m3u8 has separate audio / video streams streams...forcing transcode...

[TheKenR]

Hello,

Having a little trouble figuring this one out. I am using the NextPVR latest release with an IPTV source. I have one channel URL that will not play in NextPVR, I keep seeing "Streaming Failed (transcoder exited)" in the web client. The URL plays fine in other clients like VLC or even when I download the stream to a file using ffmpeg on the command line.  Looking into the NextPVR log files I noticed this:

2022-07-13 13:53:01.777 [DEBUG][11] m3u8 has separate audio / video streams streams...forcing transcode...
2022-07-13 13:53:01.778 [DEBUG][11] video stream: http://myURL
2022-07-13 13:53:01.778 [DEBUG][11] audio stream: http://myURL
2022-07-13 13:53:01.778 [DEBUG][26] IPTV StartStream@3.5
2022-07-13 13:53:01.778 [DEBUG][26] IPTV StartStream@3.5.1
2022-07-13 13:53:01.779 [DEBUG][26] Executing: ffmpeg -y -i "http://..." -i "http://..." -async 1 -c copy -f mpegts  -
2022-07-13 13:53:01.779 [DEBUG][26] http://myURL
2022-07-13 13:53:01.780 [DEBUG][26] IPTV StartStream@6
2022-07-13 13:53:01.780 [DEBUG][26] IPTV StartStream@7
2022-07-13 13:53:01.781 [DEBUG][26] IPTV StartStream@8
2022-07-13 13:53:01.781 [DEBUG][26] Creating writer: LIVE&/home/xxxxxx.ts
2022-07-13 13:53:01.781 [DEBUG][26] live mode
2022-07-13 13:53:01.781 [DEBUG][26] Created Mutex: Global\NPVR-mutex-89e651ece658af0c5407b1d173ef38ad
2022-07-13 13:53:01.781 [DEBUG][26] Created map: /home/xxxxxx.map
2022-07-13 13:53:01.781 [DEBUG][26] StartStream [LIVE&/home/xxxxxx.ts] allocated handle: 5
2022-07-13 13:53:01.781 [DEBUG][26] IPTV StartStream@9
2022-07-13 13:53:01.781 [DEBUG][26] Live TV handle: 0x190005
2022-07-13 13:53:01.781 [DEBUG][26] StartStream(9849:Channel 329, LIVE&/home/xxxxx.ts) allocated handle: 1638405
2022-07-13 13:53:01.781 [DEBUG][26] Handle: 190005
2022-07-13 13:53:01.781 [DEBUG][26] StreamNative@9 (storing stream handle: 1638405)
2022-07-13 13:53:01.781 [DEBUG][26] clientHandle[3dff47e2-9c55-413e-b18e-c75bdb2269db] = 1638405 *
2022-07-13 13:53:01.786 [DEBUG][4] Took 121.3613ms to query listings
2022-07-13 13:53:01.902 [DEBUG][32] ffempg exited. Likely end of VOD.


It appears to be trying to load two streams concurrently using ffmpeg but apparently fails. ffmpeg exits but I don't see a reason why? No transcoding errors in the log either. When dumping a TS file from this URL at the command prompt using ffmpeg there is no need to merge streams. It just saves the stream with good video and audio. Is there some way I can see more detailed logging from ffmpeg? Also, is there a way I can remove the redaction from the log files so I can see the full ffmpeg commands and URLs?

The source M3U8 contains multiple streams. Could NextPVR be grabbing the wrong stream?

Here's what I get from the URL when I download the HTTP response (removed sensitive data):
#EXTM3U
#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="undefined a1",DEFAULT=YES,AUTOSELECT=YES,LANGUAGE="",URI="tracks-a1/mono.m3u8?token=xxxxx"
#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="undefined a2",DEFAULT=NO,AUTOSELECT=YES,LANGUAGE="",URI="tracks-a2/mono.m3u8?token=xxxxx"
#EXT-X-MEDIA:TYPE=AUDIO,GROUP-ID="aac",NAME="undefined a3",DEFAULT=NO,AUTOSELECT=YES,LANGUAGE="",URI="tracks-a3/mono.m3u8?token=xxxxx"
#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=1320000,BANDWIDTH=1660000,AUDIO="aac",RESOLUTION=768x432,FRAME-RATE=59.940,CODECS="avc1.640028,mp4a.40.2",CLOSED-CAPTIONS=NONE
tracks-v3a1/mono.m3u8?token=xxxxx
#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=2120000,BANDWIDTH=2650000,AUDIO="aac",RESOLUTION=896x504,FRAME-RATE=59.940,CODECS="avc1.640028,mp4a.40.2",CLOSED-CAPTIONS=NONE
tracks-v2a1/mono.m3u8?token=xxxxx
#EXT-X-STREAM-INF:AVERAGE-BANDWIDTH=4280000,BANDWIDTH=5350000,AUDIO="aac",RESOLUTION=1280x720,FRAME-RATE=59.940,CODECS="avc1.640028,mp4a.40.2",CLOSED-CAPTIONS=NONE
tracks-v1a1/mono.m3u8?token=xxxxx


Can anyone give me any advice on this?

Thanks

K

[sub]

Could NextPVR be grabbing the wrong stream?

Maybe. Hard to know from what we've got here.

It sounds like your IPTV service is one of the very few rare ones using separate streams for audio and video. NextPVR doesn't attempt to handle this type of stream itself, and has to instead ask ffmpeg to mux the audio/video into a single stream so that it is in a format that NextPVR can handle.

If you're willing to PM me the an example URL, I'll check what NextPVR doesn't like about it.

[sub]

I was able to reproduce the issue with your example url, and have included a fix for the next release.

It was getting confused over a redirect, and still looking for the separate audio/video streams at the original url location, rather that redirected location.

[TheKenR]

I was able to reproduce the issue with your example url, and have included a fix for the next release.

It was getting confused over a redirect, and still looking for the separate audio/video streams at the original url location, rather that redirected location.

Ok great! Thanks for looking after this! 

Is the next release getting close?

K

[sub]

Is the next release getting close?

Yes. It wont be this weekend. I'm away next weekend, so it'll probably be weekend after that.