pica-client: VAAPI hardware acceleration

1 files changed, 101 insertions, 0 deletions

diff --git a/pica-client/vaapi.cpp b/pica-client/vaapi.cpp
new file mode 100644
index 0000000..74f036d
--- /dev/null
+++ b/pica-client/vaapi.cpp
@@ -0,0 +1,101 @@
+/*
+	(c) Copyright  2012 - 2026 Anton Sviridenko
+	https://picapica.im
+
+	This program is free software: you can redistribute it and/or modify
+	it under the terms of the GNU General Public License as published by
+	the Free Software Foundation, version 3.
+
+	This program is distributed in the hope that it will be useful,
+	but WITHOUT ANY WARRANTY; without even the implied warranty of
+	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+	GNU General Public License for more details.
+
+	You should have received a copy of the GNU General Public License
+	along with this program.  If not, see <https://www.gnu.org/licenses/>.
+*/
+#include "vaapi.h"
+
+#ifdef HAVE_VAAPI
+
+#include <QMutex>
+#include <QMutexLocker>
+#include <QDebug>
+
+extern "C" {
+#include <libavutil/hwcontext.h>
+#include <libavutil/hwcontext_vaapi.h>
+#include <libavutil/error.h>
+}
+
+namespace
+{
+	QMutex g_mutex;
+	// Created on first use and kept for the lifetime of the process: opening a
+	// VAAPI device is not cheap, and every user of it has to share the one
+	// display anyway.
+	AVBufferRef *g_device = nullptr;
+	bool g_tried = false;
+
+	// Must be called with g_mutex held.
+	void ensureDevice()
+	{
+		if (g_tried)
+			return;
+
+		g_tried = true;
+
+		// A null device name lets FFmpeg find a usable DRM render node
+		// (/dev/dri/renderD128 and friends) by itself.
+		int ret = av_hwdevice_ctx_create(&g_device, AV_HWDEVICE_TYPE_VAAPI, nullptr, nullptr, 0);
+		if (ret < 0)
+		{
+			char buf[256] = {0};
+			av_strerror(ret, buf, sizeof(buf));
+			qWarning() << "VAAPI is not usable, falling back to software video:" << buf;
+			g_device = nullptr;
+		}
+	}
+}
+
+AVFramePtr wrapAVFrame(AVFrame *frame)
+{
+	return AVFramePtr(frame, [](AVFrame *f) { av_frame_free(&f); });
+}
+
+AVBufferRef *VaapiContext::deviceRef()
+{
+	QMutexLocker locker(&g_mutex);
+	ensureDevice();
+
+	return g_device ? av_buffer_ref(g_device) : nullptr;
+}
+
+VADisplay VaapiContext::display()
+{
+	QMutexLocker locker(&g_mutex);
+	ensureDevice();
+
+	if (!g_device)
+		return nullptr;
+
+	AVHWDeviceContext *devctx = (AVHWDeviceContext *)g_device->data;
+	AVVAAPIDeviceContext *vactx = (AVVAAPIDeviceContext *)devctx->hwctx;
+
+	return vactx->display;
+}
+
+bool VaapiContext::isAvailable()
+{
+	QMutexLocker locker(&g_mutex);
+	ensureDevice();
+
+	return g_device != nullptr;
+}
+
+void VaapiContext::registerMetaTypes()
+{
+	qRegisterMetaType<AVFramePtr>("AVFramePtr");
+}
+
+#endif // HAVE_VAAPI