Mpeg-dash

[bgowland]

If anyone understands this stuff I'd appreciate some help. :eek:

I've installed GPAC on my npvr PC and it has an app called DashCast which seems to be quite happy to 'chunk' .ts files recorded with npvr into h.264 mp4 format.

The chunks seem to be created as separate audio and video files with .m4s extensions (audio filenames have an a1_ prefix and video files a v1_ prefix). There are also a1_xxx.mp4 and v1_xxx.mp4 files.

The key thing though (as far as I understand it) is any player trying to stream using mpeg-dash needs to access an MPD file which describes various things but the MPD file isn't created until the 'chunking' process is complete. On my (admittedly old and clunky PC) it takes 40 minutes to complete the process for a 1 hour recording - not good unless you want to post-process all recordings to make them playable using the mpeg-dash protocol.

Any tips would be gratefully received.

Cheers,
Brian

[mvallevand]

Personally for my two cents, I don't think we are ready to consider consumer mpeg-dash streaming of live tv at this point. It will probably help if vendors like Hauppauge are ever able to provide us with inexpensive hardware HEVC streaming solutions , but HEVC is still future tech since the embedded support isn't there yet.

Martin

[bgowland]

I'm not even considering live TV at this point Martin - only recordings.

I've discovered a command-line switch to use with Dashcast which seems to be designed to allow nearly immediate streaming of a media file which is in the process of being chunked. The MPD file is created at the same time as the first chunks which can be as little as a few seconds depending on segment size specified. Of course it means skipping during the chunking process is an unknown depending on whether the relevant chunks had been created or not.

Cheers,
Brian