mp3: audible glitches with integer decoder

[ami_stuff]

mp3float decoder seems to not be affected by this problem

​http://www.skenney.com/files/carbass.mp3

C:\>ffmpeg -i carbass.mp3 out.wav
ffmpeg version git-N-30344-g5501afa, Copyright (c) 2000-2011 the FFmpeg develope
rs
  built on May 27 2011 22:37:57 with gcc 4.5.3
  configuration: --enable-gpl --enable-version3 --enable-memalign-hack --enable-
runtime-cpudetect --enable-avisynth --enable-bzlib --enable-frei0r --enable-libo
pencore-amrnb --enable-libopencore-amrwb --enable-libfreetype --enable-libgsm --
enable-libmp3lame --enable-libopenjpeg --enable-librtmp --enable-libschroedinger
 --enable-libspeex --enable-libtheora --enable-libvorbis --enable-libvpx --enabl
e-libx264 --enable-libxavs --enable-libxvid --enable-zlib --pkg-config=pkg-confi
g
  libavutil    51.  2. 2 / 51.  2. 2
  libavcodec   53.  6. 0 / 53.  6. 0
  libavformat  53.  2. 0 / 53.  2. 0
  libavdevice  53.  0. 0 / 53.  0. 0
  libavfilter   2. 11. 0 /  2. 11. 0
  libswscale    0. 14. 0 /  0. 14. 0
  libpostproc  51.  2. 0 / 51.  2. 0
[mp3 @ 023502A0] max_analyze_duration 5000000 reached at 5015510
[mp3 @ 023502A0] Estimating duration from bitrate, this may be inaccurate
Input #0, mp3, from 'carbass.mp3':
  Metadata:
    disc            : 1
  Duration: 00:01:14.88, start: 0.000000, bitrate: 128 kb/s
    Stream #0.0: Audio: mp3, 44100 Hz, stereo, s16, 128 kb/s
Output #0, wav, to 'out.wav':
  Metadata:
    disc            : 1
    encoder         : Lavf53.2.0
    Stream #0.0: Audio: pcm_s16le, 44100 Hz, stereo, s16, 1411 kb/s
Stream mapping:
  Stream #0.0 -> #0.0
Press [q] to stop, [?] for help
[mp3 @ 023507A0] incomplete framee=1406.5kbits/s
Error while decoding stream #0.0
size=   12177kB time=70.69 bitrate=1411.2kbits/s
video:0kB audio:12177kB global headers:0kB muxing overhead 0.000353%

[Carl Eugen Hoyos]

Not a regression, afaict.