Not supporting specified multicast input network card

[ztaozhang]

Not supporting specified multicast input network card

[oskar456]

Thanks for the report. I will happily review a pull request implementing it.

[stackia]

Hi @ztaozhang, you can consider using my fork which is optimized for IPTV in China (hope this is what you are looking for). https://github.com/stackia/rtp2httpd