Tvheadend

Buy an android tablet able to decode 1080i. Any based on tegra3 will do... My wife use it on a daily basis :-)

I am using VLC on Linux to transcode Live TV for this purpose. Daroon Player is able to play back this VLC stream.
I am pretty sure it's no difference if VLC is transcoding a live stream or a recorded file.

Thank you for your reply Eric and Marcus.

@Eric: I have a nexus 7 but it doesn't keep up. I don't think it's the CPU I think it might be the network (over wifi).

@Marcus: Do you use any dlna server, or is just some VLC command? or....?

I had to struggle to find a player that was able to use hardware acceleration. Try BSPlayer (free version).

Yes I've tried BSPlayer and several others. When hardware acceleration is enabled it plays for about 1 second.

a few more questions:
Are you doing this over wifi?
What transport method are you using? dlna? nfs? samba?
If dlna, what server are you using?

thanks

On a tablet, what can I use other than WiFi? I use minidlna as a server or http from tvhguide, or now directly xbmc on the tablet and HTSP. Everythings works..

You can copy them over to your tablet and play it off of internal memory ;). Are you playing shows recorded from tvheadend? If so, do you use .ts or matroska? Also I take it that you don't do any transcoding with minidlna? Do you have a good router? Do you know the make/model? Is it running in 'n-mode'?

Sorry for all the questions.

Hi,

I use this:

cvlc --sout "#transcode{vcodec=h264,vb=2400,width=960,height=540,fps=25,acodec=mp3,ab=128,channels=2,samplerate=44100}:http{mux=ffmpeg{mux=
flv},dst=:<some_port>/<something>/}" --no-sout-rtp-sap --no-sout-standard-sap --ttl=1 --sout-keep --sout-transcode-threads 4 --sout-transcode-deinterlace <file_you_want_to_stream>

In the Daroon Player, I open this URL: http://<my_adress>:<some_port>/<something>/

As I said, I use this to stream live TV from tvheadend (for that I set "--sout-transcode-deinterlace"), so I can watch football on my phone or Nexus 7.
With this way, the playback starts immediately when the "cvlc" command is send. So you can't control the playback on your Nexus, which for live TV is not critical.

Markus

jack jack wrote:

You can copy them over to your tablet and play it off of internal memory ;). Are you playing shows recorded from tvheadend? If so, do you use .ts or matroska? Also I take it that you don't do any transcoding with minidlna? Do you have a good router? Do you know the make/model? Is it running in 'n-mode'?

Sorry for all the questions.

No I use WiFi and yes I do not any transcoding from minidlna. I want to watch live tv so copying would not be a solution. As for the router I'm using a Livebox from orange ;-)

Thanks Markus.

I just got something working, I think, so I didn't have a chance to use your solution. What I did was use a program called MediaInfo for windows to see what the saved streams contained. They are:

Matroska container
1 video stream: 13.Mbps 1920*1080 (16:9) at 29.970 fps. MPEG Video (Version 2)
1 audio stream: English 384, 48 KHz 16 bits, 6 channels, AC-3
1 audio stream: Spanish 192 Kbps, 48.0KHz 16 bits, 2 channels AC-3

With this info and a video clip I had that worked well I modfied an avconv command to properly stripout and downsample the stream.

For this to work with mediatomb:

1) Enable trancoding (change the proper section to "yes") in /etc/mediatomb/config.xml
2) Add the following profile:

      <profile name="transcode-video" enabled="yes" type="external">
          <mimetype>video/x-matroska</mimetype>
          <accept-url>yes</accept-url>
          <first-resource>yes</first-resource>
          <hide-original-resource>yes</hide-original-resource>
          <accept-ogg-theora>yes</accept-ogg-theora>
          <agent command="/opt/transcode-video" arguments="%in %out"/>
          <buffer size="1048576" chunk-size="26214" fill-size="52428"/>
      </profile>

Also add the following to your 'mimetype-profile-mappings' section:

      <transcode mimetype="video/x-matroska" using="transcode-video"/>
      <transcode mimetype="video/x-flv" using="transcode-video"/>
      <transcode mimetype="video/x-quicktime" using="transcode-video"/>
      <transcode mimetype="video/realmedia" using="transcode-video"/>

Then create a bash script (/opt/transcode-video) with the following:

#!/bin/bash
exec "/usr/bin/avconv" -threads 4 -i "$1" -c:v libx264 -profile:v high -level:v 41 -s 1280x720 -b 2953k -r 23.976 -map 0:v -map 0:a:0 -acodec ac3 -ar 48000 -ac 2 -ab 384000 -f matroska - > "$2" 

This

• uses multiple cores (-threads 4, if you have the power, i think it's a bit much, and I'm going to try and drop this to 1)
• uses h264 codec with a [email protected] profile (I couldn't get the high profile to work) (-c:v libx264 -profile:v high -level:v 41
• downsamples the feed from 1080p (-s 1280x720)
• lowers the bandwidth from the (relatively) massive 13Mps (-b 4096k)
• drops the framerate to 25fps (-r 25)
• keep the video stream (-map 0:v)
• drops the second audio stream (spanish audio) (-map 0:a:0)
• passes the ac3 audio through with some minimal downsampling (-acodec ac3 -ar 48000 -ac 2 -ab 448000)
• wraps it all in a matroska container (-f matroska)
• the default for avconv is to encode with h.264 (for this command)

Tips for others doing something similar:

• Run your avconv command form the command line on a small file and check the output to see what it is saving it as
• I got some of this info from here: http://forevercached.syphzero.net/2012/03/ps3-mediatomb-debian-configuration-cont.html

I'm using an android app called 'MX Player' but I also tried several others (BSPlayer). I like MX Player in that it allows you to swap from h/w to s/w (to 'h/w+' encoding) right from the ui with a single tap. H/W+ encoding seems to work on some streams not not on everything. I think part of it might that my tvheadend setup was in progress when these were recorded or that they are PBS streams and they are different in some way (not sure).

Thanks everyone for the help.

There is a branch of tvheadend that does transcoding without setting up dlna.

Together with the android app TVHGuide, you can launch transcoded streams with an external player (BS Player for example) or play back using an internal one with some overlay eye candy.

Server branch: https://github.com/john-tornblom/tvheadend
Android app: http://john-tornblom.github.com/TVHGuide/
mplayer wrapper script: https://github.com/john-tornblom/playground/raw/master/tv

Sadly though, development is slow since I'm busy with my thesis, but if other developers wanna contribute, let me know.