Hi to all, will the above convertion cause any problem or not optimal or is wrong? I converting some anime by the way.

Tools used:
1. VobSub\subresync to convert subtitle - .sub to .srt
2. WinAVI to convert video - .mkv to .avi(with .srt as subtitle)

Observation of output:
1. The converted video freeze a while at the start of 3rd - 4th second, and freeze a while at certain scence for a about 1-2 seconds. (Overall still watch-able)
2. Audio, video and subtitle sync well too (at least ok to me)

Problem:
Why some scence will freeze a while, is it because I downgrade from H264 to 263, or .mkv to .avi, or some else went wrong? The freezing part is annoying, can advise me where to improve or other approachs to convert .mkv to .avi. Thanks in advance.