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Coises
09-12-2014, 02:03 PM
Something unexpected happened which made me realize that I don’t understand how Mezzmo uses device profiles.

Since I first began using Mezzmo, we have used a PlayStation 3 to play files from our server. I have always kept transcoding turned off for all devices (which, up until yesterday, meant only the PS3). My approach is that I don’t want the server trying to do anything more than serve... if a file needs to be re-encoded or re-muxed, I’ll do that on my desktop machine, where I can control exactly what happens.

Yesterday my housemate got a Sony XBR55X900B television. Since it has DLNA capabilities, I thought we might be able to skip the PS3 for playing video.

Well, at first it seemed like it wouldn’t play anything except *.mpg files, even though the specifications say it should be able to handle more *.mp4 files than the PS3, and at least most of the same *.avi files.

Then I noticed that Mezzmo had detected it as a Sony Bravia KDL W. Since I had transcoding turned off, I assumed Mezzmo was just feeding it each file as it was; but on a whim, I tried changing the device in Mezzmo to say that it, also, was a Sony PlayStation 3. It now plays the files it said before it could not play.

So, what is going on?

I’m not surprised that Mezzmo doesn’t have a profile for such a new model; what I don’t understand is, with transcoding turned off, what is it doing with the profile? Is a profile needed to communicate correctly with a device even when there is no transcoding involved?

I have since experienced at least one problem using the Sony PlayStation 3 profile with the XBR55X900B. I tried to play an MP4 file that was 720x540, 4:3 aspect, 29.97 fps. The PlayStation 3 plays it as intended; but if I try to use the XBR55X900B directly, it stretches it to 16:9. It is possible that this is a TV setup problem which has nothing to do with the profile... though I don’t know why the default settings, which we haven’t changed as yet, would be to mangle aspect ratios.

Hmmm... and now I see the Advanced Tab under Device Settings, which I hadn’t noticed before. I’m not sure I understand the Help for it correctly. I’m thinking that since I never transcode, I want the first and last delivery rules to be “Always Deliver” and all the rest to be “Never Deliver”? My objective is that I don’t want Mezzmo to “guess” what the device can play, because I’ll never let it transcode anyway. I just want Mezzmo to serve the file as is, and if the device can’t play it, the device can tell me that; then I’ll tinker with the file.

But then I’m thinking that I must be misunderstanding, because why wouldn’t that be automatic when all transcoding is turned off?

Paul
09-12-2014, 03:40 PM
If you don't want Mezzmo server to transcode your files, then you just need to turn transcoding off. You can do this for all devices using the Transcoding Settings dialog, or per device using the Device Settings dialog (Transcoding tab).

I strongly recommend using the default settings on the Advanced tab on the Device Settings. It will give you the best results.

Now to explain the differences you are experiencing with transcoding turned off and switching device profiles. The device profiles tell Mezzmo what audio, video and image formats are supported by the device. With transcoding off, this is basically ignored. However, the device profiles also contain two other important pieces of information for supported formats that Mezzmo uses whether transcoding is turned on or off - namely the MIME type and DLNA Profile ID. The MIME type is delivered to devices when devices request a file. For example, for an MKV file, the device profile will probably tell Mezzmo server to deliver "video/x-matroska". But other device profiles may tell it may deliver "video/x-mkv" since that's what the device wants. Devices do respond differently based on the delivered MIME type. The DLNA Profile ID is part of the DLNA spec and is delivered to devices when listing files on devices. They describe the media file - for example an MPEG-2 file can either be MPEG_PS_PAL or MPEG_PS_NTSC. There are 100s of DLNA Profile IDs defined and devices respond differently based on what you deliver for a file.

For your housemate's new TV, I'd suggest using the "Sony Bravia KDL (2013 Models)" device profile. If that does not work well, then email us at support [at] conceiva [dot] com and we can create a "Sony Bravia KDL (2014 models)" device profile.

Coises
09-12-2014, 04:00 PM
Thank you, Paul, for the explanation. Not knowing about the MIME type and Profile ID, I was confused.

I’ve set "Sony Bravia KDL (2013 Models)" and defaults for the Advanced tab. When I’ve had a chance to test, I’ll let you know if that did the trick.

Coises
09-26-2014, 01:48 PM
I finally got a chance to test. "Sony Bravia KDL (2013 Models)" does not seem to be any better than "Sony Bravia KDL W"; however, as far as I could tell today, "Sony Bravia KDL (MP4)" works well.

Thanks, Paul.

Paul
09-29-2014, 10:06 AM
OK - glad you found a device profile that works well.