On Tue, 2008-07-01 at 01:34 -0300, Kevin Blair wrote: > i dont be leave it produced the tinny audio before, but > several things have changed (went from coax to svideo/rca input,
Kevin, That is an interesting bit of information. So here's a new hypothesis: The audio micontroller firmware is changing the digital audio baseband processing settings in the CX28543, corrupting the settings for line in audio, when it thinks it detects a TV audio standard change coming in from the tuner SIF audio input. If that is true, then simple solutions could be 1. stop the audio standard detection microcontroller firmware from running when you've switched to an audio input other than the tuner. or 2. connect an RF TV signal source to the tuner and tune the card to an active TV station before making the switch to the svideo or composite input. #2 is something you can try on your own to see if it eliminates the tinny audio. #1 you can try manually by commanding the ivtv driver to switch to the line in input and then stopping the audio microcontroller by setting bit 4 (bit 0 is the lsb, bit 7 is the msb) of register 0x803 of the CX28543 to 0 with v4l2-dbg. v4l2-ctl --log-status will then show the audio microcontroller as stopped. When the audio microcontroller is stopped, nothing should be automatically changing the processing of input audio. The problem with doing #1, is that it takes quite a few steps to get the audio microcontroller started properly again, and it's probably not a good idea to try it manually. If you can verify that stopping the audio microcontroller after switching to non-tuner inputs solves the onset of tinny audio, then work can be done on the cx28540 driver to incorporate this solution. Regards, Andy > Kevin _______________________________________________ ivtv-users mailing list [email protected] http://ivtvdriver.org/mailman/listinfo/ivtv-users
