Multipass encoding for reducing pulsing artifacts in cloud based video transcoding

Low latency video transcoding is an important feature in video sharing platforms. Typically this is achieved by splitting a clip into short segments, followed by parallel encoding of the segments. However, this introduces quality artifacts due to transients in encoder rate control. We present a model for more effectively predicting the behavior of the encoder in each encoding pass, which minimizes this problem. We learn the model using measurements from more than 500 video clips, hence ensuring reliable estimation. Finally, we show that the proposed multipass strategy delivers more stable reconstructed quality for parallel video transcoding frameworks.