sceVideocodec/sceMpegbase: stop holding on to contexts and payloads that are done

Decode looked its context up with operator[], so a game that never opened one
would still get an entry and a decoder, and only Delete ever removes those.
Require the context to exist instead.

The gathered PES payloads were likewise kept for the whole boot, so the first
decode of a movie could be handed the last packet of the previous one if the
address came round again. Hand each payload out once.

Co-Authored-By: Claude Opus 5 (1M context) <[email protected]>

Core/HLE/sceMpegbase.cpp

@@ -36,7 +36,6 @@
 // copied to. It carries audio as well as video - the destination is what tells them apart - so
 // sceVideocodec has to ask for the one matching the address it was handed.
 static std::map<u32, std::vector<u8>> g_pesPackets;
-
 // Set by sceMpegBaseCscInit / sceMpegBaseCscSetPixelMode, and used when the caller passes 0.
 static int g_mpegBaseBufferWidth = 512;
 static int g_mpegBasePixelMode = GE_CMODE_32BIT_ABGR8888;
@@ -66,7 +65,7 @@ static u32 sceMpegBasePESpacketCopy(u32 p)
 	// On hardware this is the DMA that moves the PES payload into the Media Engine's own memory,
 	// after which mpeg.prx hands sceVideocodecDecode an ME-side address we have no way to read.
 	// Since the copy is ours, gather the blocks here instead and let sceVideocodec decode from
-	// this - see MpegBaseGetPESPacket.
+	// this - see MpegBaseTakePESPacket.
 	lli = PSPPointer<SceMpegLLI>::Create(p);
 	u32 dest = 0;
 	std::vector<u8> gathered;
@@ -100,9 +99,16 @@ static u32 sceMpegBasePESpacketCopy(u32 p)
 	return 0;
 }
 
-const std::vector<u8> *MpegBaseGetPESPacket(u32 dest) {
+std::vector<u8> MpegBaseTakePESPacket(u32 dest) {
 	auto it = g_pesPackets.find(dest);
-	return it == g_pesPackets.end() ? nullptr : &it->second;
+	if (it == g_pesPackets.end()) {
+		return std::vector<u8>();
+	}
+	// Handed over, not lent: leaving it behind meant the first decode of the next movie could pick
+	// up the last packet of the previous one, if the address came round again.
+	std::vector<u8> packet = std::move(it->second);
+	g_pesPackets.erase(it);
+	return packet;
 }
 
 

Core/HLE/sceMpegbase.h

@@ -26,7 +26,8 @@ void Register_sceMpegbase();
 // Called per boot, from __MpegInit.
 void __MpegBaseInit();
 
-// The PES payload sceMpegBasePESpacketCopy gathered for a given destination. On hardware that copy
-// lands in Media Engine memory, which sceVideocodec would then read back; we keep it here instead.
-// Returns nullptr if nothing was copied to that address.
-const std::vector<u8> *MpegBaseGetPESPacket(u32 dest);
+// Takes the PES payload sceMpegBasePESpacketCopy gathered for a given destination. On hardware that
+// copy lands in Media Engine memory, which sceVideocodec would then read back; we keep it here
+// instead. The payload is moved out and dropped from the table, so each one is decoded once.
+// Empty if nothing was copied to that address.
+std::vector<u8> MpegBaseTakePESPacket(u32 dest);

Core/HLE/sceVideocodec.cpp

@@ -500,15 +500,17 @@ static int sceVideocodecDecode(u32 ctxAddr, int type) {
 	bool gotFrame = false;
 	const u8 *au = nullptr;
 	int auBytes = 0;
+	// Owns the gathered payload for as long as au points into it.
+	std::vector<u8> pes;
 	if (auSize > 0 && Memory::IsValidRange(auAddr, auSize)) {
 		au = Memory::GetTypedPointerRange<u8>(auAddr, auSize);
 		auBytes = auSize;
 	} else {
-		// Ask for the payload copied to this exact address - the same call carries audio too.
-		const std::vector<u8> *pes = MpegBaseGetPESPacket(auAddr);
-		if (pes && !pes->empty()) {
-			au = pes->data();
-			auBytes = (int)pes->size();
+		// Take the payload copied to this exact address - the same call carries audio too.
+		pes = MpegBaseTakePESPacket(auAddr);
+		if (!pes.empty()) {
+			au = pes.data();
+			auBytes = (int)pes.size();
 		}
 	}
 	if (au && auBytes > 0) {