[FFmpeg-devel] Issue with ffmpeg mp3 decoder on ARM11

Måns Rullgård mans
Tue Jul 17 19:51:55 CEST 2007

Alexy <galahad at gmail.com> writes:

> Hello,
>  Thank you for the help. I checked the file you mentioned,
> ALT_BITSTREAM_READER was already enabled (maybe because i had tried building
> ffmpeg with arch=<blank> )
> Some more things i could find out.
> 1) The input to the MP3 decoder is matching on arm and on linux.
> 2) I am using the gcc 3.3.2 compiler, but the libs on the filesystems are
> built using 3.4.4. When i configure ffmpeg with the 3.4.4 libs,
> config.errtalks about the libraries using hardware fp. As far as i
> could know ARM does
> not have hardware fp. Could this be a problem? Detailed log is given below.

There are actually two FP architectures for ARM, FPA (old) and VFP
(new), zero or one of which may be available in a specific
implementation.  It is OK to mix hardware and software implementations
of the same architecture in a build.  You didn't mention which ARM
chip you're using, so I can't say what's available on yours.  What's
in your /proc/cpuinfo?

> 3) decoding of H.263 is happening fine on ARM with the same library

H.263 decoding doesn't use floating point, so this working doesn't
contradict the theory that mismatched FP is behind the problem.

M?ns Rullg?rd
mans at mansr.com

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