>From 28fa59b0b10d3b82aedd0ba7138e93f21883c774 Mon Sep 17 00:00:00 2001 From: somuvineela <[email protected]> Date: Tue, 22 Jul 2025 19:18:03 +0530 Subject: [PATCH] Enforce framethreads to 1 for zerolatency tune
FFmpeg overrides frameNumThreads based on avctx->thread_count, so
frameNumThreads is forced to one in encoder_open() when zerolatency tune is set.
---
source/common/param.cpp | 2 ++
source/encoder/encoder.cpp | 6 ++++++
source/x265.h | 3 +++
3 files changed, 11 insertions(+)
diff --git a/source/common/param.cpp b/source/common/param.cpp
index a35b06339..598ae21b6 100755
--- a/source/common/param.cpp
+++ b/source/common/param.cpp
@@ -641,6 +641,7 @@ int x265_param_default_preset(x265_param* param, const
char* preset, const char*
}
if (tune)
{
+ param->tune = tune;
if (!strcmp(tune, "psnr"))
{
param->rc.aqStrength = 0.0;
@@ -2702,6 +2703,7 @@ void x265_copy_params(x265_param* dst, x265_param* src)
if (strlen(src->numaPools)) snprintf(dst->numaPools, X265_MAX_STRING_SIZE,
"%s", src->numaPools);
else dst->numaPools[0] = 0;
+ dst->tune = src->tune;
dst->bEnableWavefront = src->bEnableWavefront;
dst->bDistributeModeAnalysis = src->bDistributeModeAnalysis;
dst->bDistributeMotionEstimation = src->bDistributeMotionEstimation;
diff --git a/source/encoder/encoder.cpp b/source/encoder/encoder.cpp
index 2e65cb1a9..5b1efdcbf 100644
--- a/source/encoder/encoder.cpp
+++ b/source/encoder/encoder.cpp
@@ -254,6 +254,12 @@ void Encoder::create()
p->bEnableWavefront = 0;
}
+ // For zero-latency tune, frameNumThreads must be set to 1
+ if (p->tune && (!strcmp(p->tune, "zerolatency") || !strcmp(p->tune,
"zero-latency")))
+ {
+ p->frameNumThreads = 1;
+ }
+
bool allowPools = !strlen(p->numaPools) || strcmp(p->numaPools, "none");
// Trim the thread pool if --wpp, --pme, and --pmode are disabled
diff --git a/source/x265.h b/source/x265.h
index 7241beda2..fcc8337df 100644
--- a/source/x265.h
+++ b/source/x265.h
@@ -2344,6 +2344,9 @@ typedef struct x265_param
/*Frame level RateControl Configuration*/
int bConfigRCFrame;
int isAbrLadderEnable;
+
+ /*tune*/
+ const char* tune;
} x265_param;
/* x265_param_alloc:
--
2.43.0.windows.1
enforce_frame_threads_for_zerolatency_tune.diff
Description: enforce_frame_threads_for_zerolatency_tune.diff
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