Skip to main content ↑ ↓

Notice

Please note that most of the software linked on this forum is likely to be safe to use. If you are unsure, feel free to ask in the relevant topics, or send a private message to an administrator or moderator. To help curb the problems of false positives, or in the event that you do find actual malware, you can contribute through the article linked here.
Topic: VLC flac playback different from other players? (Read 7035 times) previous topic - next topic
0 Members and 1 Guest are viewing this topic.

VLC flac playback different from other players?

I recently purchased some FLAC files and noticed a loud pop at the end of each track. This was present playing in foobar and on my Squeezeboxes. I emailed the company I got them from and they said they play OK in VLC which is their recommended player. I was dubious but indeed they do play fine in VLC. I tried converting them to WAV using Soundforge, dbP and flac.exe and in all cases the pop was there, leading me to believe that the files really include the noise. So any ideas why VLC is different?

My plan is to try and figure out how to get VLC to convert to WAV and then reencode the FLACs...the first time I tried this I got garbage out but I need to RTFM

VLC flac playback different from other players?

Reply #1 –
VLC uses it's own FLAC decoder that is installed as a Windows DLL plugin called "libflac_plugin.dll" in the plugins subfolder of the main VLC folder

The others likely use FLAC's "flac.exe" file to decode FLAC files.


You should be able to have VLC save the output of any FLAC file played to a WAV file by going to Tools -> Preferences -> Audio

Set the Output Type to "File Audio Output", which will then allow you to set the name of the .wav file to save to and the location of where to put it.


EDIT:  You'll find that VLC has custom decoders for many video/audio codecs.

VLC flac playback different from other players?

Reply #2 –
Could this be caused by ID3v1 tags appended to the FLAC files? If so they should be possible to remove without reencoding.

VLC flac playback different from other players?

Reply #3 –
Quote from: WonderSlug on
You should be able to have VLC save the output of any FLAC file played to a WAV file by going to Tools -> Preferences -> Audio

Set the Output Type to "File Audio Output", which will then allow you to set the name of the .wav file to save to and the location of where to put it.

Thanks - I'll try that. Of course no way to prove the ouptut is bitperfect but it's better than cutting the pops out manually

Quote from: dv1989 on
Could this be caused by ID3v1 tags appended to the FLAC files? If so they should be possible to remove without reencoding.

I actually thought about that as I've seen instances of that before. However the usual approach of clearing all tags from inside mp3tag didn't fix the audio. Do you know of any other tools which do a good job of getting rid of ID3v1?

EDIT: I also tried the --delete-all option from id3v2 on Linux but that didn't help either, so I'm guessing they're not id3 tags (or at least not valid ones).

VLC flac playback different from other players?

Reply #4 –
Quote from: radish2 on
Thanks - I'll try that. Of course no way to prove the ouptut is bitperfect but it's better than cutting the pops out manually


You can compare the WAV file generated by VLC with one generated by FLAC.

1.) Play the FLAC file 'source.flac' with VLC and have it write the output to file 'vlcflac.wav'

2.) Use the FLAC 1.2.1 executable to decode 'source.flac' to 'flac121.wav'

3.) Open up a CMD window (cmd.exe) in Windows XP/Vista/7 and compare the two WAV files:

(assuming both WAV files are in the same directory folder)

comp vlcflac.wav flac121.wav



This will compare the files byte-by-byte and notify you of any differences.

VLC flac playback different from other players?

Reply #5 –
Right, but the point is I'm hoping they WILL be different  The output from flac.exe has the pop in it, the output from VLC (hopefully) won't. What is harder to tell is whether VLC has additionally mangled the signal (it removed the pop, who know's what else it did?). The best I can probably do is truncate them both to some portion which doesn't include the pop and compare those bits.

VLC flac playback different from other players?

Reply #6 –
Hmm...the one thing I can think of to look for specifically in the VLC-decoded WAV is whether there is a very short fade-out at the end of the file (assuming, of course, that there is audio right up until the pop...and I guess that's another question:  Does the pop occur right at the end of the active audio, or right at the very end of the track, when it's otherwise silent?).

edit:  radish2, where did you buy these FLAC files from?  I certainly wouldn't mind buying one track just to be able to examine it myself.
"Not sure what the question is, but the answer is probably no."
 

VLC flac playback different from other players?

Reply #7 –
The pop is actually in silent lead out in most of the tracks, but I'll check whether that's the case in all of them. The files came from a company called Topspin who do branded stores for artists (in this case Hybrid). I don't think you can buy the tracks individually, I got them as part of a whole album. I'd be happy to send you one if you want to see it, for research purposes of course