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Why wouldn't they use H.264 and their existing hardware ? Do you really think it makes more sense to decode H.264 on the device then re-encode it in another fo
by taligent 14y ago
Why wouldn't they use H.264 and their existing hardware ?
Do you really think it makes more sense to decode H.264 on the device then re-encode it in another format and then decode that on the adapter ? Sounds slow, illogical and bound to introduce more artifacts.
- dmishe 14y agoNope. This is _the_ question here, what prevented them from pushing framebuffer data to the adapter, which then puts it into HDMI compatible form
- jlgreco 14y agoWorse case, you have two pins, one on each side like any other, that are both actually the same pin.
- seabee 14y agoYou'd need 3Gbps to push uncompressed 1080p data. If you look at USB 3.0 and make a not-unreasonable bet that Lightning is slower, then you simply don't have the bandwidth to do so.
- StringyBob 14y agoAs well as bandwidth, power consumption. Chucking 3Gbps down a long wire is going to reduce battery life for a mobile product. Perhaps the controller can support it, but heat dissipation in the phone is significant?
- morsch 14y agoI can't imagine that compressing and decompressing MPEG 4 uses less power, given specialised hardware for each task.
- makomk 14y agoActually, that doesn't make sense - the adapter is powered from the iPhone or iPad and still has to chuck 3 Gbps down a long wire, except now you're using the iPhone's h.264 encode hardware and an entire ARM SoC in the adapter which you have to power too.
- MBCook 14y agoRetina iPads already need to re-scale the image since they're higher resolution than an HDTV. Why force the little adapter to do (some pretty massive) scaling and encoding when the iPad has a very nice GPU? It seems to me they had a system for outputting video via h.264, and they decided to use it again here. Seems like a reasonable decision at that point.