No audio when transcoding HD channels

[bgowland]

Does not te fact that NEWA streams the HD channel fine suggest that the parameters being passed to it from ndroid are not right?

The only parameters nDroid passes to the npvr web server are X & Y resolution (pixels) and bitrate (KB/s).

The presets available from the nDroid transcode option are (obviously) low, medium and high res each with 2 bitrates. Admittedly I did get the actual values from a wikipedia article but I picked them based on true 16:9 aspect ratio and the fact they're standard formats for various systems.

WHen you say NEWA streams the channel fine - what transcode settings are you using with NEWA?

[mvallevand]

NEWA doesn't use ffmpeg, it uses vlc so it is not a good comparison. sub's ffmpeg is old that the command line has changed quite a bit. A quick looks shows one major change libfaac was removed years ago, because of GPL concerns.

Martin

[gEd]

Does anything else within npvr use ffmpeg and the transcode settings?

[Graham]

At a slight tangent ... the only decoder that I can persuade to play audio for UK HD channels is LAV. ffdshow doesn't work for me. It may be that ffmpeg can't handle HE-AAC audio (or it may need an up to date version or some specific parameters).

[gEd]

ok, so Martin was right about libaac not working so I replaced it with ac3 codec (libmp3lame also works).

Also, afetr a silly amount of trial and error, I found that -cmp +chroma is not compatible with latest version of ffmpeg so I removed it.
Also.... I set maxrate to be the same as bitrate as I think it is supposed to be if you are aiming for CBR.

Seems to play HD content ok at Medium 800K setting on my Nexus 4 on my home wifi (N). The higher rates stutter. May experiment more but tbh, I don't actually play tv on my phone anyway...

<TranscodeArgs>-y -v 0 -i [SOURCE] -f mpegts -loglevel debug -acodec ac3 -ab 96k -ar 44100 -ac 2 -s [RESOLUTION] -vcodec libx264 -b [BITRATE] -maxrate [BITRATE] -flags +loop -refs 1 -coder 0 -me_range 16 -keyint_min 25 -sc_threshold 40 -i_qfactor 0.71 -bt 200k -bufsize 96K -rc_eq 'blurCplx^(1-qComp)' -qcomp 0.6 -qmin 10 -qmax 51 -qdiff 4 -level 30 -aspect [ASPECT] -g 30 -async 2 [TARGET]</TranscodeArgs>

[bgowland]

Thanks for the update - hopefully it will be useful for others in the future.

Seems to play HD content ok at Medium 800K setting on my Nexus 4 on my home wifi (N). The higher rates stutter. May experiment more but tbh, I don't actually play tv on my phone anyway...

Ultimately, streaming any media (live or recorded) will come down to network capabaility, device spec, media player app capabilities etc etc. As with npvr itself, there are a number of variables and getting the right combination might take time.

I also don't play live tv on either my phone or tablet other than for testing purposes and without an HD source I couldn't even test for that. Thanks for taking the time to work through it.

Cheers,
Brian