From c5ff5d224d167a7506e94708a4be181786ad96bc Mon Sep 17 00:00:00 2001
From: Michael Fabian 'Xaymar' Dirks <info@xaymar.com>
Date: Sun, 7 Jul 2019 11:54:47 +0200
Subject: [PATCH] ffmpeg/avframe-queue: Upgrade to shared_ptr AVFrame

Removes problems with memory leaks due to lost references and other issues.
---
 source/ffmpeg/avframe-queue.cpp | 37 ++++++++++++---------------------
 source/ffmpeg/avframe-queue.hpp | 18 ++++++----------
 2 files changed, 19 insertions(+), 36 deletions(-)

diff --git a/source/ffmpeg/avframe-queue.cpp b/source/ffmpeg/avframe-queue.cpp
index 7fa5980..555e39f 100644
--- a/source/ffmpeg/avframe-queue.cpp
+++ b/source/ffmpeg/avframe-queue.cpp
@@ -18,13 +18,15 @@
 #include "avframe-queue.hpp"
 #include "tools.hpp"
 
-AVFrame* ffmpeg::avframe_queue::create_frame()
+std::shared_ptr<AVFrame> ffmpeg::avframe_queue::create_frame()
 {
-	AVFrame* frame = av_frame_alloc();
-	frame->width   = this->resolution.first;
-	frame->height  = this->resolution.second;
-	frame->format  = this->format;
-	int res        = av_frame_get_buffer(frame, 0);
+	std::shared_ptr<AVFrame> frame =
+	    std::shared_ptr<AVFrame>(av_frame_alloc(), [](AVFrame* frame) { av_frame_free(&frame); });
+	frame->width  = this->resolution.first;
+	frame->height = this->resolution.second;
+	frame->format = this->format;
+
+	int res = av_frame_get_buffer(frame.get(), 0);
 	if (res < 0) {
 		throw std::exception(ffmpeg::tools::get_error_description(res));
 	}
@@ -32,14 +34,6 @@ AVFrame* ffmpeg::avframe_queue::create_frame()
 	return frame;
 }
 
-void ffmpeg::avframe_queue::destroy_frame(AVFrame* frame)
-{
-	if (frame == nullptr)
-		return;
-
-	av_frame_free(&frame);
-}
-
 ffmpeg::avframe_queue::avframe_queue() {}
 
 ffmpeg::avframe_queue::~avframe_queue()
@@ -89,23 +83,19 @@ void ffmpeg::avframe_queue::precache(size_t count)
 void ffmpeg::avframe_queue::clear()
 {
 	std::unique_lock<std::mutex> ulock(this->lock);
-	for (AVFrame* frame : frames) {
-		destroy_frame(frame);
-	}
 	frames.clear();
 }
 
-void ffmpeg::avframe_queue::push(AVFrame* frame)
+void ffmpeg::avframe_queue::push(std::shared_ptr<AVFrame> frame)
 {
 	std::unique_lock<std::mutex> ulock(this->lock);
 	frames.push_back(frame);
 }
 
-AVFrame* ffmpeg::avframe_queue::pop()
+std::shared_ptr<AVFrame> ffmpeg::avframe_queue::pop()
 {
 	std::unique_lock<std::mutex> ulock(this->lock);
-
-	AVFrame* ret = nullptr;
+	std::shared_ptr<AVFrame>     ret;
 	while (ret == nullptr) {
 		if (frames.size() == 0) {
 			ret = create_frame();
@@ -117,7 +107,6 @@ AVFrame* ffmpeg::avframe_queue::pop()
 				frames.pop_front();
 				if ((ret->width != this->resolution.first) || (ret->height != this->resolution.second)
 				    || (ret->format != this->format)) {
-					destroy_frame(ret);
 					ret = nullptr;
 				}
 			}
@@ -126,13 +115,13 @@ AVFrame* ffmpeg::avframe_queue::pop()
 	return ret;
 }
 
-AVFrame* ffmpeg::avframe_queue::pop_only()
+std::shared_ptr<AVFrame> ffmpeg::avframe_queue::pop_only()
 {
 	std::unique_lock<std::mutex> ulock(this->lock);
 	if (frames.size() == 0) {
 		return nullptr;
 	}
-	AVFrame* ret = frames.front();
+	std::shared_ptr<AVFrame> ret = frames.front();
 	if (ret == nullptr) {
 		return nullptr;
 	}
diff --git a/source/ffmpeg/avframe-queue.hpp b/source/ffmpeg/avframe-queue.hpp
index c0fc5ef..dd02a5d 100644
--- a/source/ffmpeg/avframe-queue.hpp
+++ b/source/ffmpeg/avframe-queue.hpp
@@ -15,10 +15,7 @@
 // along with this program; if not, write to the Free Software
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301, USA
 
-#ifndef OBS_FFMPEG_FFMPEG_AVFRAME_QUEUE
-#define OBS_FFMPEG_FFMPEG_AVFRAME_QUEUE
 #pragma once
-
 #include <deque>
 #include <mutex>
 
@@ -31,14 +28,13 @@ extern "C" {
 
 namespace ffmpeg {
 	class avframe_queue {
-		std::deque<AVFrame*> frames;
-		std::mutex           lock;
+		std::deque<std::shared_ptr<AVFrame>> frames;
+		std::mutex                           lock;
 
 		std::pair<uint32_t, uint32_t> resolution;
 		AVPixelFormat                 format = AV_PIX_FMT_NONE;
 
-		AVFrame* create_frame();
-		void     destroy_frame(AVFrame* frame);
+		std::shared_ptr<AVFrame> create_frame();
 
 		public:
 		avframe_queue();
@@ -56,16 +52,14 @@ namespace ffmpeg {
 
 		void clear();
 
-		void push(AVFrame* frame);
+		void push(std::shared_ptr<AVFrame> frame);
 
-		AVFrame* pop();
+		std::shared_ptr<AVFrame> pop();
 
-		AVFrame* pop_only();
+		std::shared_ptr<AVFrame> pop_only();
 
 		bool empty();
 
 		size_t size();
 	};
 } // namespace ffmpeg
-
-#endif OBS_FFMPEG_FFMPEG_AVFRAME_QUEUE