No response

Reproducible in the demo app?

Not tested

Reproduction steps

Play the media with ffmpeg extension enabled for flac.

Expected result

Either the media have 2 small glitches like when playing with VLC, or the media stops at the invalid data like with the Pixel MediaCodec decoder, or the media stays in buffering state.

Current behavior can't be properly detected by code and the user only see constant flash between buffering and playing and do not understand if there's an issue on the media or the player or network issues.

Actual result

The media get stuck and ExoPlayer keeps switching between playing and buffering.

2023-08-02 15:21:17.807 T:ExoPlayer 
state [eventTime=162.93, mediaPos=121.83, window=0, period=0, BUFFERING]
2023-08-02 15:21:17.807 T:ExoPlayer 
isPlaying [eventTime=162.93, mediaPos=121.83, window=0, period=0, false]
2023-08-02 15:21:17.810 T:ExoPlayer 
state [eventTime=162.94, mediaPos=121.83, window=0, period=0, READY]
2023-08-02 15:21:17.811 T:ExoPlayer 
isPlaying [eventTime=162.94, mediaPos=121.83, window=0, period=0, true]
2023-08-02 15:21:17.968 T:ExoPlayer 
state [eventTime=163.10, mediaPos=121.83, window=0, period=0, BUFFERING]
2023-08-02 15:21:17.975 T:ExoPlayer 
isPlaying [eventTime=163.10, mediaPos=121.83, window=0, period=0, false]
2023-08-02 15:21:17.980 T:ExoPlayer 
state [eventTime=163.10, mediaPos=121.83, window=0, period=0, READY]
2023-08-02 15:21:17.981 T:ExoPlayer 
isPlaying [eventTime=163.10, mediaPos=121.83, window=0, period=0, true]

Above logs is repeated indefinitively.

Media

Sent by mail.

Bug Report

• You will email the zip file produced by adb bugreport to dev.exoplayer@gmail.com after filing this issue.

[Tolriq]

Bump, still happens on last version and still very disturbing for users.

[jacobgkau]

This is still happening.

While @Tolriq suggested playing back the files with "2 small glitches like when playing with VLC," he said on his support forum that he's ideologically opposed to playing back corrupted files because they could "damage people's ears" somehow. It still seems like playing the file (as all other media players do) would be ideal, but there should at least be some kind of error-out instead of the rapid play/pause events.

[Tolriq]

It's actually Google ideology here ;) But thank again for the nice bad rating on Play Store for an issue you can fix in 10 seconds with flac command line that you are well aware of ;)

[jacobgkau]

Ok, it sounds like this library needs to expose some kind of error when encountering a corrupted file as opposited to stalling with the repeated play/pause events, then.

@rohitjoins Were you able to recreate the issue here? Do you need any more samples of affected files?

[icbaker]

or the media stops at the invalid data like with the Pixel MediaCodec decoder

This sounds similar to #2587.

What behaviour do you see when playing the file in this issue with the FLAC extension?

[Tolriq]

@icbaker The problem is really about ffmpeg decoder here and the fact that it does not error.

In this case those files seems to always have a checksum error, so it's actually OK that it errors. Errors are something that app can detect and properly report to users.

Here ExoPlayer just constantly switch between buffering and ready and never moves or error, so impossible to properly detect and warn the user (And killing battery if they don't notice).

So failing would be good and it's what's wanted as I perfectly understand not playing invalid files. Just need a way to detect.

[icbaker]

Just need a way to detect.

Does ffmpeg throw an error that we could detect if we were looking for it? If not, then I think (just as you point out this isn't your issue to solve in the thread linked above), this is likely an issue to report to ffmpeg. If there is an ffmpeg error thrown that we could detect, please let us know the details of that.

In the general case, ExoPlayer cannot promise to detect all possible forms of invalid file and always throw an error. The expected behaviour of playing an invalid file with ExoPlayer is undefined.