Change to libx264 with CPU once h264_nvenc fail to init.

src/builtins/builtins-encoder.cc

@@ -65,14 +65,28 @@ BUILTIN(InitEncodeContext) {
     bitrate->ToUint32(&bitrate_int);
     framerate->ToUint32(&framerate_int);
 
+    // First try to use h264_nvenc which may failed due
+    // to host has no GPU.
     enc = new LAIPIC_ENCODER::Encoder {
-        libpath_cppstr, outpath, width_int, height_int, bitrate_int, AV_PIX_FMT_YUV420P, 30, "h264_nvenc" };
+        libpath_cppstr, outpath, width_int, height_int, bitrate_int,
+        AV_PIX_FMT_YUV420P, 30, "h264_nvenc" };
 
     if (!enc->isReady()) {
-        // Fail to initialize LAIPIC_ENCODER::Encoder.
-        // Probaly cause of invalid arguments.
-        THROW_NEW_ERROR_RETURN_FAILURE(isolate,
-            NewEvalError(MessageTemplate::kInvalidArgument));
+        // Then try to use libx264 to working with CPU
+
+        // Release old encoder
+        enc->close();
+
+        enc = new LAIPIC_ENCODER::Encoder {
+            libpath_cppstr, outpath, width_int, height_int, bitrate_int,
+            AV_PIX_FMT_YUV420P, 30, "libx264"};
+
+        if (!enc->isReady()) {
+            // Fail to initialize LAIPIC_ENCODER::Encoder.
+            // Probaly cause of invalid arguments.
+            THROW_NEW_ERROR_RETURN_FAILURE(
+                isolate, NewEvalError(MessageTemplate::kInvalidArgument));
+        }
     }
 
     inited = true;