Bugzilla – Bug 2152
new audio format passthrough
Last modified: 2016-08-28 12:50:11 UTC
It could be very nice to add support for new multichannel file formats to be passed directly to the external receiver using the digital output of the SB2. Format I can think about are: ac3 dts wma 10 pro I tried to add ac3/dts passthrough (using wav) output but the SB2 can't play the file (error during the file open process). allowing the user to add customized extensions will avoid problems with future formats
*** Bug 2160 has been marked as a duplicate of this bug. ***
Could you upload a DTS track to ftp://electricrain.com/incoming/ thanks
Hi, I uploaded a sampe archive giuliano
I should point out that AC3 (sourced from a DVD) can be played through SB2 after a simple conversion: http://forums.slimdevices.com/showthread.php?t=19260 DVD-sourced DTS is also supported by this conversion; half-bitrate DTS plays fine but full-bitrate DTS produces FLAC files with poor compression which sound jerky when decoded by the SB2. (DTS CDs are natively supported already as WAV files.) Since AC3/DTS is understood by many receivers already, converting the files so they can be passed through is a quick win. I don't know if WMA is known to any receivers -- if not, I don't see how the SB2 could pass on the multi-channel data to the amp (except for transcoding to AC3? <wink>). My opinion is that if AC3/DTS support is desired, we're nearly there already and addressing the decoding of poor-compression FLAC or bug#128 (48kHz WAV seen as 44.1kHz when streamed natively) would finish the job more quickly.
Hi, thanks for the conversion guide. But I still think that streams that can be decoded by the amp should be sent to the sb unmodified. This saves time (no initial conversion), cpu power (no real time conversion) and multichannel streams (I don't know if converting to flac mantains this for all the channels combinations, ie 4.0, 4.1, 6.1, 5.1ex) giuliano
(In reply to comment #6) > thanks for the conversion guide. But I still think that streams that can be > decoded by the amp should be sent to the sb unmodified. This saves time (no > initial conversion), cpu power (no real time conversion) and multichannel > streams (I don't know if converting to flac mantains this for all the channels > combinations, ie 4.0, 4.1, 6.1, 5.1ex) Good question about the different channel options. I _think_ it just works, although I've only tested it with 5.1 (that was the itch I was scratching!). The utility performs minimal parsing on the source files, but doesn't interpret any actual channel data -- it just passes it all through to a padded format. So I'd imagine that an AC3 file with different channel configurations would be correctly converted. (If you have any test files, perhaps we could continue this aspect of the discussion on that guide thread.) The "real time conversion" you mention... if you mean the decoding of FLAC on the SB2, that's fair enough. There would still be work involved in converting the original file on the SB2, but that would be minimal in comparison, I think. The one-time upfront conversion is a little inconvenient, sure. There are advantages though, not the least of which is metadata -- with a FLAC file you can add tags like any other song. Another benefit to pre-converting the files is that you can play them over an S/PDIF link from a PC, if you have such a setup and set the volume appropriately. If anybody from Slim intends to support these formats natively, that'd be great. I had hoped to make my utility available under a licence which would allow you to use the code in some way; I ended up putting it under the GPL because of a DTS-related table I found in the Xine project (everything else can be determined from AC3/DTS specs). Personally I'd be happy for you to use anything in that utility to add such support to the SB2, but beware that the one table is not the result of my own work and that I can't speak for the developer who came up with it. One more thing: whether it's native support for the formats, or recognition of a special tag (say) in the converted FLAC files, it'd be great if the SB2 could automatically set the digital volume level to the max and disable the analogue outputs, when it knows it's playing a multi-channel file like this. Should I open a separate bug report for the FLAC decoding thing?
*** Bug 5581 has been marked as a duplicate of this bug. ***
Unassigned bugs cannot have a priority.
At least Transporter and SBs should not require a hard reset if they try to play these! This is a severe problem.