Is gapless working with mp3 files?

[knifeedge]

Hi! I'm considering buying wiim pro or plus (ultra was also on the list but airplay absence can be an issue sometimes for me), but I have a question:
is the gapless supported also for mp3 files?
Those files play gapless in itunes or neutron app, but I have yet to find an hardware streamer/player that does gapless on lossy formats.

Thanks in advance!
Andrea

 

[Popal]

It is. It works just like magic out of the box.
Tested with my Wiim Pro Plus with my Synology DLNA Server, Plex DLNA and SMB direct.

 

[mlsstl]

There is a limit to the ability of MP3s to be completely gapless. It's inherent in how the files are compressed to lossy format with a slight bit of padding added to the very beginning and end of each file. So, depending on how the song starts or ends you may notice a very slight pause in between tracks that you wouldn't hear with the FLAC, WAV or other lossless versions. It's not the player's or software program's fault. It is just tied to the nature of how MP3s are made. (Some other lossy formats handle that padding in a more sophisticated manner so the gap would not be as noticeable.) Wikipedia has a good technical article on gapless playback.

 

[slartibartfast]

There is a limit to the ability of MP3s to be completely gapless. It's inherent in how the files are compressed to lossy format with a slight bit of padding added to the very beginning and end of each file. So, depending on how the song starts or ends you may notice a very slight pause in between tracks that you wouldn't hear with the FLAC, WAV or other lossless versions. It's not the player's or software program's fault. It is just tied to the nature of how MP3s are made. (Some other lossy formats handle that padding in a more sophisticated manner so the gap would not be as noticeable.) Wikipedia has a good technical article on gapless playback.

MP3 is perfectly gapless with LMS. I download live concerts from dimeadozen and convert them to MP3. Works perfectly.

 

[knifeedge]

Thank you all! Yes I know, not always gapless mp3 is properly working. But, given they were properly encoded, 99.9% of the contiguous tracks is ok with proper reader. Glad to know wiim does the trick!

 

[mlsstl]

MP3 is perfectly gapless with LMS. I download live concerts from dimeadozen and convert them to MP3. Works perfectly.

Here's an illustration of what happens with FLAC versus MP3 files. The first image is the first few seconds of the second song on an album that was recorded gapless. You can see the music starts instantly.



Here's the exact same file after it was saved to MP3 format instead of FLAC. You can see the file has added a very short, silent interval before the music starts. The file format is the ONLY difference between the two files.



Now, depending on how the tracks are split and what is taking place sound-wise during three-one hundredths of added silence, this is often unnoticeable. However, on this particular recording, it would be noticed. And this added time is quite different from the longer gap that media software may introduce if it is not capable of gapless playback. And, yes, I'm aware that LMS does a fine job of handling gapless playback. I've been using that software and its previous versions since the I started with the SliMP3 player over 20 years ago. However, LMS will not fix the gap shown in the MP3 file image shown above, though you'll not notice it with many albums due to where the split between tracks was made.

 

[slartibartfast]

Here's an illustration of what happens with FLAC versus MP3 files. The first image is the first few seconds of the second song on an album that was recorded gapless. You can see the music starts instantly.

View attachment 9598

Here's the exact same file after it was saved to MP3 format instead of FLAC. You can see the file has added a very short, silent interval before the music starts. The file format is the ONLY difference between the two files.

View attachment 9599

Now, depending on how the tracks are split and what is taking place sound-wise during three-one hundredths of added silence, this is often unnoticeable. However, on this particular recording, it would be noticed. And this added time is quite different from the longer gap that media software may introduce if it is not capable of gapless playback. And, yes, I'm aware that LMS does a fine job of handling gapless playback. I've been using that software and its previous versions since the I started with the SliMP3 player over 20 years ago. However, LMS will not fix the gap shown in the MP3 file image shown above, though you'll not notice it with many albums due to where the split between tracks was made.

Which MP3 encoder produced that silence at the beginning of the track?

 

[mlsstl]

Which MP3 encoder produced that silence at the beginning of the track?

This will be present with any MP3 encoder -- refer to the technical article from Wikipedia mentioned earlier concerning gapless playback and compression artifacts. .

"Lossy audio compression schemes that are based on overlapping time/frequency transforms add a small amount of padding silence to the beginning and end of each track. These silences increase the playtime of the compressed audio data.[1] If not trimmed off upon playback, the two silences played consecutively over a track boundary will appear as a pause in the original audio content. Lossless formats are not prone to this problem.

For some audio formats (e.g. Ogg Vorbis), where the start and end are precisely defined, the padding is implicitly trimmed off in the decoding process. Other formats may require extra metadata for the player to achieve the same. The popular MP3 format defines no way to record the amount of delay or padding for later removal.[notes 1] Also, the encoder delay may vary from encoder to encoder, making automatic removal difficult.[2] Even if two tracks are decompressed and merged into a single track, a pause will usually remain between them."

 

[slartibartfast]

This will be present with any MP3 encoder -- refer to the technical article from Wikipedia mentioned earlier concerning gapless playback and compression artifacts. .

"Lossy audio compression schemes that are based on overlapping time/frequency transforms add a small amount of padding silence to the beginning and end of each track. These silences increase the playtime of the compressed audio data.[1] If not trimmed off upon playback, the two silences played consecutively over a track boundary will appear as a pause in the original audio content. Lossless formats are not prone to this problem.

For some audio formats (e.g. Ogg Vorbis), where the start and end are precisely defined, the padding is implicitly trimmed off in the decoding process. Other formats may require extra metadata for the player to achieve the same. The popular MP3 format defines no way to record the amount of delay or padding for later removal.[notes 1] Also, the encoder delay may vary from encoder to encoder, making automatic removal difficult.[2] Even if two tracks are decompressed and merged into a single track, a pause will usually remain between them."

Those articles were written in 2000/2001. LAME has evolved since then.

LAME (Lame Aint an MP3 Encoder) / Bugs / #453 gapless decoding issues

sourceforge.net

 

[mlsstl]

Those articles were written in 2000/2001. LAME has evolved since then.

LAME (Lame Aint an MP3 Encoder) / Bugs / #453 gapless decoding issues

sourceforge.net

Thanks for the update. Looks like you should make an update to the Wikipedia article!

And, lots of variables present in the Sourceforge article and it looks to apply only to LAME, and still has some situations where it still won't work quite right. Interestingly, since my car's infotainment system will not play FLAC files, I'd converted some of my music to MP3 for a thumb drive using a bulk convertor I purchased. I pulled that same song used in my prior example from the USB drive which had been converted to MP3 in 2023 by a bulk convertor. It has a .longer gap of .052 seconds instead of an .03 gap seen in my prior example (created with Adobe Audition). And a 2024 update to the bulk convertor program didn't change that.

 

[knifeedge]

If I remember well, but I have to verify and now I'm in super relax vacation, info of added silence and how to manage it, can be embedded in the mp3 file. Anyway, my mp3s sounds perfectly gapless with itunes, aimp, or neutron. Hope is the same with wiim streamers, as you all said.