wifi_streaming example returns half-corrupted images about aideck-gap8-examples

[knmcguire]

This has been completely reworked with the new AIdeck example, so this issue will probably no longer hold. If it does, please reopen!

[knmcguire]

Hi, Lets talk further here then since this is an actual bug.

There is probably something wrong indeed. Unfortunately the JPEG compression written in the SDK is not conventional. You mentioned the double buffering before in the forum, but not sure if that will fix the problem either.

This week we will not have time to look in this in more detail so this needs to be done next week at our side.

[LorenzoLamberti94]

Thank you kimberly

I printed the stream of data on both sender (GA8 to NINA) and receiver side (laptop Python script)

i might have found the source of the problem: the last packet sent is sent after the end of image string (footer = 0xffd9).
To better unverstand, this is what we should have:
header
packet
....
packet
packet
footer

what we are actually receiving
header
packet
....
packet
footer
packet

It seems also that GAP8 communicates only once to NINA the header and footer of JPEG, and NINA actually attach them to the bitstream. In this file.

I''ll look further next week. Thanks!

[knmcguire]

The streamer file on the gap8 side were sending the jpeg in a unconventional way by only sending the header and footer once first, so that is why the NINA is patching this up. But maybe something went wrong in the patching part of things

[LorenzoLamberti94]

I suppose that the problem is in these lines
https://github.com/bitcraze/AIdeck_examples/blob/master/NINA/firmware/main/ai-deck-jpeg-streamer-demo.c#L135-L142

the order is not correct, i would reorder like this:

    wifi_send_packet( (const char*) buffer, size);

    if (new_frame) {
      wifi_send_packet( (const char*) &jpeg_footer, sizeof(jpeg_footer) );
    }

    if (new_frame) {
      wifi_send_packet( (const char*) &jpeg_header, sizeof(jpeg_header) );

i would give it a try but i couldnt flash NINA correctly, maybe you can help me on this

[knmcguire]

Hi! Good call!

I will give it a go this week. I will need to go to the office to pick up a programmer since the one that I have here is malfunctioning, so once I have I can try it out.

[evoggy]

Yes, this seems to be the issue. There was also some changes needed in the python script that receives the image. I've pushed a new version of the Nina application and the python script, could you give it a try and see if it solves the issue?