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mirror of https://github.com/FFmpeg/FFmpeg.git synced 2025-11-23 21:54:53 +02:00

lavc/aarch64: Fix addp overflow in ff_pred16x16_plane_neon_10

The mismatch between neon and C functions can be reproduced
using the following bitstream and command line on aarch64 devices.

wget https://streams.videolan.org/ffmpeg/incoming/replay_intra_pred_16x16.h264
 ./ffmpeg -cpuflags 0  -threads 1 -i replay_intra_pred_16x16.h264  -f framemd5 -y md5_ref
 ./ffmpeg              -threads 1 -i replay_intra_pred_16x16.h264 -f framemd5 -y md5_neon

Signed-off-by: Bin Peng <pengbin@visionular.com>
(cherry picked from commit 3115c0c0e6)
This commit is contained in:
Bin Peng
2025-10-24 15:58:08 +08:00
committed by Martin Storsjö
parent 9e2cad409b
commit 27267cd560

View File

@@ -489,10 +489,10 @@ function ff_pred16x16_plane_neon_10, export=1
mul v2.8h, v2.8h, v0.8h
mul v3.8h, v3.8h, v0.8h
addp v2.8h, v2.8h, v3.8h
addp v2.8h, v2.8h, v2.8h
addp v2.4h, v2.4h, v2.4h
sshll v3.4s, v2.4h, #2
saddw v2.4s, v3.4s, v2.4h
saddlp v2.4s, v2.8h
addp v2.4s, v2.4s, v2.4s
shl v3.4s, v2.4s, #2
add v2.4s, v3.4s, v2.4s
rshrn v4.4h, v2.4s, #6
trn2 v5.4h, v4.4h, v4.4h
add v2.4h, v4.4h, v5.4h
@@ -506,14 +506,13 @@ function ff_pred16x16_plane_neon_10, export=1
sxtl v6.4s, v5.4h // c
mov v0.h[0], wzr
mul v0.8h, v0.8h, v4.h[0]
dup v16.4s, v2.s[0]
dup v17.4s, v2.s[0]
dup v2.8h, v4.h[0] // b
dup v3.4s, v6.s[0] // c
sshll v2.4s, v2.4h, #3 // b * 8
saddw v16.4s, v16.4s, v0.4h
saddw2 v17.4s, v17.4s, v0.8h
smlal v16.4s, v0.4h, v4.h[0]
smlal2 v17.4s, v0.8h, v4.h[0]
sub v3.4s, v3.4s, v2.4s
mov w3, #16