On Monday 03 March 2008 05:33:44 Andy Walls wrote:
> Hans,
>
> More feedback on the beta cx18 driver....
Hi Andy,
Thank you for your research on this. Unfortunately it may take a while
before I can look into this myself as I am currently investigating the
VBI issues with ivtv. Once that's done I'll get back on the cx18
problems. Since fixing the VBI problems with ivtv is time consuming, so
I do not know exactly when I get back to the cx18.
Also note that the AV digitizer registers of the cx23418 are almost, but
not entirely the same as for the cx2584x. There are some differences in
particular in the handling of the status log. So point 6 in your list
below is not true since the standard IDs have changed in the cx23418.
If it reports BTSC, then it really is BTSC.
Regards,
Hans
>
> Problem statement: auto detection of broadcast audio mode doesn't
> appear to work, mute doesn't work, and stereo audio is not available.
>
> $ v4l2-dbg -d /dev/video1 --log-status
>
> always reports "mono" and "muted"
>
> cx18-0: Detected audio mode: mono
> cx18-0: Detected audio standard: BTSC
> cx18-0: Audio muted: yes
> cx18-0: Audio microcontroller: running
> cx18-0: Configured audio standard: automatic detection
> cx18-0: Configured audio system: BTSC
> cx18-0: Specified audio input: Tuner (In8)
> cx18-0: Preferred audio mode: stereo
>
>
> My findings:
>
> 1. cx18 driver initially starts up using Tuner AF line audio via the
> CS5345 multiplexer/digitizer and not the Tuner SIF to the
> CX23418/CX25843 demodulator/digitizer. Since the AF from the tuner
> is only 1 wire, it is monoaural and never stereo.
>
> Here's how to prove that the AUDIO8(CVBS8/SIF5) input on the CX23418
> is *not* the source for the audio in the default MPEG encoding
> stream, by toggling the CS5345 Mute:
>
> $ mplayer /dev/video1
> (in second window)
> # /usr/local/bin/v4l2-dbg -d /dev/video1 -R type=i2cdrv,chip=cs5345
> ioctl: VIDIOC_DBG_G_REGISTER
>
> 00 01 02 03 04 05 06 07 08 09 0A 0B 0C 0D 0E 0F
> 00000000: e2 00 08 01 10 40 00 00 01 00 00 c0 00 00 00
> 00000010: 00
> # /usr/local/bin/v4l2-dbg -d /dev/video1 \
> -r type=i2cdrv,chip=cs5345,reg=0x04,val=0x05
> register 0x4 set to 0x5
> # /usr/local/bin/v4l2-dbg -d /dev/video1 \
> -r type=i2cdrv,chip=cs5345,reg=0x04,val=0x01
> register 0x4 set to 0x1
>
>
> 2. I cannot mute the audio by setting all the mutes in the cx25843
> core in registers 0x02c408d3 and 0x02c408e3. The registers appear to
> have only the mute bits documented in the cx25843 data sheet and no
> new ones, as writes to higher order bits in those registers don't
> work (the higher bits stay 0).
>
> The only way to mute appears to be via the CS5345 mute or by
> commanding the encoder to mute.
>
>
> 3. In trying to investigate the audio routing through the system, I
> found a block diagram of the CX23418 at
> http://www.saint-tec.co.jp/conexant.html
> showing that the CX23418 has 2 serial audio inputs.
>
> Since the CX23416 (not a typo) had 1 serial audio input, IIRC, I am
> *guessing* one serial audio input on the CX23418 corresponds to the
> CX25843 core and the other serial audio input goes to the encoder.
> *If* this is the case (can anyone confirm?), then I wouldn't know how
> to get the encoder to listen on the serial audio output of the
> CX25843 core anyway. This would leave me stuck with the Tuner AF
> mono output from the CS5345.
>
> Does anyone have a real CX23418 data sheet I can look at? Will
> Conexant want me to sign an NDA to do so, if I go to them?
>
>
> 4. The cx18 driver doesn't setup the Analog Front End (AFE) of the
> CX25843 core to properly to process Sound IF (SIF) on the AUDIO8
> input. Specifically, I think VGA_SEL_CH3, DROOP_COMP_CH3,
> CLAMP_EN_CH3 are wrong compared to what the CX25843 datasheet says in
> section 3.20 on page 3-83.
>
>
> 5. The cx18 driver allows CX25843 Chip autoconfig based on the
> setting in register 0x02c40102. This is okay, except that writes to
> the INPUT_MODE bits register 0x02c40401 have a side effect of
> changing some of the settings required for SIF on AUDIO8:
> VGA_SEL_CH3, DROOP_COMP_CH3, CLAMP_EN_CH3, etc, according to Section
> 3.4.2.1 pages 3-17,3-18 of the CX25843 datasheet. From what I can
> see, the driver makes no attempt to adjust auto-configured registers
> after writing to registers
> 0x02c40400-0x02c40403, except in the function cx18_av_initialize().
> So I don't think that will be sufficient to preserve proper
> demodulation of SIF on AUDIO8, if changing from S-Video back to
> Tuner.
>
>
> 6. v4l2-ctl --log-status reports an autodetected standard of "BTSC"
> when that status register at 0x02c40805 is reporting "0 - not
> defined" as opposed to "0xF -BTSC" and the microcontroller hasn't
> bothered to unmute any of the audio paths. Reporting BTSC in this
> situation seems misleading, as it doesn't appear that the
> microcontroller has determined the standard yet.
>
>
> -Andy
>
>
> _______________________________________________
> ivtv-devel mailing list
> [email protected]
> http://ivtvdriver.org/mailman/listinfo/ivtv-devel
_______________________________________________
ivtv-devel mailing list
[email protected]
http://ivtvdriver.org/mailman/listinfo/ivtv-devel
