[FFmpeg-cvslog] avcodec/asvenc,dvenc: Optimize unaligned checks away if possible

[Andreas Rheinhardt]

ffmpeg | branch: master | Andreas Rheinhardt <andreas.rheinhardt at outlook.com> | Tue May 27 21:46:06 2025 +0200| [23761c7acd5352e4452b24cb5fd97d6b12b9ae91] | committer: Andreas Rheinhardt

avcodec/asvenc,dvenc: Optimize unaligned checks away if possible

For certain arches (AARCH64, x86, generic) get_pixels and
get_pixels_unaligned always coincide for 8 bit input.
In these cases it is possible to avoid checks for unaligned
input in asvenc, dvenc.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt at outlook.com>

> http://git.videolan.org/gitweb.cgi/ffmpeg.git/?a=commit;h=23761c7acd5352e4452b24cb5fd97d6b12b9ae91
---

 libavcodec/asvenc.c      | 7 ++++---
 libavcodec/dvenc.c       | 7 ++++---
 libavcodec/pixblockdsp.h | 7 ++++++-
 3 files changed, 14 insertions(+), 7 deletions(-)

diff --git a/libavcodec/asvenc.c b/libavcodec/asvenc.c
index 159b070821..883edd0468 100644
--- a/libavcodec/asvenc.c
+++ b/libavcodec/asvenc.c
@@ -301,9 +301,10 @@ static int encode_frame(AVCodecContext *avctx, AVPacket *pkt,
     if (ret < 0)
         return ret;
 
-    if ((uintptr_t)pict->data[0] & 7 || pict->linesize[0] & 7 ||
-        (uintptr_t)pict->data[1] & 7 || pict->linesize[1] & 7 ||
-        (uintptr_t)pict->data[2] & 7 || pict->linesize[2] & 7)
+    if (!PIXBLOCKDSP_8BPP_GET_PIXELS_SUPPORTS_UNALIGNED &&
+        ((uintptr_t)pict->data[0] & 7 || pict->linesize[0] & 7 ||
+         (uintptr_t)pict->data[1] & 7 || pict->linesize[1] & 7 ||
+         (uintptr_t)pict->data[2] & 7 || pict->linesize[2] & 7))
         a->get_pixels = a->pdsp.get_pixels_unaligned;
     else
         a->get_pixels = a->pdsp.get_pixels;
diff --git a/libavcodec/dvenc.c b/libavcodec/dvenc.c
index b6764e9c2c..a477b84261 100644
--- a/libavcodec/dvenc.c
+++ b/libavcodec/dvenc.c
@@ -1200,9 +1200,10 @@ static int dvvideo_encode_frame(AVCodecContext *c, AVPacket *pkt,
     DVEncContext *s = c->priv_data;
     int ret;
 
-    if ((uintptr_t)frame->data[0] & 7 || frame->linesize[0] & 7 ||
-        (uintptr_t)frame->data[1] & 7 || frame->linesize[1] & 7 ||
-        (uintptr_t)frame->data[2] & 7 || frame->linesize[2] & 7)
+    if (!PIXBLOCKDSP_8BPP_GET_PIXELS_SUPPORTS_UNALIGNED &&
+        ((uintptr_t)frame->data[0] & 7 || frame->linesize[0] & 7 ||
+         (uintptr_t)frame->data[1] & 7 || frame->linesize[1] & 7 ||
+         (uintptr_t)frame->data[2] & 7 || frame->linesize[2] & 7))
         s->get_pixels = s->pdsp.get_pixels_unaligned;
     else
         s->get_pixels = s->pdsp.get_pixels;
diff --git a/libavcodec/pixblockdsp.h b/libavcodec/pixblockdsp.h
index 8d767b2fd3..d493d0e22b 100644
--- a/libavcodec/pixblockdsp.h
+++ b/libavcodec/pixblockdsp.h
@@ -22,9 +22,14 @@
 #include <stddef.h>
 #include <stdint.h>
 
+#define PIXBLOCKDSP_8BPP_GET_PIXELS_SUPPORTS_UNALIGNED \
+    !(ARCH_ARM || ARCH_MIPS || ARCH_PPC || ARCH_RISCV)
+
 typedef struct PixblockDSPContext {
     void (*get_pixels)(int16_t *restrict block /* align 16 */,
-                       const uint8_t *pixels /* align 8 for <= 8 bit, 16 otherwise */,
+                       /* align 16 for > 8 bits; align 8 for <= 8 bits
+                        * (or 1 if PIXBLOCKDSP_8BPP_GET_PIXELS_SUPPORTS_UNALIGNED is set) */
+                       const uint8_t *pixels,
                        ptrdiff_t stride);
     void (*get_pixels_unaligned)(int16_t *restrict block /* align 16 */,
                        const uint8_t *pixels,