rzeldent/esp32cam-rtsp

Feature request, clock overlay

rubin110 opened this issue · 1 comments

rubin110 commented

It would be great if there was a clock overlay on the video stream, though I'm pretty sure that's impossible due to how limited the platform is. Also I imagine you'll need to include some NTP client to grab the time. Anyhow, figured it couldn't hurt to ask. Thanks!

rzeldent commented

Hi Rubin,

Sure does not hurt to ask!

RTSP has the provision to include a timestamp in the stream. See CStreamer.cpp

    RtpBuf[8] = (m_Timestamp & 0xFF000000) >> 24; // each image gets a timestamp
    RtpBuf[9] = (m_Timestamp & 0x00FF0000) >> 16;
    RtpBuf[10] = (m_Timestamp & 0x0000FF00) >> 8;
    RtpBuf[11] = (m_Timestamp & 0x000000FF);

Not exactly clear how this is used right now. Seems to start at 0 and updated based on the fps.

This could be used to generate some overlay (lateron) but will require a dependency on NTP...

An overlay is really out of scope because the esp32 is already at the max of CPU power for processing and sending images. However, will take a look at the possibility to include a valid/NTP timestamp!