Wide Screen signaling (WSS) 寬屏幕信號標準
在電視技術中,寬屏幕信號標準(WSS) 是嵌入在類比電視信號的不可見部分中的數字元數據,描述廣播質量,特別是圖像的預期寬高比。 這使得電視廣播公司能夠啟用 4:3 和 16:9 電視機,通過以 full screen, letterbox, widescreen, pillar-box, zoomed letterbox, 等方式顯示以任一格式傳輸的圖像,以最佳方式呈現圖像。
這一發展與寬屏電視和廣播的引入有關,歐盟的 PAL系統(1990 年代中期)、日本的 Clear-Vision系統(1990 年代初)以及 在美國,需要將高清廣播縮減為標清。 WSS 信號的帶寬低,可以錄製在 VHS(當時流行的家庭視頻錄製技術)上。 它是在 Rec 上標準化的。 ITU-R BT.1119-2.[3]
現代數字等效項是活動格式描述,這是一組可以在 MPEG 視頻流中發送的標準代碼,具有類似的長寬比可能性。
625 line 系統
對於 625 Line模擬電視系統(如 PAL 或 SECAM),信號位於第 23 行。它以運行代碼開始,啟動代碼後跟 14 位信息,分為四組,如下表所示(基於標準規範 ITU-R BT.1119-2):
Bits (0 to 3) |
Aspect ratio |
Active lines |
0000 |
- |
- |
0001 |
576 | |
0010 |
430 | |
0011 |
- |
- |
0100 |
504 | |
0101 |
- |
- |
0110 |
- |
- |
0111 |
576 | |
1000 |
Letterbox 14:9 centre |
504 |
1001 |
- |
- |
1010 |
- |
- |
1011 |
undefined | |
1100 |
- |
- |
1101 |
Letterbox 16:9 centre |
430 |
1110 |
Full format 16:9 anamorphic |
576 |
1111 |
- |
- |
注:傳輸的寬高比為 4:3。 在此區域內,14:9 窗口受到保護,其中包含所有相關圖片內容,以允許在 16:9 電視機上進行寬屏顯示。
Group 2 to 4 | ||
Bit |
Item |
Group |
4 |
Camera Mode (interlaced) / PALplus Film Mode (progressive scan) |
2 - Enhanced Services |
5 |
Conventional PAL / PALplus Motion Adaptative Colour Plus encoding | |
6 |
No Vertical helper / PALplus Vertical helper present | |
7 |
Reserved / Ghost cancellation | |
8 |
No subtitles / subtitles within teletext |
3 - Subtitles |
9 |
No open subtitles / Subtitles in active image area | |
10 |
Subtitles out of active image area / Reserved | |
11 |
No surround sound / Surround sound mode |
4 - Reserved |
12 |
No copyright asserted or status unknown / Copyright asserted | |
13 |
Copying not restricted / Copying restricted |
525 Line系統
525 Line 類比電視系統(如 NTSC 或 PAL-M)規定使用脈衝來發送寬屏信號和其他參數,隨著 Clear-Vision (EDTV-II) 的開發而引入,這是一種與 NTSC 兼容的日本系統,允許寬屏廣播 . 在這些系統上,信號存在於第 22 行和第 285 行中,其中有 27 個bit,如 IEC 61880 所定義。
下表顯示了基於 Rec 的信號上存在的信息。 ITU-R BT.1119-2(“輔助”信號是 EDTV-II 特定的):
Bit |
Item |
1 |
Reference signal |
2 |
Reference signal |
3 |
Aspect ratio (4:3 full format / 16:9 letterbox) |
4 |
Even parity for B3 to B5 |
5 |
Reserved |
6 |
Field type (First field / Next field) |
7 |
Frame type (Reference frame / Other frame) |
8 |
Vertical temporal helper (no / yes) |
9 |
Vertical high resolution helper (no / yes) |
10 |
Horizontal helper (no / yes) |
11 |
Horizontal helper pre-combing (no / yes) |
12 to 14 |
For TV station use |
15 to 17 |
Reserved |
18 to 23 |
Error correction codes for B3 to B17 |
24 |
Reference signal |
25 to 27 |
Confirmation signal |
參考資料
- APPLICATION NOTE 9716: Widescreen Signaling (WSS). Renesas. 1988.
- ^Loncaric, Matej; Tralic, Dijana; Brzica, Maja; Petrovic, Juraj; Grgic, Sonja (September 17, 2009). "Managing mixed HD and SD broadcasting". pp. 79–82 – via IEEE Xplore.
- ^ Jump up to:ab c d e f RECOMMENDATION ITU-R BT.1119-2 - WIDE-SCREEN SIGNALLING FOR BROADCASTING (PDF). ITU. 1998.
- ^"RECOMMENDATION ITU-R BT.1197-1 Enhanced wide-screen PAL TV transmission system (the PALplus system)" (PDF). itu.int.
- ^FUKINUKI, Takahiko. "EDTV".
- ^Pollack, Andrew (September 15, 1994). "Japanese Taking to Wide-Screen TV" – via NYTimes.com.
- ^ETSI EN 300 294 - Television systems; 625-line television Wide Screen Signalling (WSS) (PDF). ETSI. 2003.
- ^Battiato, Farinella, Puglisi (2011). IISFA Member book 2011 - Image/Video Forensics: Casi di Studio (PDF). IISFA. p. 8.
- ^"All You Ever Wanted to Know About PALplus but were Afraid to Ask". Archived from the original on 3 March 2016.
- ^"Fluke PM5420 Application Note PALplus" (PDF). assets.fluke.com. Archived from the original (PDF) on 3 March 2016. Retrieved 12 January 2022.
- ^Nakayama, K.; Kojima, T.; Miyaguchi, H.; Sawaragi, T.; Yaguchi, Y. (August 5, 1995). "EDTV-II decoder by SVP2 (the 2nd generation of scan-line video processor)". IEEE Transactions on Consumer Electronics. 41 (3): 634–642. doi:1109/30.468089 – via IEEE Xplore.
- ^"The Journal of the Institute of Television Engineers of Japan". www.jstage.jst.go.jp.
- ^AN9716: Widescreen Signaling (WSS). Renesas Electronics Corporation. 1998.
- ^RECOMMENDATION ITU-R BT.1298 - Enhanced wide-screen NTSC TV transmission system (PDF). ITU. 1997.
- ^Kageyama, Masahiro (2010). Thesis Research on high image quality and high functionality of television (PDF).
- ^Jack, Keith; Tsatsoulin, Vladimir (2002-09-11). Dictionary of Video and Television Technology. Gulf Professional Publishing. ISBN 978-1-878707-99-4.
參考來源