Bug#660268: vlc: Dumps core when coverting to MP3

[Reinhard Tartler]

Nigel,

Can you please follow up on my question from march? Otherwise, I'd
like to close the issue.

Cheers,
Reinhard

2012/3/5 Reinhard Tartler <siretart at gmail.com>:
> On Fri, Feb 17, 2012 at 9:48 PM, Nigel Horne <njh at bandsman.co.uk> wrote:
>> Package: vlc
>> Version: 1.1.13-1+b1
>> Severity: normal
>>
>> Dear Maintainer,
>> *** Please consider answering these questions, where appropriate ***
>>
>>   * What led up to the situation?
>> Attempted to conver to MP3
>>   * What exactly did you do (or not do) that was effective (or
>>     ineffective)?
>> Media->Convert/Save->Add File->Convert/Save->Fill in destination file->select MP3 from pull down list->Press Start
>>   * What was the outcome of this action?
>>   vlc: /build/buildd-libav-extra_0.8.0.1+b1-amd64-PoqmIt/libav-extra-0.8.0.1+b1/libav/libavutil/mathematics.c:79: av_rescale_rnd: Assertion `c > 0' failed.
>>   Aborted (core dumped)
>>
>>   * What outcome did you expect instead?
>> Audio extracted into MP3 file
>
> That function (av_rescale_rnd) has not been touched since 2005, so the
> problem is most probably in its caller. The function itself starts
> like this (docstring copied from header):
>
> /**
>  * Rescale a 64-bit integer with specified rounding.
>  * A simple a*b/c isn't possible as it can overflow.
>  */
> int64_t av_rescale_rnd(int64_t a, int64_t b, int64_t c, enum AVRounding rnd){
>    int64_t r=0;
>    assert(c > 0);
>    assert(b >=0);
>    assert((unsigned)rnd<=5 && rnd!=4);
>
>
> Remi, unless I have a backtrace that shows that this is a problem
> within some libav library, there is little we can do about it. TBH, I
> rahter suspect the bug to be in the calling application.
>
> Looking in launchpad, I see this (possibly the same) crash:
> https://bugs.launchpad.net/vlc/+bug/927050
>
> Unfortunately, the backtrace does not show the offending caller:
>
> #0  0xb7798424 in __kernel_vsyscall ()
> No symbol table info available.
> #1  0xb74f2c8f in __GI_raise (sig=6) at
> ../nptl/sysdeps/unix/sysv/linux/raise.c:64
>        resultvar = <optimized out>
>        resultvar = <optimized out>
>        pid = -1218183180
>        selftid = 18107
> #2  0xb74f62b5 in __GI_abort () at abort.c:92
>        save_stage = 2
>        act = {__sigaction_handler = {sa_handler = 0xd, sa_sigaction =
> 0xd}, sa_mask = {__val = {3076784116, 3076789248, 128, 3076784116,
> 3076789248, 128, 127, 3075716637, 3076784116, 127, 3076784116, 127,
> 3075651409, 178484352, 178484352, 127, 178483592, 0, 178484352,
> 4222451712, 178484352, 178484453, 178484352, 178484352, 178484479,
> 178484652, 178484352, 178484652, 0, 0, 0, 0}}, sa_flags = 0,
> sa_restorer = 0}
>        sigs = {__val = {32, 0 <repeats 31 times>}}
> #3  0xb74eb826 in __GI___assert_fail (assertion=0xb01031e4 "c > 0",
> file=0xb01031a4
> "/build/buildd/libav-extra-0.8.0.1/libav/libavutil/mathematics.c",
> line=79, function=0xb0103520 "av_rescale_rnd") at assert.c:81
>        buf = 0xaa375b0 "vlc:
> /build/buildd/libav-extra-0.8.0.1/libav/libavutil/mathematics.c:79:
> av_rescale_rnd: Zusicherung \302\273c > 0\302\253 nicht
> erf\303\274llt.\n"
> #4  0xb00f73b5 in ?? ()
> No symbol table info available.
>
>
> Nigel, can you reproduce the crash and can ideally try to retrieve a
> proper stacktrace?
>
> --
> regards,
>     Reinhard



-- 
regards,
    Reinhard