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02-19-08, 09:39 PM
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#1 | Link |
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Senior Member
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Evaluating Digital to Analog Converter Boxes for Users of Captioning
 The purpose of this thread is to provide a central place for evaluations of how well closed captioning issues have been addressed in the different coupon-eligible converter boxes (CECBs). While all CECBs are required to relay CEA-608 caption data to analog TVs, only some of them offer the option of decoding CEA-708 caption data, which provides the user the ability to adjust the captioning to one's own preferences. The main focus of this thread is on evaluating CECBs that decode CEA-708 captions to provide advanced captioning features. However, if CECBs that don't decode CEA-708 captions have any problems relaying the CEA-608 captions used by analog TVs, that's important information as well. Collecting such evaluations is highly desirable as there have been many problems reported with captioning for some set-top boxes used for pay TV services, and it is important to evaluate how well captioning is implemented before people who rely on captioning use $40 coupons on converter boxes with poorly designed captioning features. (Once the $40 coupon is used, the customer may not be able to get the value of the coupon back, and there may be no other good converter boxes suitable for the customer at the retailer.) Advantages of Advanced Closed Captioning Well-implemented advanced closed captioning can significantly improve the lives of consumers who currently have problems with their existing televisions or other equipment: CECBs with Digital (Advanced) Closed Captioning Which coupon-eligible converter boxes (CECBs) are supposedly offering advanced closed captioning? This information is still being collected as information becomes available. (Manufacturers often aren't specifying whether they provided advanced closed captioning, CEA-708 or DTVCCs; simply saying they provide closed captioning isn't adequate information as all CECBs are required to pass through the "analog" caption data that should be in the televised signal.) The following are two source of information that are still being updated, and which also list additional features of interest: http://octopus.freeyellow.com/CECB_list_wip.xls http://www.avsforum.com/avs-vb/showt...7#post13959917 (Updated May 27, 2008) (The posting above contains a zipped Excel file.) Here's my own current and not necessarily complete list of CECBs with advanced closed captioning (and some other features): Apex DT250 Link is to negative review on separate thread. Artec T3APro Caption button does not work with digital captions decoded by boxThe links for the different CECBs are generally to documents or postings that show that the CECB has digital (CEA-708) closed captioning decoding. Many of the above CECBs may have other noteworthy features, and may have CC buttons on the remote control, but this information was not available at the time of this writing. All reported features should be confirmed prior to purchase by examining the user manual or other public documents. Please note that the menus for some CC buttons may not be well-designed. Note: S-video should provide sharper digital captions, but many analog TVs do not have S-video pass-through. If you have a TiVo or other recording device with S-video inputs, however, you may be able to use the S-video output from the CECB for higher-quality analog recordings. Evaluating Digital Closed Captioning Some of the issues to consider in evaluating the captioning features associated with a CECB are:
Suggested Evaluation Process Please look at the other evaluations that have been done to get an idea of some of the issues that have been seen. If evaluating a converter box for the first time, I suggest not changing any of the display settings on the converter box after completing the initial set-up, the auto-tuning, and the addition of any channels that weren't automatically detected. It's probably best to use the better video cable available to you, which would be either S-video, if available, or composite video. Please indicate what kind of cable you're using in your evaluation. Please also indicate what size TV you are using, its manufacturer and the approximate year or period of manufacture, and whether it has any relevant known features like advanced comb filtering (which can improve the display of the captions). Also indicate if you're using a DVR like Tivo. Analog captions decoded by analog TV: The converter box should send to the analog TV any analog closed caption data (CEA-608 captions) that is being transmitted by the television station, and may do this automatically. Leave the analog captioning activated on your analog TV and determine if closed caption data is being transmitted from the programs (not the commercials, which don't have to be captioned) on all the digital channels. Make a record of any digital channel that is not transmitting analog caption data as this will be rare. If you don't see captions on the TV, doublecheck the user manual to see whether it is necessary to turn this feature on and how to do so.FYI, I recommend buying a converter box for evaluation purposes during a trial period and NOT using the $40 coupon until you're sure that you're pleased with the converter box. It may even be useful to evaluate several converter boxes. I also found it very helpful to evaluate the converter box next to an HDTV so that I could see whether captioning was any different on the HDTV. (Of course, lots of people won't be able to do that.) Before buying a converter box, however, you may want to doublecheck whether there are actually any TV stations in your area broadcasting digital captions for their digital channels. To do this, you may need to use a neighbor's HDTV, turn on their digital closed captions, and take a note of which digital channels appear to be receiving digital closed captions. You can also go to http://www.antennaweb.org and get specific information about your own address. Finally, you can use http://www.tvguide.com/listings with your zip code to look for digital channels that use decimal points (like 4.1, 5.1, 7.1, 7.2). Thanks for reading this far, and I hope you'll help out! Tons of people need help to figure out which converter box will work best for them, and it's going to be very difficult for them to get this information except through detailed evaluations from people who fully understand the importance of good captions. To find out where to buy the converter boxes, try: http://www.ezdigitaltv.com/Converter_Box_Retailers.html *If there are CECBs without digital closed captioning features that do have a CC button, please feel free to mention those boxes here. Dana Mulvany Last edited by dmulvany; 01-19-09 at 02:15 PM.. Reason: added link to review mentioning Apex DT502's digital captions |
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02-19-08, 11:35 PM
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#2 | Link |
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Senior Member
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Insignia NS-DXA1 (same as Zenith DTT-900)
Here's my evaluation of the Insignia digital-to-analog converter box, which I purchased at Best Buy on 2/14/08. (This is the same CECB as the Zenith, but is simply produced under a different name.)
NOTE: I have used some pictures here, but it should be understood that these pictures are not high resolution (the camera used had only 4 mb pixels) and do not accurately represent how the captions actually look in reality. The pictures should only be used as an approximation of what the captions look like. I would much rather see pictures from professional photographers of these captions, so if someone else can take better pictures, please do so. (What would be even better is for the manufacturers to provide pictures of different captioning options on their web sites so that customers can judge for themselves what they might expect to see.) I copied the list of issues from the first post and inserted my answers between the numbered issues: 1. The availability of digital closed captioning features: Yes. The Insignia offers the following features for customizing digital captions: Style, Size, Font, Text Color, Text Opacity, Background Color, Background Opacity, Edge Type, Edge Color. Eight font choices were available, with Font 0 appearing to be the one for receiving font styles selected by the program or broadcaster. Eight colors were available: White, Black, (bright) Red, (bright) Green, (dark) Blue, (light mustard) Yellow, (bright) Magenta, (bright) Cyan. 2. The availability of a CC button on the remote control: Yes (marked as CCD) 3. The usability of the menu activated by the CC button: Poor (changed from very, very poor because other remote controls for other CECBs may be worse!). The first push of the button shows the current setting at the bottom of the screen. If using Service 1 (the setting for English digital captions), each push steps through the next Service (up through Service 6), then through CC1, CC2, CC3, CC4, Text1, Text2, Text3, Text4, Off. It thus takes FOURTEEN pushes of the CCD button to go to the OFF position, and there is no way to go back one step if you've gone too far. When the channel is changed, the captions go back to what was programmed (i.e., Service 1 if using digital captions). 4. The ease of reading the font provided for analog captions decoded through the converter box: Poor to Fair. I think a font with clean lines is much easier to read. See the picture of the analog captions below (darker than normal due to flash from camera):  5. The ease of reading the eight different fonts available for digital captions: Many of the fonts are too thin and seem to flicker, even when they're large, so I would judge them as poor. There are about three out of eight fonts that I would judge as very usable when using a solid black background:  Font 0  Font 3  Font 7 6. The availability of a "caption preview" of some kind when changes are made in the settings for the digital captions, and how well this predicts the largest font style: Yes. However, the caption preview doesn't accurately indicate how large the size of the captions would actually be, and there can be significant differences in size according to the choice of the font. The preview showed the effect of making changes in the edges, in the color of the text, etc., which is very important, since the process of making changes in the settings already takes a lot of steps.  Caption Preview of Font 7  Font 7 (You can see the maximum number of 32 characters take up the entire width of the screen, which is actually good; other fonts didn't seem to get this large) 7. How large the digital captions are actually capable of becoming (useful for low-vision viewers): Font 7 appeared to be the font that could become the largest and spanned the entire width of the screen (see picture above). The large-sized characters were much bigger than the ones provided by my Sharp HDTV. 8. How well the optional translucent background provides a contrast to the characters used in the captioning: Poor (for basic fonts). However, one can compensate by adding a uniform, depressed or raised edge to the characters in the same color of the font, which provides better contrast. Otherwise, it is difficult to read the characters against the translucent background, in part because the fonts tend to be too thin and can't provide enough contrast. 9. Whether there are any bugs associated with captioning, such as a failure to detect analog captions if there are no digital captions, jerky movements, cut-off captions, unexpected changes in the background, etc.: a. The Insignia did not detect analog captions automatically when there were no digital captions (from the SD channels produced by a local PBS station). I either had to switch manually to CC1 in order to get analog captions decoded, or I had to turn on my TV's captions in order to see the analog captions. b. When there were long sentences using Font 7 in large size, there would be sudden, jerky movements of all the captions to the left so that they could all be seen. This was because the captions would start off indented but then have to be jerked back to the left margin when the lines of text got very long. (I don't know if this is a converter box problem, a transmission problem, or simply an oversight in standards for captions.) c. The Insignia would display captions so low on my convex Magnavox TV that the captions on the left and right would not be completely visible on the bottoms even when using letter-box. (However, the captions were still legible, so this would not be a deal-breaker for me.) This might not happen with flat TVs. d. When I took pictures of Font 0 and Font 7 captions, a close examination of the pictures showed that the solid background behind some characters had unexpectedly become transparent or clear, which made some of the characters illegible. I only noticed this in the pictures, and not during live viewing. I'm not sure how much of a problem this is or will be.  Font 0: Look closely at last word  Font 0: Look at the background behind the "T" in the last word; it's missing but a faint "T" can be seen.  Font 7: Look closely at "21st" and "Century" e. There is no option to specify the alignment of the digital captions, although my Sharp HDTV provides this option. This would have allowed the viewer to move captions away from an area that is important to watch (such as the bottom of the screen during football games). 10. Whether the remote control has an SAP button, a raised dot on the 5 button, and dots on the Power button (useful for low vision or blind users): The control has an SAP button, a raised dot on the 5, and dots on the Power button. The remote looks usable by low vision and blind users as the buttons are well spaced. The SAP button shows the current language of the audio on the bottom of the screen. I personally have not yet verified whether the SAP button actually worked to provide a secondary audio program. 11. How well the user manual explains the different digital closed caption settings. This user manual takes less than half a page of the manual and doesn't explain that most users should select "Service 1." I've now seen some other user manuals that do much better job explaining the different features, such as that of the CASTi CAX-01. I'd judge this manual as poor. 12. Whether the CECB has crashed and what the circumstances were. The Insignia crashed five times within three weeks. I was able to take pictures of three of the crashes, and it appeared that commercials were showing during those crashes. During the last crash, there was a black screen, so I'm not sure whether a commercial was happening or if there was a transition to a commercial. I think three crashes occurred on the my20 channel, and another occurred with WJLA (local ABC affiliate) and either WTTG (local Fox affiliate) or WETA (local PBS affiliate using SD channel). All those stations have problems transmitting captions over digital channels in some way, so I suspect that something about the way those stations transmitted captioning may have precipitated the crashes (though of course, the CECB shouldn't be crashing anyway). Overall opinion: In my opinion, the most important thing to evaluate about captions is how easy they are to read on the screen and whether it's possible to come up with an arrangement that works well for the individual. (Having the ability to use a translucent background can be important for people who don't want the captions to block out information on the screen, such as that present during a football game.) With enough tweaking, I was able to get fairly good captions. I liked that the large-size captions actually are fairly tall and much larger via the Insignia than they are on my Sharp HDTV (which seems to do a poor job in this respect). Font 0 worked well with the following setting: white text, white uniform edge, large size, translucent black or blue background. Font 3, despite my earlier description of it being usable, still isn't perfect. Uppercase "M"s and "W"s look polluted by nearby black pixels and "busy" due to "dot crawl." It looks much more even in large size than in standard size, however. Font 7 did not work well in the large size because the automatic indentation from the left side present for some channels required long sentences to jerk suddenly to the left margin when the words reached the right side. In the standard size, which I hadn't tried until 2/20/08, the "T" is below the height of the other letters and makes the text look uneven. Thus I'd probably end up using Font 0 unless I was at a significant distance from the TV, in which case I might switch to Font 7. The menu for the Insignia's CCD button is far too cumbersome, but it is still better to have a CC button than none at all. When there were no digital captions being transmitted, I would click the CC button seven times to get to the CC1 setting to see whether there were analog captions available. (My analog TV's remote does not have a CC button at all, so the Insignia's remote was better for getting to analog captions.) The converter box doesn't automatically display analog captions when there are no digital captions. (However, TV stations are supposed to broadcast both digital and analog caption data for their digital programming, though at least four stations in the Washington, DC area are not doing so. ) The manufacturer did a poor job of selecting fonts for the captions, but at least there are some fonts that can be tweaked to be okay, and at least the captions can actually be large. It is troubling that the background apparently dropped out partially for the Font 0 as this font (probably the one that defaults to the font used by the program) may be the most popular one used, but this does not seem to be happening often at this time. Another problem with the Insignia (not related to captioning) was that it didn't seem to automatically detect the best way of showing the picture, unlike my HDTV. I would frequently have to hit the Zoom button to pick a better display for the picture. However, this problem seems to have gone away the longer I used the Insignia, perhaps because I ended up manually setting channels to letterbox. The picture quality is marvelous, but hopefully other converter boxes will do a great job with this as well. I'm hoping that converter boxes from other companies have been better designed to address the captioning issues. Unfortunately, despite all its problems, it could be that the Insignia is the best converter box out there for users of captions----because engineers may have done even worse at addressing captioning issues in other brands of converter boxes. I returned the Insignia on March 13th, but also evaluated the Zenith, which has the same chip and remote control and functions just like the Insignia. As other people have noted, the Insignia and Zenith are the same products manufactured under different names; the only difference is in the user guides. Added notes: As of May 7th, the Insignia/Zenith CECBs appear to be the only CECBs I know of which can provide digital captions larger than the analog captions provided by my TV. When I fast-forward a Tivo'ed program, the digital captions from the Zenith remain legible, while the captions from the DigitalStream CECB become incomplete and illegible. Thus if I want to hurry up through a Tivo'ed program, I'm in luck if I'm using a Zenith/Insignia CECB but not if I'm using the DigitalStream CECB (which may depend on comb-filtering to look sharper). Dana Mulvany Rockville, MD Here's a link to a video of the 708 captions provided by the Zenith DTT-900 CECB: http://www.youtube.com/watch?v=OORS0tC8JFw Last edited by dmulvany; 05-30-08 at 04:19 PM.. Reason: updated article and corrected minor errors |
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02-20-08, 02:06 PM
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Senior Member
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02-21-08, 08:46 AM
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New Member
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Returning Boxes
You say in your piece,
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Also, boxes bought with a coupon can be exchanged for another box, or returned, but only the out-of-pocket payment can be refunded. -agc |
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02-21-08, 01:31 PM
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#6 | Link | |
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Senior Member
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The Insignia has now crashed twice within the first week of purchase, and that might even be because I was using closed captioning. Unfortunately, engineers simply might not have run the box through its paces with all the different captioning features being turned on. I put up a post and picture about the last crash at the following high-traffic AVS thread to get more input; I also noticed problems with the audio and video going out of sync, and the captions getting delayed the longer the box was on: http://www.avsforum.com/avs-vb/showt...2#post13176692 Here's a picture of the crash (the second one):  Dana |
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02-21-08, 02:30 PM
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#7 | Link |
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Mr. Bob
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I got an HDTV Tuner several years back, Motorola HDT101, for my SD TV.
I wanted to enjoy DTV, but my wife who is hard of hearing needs CC. The problem was that some of the stations do CC OK over analog, but on the HD feed, the CC was all screwed up. I sure hope that by the time the analog shutoff come around, the stations figure out how to do DTV CC correctly. Bob Diaz |
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02-21-08, 05:01 PM
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#8 | Link | |
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Senior Member
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Getting a digital-to-analog converter box and turning on the captions can show you what the current state of affairs is. I'm going to have to do a massive letter-writing campaign myself now that I understand that some TV stations in my area are not transmitting both 608 (analog) and 708 (digital) captions as required by law. When they don't transmit both, that's when various people are going to have problems receiving captions. I can't get captions on my Sharp HDTV for some programs on digital channels even though I can get captions from the converter box for those same programs. That's probably due to problems with transmissions from the TV station.  |
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02-22-08, 01:50 PM
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Last edited by drla; 02-22-08 at 02:10 PM.. |
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02-22-08, 02:12 PM
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The inability to get captions on some channels is probably a reflection of a problem at the station end. Dana |
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02-22-08, 02:45 PM
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02-22-08, 05:50 PM
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02-22-08, 06:50 PM
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#13 | Link |
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Advanced Member
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Many American viewers who are not necessarily "hearing impaired" use closed captioning at certain times. Closed captioning is particularly effective in public lounge areas of restaurants, bars and other locations with a lot of ambient noise. Even in the home, some viewers prefer viewing as well as seeing the spoken dialogue.
While the broadcasters may bear much of the blame for these problems, I recall NTIA's specifications referred to the importance of the "robustness" of the STB design. While that may have referred to hack-resistance, it also presumably means the CECBs should be freeze-resistant and crash resistant. |
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02-22-08, 06:57 PM
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#14 | Link |
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AVS Special Member
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Very interesting stuff - the fields of closed captioning, audio description and sign language interpretation are areas where digital TV offers potential for huge improvements over analogue - but also huge pitfalls.
Over here in the UK our OTA system uses a new closed caption system called DVB Subtitles - which works like DVD subtitles, with the broadcaster sending a bit image, not text that is rendered by the receiver. This means we can't alter our type size as it appears you guys can, but it does mean that broadcasters decide the typeface not the box makers, so viewers get the same result irrespective of box. The UK broadcasters worked with disability organisation to produce the "Tiresias" typeface that is really clear for those who are both hard of hearing and suffer reduced vision. http://www.tiresias.org/fonts/index.htm The broadcasters decides the size and position of the characters (they are usually relocated to accommodate name captions) and the system supports colours, so different characters in drama have their dialogue in different hues, making it easier to follow quick dialogue. It is possible to have multiple subtitle streams, with most boxes, like DVD players, having a default language choice for channels with multiple language streams (In Wales thre are shows made in Welsh language with both optional English translatin and Welsh hard-of-hearing subtitles) Normally you just press a "Subtitles" button and it shows the subtitles of the selected language (or if there is only one stream it shows that) The very sensible US "Closed Caption on Mute" facility isn't widespread in the UK - though this may stem from our analogue TV system where subtitles were just a page number (888) on the multiple page number teletext system (News on 100s, Sport on 300s, Weather and Travel on 400s) Satellite broadcasters are using the older character based technology - more similar to closed captions - though the main satellite platform uses a much better typeface to render it in the box. I wonder if any US boxes will adopt Tiresias - it is already widely used not just for subtitles but for a lot of public signage in buildings, on train station indicator boards etc. |
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02-22-08, 07:36 PM
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Senior Member
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The choice of font makes such a huge difference. I'm concerned that many caption fonts could cause eye strain. On a different topic, I'm realizing now that when I look at my Magnavox TV's analog captions, there's no flickering---the captions are absolutely still. With the captions from the Insignia, there's a sense of movement; the captions are somehow created and fundamentally look differently than the ones from the TV. The characters don't look completely white. This can't be captured though photos, I'm afraid, and it would be hard to capture through video. The captions from my HDTV are crisp and "still" like the Magnavox's. The ones from the Insignia somehow look like they're made by moving pixels while the other ones don't. Quote:
This can be a handy feature on my TVs' remote controls. For example, when I'm not getting captions on a digital channel from the Insignia, I can put the TV's remote control on MUTE, which turns on the analog captions, and then press the Insignia's CC button six times to go to the CC1 mode, then turn off the Mute and get sound and CCs again. (The Insignia does not offer the CC on Mute option.) Quote:
Dana Last edited by dmulvany; 02-22-08 at 10:43 PM.. Reason: cleaned up strange errors! |
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02-22-08, 09:40 PM
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#16 | Link |
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AVS Special Member
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With regard to the "movement" of the captions on the Insignia box - I suspect this may be because the Insignia is inserting the captions in the composite domain, whereas TVs may insert them in the RGB domain after composite decoding, resulting in a much cleaner result.
(UK analogue TVs insert their subtitles in the RGB domain usually - meaning they are very clean and clear) As for the Tiresias fount - it was developed in the UK by UK broadcasters in association with the RNIB (Royal National Institute for the Blind) so that it was as clear as possible for visually impaired viewers who also had a hearing impairment and I believe the RNID (Royal National Institute for the Deaf) were also, of course, involved. I think the typeface may have been a more commercial proposition initially than it is now - it is certainly becoming pretty widespread in the UK. It has a clean, sans serif, appearance, with improved distinction between similar characters like i, l, 1 etc. (First impressions remind me of the London Underground typeface - also very clear and classic) |
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02-22-08, 10:23 PM
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AVS Special Member
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For info - this is what UK satellite viewers get (it is a hybrid, I believe, using World Systems Teletext packet data, the same text based system as used on analogue TV, but rendered in a more modern manner) on the dominant UK satellite platform (Sky Digital) :
 (You can see the use of multiple colours for different speakers) And this is the same broadcast on OTA Digital, with the DVB subtitles system using Tiresias. The OTA receiver is now about 6 years old, and is one of the first small SD DVB-T adaptors from Pace, though the subtitles look the same on all OTA DTVs as the fount is bitmapped by the broadcasters. This box is pretty much the same in performance terms to the UK DVB-T adaptors now selling for around US$30-50 in UK supermarkets.  IMHO the second is clearer and easier to read - though less bold. Both screenshots were from my 8 year old 16:9 SD CRT TV (am not in my usual location!) - and the in-vision signing is because the overnight the BBC repeat public service shows with added in-vision BSL (British Sign Language). BSL signing for a proportion of broadcasts is a requirement for all UK digital OTA broadcasters. Both are from the BBC One London SD 576/50i network feed - the first via satellite DVB-S, the second via OTA DVB-T. Both satellite and OTA set top boxes were connected RGB analogue SD (576/50i) not composite PAL, hence no chroma/luma interference and sharp chroma on the receiver rendered graphics. (Apologies for photos - taken quickly on a compact) Last edited by sneals2000; 02-22-08 at 10:31 PM.. |
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02-22-08, 10:37 PM
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Physiologically, I think there'd be a different effect on the eyes after reading the two different kinds of captions for several hours. Quote:
Dana Rockville, MD |
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02-22-08, 11:00 PM
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A component (or S-video for that matter) connection would minimise this (remove it in the case of component) - as, I suspect, does insertion in the TV rather than an external box. (I'm assuming US analogue TVs insert captions in the RGB / Component not composite domain - as European teletext subtitles are handled - I may be wrong. HDTVs are entirely component so should be fine) Quote:
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As they say on the site - good design for visually impaired viewers is good design for us all... Quote:
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02-22-08, 11:15 PM
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 Note: I wrote the following bracketed sentences before seeing the response above: [The new digital-to-analog converter boxes can only be connected via RF or composite, or in some cases, S-video. Do you know if that will bode ill for captions in the composite domain? ] BTW, the background behind the subtitles in the second picture is translucent, providing less contrast, while the background in the first picture is solid black. That's one reason why the second picture's subtitles would seem less bold, though I agree they look sharper than the subtitles in the first picture. Last edited by dmulvany; 02-22-08 at 11:27 PM.. |
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02-23-08, 08:43 AM
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AVS Special Member
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AIUI the receiver ignores the aspect ratio of the underlying video - and so in some cases the font for the subtitles appears stretched when overlaid over 16:9 video and not stretched when over 4:3. AIUI this is the case with SD satellite broadcasts - where 16:9 material is broadcast in 16:9 and 4:3 content is broadcast in 4:3 (with a few exceptions) rather than pillarboxed. Networks with mixed aspect ratio content actually alter the MPEG2 header to signal that the pixel aspect ratio has changed as they flip ratios. However with OTA, the BBC pillarbox their 4:3 content (i.e. always broadcast a 16:9 raster, but fill the edges with black when pillarboxing - and also send an AFD to indicate that only the central portion is active) and I suspect the DVB subtitles are added over the pillarbox content in the receiver, so the DVB subs are always going to be considered to be rendered in 16:9, but have to be 4:3 safe so that once overlaid over 4:3 content, if the receiver goes into a 4:3 centre cut it also centre cuts the subtitle overlay, rather than squeezing the subtitles horizontally. Not sure. Either that or the BBC have optimised their DVB fount for 16:9 content (pretty much everything is 16:9 apart from older reruns and the odd movie) as the Tiresias typeface as well as being a lighter typeface also appears the right shape, whereas the satellite subtitles always appear horizontally stretched in 16:9 and look better in 4:3... Another thing I meant to mention - is the use of all caps. All but one of the closed caption screengrabs in this thread seems to use all capital letters - is this the norm? My understanding is that mixed case is less tiring to read for long periods, and also faster to read, but it is also more difficult to render aesthetically in a mono-space fount, rather than a proportional one. Last edited by sneals2000; 02-23-08 at 08:50 AM.. |
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02-23-08, 09:29 AM
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#23 | Link | |
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02-23-08, 09:53 AM
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#24 | Link | |
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I suspect there will be more and more live subtitling in the UK - as the BBC have committed to 100% subtitling by the end of this year. http://www.bbc.co.uk/info/policies/subtitles.shtml We're at 95% for the main analogue services (BBC One and BBC Two) with 80% of the digital services (BBC Three, BBC Four, CBBC, CBeebies, News 24) I'm not sure if BBC Parliament is included... We don't have the smooth scrolling that CC offers. For pre-subtitled content the text just cuts on and off - though sometimes two lines will be displayed at different times, but the first will stay up when the second has appeared, to better explain fast dialogue pacing. For live subtitling one word appears at a time, so it gives the impression of being typed as you watch. (This is effectively done by constantly re-sending the entire subtitle as each word is added) The live operators also dynamically switch the colours so that the colour coding of speaker in interviews is still present on live shows, and also have the ability to reposition the subtitles to avoid obscuring name captions, sport scores etc. One interesting aspect is that many subtitlers now work from home using an off-air feed of the channel they are subtitling, combined with a PC and a broadband or ISDN connection to send their live subtitles back to the broadcast station, and also to gain access to guide scripts which are often e-mailed by productions prior to transmission, so that the subtitler is aware of the spelling of names of guests and places that may appear, what the format of the show is going to be, and in some cases where pre-recorded elements are included in live shows there may be scripts for these provided electronically. There are subtitlers on remote islands in Scotland who do live subs for the BBC I believe. The BBC is also working to ensure that its download and streaming programmes are accessible, with subtitles and audio description options being trialled. think subtitles on downloads and streaming is an area that is often overlooked - and will be increasingly important as we move away from channels to VOD etc. Last edited by sneals2000; 02-23-08 at 10:03 AM.. |
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02-25-08, 03:48 PM
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#25 | Link | |
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Rca Dta800
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Are you talking about problems with the pass-through of analog captions? Does the RCA DTA800 offer digital caption decoding? What kinds of problems do you see with the captions from channel 6.1? What is the network for the station that is broadcasting on 6.1? Added note: There's a chance that there's something about the transmission of the captions from the station that is causing a problem as time goes on. If we know what the network is of the affiliate that is broadcasting on 6.1, other users of the RCA DTA00 could try tuning to affiliates of that particular network just in case other affiliates of that same network have the same problem. Dana Last edited by dmulvany; 02-25-08 at 10:04 PM.. |
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02-25-08, 06:09 PM
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#26 | Link | |
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02-29-08, 04:04 PM
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#27 | Link | |
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http://en.wikipedia.org/wiki/Dot_crawl There's a picture illustrating dot crawl there. Here's a quote from the entry above: "Dot crawl can also make narrowly-spaced text difficult to read. "Dot crawl has long been recognized as a problem by professionals since the creation of composite video, but was first widely noticed by the general public with the advent of Laserdiscs. "Dot crawl can be greatly reduced by using a good comb filter in the receiver to separate the encoded chrominance signal from the luminance signal. However, the only complete solution to dot crawl is to not use composite video, and to use S-Video or component video processing instead." I haven't come across any converter boxes that definitively have both S-video and digital closed caption decoding, but the features of many converter boxes aren't known yet. It would certainly be nice to be able to evaluate the quality of digital closed captions when using S-video, and hopefully there'll be at least one such converter box with both features (particularly for people whose analog TVs don't have captions that are easy for them to read and who have an S-video port on the TV, VCR or DVD recorder---the digital captions can be recorded, if desired). Dana |
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03-01-08, 05:23 PM
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#29 | Link |
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sneals2000 writes:
> My understanding is that mixed case is less tiring to > read for long periods, and also faster to read, but it > is also more difficult to render aesthetically in a > mono-space fount, rather than a proportional one. Back in the 1970s, word was that Bell Labs had done a study and found that mixed case is easier to read. Which may have had something to do with Unix using mixed case. I don't know what they used in the study, but back then most computer equipment had fixed width font, other than the (rare?) photo-typesetter. |
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03-01-08, 05:36 PM
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#30 | Link | |
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http://www.ntia.doc.gov/ntiahome/frn..._technical.htm
says: "Equipment must display ... (3) Close Captioning information as required by the FCC Rules in 47 C.F.R. S:15.122 and incorporate the CEA 708/608 standard." So CEA 708/608 is the analog captions? Assuming for the moment that the answer is "yes", does "Equipment must display" mean that the box must decode and display the captions, or merely pass them through, depending on the TV to decode and display them? Older TVs don't have captions, so you could still be stuck without captions even with a shiny new converter box? |
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