It appears media-libs/x264's configure script simply checks for vsx support with the compiler rather than with the CPU. This results in a libx264 binary being built with VSX extensions, which aren't valid for older PPC chips. Reproducible: Always Steps to Reproduce: 1. emerge x264 Actual Results: Illegal instruction Expected Results: Properly running encoder/decoder It might just be a matter of passing --disable-vsx to the configure script my default and switching on this flag. However, there may need to be additional patches to this code, as I don't think they've sufficiently tested a vanilla altivec machine with this in a while (it's still trying to use xxpermdi instructions in spite of vsx=no). I may end up submitting a patch upstream for this.
Still a problem with current media-libs/x264-0.0.20231114-r1. When encoding a video on my PowerMac G5 11,2 with "ffmpeg -i input.mkv -c:v libx264 -preset slow -crf 22 -c:a copy output.mkv" ffmpeg crashes with following dmesg: ffmpeg[64720]: illegal instruction (4) at 3fffa0c9163c nip 3fffa0c9163c lr 3fffa0c91938 code 1 in libx264.so.164[3fffa0c00000+16d000] ffmpeg[64720]: code: 811f0290 28080002 41811fbc 83bf00a8 2f9d0000 419e000c 39200001 913f03ac ffmpeg[64720]: code: 837f008c 2f9b0000 409e1fb0 c19f02a8 <f00004d0> dbc10100 dbe10108 ff8c0000 Nowadays there is a CPU_FLAGS_PPC but that does not seem to help. [ebuild R ] media-libs/x264-0.0.20231114-r1:0/164::gentoo USE="interlaced threads (-opencl) -static-libs" CPU_FLAGS_PPC="altivec" 0 KiB
Created attachment 898474 [details] build.log (ppc64, 0.0.20231114-r1)
Created attachment 898475 [details] emerge --info
The issue has already been reported upstream by Adam: https://code.videolan.org/videolan/x264/-/issues/26 The patch attached in the upstream issue applies but unfortunately does not work out. Running x264 still crashes with illegal instruction on my G5.
(In reply to ernsteiswuerfel from comment #4) > The issue has already been reported upstream by Adam: > https://code.videolan.org/videolan/x264/-/issues/26 > > The patch attached in the upstream issue applies but unfortunately does not > work out. Running x264 still crashes with illegal instruction on my G5. I'm fairly certain the fix had worked 3 years ago as I managed to encode an h264 video on the G5. It's possible with ffmpeg you are using x264 features I wasn't or more vsx code is getting compiled in. I might boot up the G5 this weekend and try to troubleshoot.
(In reply to Adam Stylinski from comment #5) > I'm fairly certain the fix had worked 3 years ago as I managed to encode an > h264 video on the G5. It's possible with ffmpeg you are using x264 features > I wasn't or more vsx code is getting compiled in. I might boot up the G5 > this weekend and try to troubleshoot. This would be very welcomed! I din't use much parameters, only "ffmpeg -i input.mkv -c:v libx264 -preset slow -crf 22 -c:a copy output.mkv" But I can try tomorrow without parameters and see whether that makes a difference.
