Mailinglist Archive: radeonhd (312 mails)

[Christiaan van Dijk <dvbmail@xxxxxxxxx>]

Christian König wrote:
> Since the audio pipeline from application->alsa->audio codec->hdmi
> encoder->DTS/AC3 decoder->speaker is quite long it's hard to tell were
> the problem is.
>
> Does the frequency of those drop outs change with different display
> resolutions (or more specific with the pixel clock)? If no then i am
> pretty sure that you are right and this is a problem somewhere in the
> alsa driver. If yes this could also be a glitch in the audio clock
> recovery code.
>
> Bye, Christian.
>   
Another good pointer,

the default settings for my setup are:

Pixel clock = 148500 kHz
PLL setup: ((14320 kHz / 9) * 560) / 6 = 148503.704 kHz

RHDAudioSetClock: Using TMDS B as clock source with 148500 kHz
MUL = 2400000, DIV = 148500000; gives 24MHz
CTS_48kHz = 148500, N_48kHz = 6144

All the audio related settings match the settings made by fglrx, I did 
not check the PLL configuration so far, never looked in this area.
Playback is very strange. Using Mythtv I have allmost no dropouts. This 
is what xorg log says:
(II) RADEONHD(0): RHDHdmiUpdateAudioSettings: playing with 2 channels, 
48000 Hz sampling rate, 16 bits per sample,
(II) RADEONHD(0): RHDHdmiUpdateAudioSettings: 0x01 IEC60958 status bits 
and 0x00 category code

Now I take a divx file with mplayer. Sound is OK and mplayer gives the 
following info:

AO: [alsa] 48000Hz 2ch s16le (2 bytes per sample)

And xorg logs:
(II) RADEONHD(0): RHDHdmiUpdateAudioSettings: playing with 2 channels, 
48000 Hz sampling rate, 16 bits per sample,
(II) RADEONHD(0): RHDHdmiUpdateAudioSettings: 0x01 IEC60958 status bits 
and 0x00 category code

And now an AC3 file. Sound has dropouts every couple of minutes, mplayer 
info:

AO: [alsa] 48000Hz 2ch AC3 (1 bytes per sample)

And xorg log:
(II) RADEONHD(0): RHDHdmiUpdateAudioSettings: playing with 2 channels, 
48000 Hz sampling rate, 16 bits per sample,
(II) RADEONHD(0): RHDHdmiUpdateAudioSettings: 0x01 IEC60958 status bits 
and 0x00 category code

All combinations give the same settings but different behaviour on the 
drop outs, really strange.

Lowering the screen resolution gives a different situation:

Pixel clock = 109000 kHz
PLL setup: ((14320 kHz / 7) * 373) / 7 = 109007,35 kHz

RHDAudioSetClock: Using TMDS B as clock source with 148500 kHz
MUL = 2400000, DIV = 10900000; gives 24MHz
CTS_48kHz = 109000, N_48kHz = 6144

Now there a no drop outs in the sound. Another side effect is noticeable 
in the video playback; playback is very smooth with the lower 
resolution. In the 1920x1080 resolution playback is not smooth.
I also tried playback with video output to the null device to see if the 
video rendering has any effect; no effect what so ever.

I'm very puzzled by this behavior but will try to think of some new 
experiments.

Regds,
Christiaan.
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