tegra_multimedia_api -MutilStream sample, can not find the Implementation of "writeJPEG" .

I found the sample MutilStream can catch some JPG Images. The function is “writeJPEG”.
But I can not find the Implementation of this function.Where is the Implementation of this function?

catch the image code :tegra_multimedia_api/argus/samples/utils/JPEGConsumer.cpp

std::ostringstream fileName;
        fileName << JPEG_PREFIX << std::setfill('0') << std::setw(4) << frameCount++ << ".jpg";
        if (iJPEG->writeJPEG(fileName.str().c_str()) == STATUS_OK)
            JPEG_CONSUMER_PRINT("Captured a still image to '%s'\n", fileName.str().c_str());
            ORIGINATE_ERROR("Failed to write JPEG to '%s'\n", fileName.str().c_str());

It is defined in argus/include/EGLStream/Image.h and not open source.

hi DaneLLL
Thank you!
How can I get the image format and size information convert to opencv Mat format frome tegra_multimedia_api -MutilStream sample? do you have sample code about this?

Hi Jason,
You have posted https://devtalk.nvidia.com/default/topic/1062431/
Please not make duplicate posts for the same question.