4:1 low-latency image to baseaband modulator/demodulator

Translates incoming YUV422 video stream into I/Q samples with 4:1 ratio with a fixed end-to-end latency of about ~16 lines

Modules

• l7_encoder
  Consumes alternating YU/YV pairs and produces IQ pairs.
  No backpressure handling
• l7_decoder
  Consumes IQ pairs and produces alternating YU/YV pairs.
  Handles backpressure from the consumer.

Supported modes

The only supported mode for now is 960x720 at rates up to 200 fps.

Concept

The image resolution is quartered and filtered with wavelets, which means the amount of physically transmitted pixels is 4 times less, e.g. 960x720 is encoded as 480x360, at the decoder side the image is upscaled back with wavelets, and visually quality loss is visible only sharp edges and objects with high details.

Utilization

Utilization report for Gowin GW5A for 960x720 mode.

Module	FF	LUT/ALU	BRAM 16k
l7_encoder	1420	1108	10
l7_decoder	839	728	10

Fmax: 150Mhz