[
 {
  "name": "twoframes",
  "frame": "twoframes.zst",
  "command": "python3: pyzstd.compress(A, 3) + pyzstd.compress(B, 3), A = 5000 xorshift64 bytes, B = b'the quick brown fox ' * 500",
  "verdict": "legal",
  "plain": [
   "A.raw.gz",
   "B.raw.gz"
  ],
  "size": 15000,
  "trailing": "a second complete frame"
 },
 {
  "name": "checksum_good",
  "frame": "checksum_good.zst",
  "command": "zstd -q -c -3 --check A.bin",
  "verdict": "legal",
  "plain": [
   "A.raw.gz"
  ],
  "size": 5000
 },
 {
  "name": "checksum_flipped",
  "frame": "checksum_good.zst",
  "command": "zstd -q -c -3 --check A.bin, then the last checksum byte flipped",
  "verdict": "refused",
  "why": "pyzstd refuses it: ZstdError",
  "derive": "the last checksum byte flipped"
 },
 {
  "name": "checksum_zeroed",
  "frame": "checksum_good.zst",
  "command": "zstd -q -c -3 --check A.bin, then all four checksum bytes zeroed",
  "verdict": "refused",
  "why": "pyzstd refuses it: ZstdError",
  "derive": "all four checksum bytes zeroed"
 },
 {
  "name": "checksum_truncated",
  "frame": "checksum_good.zst",
  "command": "zstd -q -c -3 --check A.bin, then the last two bytes cut",
  "verdict": "refused",
  "why": "pyzstd refuses it: ZstdError",
  "derive": "the last two bytes cut"
 },
 {
  "name": "fcs_max_u64",
  "frame": "fcs_max_u64.zst",
  "command": "python3: pyzstd.compress(b'hello world', 3) with the descriptor rewritten to Frame_Content_Size_flag=3 declaring 18446744073709551615",
  "verdict": "refused",
  "why": "a 27-byte frame asking for a size no allocator will give; pyzstd refuses it: ZstdError"
 },
 {
  "name": "fcs_2p40",
  "frame": "fcs_2p40.zst",
  "command": "python3: pyzstd.compress(b'hello world', 3) with the descriptor rewritten to Frame_Content_Size_flag=3 declaring 1099511627776",
  "verdict": "refused",
  "why": "a 27-byte frame asking for a size no allocator will give; pyzstd refuses it: MemoryError"
 },
 {
  "name": "fcs8",
  "frame": "fcs8.zst",
  "command": "python3: pyzstd.compress(B, 3) with the descriptor rewritten to Frame_Content_Size_flag=3 and an 8-byte size",
  "verdict": "legal",
  "plain": [
   "B.raw.gz"
  ],
  "size": 10000
 },
 {
  "name": "huf_weight_overrun",
  "frame": "huf_weight_overrun.zst",
  "command": "hand-built: a compressed block whose Huffman weight description is [0x10, 0x3F] and whose FSE weight stream is 33 x 0xAA then 0x02",
  "verdict": "refused",
  "why": "the weight stream decodes past the 256th weight; pyzstd refuses it: ZstdError"
 },
 {
  "name": "rlelit_fmt0_R31",
  "frame": "rlelit_fmt0_R31.zst",
  "command": "hand-built: one compressed block, RLE literals Size_Format=0, Regenerated_Size=31, byte 0x5A, Number_of_Sequences=0",
  "verdict": "legal",
  "plain": [
   "rlelit_fmt0_R31.raw.gz"
  ],
  "size": 31
 },
 {
  "name": "rlelit_fmt1_R4000",
  "frame": "rlelit_fmt1_R4000.zst",
  "command": "hand-built: one compressed block, RLE literals Size_Format=1, Regenerated_Size=4000, byte 0x5A, Number_of_Sequences=0",
  "verdict": "legal",
  "plain": [
   "rlelit_fmt1_R4000.raw.gz"
  ],
  "size": 4000
 },
 {
  "name": "rlelit_fmt2_R70000",
  "frame": "rlelit_fmt2_R70000.zst",
  "command": "hand-built: one compressed block, RLE literals Size_Format=2, Regenerated_Size=70000, byte 0x5A, Number_of_Sequences=0",
  "verdict": "legal",
  "plain": [
   "rlelit_fmt2_R70000.raw.gz"
  ],
  "size": 70000
 },
 {
  "name": "rlelit_fmt2_R131072",
  "frame": "rlelit_fmt2_R131072.zst",
  "command": "hand-built: one compressed block, RLE literals Size_Format=2, Regenerated_Size=131072, byte 0x5A, Number_of_Sequences=0",
  "verdict": "legal",
  "plain": [
   "rlelit_fmt2_R131072.raw.gz"
  ],
  "size": 131072
 },
 {
  "name": "mixed_rle_raw",
  "frame": "mixed_rle_raw.zst",
  "command": "hand-built: [RLE 5000 x 0xAB][raw 33 bytes][RLE 40000 x 0x07] in one frame",
  "verdict": "legal",
  "plain": [
   "mixed_rle_raw.raw.gz"
  ],
  "size": 45033
 },
 {
  "name": "nofcs_windowed",
  "frame": "nofcs_windowed.zst",
  "command": "zstd -3 --no-check from stdin over b'the quick brown fox jumps over the lazy dog. ' * 24000",
  "verdict": "legal",
  "plain": [
   "text.raw.gz"
  ],
  "size": 1080000,
  "expectedSize": 1080000
 },
 {
  "name": "direct_nibble",
  "frame": "direct_nibble.zst",
  "command": "block 183 of a Copernicus GLO-30 elevation tile transcoded into a .hgtz container, lifted out as its own frame; its literals carry the direct-nibble Huffman weight form",
  "verdict": "legal",
  "plain": [
   "direct_nibble.raw.gz"
  ],
  "size": 131072,
  "attribution": "Produced using Copernicus WorldDEM-30 \u00a9 DLR e.V. 2010-2014 and \u00a9 Airbus Defence and Space GmbH 2014-2018 provided under COPERNICUS by the European Union and ESA; all rights reserved."
 },
 {
  "name": "dictflag",
  "frame": "dictflag.zst",
  "command": "python3: pyzstd.compress(A, 3) with Dictionary_ID_flag forced to 1 in the frame header descriptor",
  "verdict": "refused",
  "why": "a dictionary this decoder does not have; pyzstd refuses it: ZstdError"
 },
 {
  "name": "rle_over_max",
  "frame": "rle_over_max.zst",
  "command": "hand-built: one last RLE block declaring Block_Size 2,000,000",
  "verdict": "refused",
  "why": "RFC 8878 bounds Block_Size by Block_Maximum_Size, never over 128 KB; libzstd's one-shot decoder accepts it and returns 2 MB"
 },
 {
  "name": "rle_at_max",
  "frame": "rle_at_max.zst",
  "command": "hand-built: one last RLE block at exactly Block_Maximum_Size, 131072",
  "verdict": "legal",
  "plain": [
   "rle_at_max.raw.gz"
  ],
  "size": 131072
 },
 {
  "name": "lit_one_stream",
  "frame": "lit_one_stream.zst",
  "command": "zstd -19 -c --no-check over a file holding b'aaadaabaaaddbbaaacabbada'; from a file rather than stdin so the frame declares its own content size",
  "verdict": "legal",
  "plain": [
   "lit_one_stream.raw.gz"
  ],
  "size": 24
 },
 {
  "name": "multiblock_check",
  "frame": "multiblock_check.zst",
  "command": "python3: pyzstd.compress(body, {level: 9, checksumFlag: 1, targetCBlockSize: 8192}), body = 165,450 bytes of runs",
  "verdict": "legal",
  "plain": [
   "multiblock_check.raw.gz"
  ],
  "size": 165450
 },
 {
  "name": "trailing_junk",
  "frame": "trailing_junk.zst",
  "command": "hand-built: the lit_one_stream frame with four bytes of junk appended",
  "verdict": "refused",
  "why": "reading one frame is the whole API, so input left over after it is input this decoder does not understand; it used to be ignored"
 },
 {
  "name": "trailing_skippable",
  "frame": "trailing_skippable.zst",
  "command": "hand-built: the lit_one_stream frame followed by a skippable frame",
  "verdict": "refused",
  "why": "a trailing skippable frame was accepted and silently ignored; only a leading one was refused, and only because the magic check fired"
 }
]