FLAC encoding very slow

[adnoiseam]

Hello,

I used to encode .flac files from .wav with the frontend thingie provided on the FLAC site, but wished to switch to Dbpoweramp. I installed it, as well as a few codec, including the latest version of the FLAC one.
While decoding (flac->wav) goes smoothly, the encoding (wav->flac) is extremely slow with Dbpoweramp. All the other codecs seem to work fine, and the encoding with the basic FLAC frontend was quite fast on the same machine. Where can this problem come from?

Nicolas

[xoas]

Re: FLAC encoding very slow

Where can this problem come from?

I'm not sure. I did try downloading and installing the FLAC codec and did a few conversions. I didn't run into any problems. But here are a few things you could try:

1) lower the priority for your conversions (mine is set to below normal)-in some circumstances (by avoiding asking the processor to try to do too much at once) you can actually convert faster by converting slower. You can change the priority for a conversion on the screen that appears to show the progress of the conversion;
2) DSP effects will cause a conversion to go slower if you are applying them, you might consider turning these off for more speed (on the other hand, I was running Simple Volume Normalization on my two samples);
3) The degree of compression will affect the speed of the compression (it takes longer to wring more compression out of a file). I did find that when I set compression to "High" there was some slowdown but not as much as I would have thought (paradoxically my smallest post-conversion file size was from the "medium" setting not from the "high" setting);
4) Some of your results may depend on your system and system resources-no matter what your system the more you can do to free up system resources during conversion the faster your conversion should go (at least up to a point);
5) Spoon used to suggest that dMC works somewhat more slowly the more codecs you have installed (though right now I have about a dozen not counting Test convert, tag from filename, AAC to MP4 and Audio CD).

So those are a few ideas about known causes for slow conversion. You might see if any of these tips or ideas are useful for you. Keep us posted. If these aren't helpful enough, you might want to let us know a few more details (how slow is your conversion and for what size of wav file, what are the other characteristics of your wav files).
Best wishes,
Bill Mikkelsen

[adnoiseam]

Re: FLAC encoding very slow

thank you for your answer.

I don't use any DSP effects. And I have a lot of codecs installed, but this doesn't seem to slow down the other Codecs (see the Monkey's Audio example below). Moreover, the FLAC decoding (flac -> wav) goes all right.

Here is a test, on WinXP Pro SP1, with 512 M of RAM and a 1GHz processor

-

Original file: 1 minute of music, wav file - 10,336 Kb

-

Comparison: FLAC front End / FLAC codec for DbPowerAmp

FLAC Front End, compression level 8:
conversion time: 13 seconds - end file: 5.408 Kb

DbPowerAmp, FLAC Codec, compression level high, no DSP used, priority normal:
conversion time: 1 minute 1s (more than the duration of the track) - end file: 5,494 Kb

DbPowerAmp, FLAC Codec, compression level high, no DSP, priority low:
conversion time: 59s - end file: 5,408 Kb

-

Comparison: Monkeysaudio front End / Monkeysaudio codec for DbPowerAmp

MonkeysAudio End, compression level Extra High:
conversion time: 6 seconds - end file: 5,148 Kb

DbPowerAmp, MonkeysAudio Codec, compression level Extra High, no DSP used, priority normal:
conversion time: 6 seconds - end file: 5,155 Kb

DbPowerAmp, MonkeysAudio Codec, compression level Extra High, no DSP used, priority low:
conversion time: 6 seconds - end file: 5,155 Kb

So it all seems to be ok, except that the FLAC encoding is extremely slow (1:1, more or less 5 time slower than the Front end).

Nicolas

[Spoon]

Re: FLAC encoding very slow

What are other peoples timings for flac encoding?

BTW dBpoweramps HIGH setting for flac might be higher and slower than setting 8.

[adnoiseam]

Re: FLAC encoding very slow

BTW dBpoweramps HIGH setting for flac might be higher and slower than setting 8.

Mmmm...

FLAC Front End, compression level 8: end file: 5.408 Kb

DbPowerAmp, FLAC Codec, compression level high: end file: 5,494 Kb

Nicolas

[xoas]

Re: FLAC encoding very slow

What are other peoples timings for flac encoding?

Two trials (no DSP, Celeron 1.3 GHz processor, Windows XP Home w/SP1):
1. Wav file, 67 seconds, 11638 kb;
converted to:
FLAC Low, 7180 kb, 3 seconds
FLAC Medium, 7148 kb, 4 seconds
FLAC High, 6966 kb, 45 seconds (1.4x RealTime Encoding)

2. Wav file, 73 seconds, 12711 kb.
Converted to:
FLAC Low, 6924 kb, 2 seconds (38x RealTime Encoding)
FLAC Medium, 6740 kb, 3 seconds (21x RealTime Encoding)
FLAC High, 6871 kb, 49 seconds (1.4x RealTime Encoding)

I do think Nicolas should get MUCH better speed using the Medium setting and he may not lose any space overall (please note that the smallest file size in the second trial here and in my first trial this morning (which was unclocked and with DSP) the smallest file size was achieved from the medium setting, not from the high setting).

I remember that before Spoon went on vacation there was a thread about comparisons between the dMC FLAC settings and the FLAC levels with the FLAC front-end codec to which Spoon provided the settings for the FLAC Front End codec and the settings for the dMC FLAC codec settings. I do recall that there were some differences between the settings for FLAC front end level 8 and dMC FLAC High which may explain some of these anomalies but this is the level where it gets too high tech for me.

Best wishes,
Bill mikkelsen

[Spoon]

Re: FLAC encoding very slow

I will make a note to jig the high setting, or even add the same settings as flac encoder.

[Spoons]

Re: FLAC encoding very slow

i'm not sure what flac front end means?

anyhow , my conversion:

file size: 37.2 MB (39,046,988 bytes)
file type: wav
convert to: right click -->convert to-->Flac- medium
time: 22 seconds

P3 - 900MHZ 512ram. IBM notebook.

[adnoiseam]

Re: FLAC encoding very slow

Another comparison:

Original file:
Wav vilfe, 1 min long, 10.399 Mb

encoded with FLAC Frontend, encoding level 8:
14 seconds - end file: 5.105 Mb

encoded with DBPowerAmp, compressiong level Medium:
4 seconds (!), end file: 5. 175 Mb

encoded with DBPowerAmp, compressiong level High:
1 minutes 2 sec, end file: 5.272 Mb

Conclusion: DbPowerAmp FLAC codec with medium compression works faster and compresses more than the FLAC Frontend, and that the same codec with high compression. Seems like something is wrong with the high level of encoding...

Nicolas

[adnoiseam]

Re: FLAC encoding very slow

i'm not sure what flac front end means?

The software that comes ready to use on flac.sourceforge.net

Nicolas

[Tiscan]

Re: FLAC encoding very slow

Hey all,

First off damn fine software, I plan to register it... as soon as this particular issue is resolved. The High flac encoding is most certainly broke. As a matter of fact if you encode the same song on medium and high the high actually ends up being a larger file then the medium!!

Any idea on if/when this is going to be resolved? I have my cash and CD collection ready to go.

Thanks!

[xoas]

Re: FLAC encoding very slow

Glad you like the software.
The only person who can say when this issue (the FLAC codec high compression setting) will be resolved is Spoon. He is the person who is responsible for all the programs you see here. He might resolve it quickly, maybe not (he does have a lot of other projects going just for these programs and this is not his day job).
You may register or not. Most parts of the programs here are free. At this point in time the only parts you need to pay for are the Power Pack (which adds extra features to the other programs), the Sveta Portable Audio program (which currently is free if you have the Power Pack), and the dBpowerAMP CD Writer. Soon the whole packaging will be changing in part because Spoon is being asked to pay for the use of mp3 codecs in his programs by the mp3 license holders and in part because Spoon has been working towards greater integration of the various programs you see here. You can get an idea of the changes in this new package if you download dBpowerAMP Music Converter r. 11 beta 5a (from the Beta section of this forum). As part of these changes the mp3 codec will be made part of the Power Pack.
In the meantime, you may do aas you wish but you could always start by converting your cd collection to FLAC medium now and reconvert to FLAC High Compression when that gets fixed. Since it is lossless to lossless conversion you shouldn't lose anything. Or you could use one of the other lossless codecs at high setting if space is that critical to you.
Best wishes,
Bill Mikkelsen

[Tiscan]

Re: FLAC encoding very slow

Humm..

I have been playing with the latest beta and it seems it has the very same issue. I will post about it in the beta forum.