• Move all data transfers between processes to shared memory. Results in huge speed ups on multi core machines.
• Stream audio data in --preview mode to prevent skips for a good real-time rf monitoring experience.
• Add --head_switching_interpolation [on/off] option to turn this noise reduction feature on or off.
• Fix 8mm decoding by putting the RF low-pass filter back in. It's needed to filter out the video signals from 8mm capture data.
  • This is also re-enabled for VHS. In some cases this can help filter out noise for a minor performance impact.
• Fix Windows issue with CTRL-C causing an InterruptedException rather than cleaning up gracefully.

Benchmarks

Piping in from flac

flac -d -c --force-raw-format --endian little --sign signed hifi_rf.flac - | ~/git/vhs-decode/hifi-decode -t 16 -n -f 20MHz --auto_fine_tune off --audio_rate 48000 - hifi_decoded.flac

• Dell Laptop with 16 cores circa 2021, running 16 threads (Linux)
  • 11th Gen Intel(R) Core(TM) i9-11980HK @ 2.60GHz

- Decoding speed: 48988 kFrames/s (1.22x), 16 running processes
- Input position: 0:03:48.780
- Audio position: 0:03:40.416
- Wall time     : 0:03:06.805

• Dell Laptop with 16 cores circa 2021, running 16 threads (Windows 11)
  • 11th Gen Intel(R) Core(TM) i9-11980HK @ 2.60GHz

Decoding speed: 31265 kFrames/s (0.78x), 15 running processes
- Input position: 0:08:22.332
- Audio position: 0:08:14.460
- Wall time     : 0:10:42.668

• AMD Desktop circa 2015, running 4 threads
  • AMD A10-7860K Radeon R7, 12 Compute Cores 4C+8G

Decoding speed: 8362 kFrames/s (0.21x), 4 running processes
- Input position: 0:00:49.692
- Audio position: 0:00:46.248
- Wall time     : 0:03:57.707

• Old i7 sandybridge laptop circa 2010, running 8 threads
  • Intel(R) Core(TM) i7-2960XM CPU @ 2.70GHz

Decoding speed: 10053 kFrames/s (0.25x), 8 running processes
- Input position: 0:00:23.616
- Audio position: 0:00:18.696
- Wall time     : 0:01:33.961

• Core2 Duo machine circa ~2008, running 2 threads:
  • Intel(R) Core(TM)2 Extreme CPU X9000 @ 2.80GHz

Decoding speed: 1405 kFrames/s (0.04x), 2 running processes
- Input position: 0:00:14.760
- Audio position: 0:00:12.792
- Wall time     : 0:07:00.142

Piping in from ffmpeg

ffmpeg -i hifi_rf.flac -f s16le -acodec pcm_s16le - | ~/git/vhs-decode/hifi-decode -t 64 -n -f 20MHz --auto_fine_tune off --audio_rate 48000 - hifi_decoded.flac

• Large server with 192 cores circa 2018, running 64 threads:
  • Dell Poweredge R930 Server, 4x Intel(R) Xeon(R) CPU E7-8890 v4 @ 2.20GHz

- Decoding speed: 102333 kFrames/s (2.56x), 52 running processes
- Input position: 0:29:28.402
- Audio position: 0:29:28.740
- Wall time     : 0:11:31.233