Liquidsoap

FLAC with 24 bit decoded audio volume is too low.

Details

  • Type: Bug Bug
  • Status: Resolved Resolved
  • Priority: Minor Minor
  • Resolution: Fixed
  • Affects Version/s: None
  • Fix Version/s: 1.0.0+dev
  • Component/s: None
  • Labels:
    None
  • Environment:
    CentOS 5.5, libsamplerate-0.1.8, flac-1.2.1

Activity

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Romain Beauxis made changes -
Field Original Value New Value
Assignee Romain Beauxis [ toots ]
Romain Beauxis made changes -
Status Open [ 1 ] In Progress [ 3 ]
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Romain Beauxis added a comment -
Hi!

Thanks for including a test file!!

Unfortunately, I cannot reproduce. I have tried this and it worked:
  liquidsoap 'output.ao(single("/tmp/bla.flac")) set("log.level",4)'

Could you tell us more about your issue? And, if possible, include logs and perhaps a script?

Thanks
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Romain Beauxis added a comment - Hi! Thanks for including a test file!! Unfortunately, I cannot reproduce. I have tried this and it worked:   liquidsoap 'output.ao(single("/tmp/bla.flac")) set("log.level",4)' Could you tell us more about your issue? And, if possible, include logs and perhaps a script? Thanks
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Martin Konecny added a comment -
I'd guess this has something to do with the system libraries Liquidsoap uses for playing FLAC correct Romain? Vittee, can the command line utility mplayer play this file on your system?
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Martin Konecny added a comment - I'd guess this has something to do with the system libraries Liquidsoap uses for playing FLAC correct Romain? Vittee, can the command line utility mplayer play this file on your system?
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Vittee Nakka added a comment -
Hi,

Sorry for the delay.

After re-investigating the issue, I found out that the file can be played in Liquidsoap, with some problem.
The 24 bits FLAC sound is too quiet compared to 16 bits FLAC, I don't know what cause this, but I can hear it as usual via various players (foorbar2000, windows media player, mplayer, etc)

The issue of track begin skipped was caused by the "eat_blank" operator which I instruct it to skip a track which is too quiet.

BTW, The actual root cause of this issue is that the decoding of 24 bits FLAC file is too quiet.
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Vittee Nakka added a comment - Hi, Sorry for the delay. After re-investigating the issue, I found out that the file can be played in Liquidsoap, with some problem. The 24 bits FLAC sound is too quiet compared to 16 bits FLAC, I don't know what cause this, but I can hear it as usual via various players (foorbar2000, windows media player, mplayer, etc) The issue of track begin skipped was caused by the "eat_blank" operator which I instruct it to skip a track which is too quiet. BTW, The actual root cause of this issue is that the decoding of 24 bits FLAC file is too quiet.
Romain Beauxis made changes -
Summary FLAC with 24 bit per sample won't play. FLAC with 24 bit decoded audio volume is too low.
Description FLAC with 24 bit per sample will not play.

The decode accept the file, but when the track starts playing, it suddenly finish, forcing the next to play.
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Vittee Nakka added a comment - - edited
Hi,

I've looked into ocaml-flac source code and noticed that flac_stub.c does not handle 24 bit flac properly.

Here's just a dirty and quick fix (decoding only).

at function:

static inline double sample_to_double(FLAC__int32 x, unsigned bps)

at line 400 add this case to switch statement

    case 24:
      return (((double)x)/0x007fffffL);


and, TADA! 24 bit FLAC files are now decoded properly, I can hear it loudly and clearly :)

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Vittee Nakka added a comment - - edited Hi, I've looked into ocaml-flac source code and noticed that flac_stub.c does not handle 24 bit flac properly. Here's just a dirty and quick fix (decoding only). at function: static inline double sample_to_double(FLAC__int32 x, unsigned bps) at line 400 add this case to switch statement     case 24:       return (((double)x)/0x007fffffL); and, TADA! 24 bit FLAC files are now decoded properly, I can hear it loudly and clearly :)
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Martin Konecny added a comment -
Great! Please patch upstream :)
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Martin Konecny added a comment - Great! Please patch upstream :)
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Romain Beauxis added a comment -
Just done, thanks!

Is there any reason for you guys to release a new ocaml-flac soon? The bug does not seem that bad to me and I'd like to wait a bit to see if other issues may be reported.

However, if you need this fix pushed, I'll do it quickly..
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Romain Beauxis added a comment - Just done, thanks! Is there any reason for you guys to release a new ocaml-flac soon? The bug does not seem that bad to me and I'd like to wait a bit to see if other issues may be reported. However, if you need this fix pushed, I'll do it quickly..
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Romain Beauxis added a comment -
Ha, I forgot: it would be nice if you could confirm that I did the right thing, although I'm quite confident but you never know :-)
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Romain Beauxis added a comment - Ha, I forgot: it would be nice if you could confirm that I did the right thing, although I'm quite confident but you never know :-)
Romain Beauxis made changes -
Status In Progress [ 3 ] Resolved [ 5 ]
Fix Version/s 1.0.0+dev [ 10500 ]
Resolution Fixed [ 1 ]
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Vittee Nakka added a comment -
Hi,

Thanks for giving me credit in the source file, however, could you please update my name to Wittawas Nakkasem? as it is the real-life full name.

Thanks :)
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Vittee Nakka added a comment - Hi, Thanks for giving me credit in the source file, however, could you please update my name to Wittawas Nakkasem? as it is the real-life full name. Thanks :)
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Romain Beauxis added a comment -
Done!
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Romain Beauxis added a comment - Done!

People

  • Assignee:
    Romain Beauxis
    Reporter:
    Vittee Nakka
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Dates

  • Created:
    Updated:
    Resolved: