None of the SSTV modes are unable to decode, other than Wrasse

[radio-satellites]

I'm unable to get a decode for any of the SSTV modes, other than Wrasse. Wrasse decodes fine, but every other mode produces completely wrong results. I would suspect timing, but I've experimented with a bunch of timing values ranging from 0.4-2 and none seem to work out well. The platform is an Arduino Mega I'm using for testing.

Has anyone run into similar issues before?

/*
  RadioLib SSTV Transmit AFSK Example

  The following example sends SSTV picture using
  SX1278's FSK modem. The data is modulated
  as AFSK.

  Other modules that can be used for SSTV:
  with AFSK modulation:
  - SX127x/RFM9x
  - RF69
  - SX1231
  - CC1101
  - Si443x/RFM2x
  - SX126x/LLCC68

  NOTE: Some platforms (such as Arduino Uno)
        might not be fast enough to correctly
        send pictures via high-speed modes
        like Scottie2 or Martin2. For those,
        lower speed modes such as Wrasse,
        Scottie1 or Martin1 are recommended.

  For default module settings, see the wiki page
  https://github.com/jgromes/RadioLib/wiki/Default-configuration

  For full API reference, see the GitHub Pages
  https://jgromes.github.io/RadioLib/
*/

// include the library
#include <RadioLib.h>

// SX1278 has the following connections:
// NSS pin:   10
// DIO0 pin:  2
// RESET pin: 9
// DIO1 pin:  3
SX1278 radio = new Module(10, 2, 9, 3);

// or detect the pinout automatically using RadioBoards
// https://github.com/radiolib-org/RadioBoards
/*
#define RADIO_BOARD_AUTO
#include <RadioBoards.h>
Radio radio = new RadioModule();
*/

// create AFSK client instance using the FSK module
// this requires connection to the module direct
// input pin, here connected to Arduino pin 5
// SX127x/RFM9x:  DIO2
// RF69:          DIO2
// SX1231:        DIO2
// CC1101:        GDO2
// Si443x/RFM2x:  GPIO
// SX126x/LLCC68: DIO2
AFSKClient audio(&radio, 5);

// create SSTV client instance using the AFSK instance
SSTVClient sstv(&audio);

uint32_t line[320] = {
  // black
  0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000,
  0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000, 0x000000,

  // blue
  0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF,
  0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF, 0x0000FF,

  // green
  0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00,
  0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00, 0x00FF00,

  // cyan
  0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF,
  0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF, 0x00FFFF,

  // red
  0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000,
  0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000, 0xFF0000,

  // magenta
  0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF,
  0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF, 0xFF00FF,

  // yellow
  0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00,
  0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00, 0xFFFF00,

  // white
  0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF,
  0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF, 0xFFFFFF
};


void setup() {
  Serial.begin(9600);

  // initialize SX1278 with default settings
  Serial.print(F("[SX1278] Initializing ... "));
  int state = radio.beginFSK();
  if (state == RADIOLIB_ERR_NONE) {
    Serial.println(F("success!"));
  } else {
    Serial.print(F("failed, code "));
    Serial.println(state);
    //while (true) { delay(10); }
  }

  // when using one of the non-LoRa modules for SSTV
  // (RF69, SX1231 etc.), use the basic begin() method
  // int state = radio.begin();

  // initialize SSTV client
  Serial.print(F("[SSTV] Initializing ... "));
  // SSTV mode:                   Wrasse (SC2-180)
  state = sstv.begin(Wrasse); //If this is anything other than Wrasse, decoding breaks
  if(state == RADIOLIB_ERR_NONE) {
    Serial.println(F("success!"));
  } else {
    Serial.print(F("failed, code "));
    Serial.println(state);
    //while (true) { delay(10); }
  }

  // set correction factor
  // NOTE: Due to different speeds of various platforms
  //       supported by RadioLib (Arduino Uno, ESP32 etc),
  //       and because SSTV is analog protocol, incorrect
  //       timing of pulses can lead to distortions.
  //       To compensate, correction factor can be used
  //       to adjust the length of timing pulses
  //       (lower number = shorter pulses).
  //       The value is usually around 0.95 (95%).
  Serial.print(F("[SSTV] Setting correction ... "));
  state = sstv.setCorrection(0.949);
  if(state == RADIOLIB_ERR_NONE) {
    Serial.println(F("success!"));
  } else {
    Serial.print(F("failed, code "));
    Serial.println(state);
    while (true) { delay(10); }
  }
  sstv.idle();

  // to help tune the receiver, SSTVClient can send
  // continuous 1900 Hz beep
  /*
    sstv.idle();
    while (true) { delay(10); }
  */
}

void loop() {
  // send picture with 8 color stripes
  Serial.print(F("[SSTV] Sending test picture ... "));

  // send synchronization header first
  sstv.sendHeader();

  // send all picture lines
  for(uint16_t i = 0; i < sstv.getPictureHeight(); i++) {
    sstv.sendLine(line);
  }


  Serial.println(F("done!"));

}

[jgromes]

I was not able to reproduce this - see the image below, sent in Scottie 2 mode. I was using Raspberry Pi (and SX1262), so the timing is all over the place, but it definitely receives and decodes correctly.