Stream drops to audio after a short time (1 Viewer)

[cheezey]

There are a number of reports now of this issue, could I ask anyone you wants to help diagnose this to post the following logs:

1. %ProgramFiles%\iPiMP\Apache\logs\error.log
2. %ProgramFiles%\iPiMP\Apache\logs\access.log
3. %AppData%\Team MediaPortal\MediaPortal TV Server\log\tv.log

Please also test streaming Live TV, TV Recordings & TV Series and confirm your connection (3G / wifi etc.)

[EDIT] - Please also give an idea of your PC specs and if possible your CPU usage whilst streaming.

Thanks

 

[Lolento]

Cheezey,

Here are my logs.....I stopped the stream shortly after the video dropped out.

 

[griffindodd]

Here you go Cheezey.

Streaming from Win 7 Ultimate 32bit to iPhone 4.0 4.1

CPU usage very high on transcode at 70% average on a Core Duo 2 @ 3.43ghz with 4gb DDR2

 

[griffindodd]

It looks like this issue is related to rebuffering from the transcoder not being able to keep up with the input. I am using 1080i input from a HVR-1255 as my source.

If I bypass the iphone and go access the stream through a browser on my desktop at work over our dual T1 I notice that the stream buffers the first 25 seconds of the broadcast but then stops playback. I would guess that the transcoder is falling behind.

I get slightly better performance out of FFMpeg transcoding so my computer can spit out the stream quicker and delay the rebuffering.

Better performance again when choosing a lower quality output from the FFmpeg options, choosing libx264-ipod320 obviously gives better results as it has less to spit out.

Also if I test the service using a loopback IP address of 127.0.0.1 in my browser on the MPTV Server computer I get the same issues which would cut out the possibility of the problem being connection/bandwidth related.

 

[Lolento]

It looks like this issue is related to rebuffering from the transcoder not being able to keep up with the input. I am using 1080i input from a HVR-1255 as my source.

If I bypass the iphone and go access the stream through a browser on my desktop at work over our dual T1 I notice that the stream buffers the first 25 seconds of the broadcast but then stops playback. I would guess that the transcoder is falling behind.

I get slightly better performance out of FFMpeg transcoding so my computer can spit out the stream quicker and delay the rebuffering.

Better performance again when choosing a lower quality output from the FFmpeg options, choosing libx264-ipod320 obviously gives better results as it has less to spit out.

Also if I test the service using a loopback IP address of 127.0.0.1 in my browser on the MPTV Server computer I get the same issues which would cut out the possibility of the problem being connection/bandwidth related.

If that is the case then I suppose ffmpeg with dxva will work (or at least better) but I see no difference trying both.

 

[SiLenTYL]

cheesey ...

whats the lowest setting possible...for when i have bad reception on my phone and using the lowest amount of cpu on the pc running MP ?

best to use ffmpeg or handbrake?

 

[cheezey]

Don't know about the lowest setting - it's trial and error really and very dependent on your PC specs and the video source, e.g. it takes a lot more to transcode a full HD channel than a SD one. It obviously needs more thought into streaming, one profile will not fit all.

One thing though - ffmpeg is always used for streaming now, the ffmpeg/handbrake choice in the installer is for the iPiMPTranscodeToMP4 plugin for automatic/manual transcoding of your recordings. I'll continue to maintain this but it will be spun off into a separate TV Server plugin installer in one of the next versions and integration with iPiMP removed. If you want to try different transcode settings for streaming look in C:\program files\iPiMP\Aspx\config.xml

 

[griffindodd]

Ahh ok that is good to know thanks Cheezey I will check that out and see if I can get any different results.

Also do you know if FFMpeg supports QUad core in the windows build? I have been considering upgrading my CPU and I'm wondering if going to a Quad core will improve performance in areas like transcoding and decoding of video material.

 

[webcris77]

i send my log, can anyone help me?

 

[griffindodd]

Interesting...

I changed the bandwidth variable for video (which I assume is the -b flag) and it didn't seem to make any difference. I turned it all the way down to 10k but the stream still looked very high quality on the iPhone.

Here's the variable and profile I altered...

<transcoder name="LiveTV" usetranscoding="1" filename="&quot;C:/Program Files/iPiMP/Utilities/ffmpeg\ffmpeg.exe&quot;" args="-i - -threads 0 -re -vcodec libx264 -fpre &quot;C:/Program Files/iPiMP/Utilities/ffmpeg/ffpresets/libx264-iPiMP.ffpreset&quot; -b 256k -s 480x272 -aspect 480:272 -acodec libfaac -ac 2 -ab 64k -ar 48000 -ac 2 -async 2 -f ism http://127.0.0.1:1972/SmoothStream.isml/Streams(SmoothStream)?dvr_window_length=15" inputmethod="2" outputmethod="4" />

Could it be that FFMpeg is ignoring the conditions set in this config??

UPDATE::

Ok I fixed the bitrate issue by specifying the buffer size and managing the min/max bitrates...

-b 256k -bufsize 100000K -minrate 128K -maxrate 312K

So at least it's not ignoring the bitrate now.

However this doesn't solve the dropout problem.

FOUND THIS

I noticed that if I left the video to buffer for a few minutes before playing it still drops out after a few seconds, it seems that playback starts 5 seconds from the end of the buffer rather than starting from the beginning, so even letting the stream buffer for 2 minutes, when you press play it starts playback from 1:55 and then of course runs out of buffer quickly.

I noticed it does the same on Flash streaming in a web browser and the iPhone playback, so it's not just isolated to the iPhone as such.

Not sure how to stop this.