Texas Instruments TMS320C64x DSP manual Capture Window Not Requiring Edge Pixel Replication

Video Input Filtering

Figure 3–16 shows an example of a capture window that is smaller than the BT.656 active line. Sample a is the first sample in the horizontal capture window and sample n is the last sample. In this case, any filtering done on the first sample location uses the m leading edge captured pixels (m is 3 in this example), and any filtering done on the last sample location uses the m trailing captured pixels. (From an implementation standpoint, the mirroring and filter- ing can still begin and end with SAV and EAV, but the samples before VCXSTART or after VCXSTOP must not be saved to the YCbCr buffers.)

Figure 3–16. Capture Window Not Requiring Edge Pixel Replication

XSTART

XSIZE

SAV a–4 a–3 a–2 a–1 a b c d e n–4 n–3 n–2 n–1 n n+1 n+2 n+3 n+4 EAV

Active line

a–4 a–3 a–1 a b c d e

n–4 n–3 n–2 n–1 n n+1 n+2 n+3

Leading edge replicated pixels

– Luma (Y) sample

Trailing edge replicated pixels

– Chromasamples (Cb/Cr)

3-30 Video Capture Port SPRU629