Questions about transcoding from IPTV sources

[mvallevand]

Ok, not sure we the recording demux doesn't like this stream, the playback demux doesn't mind. FWIW it would probably record with the Network Recorder plugin.

Martin

[JP23]

Thanks, I will give that a try.

I've also tried restreaming this source using VLC, doing no transcoding at all, and when I add the VLC stream address as an H264 source it works fine.

I'm 90% convinced it just needs to buffer for a second or so more for it to work.
Alternatively if there was some way to get ffmpeg to just pass through the original audio and video tracks rather than doing the full transcode it would presumably not be so CPU intensive.

[mvallevand]

From my experience with Network Recorder buffering is only an issue with live tv and it doesn't explain your zero byte recordings.

Martin

[sub]

That recording played ok here.

[sub]

If I set the IPTV source type to H264 it doesn't play, and any recording that I attempt just results in a 0 byte file.

Obviously if I set the IPTV source type to 'Internet sourced...' it gets transcoded. That's not what I've done for this sample.

I thought you just wanted a sample of the raw video, so I just downloaded it directly from the stream address.

That "H264 TS" will only work wth a transport stream. It will not work with other types of stream that happen to have H.264 video. It is not common for a transport stream to be used for IPTV, so I'm guessing your stream is not one.

If you want to post or PM me an example URL, I'll confirm if it's a transport stream.

[JP23]

The sample I posted really is the raw stream content, I haven't recorded it or transcoded it with NPVR or anything else.

I just put the url into internet explorer, selected 'save' and then cut the download off after a minute or so by terminating the IE process. The only change I've made is to remove ".part." from the end of the filename.

[mvallevand]

The "part" makes me think that it is a segment of an HLS stream and not a direct stream to video. If the source is .m3u8 or .mpd then the client needs to smarts.

Martin

[JP23]

That's just what IE does to a partial download - it would download forever if I let it, and it deletes the file if you press cancel on the download, so I killed the process and was left with a .part file.
The path to the stream ends in a .ts, not .m3u8 or .mpd or anything else.

[sub]

Martin is correct - an HLS stream is not the same as a transport stream, even though it contains lots of small transport stream files. Those "MPEG2 TS" and "H264 TS" are for straight transport streams. ie, a big long series of 188 byte transport stream packets, not HLS which is a continually updating .m3u8 url and a series of small .ts file urls. Also, sometimes HLS can contain mp4 or fmp4 files, so not always .ts.

[JP23]

I did take a look at configuring Network Recorder for this source, but when I searched for some guidance on how to set it up I ended up in a thread from 6 years ago where I was struggling to set up Network Recorder...

Bringing this topic back to a couple of questions that may be relevant to users other than myself:

1 - Is there any prospect of allowing some control of the transcoding process for IPTV sources, ie via config.xml in a future release?

2 - Will the ffmpeg used by NPVR use hardware acceleration if available - and how might this be configured?