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Elite Member
您的住址: Cape Crozier
文章: 6,122
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所以小弟不是說了嗎？處裡的方式就是一個流程，請不要再用 cpu 執行程式的方式來想了。會花多少時間，能搞定就搞定，不能搞定就就想辦法用替代方案。
如果每個 frame 都有錯，就每次都要去算，這本來就很合理。但是，這點在設計晶片時便可知道。所以，前面才有人對您的花的時間久所以搞不定提出質疑，換句話說，就是只有搞定，與搞不定，只要他在時間內搞定就好。
至於其他，小弟都說了，沒時間看囉~ 所以，既然這是討論，如果您真的看了，何必藏私，是要等到抓到別人漏洞再說嗎？小弟只是把自己找到的，提供出來。至於內容，希望有興趣有時間的人幫忙看。
專門設計的硬體其執行方式，是每個部份可以負責一部分的流程 (運算)，就像工廠的一條龍加工一樣，一個部分搞定，把資料丟到下一級。就算每個 FRAME 都有錯，還是一一經過這些機構。而硬體設計者，要保證的，就是設計的這級要能再一個固定的時間內即時搞定，不然，就要舉手投降，找替代方案。
那篇文章也說過，有其限制，所以，以前的可能遜，後期的可能較佳，但是，硬體設計者絕對要決定放棄的時間，總不能讓 CD 有錯，就再也不放出聲音吧... 
引用:
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With a 4K buffer to hold the data between the C1 and C2 stage, it is possible to redo the C1 fix-one-error operation after you have done the C2 fix-four-errors stage. Since each byte of the C2 stage comes from a different C1, any time that we correct a C2's error, we can go back to the C1 of which that byte was a part, fix a single error if possible, and clear the flag that marks that C1 frame as bad for the C2's yet to come. This means that at best we can be fixing 32 errors at C1, and also 28 errors at C2, but those are extreme conditions. Often of course you will be fixing C1 errors too late to benefit the C2's that have already gone by, but on average you will be fixing about 40 percent more C2 errors. Given infinite storage and processor power, you could continue to reprocess C1 and C2 frames, but since decoding is normally done real time, this is not usually practical. This is a fairly radical correction strategy described in this paragraph, please contact me for more information.
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