cue problem

[Jirosan]

Sorry for bothering!

Poweramp is the most convenient app to listen to music i think.

It can identify cue files but there is a problem that when i listen to some tracks of cue and they start exactly at the first three seconds or further instead of zero second.

What's worse is that some tracks' beginnings are put into their last tracks' endings.

The mistake of dividing cue files is serious. I hope that it can be solved soon. Please give me some methods.

Thank you!

 

[andrewilley]

CUE files generally simply contain a series of timecode indexes for each 'song' that needs to be derived from a single large audio file. They are quoted as mm:ss:ff (where ff is frames, 75 per second, based from the original CD sector encoding). Poweramp will seek to that position within the long audio file (allowing for any silent pregap defined prior to the index point) and play up until the next index point.

There are two possibilities I can thing of: First, the CUE file entries might be wrong. You can easily edit a CUE file in a text editor, so try adjusting the start point ("INDEX 01") for one or two of the tracks, and after a rescan in PA see if it shows slightly different track durations and plays the music from a different starting point.

The second issue could be that your audio file does not contain sufficient seek 'helper' information, so although PA knows the exact minutes and seconds position into the file that it wants to play, it is unable to seek accurately to that location and has to make a best guess based on the sampling and bitrate and number of bytes into the file. That sort of problem could be exacerbated by variable bitrate encoding (VBR) and anything large stored in the header block (such as a big cover image). To test this, you could use an audio editor to create a plain uncompressed WAV file, with no header metadata or artwork at all, just raw 44.1kHz audio data. Then see if a CUE file pointed to it is able to seek to more accurate points within the file. 

Andre

[Jirosan]

Thank you for your advice!

I have tested these cue files in Foobar2000.They don't have problems.

I search the files with cue through my phone and listen to them again on the Poweramp:

"ALAC" don't have the problem.

"APE HIGH" have a little,but it is not worst. Most of them start a few milliseconds faster,but their endings is ok.

I search the worst one and find that its format is "TAK". But the header block isn't stored with anything large. 

Is it because of the format?

 

[andrewilley]

TAK files? Never heard of them until you said. Googling it, TAK was apparently originally called YALAC (Yet Another Lossless Audio Codec) which kinda says it all.  

ALAC is Apple proprietary, so probably harder to debug. APE is another fringe format, but quite heavy on processing for decoding so could use battery more quickly.  CUEs were originally designed for uncompressed WAV files of course, but that's not something you'd want to clog a phone up with.

For CUE-based music, probably best to stick with tried-and-tested formats like FLAC (for lossless) or MP3 (either CBR or with decent seek tables).

@maxmp might be able to check some of the other formats for you though if you submit test files with CUE sheets (would need to be via a file sharing facility as the files will be very big).

Andre

[maxmp]

Some formats or format encodings do not allow fast accurate seeking. Cue handling is based on seeking to the track position within large file, so this inaccurate seeking make cue tracks to be off.

I can say more if you share the track+cue (gpmaxmpz@gmail.com) for tests.

[ScarletNeko]

As a long time TAK user, I can say that Poweramp can play it fine, but it will be pretty hard to seek on higher profiles, and the wave seekbar will be kinda bugged sometimes. Same for APE, but turned up to 11 as APE compression can go pretty crazy.

If you want to use APE at insane or TAK at p5m, better to use a simple seekbar and not seek on them at all, just start the first song and let it play undisturbed. Also be mindful of your device power (as in performance) and battery because these formats at these settings are quite the thing to deal with.

These are better reserved to a PC since it is way more powerful (check your cpu usage when seeking on these files, it will spike), or to long playblack sessions where you won't be seeking on them.

Edit: if you want/need a format that compresses a bit better than flac and is easier to deal with, I recommend checking on wavpack. I've been using wavpack for a long time on Poweramp and they seek just fine while compressing better than flac, it also can do 32bit int and float but it does take a lot longer to encode. I recommend using -h -x4 settings.

Edited May 23, 2022 by ScarletNeko
Added a suggestion for another codec

[andrewilley]

58 minutes ago, ScarletNeko said:

As a long time TAK user, I can say that Poweramp can play it fine, but it will be pretty hard to seek on higher profiles, and the wave seekbar will be kinda bugged sometimes.

Which of course, as discussed above, wrecks any use of CUE sheets to create 'tracks' within a longer audio file. They rely on being able to seek to an exact mm:ss:ff position in order to commence playback of each individual song.

Andre 

[jaybeee]

I've been using Poweramp for many years now (it's a great player and love it, so many thanks) and it *seems* that the issue with inaccurate seeking/playback for vbr mp3s has become more prevalent. I cannot be sure on this, but I hadn't noticed the issue until very recently (using build-941-944).

I have 1000s of audio files that are DJ mixes (often 1-2hrs long) and many have cue sheets. Most of them are in the mp3 format.

So far, all the cbr ones play fine with a cue sheet, but the vbr ones are often considerably out of time. One file (57 mins long with 9 tracks in the cue sheet) I've just tested was almost exactly 60 seconds late!

Using that one as an example, it's a LAME 3.100 -V0 encoded mp3. So, a new mp3 encode with full seek tables (vbr header info etc) and fully compliant.

I used a tool called MP3Packer (actually used the frontend called WinMP3Packer) to "losslessly" (no re-encoding) change the vbr mp3 to a cbr mp3. When tested with the cue sheet it works fine.

I did this to prove that the file  isn't the issue, but it being a vbr and how Poweramp handles it with the cue sheet is.

So, I'm wondering has something changed in Poweramp?

If not, then could this be looked at please? Maybe looking into the mp3 decoder.

I don't have any issues accurately playing vbr mp3s with cue sheets in the Android foobar2000 app nor the foobar2000 Windows program (my main media player on my computer) with these files, just to give some comparison.

-

I understand that the way to eliminate this issue for the user is to use cbr mp3s or a format like aac when using cue sheets. The latter (and other formats) is fine when those are the native formats (or if there's a lossless version that can be transcoded to cbr mp3 or aac etc), but as I mentioned at the start, 1000s of these long (DJ mix) mp3s have been acquired over 20+ years of internet usage and that's the only format I have.

Plus, I wasn't expecting a modern player such as Poweramp to have issues with vbr mp3 playback with cue sheets. I know in the early to mid 2000s many mp3s were created without seek tables, which caused playback issues, but lame resolved that and decoders were improved to handle it.

I'm happy to provide the mp3 (vbr & cbr) files with cue sheet for someone to look at / test.

[andrewilley]

Please could you upload a sample file (would need to be a temporary file-sharing site due to the size).

CUE files of course were originally created to provide index points within CD rips - so usually constant-rate WAV files - and even if the CUE file is 100% accurate it may not be possible to perfectly seek to a location within a very long VBR MP3 file. Seek tables should help with that, and Max would be able to check that from your sample MP3-VBR / CUE files.

Andre

[jaybeee]

Many thanks.

Click for files

 

wrt vbr mp3s: as I say, foobar2000 (android app and pc) has no issues with any length + cuesheet I've ever tried - I have some 4hr+ files.

EDIT: meant to say that I think the transition from (cue sheet) track 5 to 6 is likely the best one to focus on when testing as it's the most obvious track change.

Edited October 18, 2022 by jaybeee
clarity over which cue sheet tracks to focus on