that makes sense, because almost no application of OMAP really used all it's features...
I'm not sure why you say that. All accelerated video encoding/decoding is done on the DSP. This is in contrast to the Freescale i.MX5 series, for example, which has dedicated hardware blocks for this.
The OMAP4 has dedicated video encode decode, dedicated "still image" processor, and a general purpose DSP (which isn't used for the most part and would be a lot slower than the dedicated hardware units).
EDIT: The thing though is that its footprint is so small that it doesn't matter much.
I'm not sure why you say that. All accelerated video encoding/decoding is done on the DSP. This is in contrast to the Freescale i.MX5 series, for example, which has dedicated hardware blocks for this.