FLAC Decoding Using GPU Acceleration

摘要

Free Lossless Audio Codec (FLAC) format is a widely used format for audio storage. Using a lower performance single threaded approach, FLAC is easily decoded faster than the rate at which it is played at. However, if you wish to transcode or edit long FLAC audio files then decoding times using single thread CPU approaches becomes significant. The FLAC format contains a sequence of frames, these frames vary in size so start locations are unknown until the previous frame is decoded. This complicates parallelizing decoding. However, frames start with known fixed bit patterns and each frame contains a frame index, it is possible to locate and decode frames in parallel. In this paper, we present an approach that exploits this characteristic enabling all the frames to be decoded in parallel. This approach is implemented and evaluated using an NVIDIA GeForce GTX 1080 graphics card showing a 5 times performance improvements than the widely used official implementation running on an Intel CoreTM i7-6770K CPU.