Please update to latest media samples ver. 184.108.40.206 here: https://software.intel.com/en-us/media-client-solutions-support/code-samples. We have documented all the different classes and functions used in sample_multi_transcode in our mediaSDK manual.pdf in media-sdk/doc folder. We understand samples code structure is complex to understand and we in process to simplify this. Let me know if your have any questions.