[FFmpeg-user] questions about libavcodec

Carl Eugen Hoyos cehoyos at ag.or.at
Mon Feb 27 10:58:42 CET 2012

卜弋天 <buyit <at> live.cn> writes:

> 1. when compiling, how can i specify this library is compiled for ARM? 

I suspect you have to specify --target=arm

> and it includes NEON instruction supports? 

Use --disable-neon if you don't want neon support.

(So far, ./configure --help should have answered the questions, 
if this is not true, please suggest improvements.)

> 2. suppose ARCH_ARM and HAVE_NEON are defined, which i mentioned in
> question 1, does it mean this library can only be executed on ARM 
> platform and the ARM chipset must have NEON module? 

I suspect so, but please test.

> 3. suppose the answer of quesion 2 is yes, then how can user choose 
> libavcodec.so as they want? for example, there is an Android 
> application "ROAMSAVE", it will use libavcodec.so, then how can i 
> choose a suitable version libavcodec.so for roamsave? suppose i do 
> not have any source code, and just want to download this
> library from internet, how can i find the correct libavcodec?

I don't understand how this should be possible on any platform, 
please explain.

For the problems with insufficient alignment, afaiu, you already 
have patches for some crashes, please send them to -devel.

Thank you, Carl Eugen

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