[Libav-user] No accelerated colorspace conversion - What does it mean?
Paul B Mahol
onemda at gmail.com
Sat Apr 20 20:19:45 CEST 2013
On 4/20/13, Gary Overall <goverall at hotmail.com> wrote:
> I receive the following message:
> [swscaler @ 0x8b0de00] No accelerated colorspace conversion found from
> yuv420p to rgb24.
> when issuing:
> sws_ctx =
> in my iOS app when running the iPhone or IPad simulator. I am decoding and
> h264 video. I had to turn off assembler optimizations (--disable-asm) in my
> configure script for the i386 compile in order to avoid the following error
> during the make of the i386 libraries:
> cc1: error in backend: Ran out of registers during register allocation!make:
> *** [libavcodec/h264_cabac.o] Error 1
This is bug that should be reported if it's not already reported.
Additionally it should be possible to disable optimizations only for
> My questions:
> 1) Does "No accelerated colorspace conversion found" mean that
> there were no assembler optimizations?
It means there where no assembler optimizations enabled at compilation.
> 2) If so, is there a way to make it
> run without assembler optimizations? ( I don't mind if it is slow on the
You are already running without optimizations.
> 3) If so again, how do I avoid the error when attempting the make
> with assembler optimizations?
If assembler optimizations are enabled error will not be displayed.
> 4) Most importantly, am I even on the right
> path to solving this problem?
> I truly appreciate your kind response:
> Here is a copy of my configure command for the i386 build.
> ./configure \--prefix=i386 \--disable-programs \--enable-avresample
> \--disable-bzlib --disable-doc --enable-pic --disable-zlib
> --enable-decoder=h264 --enable-demuxer=h264 --enable-parser=h264
> --disable-libschroedinger --disable-libspeex --disable-libtheora
> --disable-libvorbis --disable-libvpx \--enable-cross-compile
> \--extra-cflags="-arch i386" \--extra-ldflags="-arch i386 -isysroot
> \--arch=i386 \--cpu=i386 \--enable-pic \--disable-asm \
--disable-asm means no asm optimizations will be compiled in, thus
that warning happens.
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