Newbie here, hello. My hd is not very good, why?

[KKlare]

Remember OTA is MPEG-2 and Dish is MPEG-4.
One difference MPEG-4 reduces the bandwidth by about 2X.
It may be more likely it will introduce artifacts.
Storing 2X save a lot of disk space with only slight distortion.
So it may be best to use MPEG-4 for archival and MPEG-2 for volatile recordings.
-Ken

 

[rfc]

So many little inaccuracies in this post, but I'll just focus on OTA compression. OTA IS compressed, just not as compressed as satellite. You will see compression artifacts on channels that have a lot of subchannels on the same RF channel.

I found this interesting when doing a google search on OTA compression:

"KAXT-CD in San Francisco is believed to have the most feeds of any individual over-the-air broadcaster, with twelve video feeds (all SDTV) and several audio feeds"

I just ran across this article, that says no compression of signal occurs prior to you receiving it...

"Off-air antenna reception is the best way to enjoy digital programs at the full resolution the TV networks intended since no compression of signal occurs prior to you receiving it."

http://www.skyvision.com/digital/OTA-FAQ.html

 

[Bobby]

Skyvision is not OTA, it is a direct satellite feed. OTA, like from your local stations, all compress their signal, otherwise there wouldn't be enough bandwidth to get a picture to your house....

 

[rfc]

Just found this on the net too. Much easier to understand.

http://www.differencebetween.net/technology/difference-between-mpeg2-and-mpeg4/

Difference Between MPEG2 and MPEG4

• Categorized under Protocols & Formats,Technology | Difference Between MPEG2 and MPEG4

MPEG2 vs. MPEG4
The Moving Pictures Experts Group, or MPEG, is the body responsible for the standards that we often use for video encoding. MPEG2 is the standard that was created to encode high quality videos, meant to be used for the, then emerging, DVD media. MPEG4 was developed much later, as an encoding method for devices with limited resources. Portable devices, like media players and mobile phones, use this format, as well as online stores who provide the hiring of video and audio files.MPEG4 is the preferred format for devices, as it yields a file that is under 1G for most full length movies. This is a far cry from MPEG2, which can only produce files with five times the size. Storing MPEG2 files will not be a problem on DVDs, as the usual DVD capacity is over 4GB, but is a major issue with portable devices. MPEG4 also made it practical to buy and download videos online, as MPEG2 videos are quite large, and take a long time to download. The small file size of MPEG4 files directly translates to a lower bandwidth needed, when streaming recorded or real-time videos through the internet.Setting file size aside when considering the better format, MPEG2 wins hands-down, as it provides a far superior image quality. The difference in quality is minor when viewing the files through a tiny screen, like those installed in mobile phones and even netbooks, but when it comes to large displays, like most current HDTV displays, you can clearly notice the difference in the final picture. We can attribute this to the amount of data lost, since both MPEG2 and MPEG4 are compression methods that lose data. MPEG4 simply discards more information, which results in poorer picture.MPEG2 compresses the video by discarding the information in portions of the image that do not change from one frame to another, and saving only the portions of the image where new information is added. The MPEG4 compression mechanism is a bit more complicated compared to that of MPEG2, as it needs better algorithms to scan and determine which pixels can be discarded, to reduce the data even further.

Summary:
1. MPEG2 is the encoding method for DVDs, while MPEG4 is the encoding method of choice for portable devices and online use.
2. MPEG2 encoded video files are much bigger compared to MPEG4.
3. MPEG2 requires a lot more bandwidth for streaming compared to MPEG4.
4. MPEG2 produces the best video quality compared to MPEG4.
5. MPEG2?s compression is much simpler compared to MPEG4.

 

[budda]

I just ran across this article, that says no compression of signal occurs prior to you receiving it...

"Off-air antenna reception is the best way to enjoy digital programs at the full resolution the TV networks intended since no compression of signal occurs prior to you receiving it."

http://www.skyvision.com/digital/OTA-FAQ.html

The more sub channels. The lesser the quality on any of those used. Example 6-1,6-2,6-3,6-4. On those OTA channels the bandwidth is reduced making the channels less then they could be. So if your local affiliate is using the subs your main channel suffers. You can find a breakdown of this on the net. More for the geeks if interested.

 

[rfc]

Remember OTA is MPEG-2 and Dish is MPEG-4.
One difference MPEG-4 reduces the bandwidth by about 2X.
It may be more likely it will introduce artifacts.
Storing 2X save a lot of disk space with only slight distortion.
So it may be best to use MPEG-4 for archival and MPEG-2 for volatile recordings.
-Ken

Ken, good to know and thank you for bring me up to speed on that.
Cheers!

 

[KKlare]

Correction: Dish is MPEG-2 for Western Arc SD shows. MPEG-4 all shows on Eastern Arc. Someday MPEG-4 all around.
OTA is only MPEG-2, which is a compression so ignore those that say without compression (except analog if you have some of those).
Dish recorders do not record analog.
-Ken