[HDMI2USB] Convert the JPEG encoder from VHDL to Migen/MiSoC

[mithro]

Brief explanation

The HDMI2USB firmware currently has a JPEG encoder written in VHDL. We would prefer it be written in Migen / MiSoC to allow better integration into the firmware.

Expected results

The HDMI2USB MiSoC Firmware correctly generates JPEG output using new Migen / MiSoC JPEG encoder.

The new Migen / MiSoC JPEG encoder has a strong test suite.

Detailed Explanation

The current JPEG encoder is based on mkjpeg from opencores but has been slightly modified by @enjoy-digital and @ajitmathew. The current encoder has the following problems;

• It is written in VHDL which means;
  • Isn't easy to simulate using FOSS tools,
  • An adapter between migen/misoc is needed,
• It has been the cause of numerous bugs.
• It doesn't have a strong test suite making modification hard.

Using Migen / MiSoC would allow a lot of better testing.

As there is an existing implementation of the encoder, it makes the conversion process a simpler. cfelton's JPEG encoder example might be useful source too.

Further reading

• Replace VHDL jpeg encoder with Verilog version
• Migen / MiSoC
• cfelton's JPEG MyHDL repo
• JPEG encoding
• mkjpeg from opencores

  Contacts

• Potential Mentors: @shenki @mithro @enjoy-digital
• Mailing list: hdmi2usb@groups.google.com

[adarsh1001]

I believe this particular problem was addressed in last year's GSoC also. How much work is left?

[mithro]

@ishan98 was working on it last year. You can find a lot of his work here -> https://github.com/ishan98/litejpeg

GitHub

ishan98/litejpeg

litejpeg - Small footprint and configurable JPEG encoder and decoder (WIP)