In general, WEBRTC's AEC algorithm is simple, practical, and easy to commercialize, on the other hand, the C code has some reservations.
The AEC algorithm in WEBRTC has been studied recently because of the need for work. According to the FULLAEC.M file inside the source code,
Overall, I think the AEC algorithm belongs to the segmented fast frequency domain adaptive filtering algorithm, partioned block Frequeney domain adaPtive filter (PBFDAF). Refer to Paez Borrallo J m and Otero m G for details
There are two points to note when using the AEC algorithm:
1) delay to small, because the algorithm default filter length is divided into 12 blocks, 64 points per block, according to 8000 sampling rate, that is, 12*8ms=96ms data, and beyond this length is not processed.
2) The delay jitter is small, because the algorithm is the default 10 block also calculates the position of the reference data (that is, the filter energy the largest piece), so if the jitter is very large, if the reference data is not accurate, so that the echo can not be removed.