[mythtv-users] Recording from input video on demand, no tuner; update: troubles capturing video using RPI4

[Stephen Worthington]

On Tue, 28 Feb 2023 14:39:03 -0500, you wrote:

>
>
>> 
>>> 
>>> I don't know if it will help you, but as of Mythtv v33, the mythexternrecorder application now lets you set "per channel" tuning command. See:
>>> https://www.mythtv.org/wiki/Example_Configuration_files#Mythtv_v33_Example
>>> 
>>> That means your tuning command could be a no-op for specific channels that you have defined.
>>> 
>>> John
>> 
>> 
>
>So I have been ‘experimenting’ with this and I think I have set up something incorrect for incoming video. 
>
>The hdmi device is usb, one of those that are 10-20 bucks, and from what I can tell it is creating a v4l2 mjpeg video stream with a PCM audio stream on  USB audio. 
>
>Using ffmpeg, I can create an avi with it, and also an mkv with it , and have tried multiple ways to create an output stream for mythtv to use.
>
>I am trying to keep processing down to a minimal amount since I am trying to use a Raspberry Pi 4b with 4GB ram running mythbackend to capture the video stream.
>
>If I try to use any mpeg2 or mp4 transcoding, I get in trouble with using too much cpu. Any ideas as to what I can try to capture with little or no transcoding effort on the RPI 4b? Or am I asking too much from the RPI4 to capture it.
>
>Regards!

I know nothing about those cheap devices, but the first thing I would
try would be to just store the data directly to a .ts file, as
mythbackend does for DVB streams.  If mythfrontend can play the
result, then all is well.  If not, then you can set up an automatic
non-real time transcoding job to be run at low priority after the
recording finishes (or the job can be run in parallel with the
recording).