[mad-dev] Calculation error

[Tim Dylla]

Hi list again,

   there is a bug in madplay 0.15.2b, which skips some frames in certain 
conditions. Rob Leslie seems to have a patch already in the pipeline.
libmad is not affected at all.

Best,
	Tim Dylla



Tim Dylla schrieb:
> 
> 
> Andre schrieb:
>> Tim Dylla <tim.dylla at gmx.net> wrote:
>>> MAD in contrast introduces a perceivable error right on the first
>>> half wave of the sine sweep. I think, it's an overflow in the
>>> requantization or the IMDCT (when I remember right, the huffman
>>> decoder produces very high output at this moment).
>>
>> Just a hunch, but if you are able to build MAD from source, maybe you
>> could try the follow patch posted to the list a few years back...
>> perhaps it helps ??
>>
>> diff -ruN mad-0.14.2b_orig/libmad/layer3.c
>> mad-0.14.2b/libmad/layer3.c
>> --- mad-0.14.2b_orig/libmad/layer3.c    Thu Nov  8 15:28:02 2001
>> +++ mad-0.14.2b/libmad/layer3.c    Tue Mar 25 15:21:12 2003
>> @@ -910,7 +910,7 @@
>>        fprintf(stderr, "requantize overflow (%f * 2^%d)\n",
>>            mad_f_todouble(requantized), exp);
>>  # endif
>> -      requantized = MAD_F_MAX;
>> +      requantized = MAD_F_MAX / 2;
>>      }
>>      else
>>        requantized <<= exp;
> 
> Nope, same Result. I'm sorry, I'm still sticking with my diploma, so I 
> don't have the time for extensive tests right now. Maybe someone can 
> confirm the problem and have a look at? Feel free to contact me for the 
> Bitstream in Question and the correct decoder output.
> 
> Best,
> 
>     Tim Dylla
> 
> 
>>
>>
>> Andre
>> -- 
>>
>>
> 
>