ffmpeg: Add another patch and tweak recipe for rebuild attempt.

media-video/ffmpeg/ffmpeg6-6.1.2.recipe

@@ -143,7 +143,7 @@ CONFLICTS_devel="
 # (Later versions do not compile with GCC 2 at all.) So instead, we now compile
 # FFmpeg for x86_gcc2 with a modern GCC.
 #
-# This works because GCC's C ABI has not changed between 2 and 13; only the C++
+# This works because GCC's C ABI has not changed between 2 and now; only the C++
 # ABI has, and no BeOS applications expect a system FFmpeg at all, so we can
 # break its ABI all we like.
 if [ "$effectiveTargetArchitecture" = x86_gcc2 ] && \

media-video/ffmpeg/patches/ffmpeg-6.1.2.patchset

@@ -77,3 +77,26 @@ index 2c00c7c..98f6edb 100644
 -- 
 2.45.2
 
+
+From 7adb2a122e95571b37700c5c66b213e98368100c Mon Sep 17 00:00:00 2001
+From: Augustin Cavalier <waddlesplash@gmail.com>
+Date: Fri, 21 Feb 2025 14:35:08 -0500
+Subject: libavutil: Give slicethreads names.
+
+
+diff --git a/libavutil/slicethread.c b/libavutil/slicethread.c
+index e6b82e3..4e240da 100644
+--- a/libavutil/slicethread.c
++++ b/libavutil/slicethread.c
+@@ -73,6 +73,8 @@ static void *attribute_align_arg thread_worker(void *v)
+     WorkerContext *w = v;
+     AVSliceThread *ctx = w->ctx;
+ 
++    ff_thread_setname("av:slicethread");
++
+     pthread_mutex_lock(&w->mutex);
+     pthread_cond_signal(&w->cond);
+ 
+-- 
+2.45.2
+