From a1b7cd51b44d72b024294e95799d1edfe22ae17e Mon Sep 17 00:00:00 2001
From: CamilleLaVey <camillelavey99@gmail.com>
Date: Tue, 7 Jul 2026 19:01:42 -0400
Subject: [PATCH] [android] Initial implementation for MediaCodec

---
 externals/ffmpeg/CMakeLists.txt  |  5 +++++
 src/common/android/id_cache.cpp  |  4 ++++
 src/common/android/id_cache.h    |  1 +
 src/video_core/host1x/ffmpeg.cpp | 13 +++++++++++++
 4 files changed, 23 insertions(+)

diff --git a/externals/ffmpeg/CMakeLists.txt b/externals/ffmpeg/CMakeLists.txt
index 7908e0a619..0baff02c84 100644
--- a/externals/ffmpeg/CMakeLists.txt
+++ b/externals/ffmpeg/CMakeLists.txt
@@ -59,6 +59,11 @@ endif()
 if (PLATFORM_PS4 OR PLATFORM_MANAGARM)
     # Doesn't support VA-API, don't go thru the embarrassment of trying to enable it
     list(APPEND FFmpeg_HWACCEL_FLAGS --disable-vaapi)
+elseif (ANDROID)
+    list(APPEND FFmpeg_HWACCEL_FLAGS
+        --enable-mediacodec
+        --enable-jni
+    )
 elseif (UNIX AND NOT DEFINED FFmpeg_IS_CROSS_COMPILING AND NOT ANDROID)
     find_package(PkgConfig REQUIRED)
     pkg_check_modules(LIBVA libva)
diff --git a/src/common/android/id_cache.cpp b/src/common/android/id_cache.cpp
index 76af1e0fb2..a56dbc199b 100644
--- a/src/common/android/id_cache.cpp
+++ b/src/common/android/id_cache.cpp
@@ -123,6 +123,10 @@ namespace Common::Android {
         return owned.env;
     }
 
+    JavaVM *GetJavaVM() {
+        return s_java_vm;
+    }
+
     jclass GetNativeLibraryClass() {
         return s_native_library_class;
     }
diff --git a/src/common/android/id_cache.h b/src/common/android/id_cache.h
index 6b48f471b7..2ae2cdc4cb 100644
--- a/src/common/android/id_cache.h
+++ b/src/common/android/id_cache.h
@@ -12,6 +12,7 @@
 namespace Common::Android {
 
 JNIEnv* GetEnvForThread();
+JavaVM* GetJavaVM();
 
 /**
  * Starts a new thread to run JNI. Intended to be used when you must run JNI from a fiber.
diff --git a/src/video_core/host1x/ffmpeg.cpp b/src/video_core/host1x/ffmpeg.cpp
index 88df6695d8..36364ba3c2 100644
--- a/src/video_core/host1x/ffmpeg.cpp
+++ b/src/video_core/host1x/ffmpeg.cpp
@@ -19,8 +19,16 @@ extern "C" {
 #endif
 
 #include <libavutil/hwcontext.h>
+
+#if defined(__ANDROID__)
+#include <libavcodec/jni.h>
+#endif
 }
 
+#if defined(__ANDROID__)
+#include "common/android/id_cache.h"
+#endif
+
 namespace FFmpeg {
 
 namespace {
@@ -290,6 +298,11 @@ bool DecodeApi::Initialize(Tegra::Host1x::NvdecCommon::VideoCodec codec) {
 
     // Enable GPU decoding if requested.
     if (Settings::values.nvdec_emulation.GetValue() == Settings::NvdecEmulation::Gpu) {
+#if defined(__ANDROID__)
+        static const int jni_vm_result =
+            av_jni_set_java_vm(Common::Android::GetJavaVM(), nullptr);
+        (void)jni_vm_result;
+#endif
         m_hardware_context.emplace();
         m_hardware_context->InitializeForDecoder(*m_decoder_context, *m_decoder);
     }