Hi Experts:
 
    plase help, thanks very much.
 
Best Regards
 


From: bu...@live.cn
To: libav-user@ffmpeg.org
Subject: question about libavcodec
Date: Sun, 26 Feb 2012 22:19:38 +0800





Hi experts:
 
    i have some questions about the libavcodec.so: 
 
    1. when compiling, how can i specify this library is compiled for ARM? and 
it includes NEON instruction supports? 
    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 chipset must have NEON module? 
    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?
    4. if the application roamsave together with a specific libavcodec run well 
on Samsung smart phone, and i am sure this version libavcodec support ARM and 
execute NEON instruction. but when i use them on another smart phone(Motorola), 
it crashs in libavcodec.so, the problem is alignment of second parameter of 
function ff_scalarproduct_int16_neon(), how can i find the root cause?the 
libavcodec runs NEON instruction well on Samsumg phone, so it means this 
library compiled with correct GCC version and can handle stack alignment well , 
right? but why it crashs because of alignment problem when run on another smart 
phone which also support NEON instruction? i am very confused about this issue, 
please help me, thanks very much.  
 
Best Regards 
                                          
_______________________________________________
Libav-user mailing list
Libav-user@ffmpeg.org
http://ffmpeg.org/mailman/listinfo/libav-user

Reply via email to