Just wanted to give you all a heads up on some stuff we’ve been working on:
Closed captions for the hearing impaired seems to be one of those features that is ignored all too often in Linux TV. Application support is poor, driver support is rarely present. Being a little hard-of-hearing myself, I can appreciate though why this would be important though.
In the past KernelLabs has added driver support for em28xx based devices, saa7164 (better known as the HVR-2250) and the HVR-950q, and done a bunch of work on the tvtime application to better support it.
Going forward, KernelLabs has been contracted to improve closed captioning support for the popular VLC application. I’ve got patches to make it work with V4L2 devices, and I’ve started to look at improving the quality of the EIA-608 decoder.
But wait! If you go to the VLC features page, it says that it already supports closed captions! Unfortunately, if you actually try the functionality, the definition of “supports” means:
- No support for colors
- No support for styles (bold, italics, underlining)
- No support for positional placement of captions
- No support for mid-row codes
- All captions are rendered horizontally centered at the bottom of the screen
- Certain international characters are not rendered properly, including some popular ones such as ‘Â¡’ character commonly found in Spanish.
We look forward to making improvements in this area, meeting the FCC requirements in providing a compliant EIA-608 decoder.
The work has also uncovered several bugs in different drivers, for which I have already started submitting patches to the linux-media mailing list.