7 replies to this topic

[macnuts]

I have the DM8000 (genuine) connected to the amplifier with optical cable. The amplifier is capable of playing AC3+ (Dolby Digital Plus) source. The DM8000 has two embedded DVB-S2 tuners and one Philips TU1216 DVB-T tuner.

The provider of DVB-T content added the AC3+ sound track to one of its services. The service has three sound tracks, MPEG, AC3 and AC3+ now. The DM8000 recognizes them correctly; I can confirm it after pressing the yellow button. The audio pids are OK too. Also, the bitrate plugin reports OK on any (MPEG/AC3/AC3+) sound track. I have the AC3 downmix disabled.

However, when I switch to the AC3+ no sound is passed to the amplifier. I can guess it from the mute button behavior: I get the feedback from the amplifier (on its display) when I press the mute button on the DM remote while MPEG/AC3 sound is selected; when I do the same when AC3+ is selected I get nothing from the amplifier.

Is it any chance to "force" the DM8000 to pass through the AC3+ stream? I think that passing through the stream does not require any AC3+ license? But I can be wrong about that.

[pieterg]

I guess the dm8k drivers do not recognise the ac3+ codec, therefore they do not enable the passthrough mode (even though passthrough would probably have worked, without having the ac3+ license)

[macnuts]

You are probably right.

I got the following dmesg ouput while switching audio to AC3+ (line 3 is of special interest here):

start audio on dmx 0 pid:6c
audio xpt start
unsupported audio bypass type 34
audio: decoder start 0
audio delay 18000 (200 ms)
total video delay: 18000 (200 ms)
ch0: lock
ch0: lock
RAP first pts 0x179edaa4e, stc 0x179eda572, pcr valid
RAP sampling rate info isr

[macnuts]

Line 3 comes from bcm7400.ko, so indeed dm8k drivers are to blame.
Thanks for response anyway.

[Jeroensky]

How about posting it on Dream Multimedia forum (or contact them), what is the response of Dream Multimedia themselves?

[macnuts]

Yes, that will be my next step. I will report about the progress, if any.

[Jeroensky]

They have money for AC3+ license don't you agree. I mean they sell DM8000 pvr's /images/smiley/grin.gif

To Openpli. If they add AC3+, is their a way to add functionality to convert in realtime AC3+ to AC3 output on sp/dif with keeping the 5.1 channels?
My amp supports DTS & AC3 only, has no AC3+ decoders onboard. (and no i'm not going to buy a amp with the newer codecs, this one works fine. Would be nice if a multichannel amplifier has sort of opensource software on board, so that 4 ecxample extra audio related functionality can be added, like extra codecs. So bigger cpu instead of multimediachip that has fixed decoders).

[pieterg]

that conversion will have to be done in hardware