Bug When Saving WAV File For Scottie DX Encoding Mode

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Introduction

The Scottie DX mode is a popular encoding mode used in Single Side Band (SSB) communication. It is known for producing long audio files due to its slower line scan rate. However, users have reported a bug where WAV files saved in Scottie DX mode are truncated after 90 seconds. In this article, we will investigate the cause of this bug and provide a solution.

Background

The Scottie DX mode is a type of SSB encoding that uses a slower line scan rate to produce a longer audio signal. This mode is commonly used in amateur radio communication and is known for its high-quality audio output. However, the longer audio signal also means that it requires more processing power and memory to encode and decode.

The Bug

The bug in question occurs when saving WAV files in Scottie DX mode. The files are truncated after 90 seconds, which is significantly shorter than the expected duration of the audio signal. This bug has been reported by several users and has been identified as a problem with the sstvSignalDuration variable in the encode.js file.

Investigation

To investigate this bug, we need to examine the encode.js file and identify the cause of the truncated audio signal. The encode.js file is responsible for encoding the audio signal in Scottie DX mode and saving it as a WAV file. The file contains a variable called sstvSignalDuration which is used to calculate the duration of the audio signal.

Upon inspection of the encode.js file, we notice that the sstvSignalDuration variable is set to 91.0186 seconds. This is significantly shorter than the expected duration of the audio signal, which is around 272 seconds. This suggests that the bug is caused by an incorrect calculation of the sstvSignalDuration variable.

Solution

To solve this bug, we need to modify the encode.js file to correctly calculate the sstvSignalDuration variable. The correct calculation should take into account the encoding times and produce a value that reflects the actual duration of the audio signal.

Here is an example of how the modified encode.js file could look:

// ...

// Calculate the duration of the audio signal
sstvSignalDuration = (lineScanRate * audioDuration) / 1000;

// ...

// Save the WAV file
fs.writeFileSync('output.wav', audioBuffer);

In this modified version, we calculate the sstvSignalDuration variable by multiplying the line scan rate by the audio duration and dividing by 1000. This should produce a value that reflects the actual duration of the audio signal.

Testing

To test the modified encode.js file, we need to save a WAV file in Scottie DX mode and verify that it is not truncated after 90 seconds. We can use a tool like Audacity to play back the WAV file and verify that it is the correct duration.

Conclusion

In conclusion, the bug in question is caused by an incorrect calculation of the sstvSignalDuration variable in the encode.js file. By modifying the file to correctly calculate the variable, we can solve the bug and produce WAV files that are truncated after 90 seconds. This solution should be tested thoroughly to ensure that it works correctly and produces the expected results.

Browser Compatibility

The bug in question was tested in Google Chrome version 135.0.7049.52 (Official Build) (64-bit). However, the solution should be compatible with other browsers as well.

Future Work

In the future, we can improve the solution by adding more error checking and handling to the encode.js file. We can also add more features to the file, such as support for multiple encoding modes and improved audio quality.

References

Introduction

In our previous article, we investigated the bug that occurs when saving WAV files in Scottie DX mode. We identified the cause of the bug and provided a solution to fix it. In this article, we will answer some frequently asked questions (FAQs) related to the bug and its solution.

Q: What is the Scottie DX mode?

A: The Scottie DX mode is a type of Single Side Band (SSB) encoding that uses a slower line scan rate to produce a longer audio signal. It is commonly used in amateur radio communication and is known for its high-quality audio output.

Q: What is the bug in question?

A: The bug occurs when saving WAV files in Scottie DX mode. The files are truncated after 90 seconds, which is significantly shorter than the expected duration of the audio signal.

Q: What is the cause of the bug?

A: The bug is caused by an incorrect calculation of the sstvSignalDuration variable in the encode.js file. The variable is set to 91.0186 seconds, which is significantly shorter than the expected duration of the audio signal.

Q: How do I fix the bug?

A: To fix the bug, you need to modify the encode.js file to correctly calculate the sstvSignalDuration variable. The correct calculation should take into account the encoding times and produce a value that reflects the actual duration of the audio signal.

Q: What is the correct calculation for the sstvSignalDuration variable?

A: The correct calculation for the sstvSignalDuration variable is:

sstvSignalDuration = (lineScanRate * audioDuration) / 1000

Q: How do I test the modified encode.js file?

A: To test the modified encode.js file, you need to save a WAV file in Scottie DX mode and verify that it is not truncated after 90 seconds. You can use a tool like Audacity to play back the WAV file and verify that it is the correct duration.

Q: Is the solution compatible with other browsers?

A: Yes, the solution should be compatible with other browsers as well. However, it was tested in Google Chrome version 135.0.7049.52 (Official Build) (64-bit).

Q: What are the future plans for improving the solution?

A: In the future, we can improve the solution by adding more error checking and handling to the encode.js file. We can also add more features to the file, such as support for multiple encoding modes and improved audio quality.

Q: Where can I find more information about the Scottie DX mode?

A: You can find more information about the Scottie DX mode on Wikipedia: Scottie DX mode

Q: Where can I find more information about the WAV file format?

A: You can find more information about the WAV file format on Wikipedia: WAV file format

Conclusion

In conclusion, the bug in question is caused by an incorrect calculation of the sstvSignalDuration variable in the encode.js file. By modifying the file to correctly calculate the variable, we can solve the bug and produce WAV files that are truncated after 90 seconds. We hope that this Q&A article has provided you with the information you need to fix the bug and improve your experience with the Scottie DX mode.