audio gapless playback and cue sheet support

[VLC_help]

Small gap is OK (something like below 20-50 ms). I am guessing other players also use dual input, because I think you cannot initialize (load code, load part of audio file and decode it to playback butter) certain audio decoders real time, so before the first file ends, players start second input thread, do all needed steps and wait 'till first thread ends and immediately insert decoded audio to playback buffer. Crossfade also helps, but I don't know if iTunes or Foobar use it.

[kotao_78]

I can't evaluate how long (say 20~30ms)about the "gap" while playing mp3 , but I'm sure i can hear it by my ears , but neither does iTunes & foobar.

Are you sure the "gap" is caused by decoder cost time before output to alsa , not the generated by decoder itself?

[kotao_78]

I can't evaluate how long (say 20~30ms)about the "gap" while playing mp3 , but I'm sure i can hear it by my ears , but neither does iTunes & foobar.

Are you sure the "gap" is caused by decoder cost time before output to alsa , not the generated by decoder itself?

If yes , maybe we can do "pre-decoding" work before output.

[VLC_help]

Currently the gap is ~150 ms using 1.0.0 git builds under Win32 when changing between two WAV samples. (you can use Audacity and record stereo-mix/what-u-hear to measure the gap). Gap is generated in VLC because of closing down the old input (including playback device and decoder) and opening new input (including playback device and decoder).

[SDO]

if the next item to be played in a playlist is a file, local or not, it should not be a big deal to simply start feeding that data into the play buffer and continue so you have gapless playback. One thing that is making my head spin is how iTunes can do it, and VLC won't. I can understand with significantly different sources being a problem, but with the files being local there should be no issues of doing seamless/gapless playback but yet there is... Sad, VLC should do this without much effort.

[Jean-Baptiste Kempf]

if the next item to be played in a playlist is a file, local or not, it should not be a big deal to simply start feeding that data into the play buffer and continue so you have gapless playback. One thing that is making my head spin is how iTunes can do it, and VLC won't. I can understand with significantly different sources being a problem, but with the files being local there should be no issues of doing seamless/gapless playback but yet there is... Sad, VLC should do this without much effort.

Unfortunately, you don't seem to understand that dealing with lots of different codecs is not always easy. Moreover, VLC is more focused on VIdeo, so gapless video is way harder.

[kotao_78]

if the next item to be played in a playlist is a file, local or not, it should not be a big deal to simply start feeding that data into the play buffer and continue so you have gapless playback. One thing that is making my head spin is how iTunes can do it, and VLC won't. I can understand with significantly different sources being a problem, but with the files being local there should be no issues of doing seamless/gapless playback but yet there is... Sad, VLC should do this without much effort.

VLC support too much formats , i understand it's very hard to support lossy format , for lossless actually you just do some modifications.

[scar]

i would also appreciate gapless playback, with audio cd's and flac's, at least. mplayer can do it, check out their code. i can't find anything in linux that will do it except mplayer. problem is there are no decent frontends for mplayer.

[VLC_help]

mplayer and VLC playback architectures are different so copy&paste of code doesn't work.

[kotao_78]

i would also appreciate gapless playback, with audio cd's and flac's, at least. mplayer can do it, check out their code. i can't find anything in linux that will do it except mplayer. problem is there are no decent frontends for mplayer.

It's very easy if want to support CD gapless back , you know , CD has not gap between each tracks , just player separate by TOC information , you can ignore track EOF signal and do not open next input is enough , but you need modify some code of demux ... since you need compute duration and so on...

[intuited]

As someone entirely unacquainted with the VLC codebase, I have a few potentially stupid questions:
- is it possible to implement an option for certain types of sources (ie different codecs) and not others? Judging from the way the options are laid out this would seem to be true.
- could this feature be implemented on a best-effort basis, where if the option is checked and the next file is of a compatible format it will feed it into the buffer directly after the currentlly-playing file?
- are there unforeseen complications involved in testing for & skipping over silence at the beginning and end of tracks?
- how complicated is it to decode a source into buffer format (presumably raw audio/video) without actually sending it to the playback buffer right away?
- is it possible to apply the techniques used in making mplayer's gapless playback work to VLC without necessarily cut-and-pasting the code? Rhythmbox is another open-source app that supports this feature. granted, it doesn't support nearly the range of input types that VLC does.
- since you guys are so busy, how difficult and/or permissible would it be for somebody who considers this a high priority to jump in and work on it?
by the way, thanks for all your hard work. vlc is already the best player for pretty much any video format, and has tons of potential to be much more than that.

[Jean-Baptiste Kempf]

1) yes, but be carefull to differentiate, codec, demuxer, access
2) Nope
3) you cannot read a file too much ahead
4) Quite difficult
5) not at all
6) Everyone is welcome...

So, now, you want my real answer:
To have audio gapless, you should make VLC start opening/buffering the next item a few second before the end of the previous one (this means a change to the input core)
Once you have done that, this is easy, just mix the two audio channels together.

[felipead]

Please, this feature would be really, really, helpfull! Cuesheet is currently the only way to index continuous DJ mixes without spliting the WAV/FLAC/MP3 file (which would introduce gaps in the mix).

[pianoman]

Dear Team!

Me too, I would love so see the feature of playing back "cue sheet + large audio file" with VLC.
This would make it possible to have on my McBook the same playing capabilities as on my windows PC.
I really have many big FLAC files with a cue sheet, as I used to backup up my whole Jazz-CD collection in this way.

This is actually the last big feature I miss in VLC, on Windows-PCs there is foobar for this purpose.

With best regards.

[dima1]

I'm missing this feature to. Actualy it plays "big files with cue's" but in strange way... Seek bar is for all file, duration for each song is same and it is a duration of whole file... A name of song changes when I start playin it to a name of first song of cue... I dont understand why vlc cant normally play cue's like foobar or aimp or... others)

[DGMurdockIII]

i would like to see gapless playback of audio files

[djcsurf]

v1.1.4

It's good that I can play mix albums using the .CUE sheet but there is a problem with the playlist.

Initially it opens showing all the correct song titles & Im able to double click & play different tracks.
The problem is once I click a file the song title in the playlist changes to the default album name ie. "Cream 2006" instead of remaining as the track title.

So once I've listened to several tracks my playlist now just shows "Cream 2006" for all the different track titles, making the .CUE file now pretty useless.

[djcsurf]

Can j-b please give an answer regarding the CUE file/Playlist issue.
Will it be looked into & possibly fixed or left as is!

VLC is a great media player but for some audio fans the CUE file/Playlist problem is an issue causing people to use alternate software. The gapless playback via the CUE files is fine it's just the playlist problem.

[VLC_help]

Problem in your case is that VLC gets the first info from playlist file, but when file is played the VLC updates the info from the actual media file. If you remove metadata parsing from VLC, it might work as you want it to work, but naturally you would lose metadata support completely.

[djcsurf]

Thanks for the response...
If you mean 'Automatically preparse files' under 'Playlist' preferences, I de-selected & saved but the problem remains.

[VLC_help]

Preparse won't help in this case.

[Jean-Baptiste Kempf]

Can j-b please give an answer regarding the CUE file/Playlist issue.

File a bug with samples.

[djcsurf]

Bug report #4143 filed.

[adamlogan]

Seriously, the (well executed) addition of this feature would mean not only do you attract video fanatics, but you get audio fanatics too. For me, it would mean I need one program for video and audio. I wouldn't have to worry about finding various niche audio players with this capability on various OSes. VLC would be all I need. Don't forget to leave out the Ogg Vorbis (.ogg) format as well.

Get VLC to digest the .cue sheet in the playlist, figure out the cover art stuff, and VLC doubles in value in my opinion 200% gold.

[Jean-Baptiste Kempf]

Seriously, the (well executed) addition of this feature would mean not only do you attract video fanatics, but you get audio fanatics too. For me, it would mean I need one program for video and audio. I wouldn't have to worry about finding various niche audio players with this capability on various OSes. VLC would be all I need. Don't forget to leave out the Ogg Vorbis (.ogg) format as well.

Get VLC to digest the .cue sheet in the playlist, figure out the cover art stuff, and VLC doubles in value in my opinion 200% gold.

Then help us by providing .cue samples you need support of.