I have developed a mp3 player with Delphi (XE) using the BASS library.
Due to certain reasons, I want to remove the BASS libraries and want to use the TMediaPlayer
component in Delphi (also want to "move" the project to Delphi 10 Seattle).
Now I found out that some of my mp3 files have a "strange" jpg image embedded.
Means, that the Delphi components run into an error due to the image.
With long time debugging I can say the following:
try
mplMain.FileName := CurrentSong;
progbSong.Max := mplMain.Duration;
lblDuration.Text := DurationToString(mplMain.Duration);
PlayClick(Self);
except
on E: Exception do
begin
FMX.Dialogs.MessageDlg('Cannot play song: ' + CurrentSong + #10 + #13 +
'Reason: ' + E.Message,
TMsgDlgType.mtWarning, [TMsgDlgBtn.mbOK], 0,
procedure(const AResult: TModalResult)
begin
MediaNext;
end
);
end;
end;
This line:
mplMain.FileName := CurrentSong;
causes the problem.
Diving deeper in debugging it comes to here:
FMX.Media
library:
procedure TMediaPlayer.SetFilename(const Value: String);
...
FMedia := TMediaCodecManager.CreateFromFile(FFileName);
...
At the end it ends up in FMX.Media.Win
:
constructor TWindowsMedia.Create(const AFileName: string);
...
HR := FGraphBuilder.RenderFile(PChar(AFileName), nil);
...
When the line
HR := FGraphBuilder.RenderFile(PChar(AFileName), nil);
is called, in debug mode, the program just returns to the IDE.
In runtime mode, nothing happens. No error message, just "nothing".
As you can see, I wrapped the related line into a try...except
block, but no error is raised. The program/player doesn't continue.
That's very bad for me, because I wanted to catch this "special case" and log the affected mp3 files to a logfile so that I can change the embedded image.
I found out that it is only caused by some images. Maybe they are "somehow corrupt", but shown in all other players.
When I remove the image and embed a "new" one and save the file, everything is fine and the TMediaPlayer
can play the file.
How can I catch this certain kind of "error" to get the list of affected files?
I got it managed now. Only in debug mode the application/player is exited without any thrown error and I find myself back in the IDE.
During runtime the try...except block works, when I chose an "affected file" manually. For the case that one file is played ("good one") and the next file is a "bad one", I had to change my "MediaNext" procedure. In this procedure I also had a try...except block when the filename was associated to the TMediaPlayer, but I just had set a bool variable for further use and didn't "jump" to the next file.
The code just was:
Here I can implement a routine to log the affected mp3 files into a logfile and then jump to the next file (if exists). :-)
Thanks again to all!