On Sat, 2010-04-10 at 18:54 -0400, Andy Walls wrote: > On Sat, 2010-04-10 at 18:28 -0400, Mark Lord wrote: > > On 15/03/10 07:51 AM, Andy Walls wrote: > > > On Sun, 2010-03-14 at 22:48 -0400, Mark Lord wrote: > > >> On 03/02/10 07:40, Andy Walls wrote: > > .. > > >> after updating to the tip of the v4l2-dvb git tree last week, > > >> I've been hitting the "no audio" on analog recordings bug much more often. > > >> > > >> Digging through google, it appears this problem has been around as long > > >> as the cx18 driver has existed, with no clear resolution. Lots of people > > >> have reported it to you before, and nobody has found a silver bullet fix. > > .. > > > Here are all the potential problem areas I can think of: > > > > > > 1. A/V digitizer/decoder audio detection firmware load and init. (I've > > > added firmware readback verification to try and head this off.) > > > > > > 2. A/V digitizer decoder audio microcontroller hard reset and "soft" > > > reset sequencing. (I think the cx18 driver has this wrong ATM.) > > > > > > 3. APU load and init. (The double load is to fix a DTV TS stream bug on > > > every other APU& CPU firmware load sequence. The APU_AI_RESET is to > > > fix the audio bitrate problem on first capture after a double firmware > > > load.) > > > > > > 4. AI1 Mux setting failing when switching between the internal A/V > > > decoder's I2S output and the external I2S inputs. (I thought I had this > > > fixed, but I don't have detailed register specs for that register - so > > > maybe not.) > > > > > > 5. A/V decoder audio clock PLL stops operating due to being programmed > > > out of range. (This was a problem for 32 ksps audio a while ago, but > > > I'm pretty confident I have it fixed.) > > > > > > 6. A/V decoder analog frontend setup for SIF wrong?. (I fixed this due > > > to a problen Helen Buus reported with cable TV.) > > > > > > I think #2 is the real problem. I just started to disassmble the > > > digitizer firmware 2 nights ago to see if I could get some insight as to > > > how to properly reset it. > > > > > > I've got a first WAG at fixing the resets of the audio microcontroller's > > > resets at: > > > > > > http://linuxtv.org/hg/~awalls/cx18-audio > > > > > > If it doesn't work, change the CXADEC_AUDIO_SOFT_RESET register define > > > from 0x810 to 0x9cc, although that may not work either. > > .. > > > Thanks for the troubleshooting and reporting. > > .. > > > > Back at this again today, after a month away from it -- getting tired > > of watching "Survivor" with closed-captioning instead of audio. :) > > > > I pulled your (Andy) repository today, and merged the cx18 audio reset > > changes from it into today's tip from v4l-dvb. Patch attached for reference. > > > > So far, so good. I'll keep tabs on it over time, and see if the audio > > is stable, or if it still fails once in a while. > > Hmmm. Darren's having problems (loss of video/black screen) with my > patches under my cx18-audio repo, but I'm not quite convinced he doesn't > have some other PCI bus problem either. > > Anyway, my plan now is this: > > 1. on cx18-av-core.c:input_change() > a. set register 0x808 for audio autodetection > b. restart the format detection loop > c. set or reset a 1.5 second timeout > > 2. after the timer expires, if no audio standard was detected, > a. force the audio standard by programming register 0x808 > (e.g. BTSC for NTSC-M) > b. restart the format detection loop so the micrcontroller will > do the unmute when it detects audio > > > > Darren is in NTSC-M/BTSC land. What TV standard are you dealing with? Hey, I just found an OTA analog broadcast on channel 23! I even can reproduce the problem of the audio microcontroller not detecting the audio standard (shoot it just kicked in and figured it out). Anyway this will help me turn around something. Regards, Andy -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
