Simple LZ Compression — Handmade Hero — Episode Guide

0:21Recap and set the stage for the day

1:55simple_compressor.cpp: Look through the code and note the relative simplicity of the decompressor

8:48simple_compressor.cpp: Introduce LZDecompress()

10:59Blackboard: What CopyDistance refers to

13:15simple_compressor.cpp: Simplify and empower LZDecompress()

21:24simple_compressor.cpp: Consider the respective trade-offs of LZDecompress() and RLEDecompress()

23:35simple_compressor.cpp: Introduce LZCompress(), in order first to do RLE with an LZ backend

31:20simple_compressor.cpp: Introduce a "test" command, which compresses and decompresses, and then tests that the output matches the original

34:23Step through LZCompress() and LZDecompress() and watch what they do

37:01Assess how effectively it compresses test1.hha and intro_art.hha

39:01simple_compressor.cpp: Enable LZCompress() to perform look-backs for actual LZ compression

50:38Run the compressor on test1.hha and assess its effectiveness

52:24simple_compressor.cpp: Make LZCompress() output runs under stricter conditions

54:09Consider the compressor's new effectiveness, run it on intro_art.hha and break briefly to get a drink

56:55Blackboard: Optimal Parse

1:00:24Blackboard: Parsing interleaved data

1:04:28Assess the compressor's effectiveness on intro_art.hha

1:05:14simple_compressor.cpp: Note some fun things we can do with this code to try and make it better

1:09:18simple_compressor.cpp: Introduce the ability to gather and output statistics

1:12:39simple_compressor.cpp: Define handlers for the compressors and decompressors

1:20:33Run the compressor on test1.hha, crash and step in to investigate what's happening

1:21:39simple_compressor.cpp: Fix up the documentation and typos

1:22:37simple_compressor.cpp: Output the supported compression algorithms and continue implementing statistic gathering

1:25:11simple_compressor.cpp: Introduce GetStatName(), PrintStats(), Percent() and Increment()

1:34:03simple_compressor.cpp: Enable RLECompress() to gather stats, and make it and LZCompress() flush the buffer if they are at the end

1:37:47Run the compressor and make RLECompress() encode runs more smartly

1:43:15simple_compressor.cpp: Call PrintStats()

1:44:39Run the compressor, crash and fix up Percent() and PrintStats()

1:45:39Run the RLE compressor on test1.hha and consult the statistics

1:46:35simple_compressor.cpp: Enable LZCompress() to gather statistics

1:48:06Run the LZ compressor on test1.hha and consult the statistics

1:50:07Q&A

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1:50:07Q&A

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1:50:07Q&A

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1:51:51Miblo Amazing. I think I followed it, but definitely want to re-watch (during and after annotating)

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1:51:51Miblo Amazing. I think I followed it, but definitely want to re-watch (during and after annotating)

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1:51:51Miblo Amazing. I think I followed it, but definitely want to re-watch (during and after annotating)

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1:52:04garryjohanson Forgive me if this information was somehow implicit in today's lecture and I missed it, but is compression ever used for locality wins?

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1:52:04garryjohanson Forgive me if this information was somehow implicit in today's lecture and I missed it, but is compression ever used for locality wins?

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1:52:04garryjohanson Forgive me if this information was somehow implicit in today's lecture and I missed it, but is compression ever used for locality wins?

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1:52:43graeme7 Do you know off-hand what kind of compression ratio and decompression speed are needed before it's faster to load compressed data and decompress, over loading decompressed data?

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1:52:43graeme7 Do you know off-hand what kind of compression ratio and decompression speed are needed before it's faster to load compressed data and decompress, over loading decompressed data?

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1:52:43graeme7 Do you know off-hand what kind of compression ratio and decompression speed are needed before it's faster to load compressed data and decompress, over loading decompressed data?

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1:54:01nxsy inttypes.h and PRIu64 is probably what you are supposed to do for %llu for 64-bit printfs

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1:54:01nxsy inttypes.h and PRIu64 is probably what you are supposed to do for %llu for 64-bit printfs

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1:54:01nxsy inttypes.h and PRIu64 is probably what you are supposed to do for %llu for 64-bit printfs

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1:54:38ieee754 You still have to uncompress your images for display, right? So do you have plans for using block compression?

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1:54:38ieee754 You still have to uncompress your images for display, right? So do you have plans for using block compression?

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1:54:38ieee754 You still have to uncompress your images for display, right? So do you have plans for using block compression?

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1:55:16garryjohanson Make data fit in cache

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1:55:16garryjohanson Make data fit in cache

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1:55:16garryjohanson Make data fit in cache

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1:57:08mtsmox Why is 255 not a good look back limit for images? You wanted to elaborate on that

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1:57:08mtsmox Why is 255 not a good look back limit for images? You wanted to elaborate on that

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1:57:08mtsmox Why is 255 not a good look back limit for images? You wanted to elaborate on that

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1:57:47Blackboard: Choosing your look back window for image compression

1:59:22bluespide Have you ever heard of random seed data compression?

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1:59:22bluespide Have you ever heard of random seed data compression?

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1:59:22bluespide Have you ever heard of random seed data compression?

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1:59:46kknewkles Probably more of Jeff and Fabian's territory, but is there generally such a thing as a compressor that compresses a lot and fast? Would some RAD compressor leave 10% of initial size and be considerably faster than LZ? I guess BINK is hyperfast, isn't it like live decompression or something?

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1:59:46kknewkles Probably more of Jeff and Fabian's territory, but is there generally such a thing as a compressor that compresses a lot and fast? Would some RAD compressor leave 10% of initial size and be considerably faster than LZ? I guess BINK is hyperfast, isn't it like live decompression or something?

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1:59:46kknewkles Probably more of Jeff and Fabian's territory, but is there generally such a thing as a compressor that compresses a lot and fast? Would some RAD compressor leave 10% of initial size and be considerably faster than LZ? I guess BINK is hyperfast, isn't it like live decompression or something?

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2:00:59ieee754 I meant block compression that's GPU-supported (BC1-BC7). You upload the compressed image to the GPU, and hardware decodes it when sampled

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2:00:59ieee754 I meant block compression that's GPU-supported (BC1-BC7). You upload the compressed image to the GPU, and hardware decodes it when sampled

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2:00:59ieee754 I meant block compression that's GPU-supported (BC1-BC7). You upload the compressed image to the GPU, and hardware decodes it when sampled

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2:03:43Close this off

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2:03:43Close this off

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2:03:43Close this off

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