TH: I know you can’t speak for Nvidia, but with both Stream and CUDA we only see acceleration for MPEG-4, layer 10. This ignores all of the media users currently have in formats such as DivX and Xvid. Why are we side-stepping MPEG-4, layer 2? And wasn’t there supposed to be acceleration support for Windows and WMV?
AMD: There are two points to your questions: acceleration of Microsoft applications and codecs supported in ATI Stream transcoding. From what I recall in material from last November, we included Microsoft applications like PowerPoint or Microsoft Expression that used GPU acceleration in their processing. It was not specific to transcoding. As for the codecs supported in ATI Stream transcoding framework, we had to make choices to be both effective in focusing our efforts while also covering the most use cases possible in a first iteration.
So why MPEG-2 and MPEG-4 AVC for GPGPU acceleration? We approached it this way: sources and targets.
- DVDs: MPEG-2 SD
- Blu-ray: MPEG-2 HD, MPEG-4 AVC, VC-1
- Digital broadcast: MPEG-2 (SD & HD)
- HDV (which is a variant of MPEG-2 with resolution of 1440x1080)
- AVCHD for the new camcorders
- Portable devices: H.264 (MPEG-4) & WMV
- DVD authoring: MPEG-2 SD
- Blu-ray authoring: MPEG-2 HD, MPEG-4 AVC, VC-1
- File archiving with high quality/compression ratio: MPEG-4 AVC, DivX, Xvid
- YouTube: H.264
As you can see, with these two codecs, MPEG-4 and MPEG-2, we cover most user scenarios. Is there room of improvement? Of course, and we will work on it in future updates.
A note on DivX and Xvid: DivX is proprietary, and we would welcome having DivX support GPGPU acceleration, but that is a decision that is theirs to make. As for Xvid, it is open source, and the ATI Stream team welcomes developers on our amd.com Web site to communicate with them and get support if they want to develop a version that is ATI Stream-accelerated.
- Underground Stream: A GPGPU History
- Whither Avivo Video Converter?
- The “Balanced Platform”
- CyberLink Serves Up Espresso
- Let’s Pull Some Shots!
- Add Shots
- Mixed Messages
- Heavier Lifting
- Sim(ply Not Ready)HD
- In AMD’s Words
- Why Only These Codecs?
- Putting The “General” In GPGPU
- AMD On Stream’s Prospects