Closed caption problems

[Dale Dewing]

I have been working on getting digital over the air captions. Tried different video decoders. Ffdshow, Lav, and Microsoft decoders. No captions. Arcsoft decoder, no picture. AMD, video would not always start. I am using Main Concept decoder now. Sometimes the captions are fine and sometimes they are scrambled. Recordings about half the time are scrambled. Just checked live TV and 9 of 10 are good. The scrambled show was fine on another TV. I tried different tuners, no difference.
Has anybody had better luck.

Dale

[mvallevand]

The ATI Decoder is pretty code for HD OTA. Do you have sample of one of these "scrambled" files that you could post somewhere and I can test it for you.

Martin

[Dale Dewing]

Do you want the TS file? I tried attaching one to this reply but saw a message that said that the max file size is 25 Meg. An hour TS file is 2.6 Gig. By the way, the video is fine. Only the captions are scrambled.

Dale

[sub]

Do you want the TS file? I tried attaching one to this reply but saw a message that said that the max file size is 25 Meg. An hour TS file is 2.6 Gig.

You'd need to have put it on site like dropbox/onedrive etc, and provided a link.

By the way, the video is fine. Only the captions are scrambled.

To be honest, there is probably not a lot that can be done. When it comes closed captions, NextPVR has only a very limited role in it's function. We basically pass the unmodified closed caption information to a Microsoft's closed caption decoder, and let it take care of the decoding, then we just display the overlay it produces. If the Microsoft closed caption decoder is producing scrambled captions, there probably isn't much we can do about it.

[Dale Dewing]

I use the Main Concept video decoder. What is the route of the captions between the decoder, the renderer and NextPVR. It it possible to see the captions between these for troubleshooting.

Thanks
Dale

[sub]

I use the Main Concept video decoder. What is the route of the captions between the decoder, the renderer and NextPVR. It it possible to see the captions between these for troubleshooting.

The app never sees the text in the closed captions, so it's not logged anywhere.

When you've got closed captions enabled, it basically connects the Microsoft 'Line 21 Decoder' to the video decoder, which outputs bitmaps, which the app collects, and mixes in the OSD layer over the video.

I've looked at a couple of sample .ts files in the past that show garbage in places, and narrowed it down to the Line 21 Decoder occasionally not handling the closed captions correctly, leading to generation of a bitmap containing garbage captions.

[Dale Dewing]

If You would look there is a TS file here: https://onedrive.live.com/redir?resid=2C...=folder%2c
It might take a little while for it to be there.
Thanks for your concern.

dale

[mvallevand]

I didn't need a large sample the first 3 minutes play fine with the ATI decoder.

It's part of the AMD Media Code Pack,

Martin

[Dale Dewing]

I tried the AMD decoder and the captions are fine on a couple shows I checked. I tried this decoder before and I had a problem with the video not always starting. I will try it again. If I still have problems I will see if I can find a newer decoder then the one I have.
Thanks
Dale

[Dale Dewing]

You are right in that the AMD Decoder does captions very well, but if you do a commercial skip or the 60 second skip ahead, about half the time the video will not start until you hit FF or REW for a second or two. I deleted the AMD drivers and decoder and installed a later version. No help. I am becoming discouraged. I thank you for all your help even though I would think that is not a NexrPVR problem, but a decoder problem.

Dale