[FFmpeg-devel] [PATCH] AAC Pulse data boundaries

Robert Swain robert.swain
Mon Sep 15 01:36:21 CEST 2008

2008/9/14 Alex Converse <alex.converse at gmail.com>:
> Currently the AAC pulse_data tool can try to apply pulses to offsets outside
> of the boundaries of the spectral coefficients. This leads to a crash
> (SIGSEGV) with a stream generated wit the following command:
> zzuf -s16 -r0.001:0.1 -b1193- <
> mpeg4audio-conformance/compressedMp4/al04_08.mp4 > fuzzed.mp4
> Attached is a patch to clip pulse positioning to 1023.

The code changes look OK but is clipping the best solution to this or
should those pulses rather be discarded? Michael?

It would seem to me that if there are multiple pulses, clipping them
could lead to multiple pulses being applied to position 1023. Is a
spike in the spectral data better than no spike or vice versa? My
guess is that ignoring incorrectly positioned pulses may be a better


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