Add compression version to the encoded FP

acoustid · Apr 11, 2024 · 85f332b · 85f332b
1 parent ab8a125
commit 85f332b
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Showing 3 changed files with 27 additions and 13 deletions.
diff --git a/src/chromaprint.cpp b/src/chromaprint.cpp
@@ -209,17 +209,19 @@ int chromaprint_decode_fingerprint(const char *encoded_fp, int encoded_size, uin
 	if (base64) {
 		encoded = Base64Decode(encoded);
 	}
-	std::vector<uint32_t> uncompressed;
 	int algo;
-	auto ok = DecompressFingerprint(encoded, uncompressed, algo);
-	if (!ok) {
-		*fp = nullptr;
-		*size = 0;
-		if (algorithm) {
-			*algorithm = 0;
-		}
-		return 0;
-	}
+	auto uncompressed = DecompressFingerprintV2(encoded, algo);
+        if (uncompressed.empty()) {
+                auto ok = DecompressFingerprint(encoded, uncompressed, algo);
+                if (!ok) {
+                        *fp = nullptr;
+                        *size = 0;
+                        if (algorithm) {
+                                *algorithm = 0;
+                        }
+                        return 0;
+                }
+        }
 	*fp = (uint32_t *) malloc(sizeof(uint32_t) * uncompressed.size());
 	*size = int(uncompressed.size());
 	if (algorithm) {

diff --git a/src/fingerprint_compressor_v2.cpp b/src/fingerprint_compressor_v2.cpp
@@ -34,7 +34,9 @@ bool CompressFingerprintV2(const std::vector<uint32_t> &hashes, int algorithm, s
 
     compressed.resize(compressed_size + 4);
 
-    compressed[0] = algorithm;
+    int compression_version = 1;
+
+    compressed[0] = (compression_version & 0x3) << 6 | (algorithm & 0x3f);
     compressed[1] = num_hashes >> 16;
     compressed[2] = num_hashes >> 8;
     compressed[3] = num_hashes;
@@ -48,7 +50,12 @@ std::vector<uint32_t> DecompressFingerprintV2(const std::string &data, int &algo
         return std::vector<uint32_t>();
     }
 
-    algorithm = data[0];
+    int compression_version = (data[0] >> 6) & 0x3;
+    if (compression_version != 1) {
+        return std::vector<uint32_t>();
+    }
+
+    algorithm = data[0] & 0x3f;
     size_t num_hashes = (data[1] << 16) | (data[2] << 8) | data[3];
 
     std::string packed;

diff --git a/src/fingerprint_decompressor.cpp b/src/fingerprint_decompressor.cpp
@@ -44,7 +44,12 @@ bool FingerprintDecompressor::Decompress(const std::string &input)
 		return false;
 	}
 
-	m_algorithm = input[0];
+        int compression_version = (input[0] >> 6) & 0x3;
+        if (compression_version != 0) {
+		return false;
+        }
+
+        m_algorithm = input[0] & 0x3f;
 
 	const size_t num_values =
 		((size_t)((unsigned char)(input[1])) << 16) |