fixes bug with device id provided by user (#171)

* fixes bug when setting env variable

* fix for device id

samples/videoDecodeFork/videodecodefork.cpp

@@ -167,7 +167,10 @@ int main(int argc, char **argv) {
         for (int i = 0; i < n_fork; i++) {
             std::unique_ptr<VideoDemuxer> demuxer(new VideoDemuxer(input_file_path.c_str()));
             rocDecVideoCodec rocdec_codec_id = AVCodec2RocDecVideoCodec(demuxer->GetCodecID());
-            v_device_id[i] = (i % 2 == 0) ? 0 : sd;
+            if (device_id % 2 == 0)
+                v_device_id[i] = (i % 2 == 0) ? device_id : device_id + sd;
+            else
+                v_device_id[i] = (i % 2 == 0) ? device_id - sd : device_id;
             std::unique_ptr<RocVideoDecoder> dec(new RocVideoDecoder(v_device_id[i], mem_type, rocdec_codec_id, b_force_zero_latency, p_crop_rect));
             v_demuxer.push_back(std::move(demuxer));
             v_viddec.push_back(std::move(dec));