extremely slow 5.1 float aiff decoding since ffmpeg 2.x

[Robin]

Summary of the bug: Decoding an aiff file with float samples and more than 2 channels is extremely slow since ffmpeg 2.x (but very fast with ffmpeg 1.2)
How to reproduce:

% ffmpeg -i 5.1-32f.aif 5.1-32f.wav
ffmpeg version: any version since ffmpeg 2.x
built on windows platform

Patches should be submitted to the ffmpeg-devel mailing list and not this bug tracker.

[Robin]

aiff files reproducing the bug

[Carl Eugen Hoyos]

Please test current FFmpeg and please provide your "slow" command line together with the complete, uncut console output to make this a valid ticket.

[Robin]

I've just tested with ffmpeg 2.2.2 from ​http://ffmpeg.zeranoe.com/builds/ (both 32 and 64 bits) and it shows the same very slow behaviour.
Repro steps:
unpack the attached file, then run ffmpeg -i 5.1-32f.aif output.wav

Notice that the problem doesn't happen with the stereo 32bit float file, nor does it happen with the 5.1 16bit signed file.
It is specific to all aif files with more than 2 channels, float samples, and with any ffmpeg 2.x.y version

[Robin]

output from the command line:

ffmpeg.exe -i 5.1-32f.aif output.wav
ffmpeg version 2.2.2 Copyright (c) 2000-2014 the FFmpeg developers

built on May 22 2014 19:53:12 with gcc 4.8.2 (GCC)
configuration: --enable-gpl --enable-version3 --disable-w32threads --enable-av

isynth --enable-bzlib --enable-fontconfig --enable-frei0r --enable-gnutls --enab
le-iconv --enable-libass --enable-libbluray --enable-libcaca --enable-libfreetyp
e --enable-libgme --enable-libgsm --enable-libilbc --enable-libmodplug --enable-
libmp3lame --enable-libopencore-amrnb --enable-libopencore-amrwb --enable-libope
njpeg --enable-libopus --enable-librtmp --enable-libschroedinger --enable-libsox
r --enable-libspeex --enable-libtheora --enable-libtwolame --enable-libvidstab -
-enable-libvo-aacenc --enable-libvo-amrwbenc --enable-libvorbis --enable-libvpx
--enable-libwavpack --enable-libwebp --enable-libx264 --enable-libx265 --enable-
libxavs --enable-libxvid --enable-decklink --enable-zlib

libavutil 52. 66.100 / 52. 66.100
libavcodec 55. 52.102 / 55. 52.102
libavformat 55. 33.100 / 55. 33.100
libavdevice 55. 10.100 / 55. 10.100
libavfilter 4. 2.100 / 4. 2.100
libswscale 2. 5.102 / 2. 5.102
libswresample 0. 18.100 / 0. 18.100
libpostproc 52. 3.100 / 52. 3.100

Input #0, aiff, from 'C:\temp\ffmpegbug\5.1-32f.aif':

Duration: 00:00:10.00, start: 0.000000, bitrate: 9220 kb/s

Stream #0:0: Audio: pcm_f32be (fl32 / 0x32336C66), 48000 Hz, 5.1, flt, 9216

kb/s
File 'C:\temp\ffmpegbug\output.wav' already exists. Overwrite ? [y/N] y
Output #0, wav, to 'C:\temp\ffmpegbug\output.wav':

Metadata:

ISFT : Lavf55.33.100
Stream #0:0: Audio: pcm_s16le ([1][0][0][0] / 0x0001), 48000 Hz, 5.1, s16, 4

608 kb/s
Stream mapping:

Stream #0:0 -> #0:0 (pcm_f32be -> pcm_s16le)

Press [q] to stop, ? for help
size= 5625kB time=00:00:10.00 bitrate=4608.1kbits/s
video:0kB audio:5625kB subtitle:0 data:0 global headers:0kB muxing overhead 0.00
1771%

[Carl Eugen Hoyos]

For future tickets: Please always test current FFmpeg git head, and please tell us if you believe this isn't explained well on ​http://ffmpeg.org/bugreports.html

Regression since 9526c9cc

[Carl Eugen Hoyos]

Fixed in 763e7144 - thank you for the report!