Performance during Hardware Video Encoding
This time besides the gaming tests, we decided to also check out the performance and efficiency during video encoding by the GPU. To accomplish that we used the official ATI Avivo converter and the new Cyberlink MediaShow Espresso converter that supports both: Nvidia CUDA and ATI Stream.
One of the most common video encoding tasks is transcoding from high-definition formats in formats supported by portable playback devices. We decided to transcode the initial file into the format supported by popular iPod players in 640x360 resolution and with 2.5Mbit bitrate.
Unfortunately, we faced a number of problems. Namely, our attempt to work with a video in H.264 1080p format with about 10Mbit bitrate (MP4 container) failed, because Avivo converter refused to work with it at all, while MediaShow Espresso didn’t demonstrate any improvement in transcoding time with ATI Stream mode enabled.
We undertook a second attempt. This time we took a WMV HD 1080p video (Windows Media container) with about 7.5Mbit bitrate. This time transcoding completed successfully with the following results:
MediaShow Espresso needed almost equal amount of time for transcoding by CPU and GPU, while the brand name ATI Avivo converter performed a little better. Nevertheless, it is still early to claim the victory of GPGPU, because a number of sources report image quality issues in videos transcoded with ATI Avivo. Things will definitely get better as time goes on and we will certainly get back to this interesting topic, but at this point ATI solutions are still not the best choice for those who work with video on a PC platform a lot.