hi,
me and my friend are making a console and we would like it to output HDMI(preferably 1080p) using ESP32 but, after looking for ages we haven't found anything.
You can get a VGA card for it, but that is probably the limit of what can be achieved in terms of processing power.
However, it should be sufficient for retro-style consoles. For anything more, you'd need more powerful hardware.
The ESP32 does not produce video output of any kind. Have a look at the data sheet
Actually, you can produce video with the ESP. Look into what Bitluni has done. Also, there is others that have produced code for emulators all on the ESP32 with composite video and VGA outputs.
Youtube search for bitluni, or "esp32 composite video"
I have built several ESP32 clocks out of CRT TVs (color and black/white).
Related
We are trying to use a full-duplex stream from two different devices on two different clock domains. PortAudio reports flags periodically, which I've put down to the interfaces being on different clock domains.
I have read and understood the behaviour documented in http://www.portaudio.com/docs/proposals/001-UnderflowOverflowHandling.html, and it is consistent with my observations. These flags are of course accompanied by clicks. I can reproduce this behaviour easily in the pa_fuzz example, so I believe it to be expected behaviour.
What I'm unsure of exactly what I should do with this information? The flags tell me that an overflow/underflow has already happened; how could I feasibly implement any resampling with this?
Am I going about this completely wrong? What is the typical usage pattern for PortAudio full-duplex using two different devices?
I'm using Core Audio. Thanks!
I don't have a proper answer for handling it at the PortAudio level, but there is a platform-specific solution that you could consider.
On OS X, you can create an aggregate device that combines the two devices, and enable drift correction to have CoreAudio perform the resampling. The resulting aggregate will have the inputs and outputs for both devices, so it may take additional logic to select the input and output channels of interest.
You could try it first by creating an aggregate device using Audio MIDI Setup.app. Apple does have some support notes on it, like
Create an Aggregate Device to combine multiple audio interfaces, and Set aggregate device settings in Audio MIDI Setup on Mac (which may have conflicting guidance on selecting drift correction)
I'm not sure it's formally documented other than headers like AudioHardware.h, but it is possible to create an aggregate device programatically as well. I have only experimented with it myself, and recall having some intermittent issues configuring the device (perhaps an asynchronous behavior with some operations? ).
Of course, if you're using PortAudio and trying to find a portable solution, this won't solve the issue generally.
I want to write a program to make the entire screen black every N frames, while using a computer otherwise normally. I'm guessing I can do this by digging around enough in an open source video driver like nouveau, but I also want to do it in windows. Given that I cannot modify a proprietary video driver, is there an easier way to do this in a way that would not hang or make too many timing errors as a result of what the CPU is doing? Perhaps involving system interrupts or something?
Simply put, I need to take results from a DAQ and display them visually in a UI (no interaction needed) that gets information updated in real time. The DAQ I am using has an "utility" to plug into Labview, so it seems that the easiest way is to grab this data from Labview and then transmit that data to some UI using one of these methods.
I am using Windows 10 (although I could boot to Ubuntu), just not sure what UI application would be best / easiest to use.
You can use this National Instrument's tool for DAQ UI visualization. As it is native it should be quite straightforward to use.
You may want to use the DAQExpress VI in LabVIEW as #MateoRandwolf suggested. The neat thing about it is that it almost creates your first programm automatically -- besides the configuration of your NI modules.
There are just two things missing:
a waveform chart, and
a write to a TDMS file
Here is a snippit of a simple program doing this (the stop button is important to actually close the TMDS file before aborting the program)
If you really want to stream the data to a different device, you I suggest to use TCP/IP. There exist good examples in the documentation from which you can start (Help > Find Examples... > Search-tab). If you cannot accept the roughly 40ms buffer that TCP/IP has (because of shake-hands etc.), have a look on UDP.
You can use Dewesoft's DAQ systems which use dual mode capability. They use dual data buses (EtherCAT and USB). USB for high-speed buffered data storage to the PC's SSD hard drive and the EtherCAT bus for low latency real-time stream to any 3rd party EtherCAT master.
The DAQ systems are also capable of visualising data in real-time on the display using various pre-build visual displays like recorders, XY graphs, 3D graphs, osciloscopes, FFTs, GPS, video, and numerous other...
OK, the first issue. I am trying to write a virtual soundboard that will output to multiple devices at once. I would prefer OpenAL for this, but if I have to switch over to MS libs (I'm writing this initially on Windows 7) I will.
Anyway, the idea is that you have a bunch of sound files loaded up and ready to play. You're on Skype, and someone fails in a major way, so you hit the play button on the Price is Right fail ditty. Both you and your friends hear this sound at the same time, and have a good laugh about it.
I've gotten OAL to the point where I can play on the default device, and selecting a device at this point seems rather trivial. However, from what I understand, each OAL device needs its context to be current in order for the buffer to populate/propagate properly. Which means, in a standard program, the sound would play on one device, and then the device would be switched and the sound buffered then played on the second device.
Is this possible at all, with any audio library? Would threads be involved, and would those be safe?
Then, the next problem is, in order for it to integrate seamlessly with end-user setups, it would need to be able to either output to the default recording device, or intercept the recording device, mix it with the sound, and output it as another playback device. Is either of these possible, and if both are, which is more feasible? I think it would be preferable to be able to output to the recording device itself, as then the program wouldn't have to be running in order to have the microphone still work for calls.
If I understood well there are two questions here, mainly.
Is it possible to play a sound on two or more audio output devices simultaneously, and how to achieve this?
Is it possible to loop back data through a audio input (recording) device so that is is played on the respective monitor i.e for example sent through the audio stream of Skype to your partner, in your respective case.
Answer to 1: This is absolutely feasable, all independent audio outputs of your system can play sounds simultaneously. For example some professional audio interfaces (for music production) have 8, 16, 64 independent outputs of which all can be played sound simultaneously. That means that each output device maintains its own buffer that it consumes independently (apart from concurrency on eventual shared memory to feed the buffer).
How?
Most audio frameworks / systems provide functions to get a "device handle" which will need you to pass a callback for feeding the buffer with samples (so does Open AL for example). This will be called independently and asynchroneously by the framework / system (ultimately the audio device driver(s)).
Since this all works asynchroneously you dont necessarily need multi-threading here. All you need to do in principle is maintaining two (or more) audio output device handles, each with a seperate buffer consuming callback, to feed the two (or more) seperate devices.
Note You can also play several sounds on one single device. Most devices / systems allow this kind of "resources sharing". Actually, that is one purpose for which sound cards are actually made for. To mix together all the sounds produced by the various programs (and hence take off that heavy burden from the CPU). When you use one (physical) device to play several sounds, the concept is the same as with multiple device. For each sound you get a logical device handle. Only that those handle refers to several "channels" of one physical device.
What should you use?
Open AL seems a little like using heavy artillery for this simple task I would say (since you dont want that much portability, and probably dont plan to implement your own codec and effects ;) )
I would recommend you to use Qt here. It is highly portable (Win/Mac/Linux) and it has a very handy class that will do the job for you: http://qt-project.org/doc/qt-5.0/qtmultimedia/qaudiooutput.html
Check the example in the documentation to see how to play a WAV file, with a couple of lines of code. To play several WAV files simultaneously you simply have to open several QAudioOutput (basically put the code from the example in a function and call it as often as you want). Note that you have to close / stop the QAudioOutput in order for the sound to stop playing.
Answer to 2: What you want to do is called a loopback. Only a very limited number of sound cards i.e audio devices provide a so called loopback input device, which would permit for recording what is currently output by the main output mix of the soundcard for example. However, even this kind of device provided, it will not permit you to loop back anything into the microphone input device. The microphone input device only takes data from the microphone D/A converter. This is deep in the H/W, you can not mix in anything on your level there.
This said, it will be very very hard (IMHO practicably impossible) to have Skype send your sound with a standard setup to your conversation partner. Only thing I can think of would be having an audio device with loopback capabilities (or simply have a physical cable connection a possible monitor line out to any recording line in), and have then Skype set up to use this looped back device as an input. However, Skype will not pick up from your microphone anymore, hence, you wont have a conversation ;)
Note: When saying "simultaneous" playback here, we are talking about synchronizing the playback of two sounds as concerned by real-time perception (in the range of 10-20ms). We are not looking at actual synchronization on a sample level, and the related clock jitter and phase shifting issues that come into play when sending sound onto two physical devices with two independent (free running) clocks. Thus, when the application demands in phase signal generation on independent devices, clock recovery mechanisms are necessary, which may be provided by the drivers or OS.
Note: Virtual audio device software such as Virtual Audio Cable will provide virtual devices to achieve loopback functionnality in Windows. Frameworks such as Jack Audio may achieve the same in UX environment.
There is a very easy way to output audio on two devices at the same time:
For Realtek devices you can use the Audio-mixer "trick" (but this will give you a delay / echo);
For everything else (and without echo) you can use Voicemeeter (which is totaly free).
I have explained BOTH solutions in this video: https://youtu.be/lpvae_2WOSQ
Best Regards
Is there an API that is suitable for doing this? A possible application of this is for writing a visualiser, and to play with real time signal processing.
EDIT: The operating system in question is Windows. On Linux, a roundabout way to accomplish this is with Jack, but I'm hoping for a way to read the data in the audio buffer without having to couple apps to Jack.
EDIT: A good answer is found here.
If sound board used for playback has recording device/line like "Stereo Mix", "What U Hear", etc., then it is enought to write simple recording application, that is capable to record from a specified recording device/line and record from the "Stereo Mix",...
General case (for "all sound boards") will require to write special driver. Examples of applications with such spesial drivers: Virtual Audio Cable (http://software.muzychenko.net/eng/vac.html); Total Recorder (http://www.totalrecorder/com).