Bug#908352: out-of-order: Sound is broken (MOD support in Alure)

[Tobias Hansen]

Control: retitle -1 out-of-order: Sound is broken during the intro

Hi Bill and Chris,

the problem is that the library that manages audio playback for the SLUDGE engine (Alure 1.2) does not support MOD files anymore. Luckily I think the song during the intro is the only one in MOD format, so the sound later in the game should actually work fine.

This bug has a long history. When I ported SLUDGE from a non-free sound library to OpenAL with Alure it worked. Then support for MOD files was removed from Alure. Since then the intro song was simply not played. What happened more recently is that for some reason the intro song is now handed to libmpg123 which tries to play it, leading to this annoying noise. That this happens makes sense, given the reason why MOD support was disabled in the first place (see below), however I don't know what caused the recent change in behavior.

On 06/02/2011 03:06 AM, Chris Robinson wrote:
> On Wednesday, June 01, 2011 5:18:44 PM you wrote:
>> Hi,
>>
>> why did you disable MOD support in Alure? There's a SLUDGE game (Out of
>> Order) using at least one MOD file. Just wondering, because libdumb and
>> libmodplug are supposed to support MOD.
>
> Support for .mod files was disabled because they don't have any identifying
> header information. The MOD decoder, along with the MP3 decoder, would
> continually try to "steal" each other's files (MP3s try playing through
> libdumb/libmodplug, or MODs trying to play libmpg123), depending on the order
> the decoders are tried. So the module decoders needed to be limited to what
> can be identified (XM, IT, and S3M).
>
> If there was a non-obtrusive way to identify .mod files with a low risk of
> false-positives, I'd be more than willing to look into supporting them again.
>

Internally SLUDGE distinguishes module files and other sound files, so the problem can be solved by telling Alure that all our module files should be played using libdumb. In Alure 2, which is under development, this is possible and actually necessary since libdumb is not supported by default anymore. An example how to do this with libdumb is included with Alure.

For Alure 1.2 however, it seems that the detection of the decoder is always done by Alure. Is this correct Chris? Do you see a way to fix this using Alure 1.2?

Best,
Tobias


On 09/08/2018 11:02 PM, Bill Allombert wrote:
> Package: out-of-order
> Version: 1.0-2
> Severity: normal
>
> Dear maintainer,
>
> out-of-order audio no more work (it worked with jessie).
> Instead it beeps and prints in the terminal hundred of lines like:
>
> Note: Illegal Audio-MPEG-Header 0x03f6e122 at offset 33526.
> Note: Trying to resync...
> Note: Skipped 19 bytes in input.
>
> Warning: Big change from first (MPEG version, layer, rate). Frankenstein
> stream?
> Note: Illegal Audio-MPEG-Header 0xbe096eed at offset 36475.
> Note: Trying to resync...
> Note: Skipped 260 bytes in input.
> Note: Illegal Audio-MPEG-Header 0xbe096eed at offset 36475.
> Note: Trying to resync...
> Note: Skipped 260 bytes in input.
>
> The game is still playable if the sound is muted.
>
> -- System Information:
> Debian Release: 9.5
>   APT prefers stable-updates
>   APT policy: (500, 'stable-updates'), (500, 'stable')
> Architecture: amd64 (x86_64)
> Foreign Architectures: i386
>
> Kernel: Linux 4.9.0-7-amd64 (SMP w/4 CPU cores)
> Locale: LANG=fr_FR.UTF-8, LC_CTYPE=fr_FR.UTF-8 (charmap=UTF-8), LANGUAGE=fr_FR.UTF-8 (charmap=UTF-8)
> Shell: /bin/sh linked to /bin/dash
> Init: systemd (via /run/systemd/system)
>
> Versions of packages out-of-order depends on:
> ii  sludge-engine  2.2.1-2+b1
>
> out-of-order recommends no packages.
>
> out-of-order suggests no packages.
>
> -- no debconf information
>
> Cheers,