Dolby 5.1 playable? Iriver H120

[ad2003]

Hi!

First I have to say, that I love Rockbox! It really enhanced the Iriver120 with many features - and so the "old" player is still up-to-date.

My question is: Can I play any dolby digital (5.1) files from the player through the optical out?

Why do I post this into the recording Forum - well, I want to record several sounds and finnaly I want to put them together in samplitude, or something....

I have a 5.1 DD Surround Decoder with optical in. Thank you!

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[ad2003]

Has noone an idea? Or is this too stupid? I can't find anything in the search....

thx

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[Chronon]

I honestly don't know what will happen.  It may do what you want, or it may downmix it to stereo.  The SoundCodecs page on the wiki mentions that the AC3 codec can downmix 5.1 streams to stereo so it seems like this may be what happens if my assumptions are correct.  I am guessing that the file gets processed by the codec and delivered to the optical out just before being sent to the internal DAC.  Isn't this something you can test easily?

[ad2003]

Hi Thanks for your post! Yeah - maybe I can test it - but I don't know which codec to use with! I think rockbox can't play vob files - or mpg2? Maybe someone can tell me, which codec I should use? Does wma support 5.1?

Thank you!

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[saratoga]

Hi Thanks for your post! Yeah - maybe I can test it - but I don't know which codec to use with! I think rockbox can't play vob files - or mpg2?

You asked about dolby files before, not VOB or WMA.  By dolby did you actually mean "5.1 audio"?

If so, I think the answer is no.  In theory it might be possible to feed raw dolby files to the digital out (i.e. disable rockbox decoding and just do pass through), but I doubt anyone has written a plugin for that.  Though I've never looked for one either.

[Chronon]

ad2003: Regarding codec, isn't Dolby Digital == AC3? 

saratoga: Is it generally true that the data that comes from optical out is 16-bit PCM (either mono or stereo) with sample rate corresponding to the source files?

[saratoga]

I have no idea how the optical out works.  I never had an iRiver player.

[Vchat20]

Generally speaking when you are feeding a receiver via optical or coaxial connections, you have a choice of 2 formats: 2 channel PCM or multi-channel AC3/Dolby Digital (there are other's like 'TrueHD' and such, but for the sake of confusion I'll leave them be. They are primarily focused on blueray discs and only the most recent receivers support them. There is also a 'WMAPro' multichannel codec that 'some' receivers support, but I'll also leave that out to save headaches.). While it is possible to re-encode them on the player with some handy work, rockbox currently does not support this (there are a number of variables involved here. Needless to say I have high doubts rockbox even remotely supports transcoding of this nature considering it's focus on stereo audio/music playback).

So your best bet would be to either leave it as AC3 or transcode it on your computer if it is not already. Then just jump in and play it back on your player and see what it does.

[ad2003]

Hi -
ok, thank you - I still don't know, which fileformat I could try, but I will check it out, soon.

thanks for the answers!

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[saratoga]

If you don't have dolby files and don't know what they are, why exactly are you curious about playing them?

[ad2003]

I am going to make a 5.1 radio play in my studies - I just wanted to put the files onto the player and play it on my DD 5.1 receiver.
I thought that maybe someone has already experiences with dd 5.1 on Iriver...The problem is that I don't know which container or fileformat I can use with Rockbox. WMV, FLAC, OGG, etc. - which one supports dolby digital - or ac3?

thanks.

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[froggyman]

I don't know which container or fileformat I can use with Rockbox. WMV, FLAC, OGG, etc. - which one supports dolby digital - or ac3?

You would simply use the AC3 file format for dolby 5.1 playback(if 5.1output is supported), because AC3 is a file format that is used for dolby 5.1 sound encoding, , similar to how FLAC, AAC, and MP3 are supported file formats.