diff --git a/play.lua b/play.lua
index 84b4a09..c105d4e 100644
--- a/play.lua
+++ b/play.lua
@@ -400,25 +400,42 @@ local function httpResponseHandler()
             local batch = pendingRequests[url]
             if batch then
                 pendingRequests[url] = nil
-                local binData = handleOrErr.readAll()
-                handleOrErr.close()
-
-                local success, batchFrames = pcall(unpackFramePack, binData)
-                if success then
-                    for idx = 1, #batchFrames do
-                        local globalIdx = batch.start + idx - 1
-                        if not allFrameData[globalIdx] then
-                            allFrameData[globalIdx] = batchFrames[idx]
-                        end
-                    end
-                    local sizeInMB = #binData / (1024 * 1024)
-                    
-                    print("[V] Cached batch: " .. batch.start .. " - " .. (batch.start + #batchFrames - 1) .." ("..tonumber(string.format("%.1f", sizeInMB)).." Mb)")
+                
+                -- [优化] 检查整个批次是否已经完全过期待（最晚的一帧都小于 frameIndex - 10）
+                -- 虽然 unpacking 很快，但在极端延迟下可以直接跳过解包
+                local batchEndIdx = batch.start + #batch.urls - 1
+                if batchEndIdx < frameIndex - 10 then
+                   -- 批次过旧，直接丢弃，仅释放句柄
+                   handleOrErr.close()
+                   print("[X] Drop old batch (too late): " .. batch.start)
                 else
-                    print("[R] Unpack failed for batch " .. batch.start .. ": " .. tostring(batchFrames))
-                    -- 标记这些帧可重试
-                    for j = batch.start, batch.start + #batch.urls - 1 do
-                        downloadedFrames[j] = nil
+                    local binData = handleOrErr.readAll()
+                    handleOrErr.close()
+
+                    local success, batchFrames = pcall(unpackFramePack, binData)
+                    if success then
+                        for idx = 1, #batchFrames do
+                            local globalIdx = batch.start + idx - 1
+                            
+                            -- [核心修改] 只有当帧号 >= 当前帧 - 10 时才存入内存
+                            -- 防止旧数据占用内存或被错误地重新缓存
+                            if globalIdx >= frameIndex - 10 then
+                                if not allFrameData[globalIdx] then
+                                    allFrameData[globalIdx] = batchFrames[idx]
+                                end
+                            end
+                        end
+                        -- 仅计算大致大小用于日志，逻辑不变
+                        local sizeInMB = #binData / (1024 * 1024)
+                        print("[V] Cached batch: " .. batch.start .. " - " .. (batch.start + #batchFrames - 1) .." ("..tonumber(string.format("%.1f", sizeInMB)).." Mb)")
+                    else
+                        print("[R] Unpack failed for batch " .. batch.start .. ": " .. tostring(batchFrames))
+                        -- 这里如果解包失败，如果数据还算新才许重试
+                        if batchEndIdx >= frameIndex - 10 then
+                            for j = batch.start, batch.start + #batch.urls - 1 do
+                                downloadedFrames[j] = nil
+                            end
+                        end
                     end
                 end
             end
@@ -427,22 +444,38 @@ local function httpResponseHandler()
             local batch = pendingRequests[url]
             if batch then
                 pendingRequests[url] = nil
-                batch.retry = (batch.retry or 0) + 1
-                if batch.retry < 3 then
-                    print("[R] Retrying batch " .. batch.start .. " (attempt " .. (batch.retry + 1) .. ") Error: "..handleOrErr)
-                    -- 允许重试
-                    for j = batch.start, batch.start + #batch.urls - 1 do
-                        downloadedFrames[j] = nil
-                    end
-                    -- 重新触发 cacheAhead 下一轮会重发
-                else
-                    print("[X] Giving up on batch " .. batch.start)
-                    print("[E] " .. batch.start.." "..handleOrErr)
-
-                    -- 永久失败，不再重试
+                
+                -- [核心修改] 检查批次时效性
+                -- 如果该批次最晚的一帧都比 (frameIndex - 10) 还旧，直接丢弃，不再重试
+                local batchEndIdx = batch.start + #batch.urls - 1
+                
+                if batchEndIdx < frameIndex - 10 then
+                    -- 这里的 print 可以注释掉，或者保留用于调试
+                    print("[X] Drop old batch (too late): " .. batch.start)
+                    
+                    -- 标记已下载(尽管是失败)，防止 cacheAhead 再次死循环请求它
                     for j = batch.start, batch.start + #batch.urls - 1 do
                         downloadedFrames[j] = true
                     end
+                else
+                    -- 只有数据还比较“新鲜”时，才进行重试逻辑
+                    batch.retry = (batch.retry or 0) + 1
+                    if batch.retry < 3 then
+                        print("[R] Retrying batch " .. batch.start .. " (attempt " .. (batch.retry + 1) .. ") Error: "..tostring(handleOrErr))
+                        -- 允许重试
+                        for j = batch.start, batch.start + #batch.urls - 1 do
+                            downloadedFrames[j] = nil
+                        end
+                        -- 重新触发 cacheAhead 下一轮会重发
+                    else
+                        print("[X] Giving up on batch " .. batch.start)
+                        print("[E] " .. batch.start.." "..tostring(handleOrErr))
+
+                        -- 永久失败，不再重试
+                        for j = batch.start, batch.start + #batch.urls - 1 do
+                            downloadedFrames[j] = true
+                        end
+                    end
                 end
             end
 
@@ -540,7 +573,7 @@ local function renderVideo()
         else
             print("[E] "..frameIndex.." is nil")
             nil_e =  nil_e + 1
-            if nil_e >= 200 then
+            if nil_e >= 5 then
                 error("\n[E] No available video data for 10 seconds \nDownload speed is below the minimum threshold! \nPlease try checking your network bandwidth or adjusting the resolution.")
             end
             sleep(2)