From 29f8890fa9150f4077c8a15bd60365f0c5c98a3b Mon Sep 17 00:00:00 2001
From: "Steinar H. Gunderson" <sgunderson@bigfoot.com>
Date: Wed, 4 Mar 2020 19:53:49 +0100
Subject: [PATCH] Fix MJPEG white balance information when VA-API is in use.

The JPEG headers were cached (per resolution) and never invalidated,
causing wrong/outdated information to be sent.

I can't really remember why I wanted to cache these, but I suppose
I had a reason, so I'm a bit reluctant to just kill the cache.
Hopefully, the white balance won't change often enough, and these
objects are so small, that we won't need invalidation; we can just
let it grow until program exit.
---
 nageru/mjpeg_encoder.cpp | 12 ++++++------
 nageru/mjpeg_encoder.h   | 20 ++++++++++++++++++--
 2 files changed, 24 insertions(+), 8 deletions(-)

diff --git a/nageru/mjpeg_encoder.cpp b/nageru/mjpeg_encoder.cpp
index 19ffd58..4cc929b 100644
--- a/nageru/mjpeg_encoder.cpp
+++ b/nageru/mjpeg_encoder.cpp
@@ -660,11 +660,11 @@ vector<uint8_t> MJPEGEncoder::get_jpeg_header(unsigned width, unsigned height, c
 	return dest.dest;
 }
 
-MJPEGEncoder::VAData MJPEGEncoder::get_va_data_for_resolution(unsigned width, unsigned height, const RGBTriplet &white_balance)
+MJPEGEncoder::VAData MJPEGEncoder::get_va_data_for_parameters(unsigned width, unsigned height, const RGBTriplet &white_balance)
 {
-	pair<unsigned, unsigned> key(width, height);
-	if (va_data_for_resolution.count(key)) {
-		return va_data_for_resolution[key];
+	VAKey key{width, height, white_balance};
+	if (va_data_for_parameters.count(key)) {
+		return va_data_for_parameters[key];
 	}
 
 	// Use libjpeg to generate a header and set sane defaults for e.g.
@@ -765,7 +765,7 @@ MJPEGEncoder::VAData MJPEGEncoder::get_va_data_for_resolution(unsigned width, un
 	ret.q = q;
 	ret.huff = huff;
 	ret.parms = parms;
-	va_data_for_resolution[key] = ret;
+	va_data_for_parameters[key] = ret;
 	return ret;
 }
 
@@ -786,7 +786,7 @@ void MJPEGEncoder::encode_jpeg_va(QueuedFrame &&qf)
 		release = ReleaseVAResources(this, resources);
 	}
 
-	VAData va_data = get_va_data_for_resolution(width, height, qf.white_balance);
+	VAData va_data = get_va_data_for_parameters(width, height, qf.white_balance);
 	va_data.pic_param.coded_buf = resources.data_buffer;
 
 	VABufferID pic_param_buffer;
diff --git a/nageru/mjpeg_encoder.h b/nageru/mjpeg_encoder.h
index eff361e..87bf3b5 100644
--- a/nageru/mjpeg_encoder.h
+++ b/nageru/mjpeg_encoder.h
@@ -154,6 +154,22 @@ private:
 	std::unique_ptr<VADisplayWithCleanup> va_dpy;
 	VAConfigID config_id;
 
+	struct VAKey {
+		unsigned width, height;
+		movit::RGBTriplet white_balance;
+
+		bool operator< (const VAKey &other) const {
+			if (width != other.width)
+				return width < other.width;
+			if (height != other.height)
+				return height < other.height;
+			if (white_balance.r != other.white_balance.r)
+				return white_balance.r < other.white_balance.r;
+			if (white_balance.g != other.white_balance.g)
+				return white_balance.g < other.white_balance.g;
+			return white_balance.b < other.white_balance.b;
+		}
+	};
 	struct VAData {
 		std::vector<uint8_t> jpeg_header;
 		VAEncPictureParameterBufferJPEG pic_param;
@@ -161,8 +177,8 @@ private:
 		VAHuffmanTableBufferJPEGBaseline huff;
 		VAEncSliceParameterBufferJPEG parms;
 	};
-	std::map<std::pair<unsigned, unsigned>, VAData> va_data_for_resolution;
-	VAData get_va_data_for_resolution(unsigned width, unsigned height, const movit::RGBTriplet &white_balance);
+	std::map<VAKey, VAData> va_data_for_parameters;
+	VAData get_va_data_for_parameters(unsigned width, unsigned height, const movit::RGBTriplet &white_balance);
 
 	std::list<VAResources> va_resources_freelist;
 	std::mutex va_resources_mutex;
-- 
2.39.2