HDMI 線材差異 ... 從科學角度到正反理念作深思 (轉載)

gikifk

但係睇極都無話邊條最好，就以2M為例
最多人買都係2M，最平由$50起至$3000都有，當然$3000果條外表就一定好靚（我係講外表，線材就話用銀包99.9999%銅）至於幾十蚊當然一睇就知平野。
成日睇D文章比較幾條線HDMI線，幾百至幾千比較，睇完都無話邊條最好邊條唔好。
如果能夠發起一次HDMI大比較就最好喇...................可能係茫想

ropresident

原來HDMI都有咁多學問

bbq2005

學到野,Thanks

bois

原來咁大學問的, 學到嘢.

bbsai

個理解都係唔岩,有失真同無失真兩種格式都同條線係無關,
係同個CODEC有關,呢個係更高LAYER做的,同線無關係, ...
lunerelf 發表於 2010-8-16 08:42

在 digitial signal 傳送世界, 有好多 check packet error 的技術, 最簡單基本有CRC, 這些技術確保數據準確.....
digital 世界只有 0 同 1,

例如 :
十進制 ( 1 ) = 二進制-2bit (0001)

若果因傳送二進制有錯誤....
變成...

二進制-2bit (0011), 就會變成十進制的 (2)

所以在digitial 世界, 要絕對準確.

其中HDMI內, TMDS pin 位有做 error correction 的動作.
TMDS

Transition Minimized Differential Signaling (TMDS) on HDMI carries video, audio and auxiliary data via one of three modes, called the Video Data Period, the Data Island Period and the Control Period.[82] During the Video Data Period, the pixels of an active video line are transmitted.[82] During the Data Island period (which occurs during the horizontal and vertical blanking intervals), audio and auxiliary data are transmitted within a series of packets.[82] The Control Period occurs between Video and Data Island periods.[82]

Both HDMI and DVI use TMDS to send 10-bit characters that are encoded using 8b/10b encoding for the Video Data Period and 2b/10b encoding for the Control Period. HDMI adds the ability to send audio and auxiliary data using 4b/10b encoding for the Data Island Period.[82] Each Data Island Period is 32 pixels in size and contains a 32-bit Packet Header, which includes 8 bits of BCH ECC parity data for error correction and describes the contents of the packet.[83] Each Packet contains four subpackets, and each subpacket is 64 bits in size, including 8 bits of BCH ECC parity data, allowing for each Packet to carry up to 224 bits of audio data.[84] Each Data Island Period can contain up to 18 Packets.[85] Seven of the 15 Packet types described in the HDMI 1.3a specifications deal with audio data, while the other 8 types deal with auxiliary data.[83] Among these are the General Control Packet and the Gamut Metadata Packet. The General Control Packet carries information on AVMUTE (which mutes the audio during changes that may cause audio noise) and Color Depth (which sends the bit depth of the current video stream and is required for Deep Color).[86][87] The Gamut Metadata Packet carries information on the color space being used for the current video stream and is required for xvYCC.[49][88][89]

http://en.wikipedia.org/wiki/HDMI

pspfai

想請問一下版主，我家電視沒有HDMI，只有DVI。我的PS3, 電腦等都是經過一條HDMI-->DVI轉換線接駁電視，沒有問題，可是機頂盒接駁電視卻沒有畫面？機頂盒支援HDMI1.3和HDCP，電視也支援HDCP。請問會是什麽原因呢？