Raspberry Pi Forums

vadim

Hmmm, what's the point of overloading the system? The tasks I do regularly that take up to 100% of cpu power are compilation, live aac encoding and VPN gateway at high speeds with encryption. Don't fancy doing them all at the same time

vadim

I2S defines 50% duty cycle for stereo link. That's what is implemented in bcm2708-i2s. Nevertheless, BCM2835 is flexible in terms of timing and can be made clock slave. Anyway, the other formats are in TODO for the driver but will never get done unless there is demand and perseverance :) Is it safe ...

vadim

The current version of PCM driver understands only I2S format, but can be tricked to work. I would tie all BCLK and MCLK pins and drive them from RPi's PCM clock (integer division from 19.2MHz is possible in your case). Adjust frame length and position of words in bcm2708-i2s. Read the BCM2835 manua...

vadim

any news?

vadim

I would test the voltage at the moment this happens and if that's fine then switch to a fresh SD card.

vadim

--disable-asm is the right option for configuring libx264

vadim

Perhaps, some library was compiled with assembler code that is not compatible with RPi. Try to rebuild libx264 without asm (there should be a .configure option for that). Actually, I don't understand why you need to transcode the video, anyway. Use -vcodec copy for video.

vadim

make sure it is accessible from your iphone only

vadim

What did you try before concluding that only reinstallation helps?

vadim

what codec is on the module? perhaps, there is a driver for it.

vadim

if they are 3 least significant bits i see no problem at all. Treat them as 16 bit anyway

vadim

it is possible to connect. getting it to work will involve writing kernel modules and modifying i2s driver. look for asoc driver and its author Florian who might have started to make the driver universal. your bit wide FS on mono sourceand 65 bit frames are a deviation from defaults

vadim

Yes, manipulations should be done only before I-frames. It is good that I-frames can be forced. In my case one I-frame instead of 2 P-frames per 8 seconds shouldn't affect the bitrate, so I don't see any downside to this approach.
Unfortunately, I'm not a C programmer

Is mmal well documented?

vadim

Thanks, Andy. I tried to use resampling and that would work if the framerates of the incoming stream were known. The problem with raspivid stream is that the actual framerate is not known. So ffmpeg makes a wrong assumption and resamples to that wrong framerate. Over time extra frames keep adding up...

vadim

Thanks for this additional info.
Time for hacking raspivid then

I still think that if I ask raspivid to give me 25fps then it should make sure I get 25fps (on average with bearable jitter).

vadim

There are several electronic and paper magazines that publish projects that work. Linux User and Developer magazine devotes a lot of attention to RasPi. Some months ago it published Top 10 relatively easy projects. http://www.raspberry-pi-geek.com/ is a new magazine covering various aspects of RPi i...

vadim

Thank you. So now we have a downside of moving clock source to the camera board. I think raspivid can still sync camera stream to OS time by droping excess frame(s) at end of GOP whenever the number of frames captured exceedes the expected number of frames. At the same time SPS/IPS could be added be...

vadim

I hope someone can help me with this issue or give some useful tips. The problem I have is that when recording or streaming video with audio the video stream starts to lag behind sound and the lag keeps increasing. To isolate the problem I recorded 5Hr of video with this command: raspivid -w 360 -h ...

vadim

most probably some control commands are not implemented in the card driver. try muting/unmuting in alsa mixer.

vadim

make sure you have bcm2708 platform selected

vadim

This is exactly how I tested. I connected both LCRIN and LCROUT to PCM_FS and used 44,1khz for recording with arecord. Today I tested again to check whether I made something wrong before, but it still does not work. Using wm8731 recording works (If I use 48khz, 8khz and 32khz are not working at the...

vadim

Vhigh=2V, so Pi can give that. As a general precaution use short leads for clocks and use resistors on digital lines because you're using different power sources on both ends of i2s.

vadim

Well, luckily in my configuration I need to output only MCLK because I will configure one of ADCs to work as master. My biggest problem will be soldering SMD, I have never done it before :lol: joy, oh joy! sounds like fun. soic-8 was difficult enough for me.good luck with wm8782! btw, from my memor...

vadim

Do you know how to make Pi act as a slave? By removing quartz oscillator :mrgreen: and connecting external clock instead of it? What about outputting clock on GPIO pin? Pi can be a slave and that's probably the best configuration. It doesn't need MCLK in as some codecs do. In my test the MCLK was c...

vadim

Since WM8783 recreates own BCLK from LRCLK and all the clocks should be in sync I run into problems at higher rates. In my case codec's MCLK and Pi's BCLK are generated independently although from one PLLD. At higher rates the jitter and phase shifts create nice :twisted: white noise masking the inc...

Search found 129 matches

Re: The busiest Pi...

Re: I2S: Anyone got it running? (answer is yes!)

Re: I2S: Anyone got it running? (answer is yes!)

Re: Multiple I2S input

Re: Ethernet Dropping Out

Re: trying to stream raspicam but no success

Re: trying to stream raspicam but no success

Re: Basic way to shutdown via web

Re: Ethernet Dropping Out

Re: I2S: Anyone got it running? (answer is yes!)

Re: I2S: Anyone got it running? (answer is yes!)

Re: I2S: Anyone got it running? (answer is yes!)

Re: Imprecise camera fps

Re: Imprecise camera fps

Re: Imprecise camera fps

Re: HELP losing motivation as a beginner

Re: Imprecise camera fps

Imprecise camera fps

Re: I2S: Anyone got it running? (answer is yes!)

Re: I2S: Anyone got it running? (answer is yes!)

Re: I2S: Anyone got it running? (answer is yes!)

Re: I2S: Anyone got it running? (answer is yes!)

Re: Multiple I2S input

Re: Multiple I2S input

Re: Multiple I2S input