Re: Changing container format and/or audio codec on the fly

[Jens Georg <mail jensge org>]

On Sa, 2013-08-10 at 11:35 +0100, Tony Houghton wrote:
> On Fri, 09 Aug 2013 21:33:34 +0200
> Jens Georg <mail jensge org> wrote:
>
> > On Fr, 2013-08-09 at 15:05 +0100, Tony Houghton wrote:
>
> [DLNA client only accepts mp4 format]
>
> > > I used avconv to convert a .mkv to .mp4 and the player was then able to
> > > play the video, but there was no sound, so it looks like I also need to
> > > transcode the audio from AC3 to M4A. I think my HTPC should be able to
> > > manage that in terms of CPU power, but is there a way to get Rygel to do
> > > this on the fly? I tried reading man rygel.conf but couldn't find the
> > > information I need.
> >
> > Rygel does a very low-quality (15fps, 320x240) on-the-fly conversion to
> > H.264/AAC already.
>
> The video stream is already H264, so it doesn't need to transcode that,
> just the audio from AC3 and change the container from mkv to mp4.
> Hopefully it would also accept PCM, making the conversion more
> economical and less lossy.

matching stuff should be passed as-is (i.e. remuxing) unless rescaling
or other adaptations are required.

> > I'm afraid there's no way to do this by configuration, but you could try
> > to tweak this by modifying
> > src/media-engines/gstreamer/rygel-avc-transcoder.vala.
>
> On Googling I found that it's quite common for DLNA clients to be picky
> like this, and some other servers have "profiles" to deal with it. There
> are commercial servers like plex and serviio available for Linux, which
> I think have this ability, but I'd rather stick to open source. This is

Serviio is free (IIRC as in beer)

> the sort of thing gstreamer should be able to do very effectively so
> it's a shame for rygel to miss out.

Well. Lowest common denominator is MPEG2. All non-mobile DLNA devices
have to support that.