From b26dc3b5e8d09dbd49cb148ac0ec68ee6066fa5f Mon Sep 17 00:00:00 2001
From: Cameron Gutman <aicommander@gmail.com>
Date: Mon, 28 Oct 2024 23:30:57 -0500
Subject: [PATCH] fix(vaapi): use VBR rate control mode

---
 src/platform/linux/vaapi.cpp | 10 ----------
 src/video.cpp                |  6 ++++--
 2 files changed, 4 insertions(+), 12 deletions(-)

diff --git a/src/platform/linux/vaapi.cpp b/src/platform/linux/vaapi.cpp
index ada6370034a..cd1d81f61d4 100644
--- a/src/platform/linux/vaapi.cpp
+++ b/src/platform/linux/vaapi.cpp
@@ -129,16 +129,6 @@ namespace va {
       return 0;
     }
 
-    void
-    init_codec_options(AVCodecContext *ctx, AVDictionary *options) override {
-      // Don't set the RC buffer size when using H.264 on Intel GPUs. It causes
-      // major encoding quality degradation.
-      auto vendor = vaQueryVendorString(va_display);
-      if (ctx->codec_id != AV_CODEC_ID_H264 || (vendor && !strstr(vendor, "Intel"))) {
-        ctx->rc_buffer_size = ctx->bit_rate * ctx->framerate.den / ctx->framerate.num;
-      }
-    }
-
     int
     set_frame(AVFrame *frame, AVBufferRef *hw_frames_ctx_buf) override {
       this->hwframe.reset(frame);
diff --git a/src/video.cpp b/src/video.cpp
index 3824c295727..4a2c85d969e 100644
--- a/src/video.cpp
+++ b/src/video.cpp
@@ -859,6 +859,7 @@ namespace video {
         { "low_power"s, 1 },
         { "async_depth"s, 1 },
         { "idr_interval"s, std::numeric_limits<int>::max() },
+        { "rc_mode"s, "VBR"s },
       },
       {},  // SDR-specific options
       {},  // HDR-specific options
@@ -878,6 +879,7 @@ namespace video {
         { "async_depth"s, 1 },
         { "sei"s, 0 },
         { "idr_interval"s, std::numeric_limits<int>::max() },
+        { "rc_mode"s, "VBR"s },
       },
       {},  // SDR-specific options
       {},  // HDR-specific options
@@ -897,6 +899,7 @@ namespace video {
         { "async_depth"s, 1 },
         { "sei"s, 0 },
         { "idr_interval"s, std::numeric_limits<int>::max() },
+        { "rc_mode"s, "VBR"s },
       },
       {},  // SDR-specific options
       {},  // HDR-specific options
@@ -909,8 +912,7 @@ namespace video {
       std::make_optional<encoder_t::option_t>("qp"s, &config::video.qp),
       "h264_vaapi"s,
     },
-    // RC buffer size will be set in platform code if supported
-    LIMITED_GOP_SIZE | PARALLEL_ENCODING | SINGLE_SLICE_ONLY | NO_RC_BUF_LIMIT
+    LIMITED_GOP_SIZE | PARALLEL_ENCODING | SINGLE_SLICE_ONLY
   };
 #endif