[FFmpeg-devel] [PATCH 01/10] crc: add AV_CRC_8_SBC as a 8 bits CRC with polynomial 0x1D

Aurelien Jacobs aurel at gnuage.org
Wed Dec 20 21:58:05 EET 2017


---
 libavutil/crc.c       | 26 ++++++++++++++++++++++++++
 libavutil/crc.h       |  1 +
 libavutil/tests/crc.c |  7 ++++---
 3 files changed, 31 insertions(+), 3 deletions(-)

diff --git a/libavutil/crc.c b/libavutil/crc.c
index d44550c9c0..8e44a76ec8 100644
--- a/libavutil/crc.c
+++ b/libavutil/crc.c
@@ -52,6 +52,30 @@ static const AVCRC av_crc_table[AV_CRC_MAX][257] = {
         0xDE, 0xD9, 0xD0, 0xD7, 0xC2, 0xC5, 0xCC, 0xCB, 0xE6, 0xE1, 0xE8, 0xEF,
         0xFA, 0xFD, 0xF4, 0xF3, 0x01
     },
+    [AV_CRC_8_SBC] = {
+        0x00, 0x1D, 0x3A, 0x27, 0x74, 0x69, 0x4E, 0x53, 0xE8, 0xF5, 0xD2, 0xCF,
+        0x9C, 0x81, 0xA6, 0xBB, 0xCD, 0xD0, 0xF7, 0xEA, 0xB9, 0xA4, 0x83, 0x9E,
+        0x25, 0x38, 0x1F, 0x02, 0x51, 0x4C, 0x6B, 0x76, 0x87, 0x9A, 0xBD, 0xA0,
+        0xF3, 0xEE, 0xC9, 0xD4, 0x6F, 0x72, 0x55, 0x48, 0x1B, 0x06, 0x21, 0x3C,
+        0x4A, 0x57, 0x70, 0x6D, 0x3E, 0x23, 0x04, 0x19, 0xA2, 0xBF, 0x98, 0x85,
+        0xD6, 0xCB, 0xEC, 0xF1, 0x13, 0x0E, 0x29, 0x34, 0x67, 0x7A, 0x5D, 0x40,
+        0xFB, 0xE6, 0xC1, 0xDC, 0x8F, 0x92, 0xB5, 0xA8, 0xDE, 0xC3, 0xE4, 0xF9,
+        0xAA, 0xB7, 0x90, 0x8D, 0x36, 0x2B, 0x0C, 0x11, 0x42, 0x5F, 0x78, 0x65,
+        0x94, 0x89, 0xAE, 0xB3, 0xE0, 0xFD, 0xDA, 0xC7, 0x7C, 0x61, 0x46, 0x5B,
+        0x08, 0x15, 0x32, 0x2F, 0x59, 0x44, 0x63, 0x7E, 0x2D, 0x30, 0x17, 0x0A,
+        0xB1, 0xAC, 0x8B, 0x96, 0xC5, 0xD8, 0xFF, 0xE2, 0x26, 0x3B, 0x1C, 0x01,
+        0x52, 0x4F, 0x68, 0x75, 0xCE, 0xD3, 0xF4, 0xE9, 0xBA, 0xA7, 0x80, 0x9D,
+        0xEB, 0xF6, 0xD1, 0xCC, 0x9F, 0x82, 0xA5, 0xB8, 0x03, 0x1E, 0x39, 0x24,
+        0x77, 0x6A, 0x4D, 0x50, 0xA1, 0xBC, 0x9B, 0x86, 0xD5, 0xC8, 0xEF, 0xF2,
+        0x49, 0x54, 0x73, 0x6E, 0x3D, 0x20, 0x07, 0x1A, 0x6C, 0x71, 0x56, 0x4B,
+        0x18, 0x05, 0x22, 0x3F, 0x84, 0x99, 0xBE, 0xA3, 0xF0, 0xED, 0xCA, 0xD7,
+        0x35, 0x28, 0x0F, 0x12, 0x41, 0x5C, 0x7B, 0x66, 0xDD, 0xC0, 0xE7, 0xFA,
+        0xA9, 0xB4, 0x93, 0x8E, 0xF8, 0xE5, 0xC2, 0xDF, 0x8C, 0x91, 0xB6, 0xAB,
+        0x10, 0x0D, 0x2A, 0x37, 0x64, 0x79, 0x5E, 0x43, 0xB2, 0xAF, 0x88, 0x95,
+        0xC6, 0xDB, 0xFC, 0xE1, 0x5A, 0x47, 0x60, 0x7D, 0x2E, 0x33, 0x14, 0x09,
+        0x7F, 0x62, 0x45, 0x58, 0x0B, 0x16, 0x31, 0x2C, 0x97, 0x8A, 0xAD, 0xB0,
+        0xE3, 0xFE, 0xD9, 0xC4, 0x01
+    },
     [AV_CRC_16_ANSI] = {
         0x0000, 0x0580, 0x0F80, 0x0A00, 0x1B80, 0x1E00, 0x1400, 0x1180,
         0x3380, 0x3600, 0x3C00, 0x3980, 0x2800, 0x2D80, 0x2780, 0x2200,
@@ -305,6 +329,7 @@ static void id ## _init_table_once(void)
 #define CRC_INIT_TABLE_ONCE(id) ff_thread_once(&id ## _once_control, id ## _init_table_once)
 
 DECLARE_CRC_INIT_TABLE_ONCE(AV_CRC_8_ATM,      0,  8,       0x07)
+DECLARE_CRC_INIT_TABLE_ONCE(AV_CRC_8_SBC,      0,  8,       0x1D)
 DECLARE_CRC_INIT_TABLE_ONCE(AV_CRC_16_ANSI,    0, 16,     0x8005)
 DECLARE_CRC_INIT_TABLE_ONCE(AV_CRC_16_CCITT,   0, 16,     0x1021)
 DECLARE_CRC_INIT_TABLE_ONCE(AV_CRC_24_IEEE,    0, 24,   0x864CFB)
@@ -351,6 +376,7 @@ const AVCRC *av_crc_get_table(AVCRCId crc_id)
 #if !CONFIG_HARDCODED_TABLES
     switch (crc_id) {
     case AV_CRC_8_ATM:      CRC_INIT_TABLE_ONCE(AV_CRC_8_ATM); break;
+    case AV_CRC_8_SBC:      CRC_INIT_TABLE_ONCE(AV_CRC_8_SBC); break;
     case AV_CRC_16_ANSI:    CRC_INIT_TABLE_ONCE(AV_CRC_16_ANSI); break;
     case AV_CRC_16_CCITT:   CRC_INIT_TABLE_ONCE(AV_CRC_16_CCITT); break;
     case AV_CRC_24_IEEE:    CRC_INIT_TABLE_ONCE(AV_CRC_24_IEEE); break;
diff --git a/libavutil/crc.h b/libavutil/crc.h
index fe9a7c8fcb..e57a1af903 100644
--- a/libavutil/crc.h
+++ b/libavutil/crc.h
@@ -54,6 +54,7 @@ typedef enum {
     AV_CRC_32_IEEE_LE,  /*< reversed bitorder version of AV_CRC_32_IEEE */
     AV_CRC_16_ANSI_LE,  /*< reversed bitorder version of AV_CRC_16_ANSI */
     AV_CRC_24_IEEE,
+    AV_CRC_8_SBC,
     AV_CRC_MAX,         /*< Not part of public API! Do not use outside libavutil. */
 }AVCRCId;
 
diff --git a/libavutil/tests/crc.c b/libavutil/tests/crc.c
index 9825d6bec9..3fdc335cc3 100644
--- a/libavutil/tests/crc.c
+++ b/libavutil/tests/crc.c
@@ -25,20 +25,21 @@ int main(void)
 {
     uint8_t buf[1999];
     int i;
-    static const unsigned p[6][3] = {
+    static const unsigned p[7][3] = {
         { AV_CRC_32_IEEE_LE, 0xEDB88320, 0x3D5CDD04 },
         { AV_CRC_32_IEEE   , 0x04C11DB7, 0xC0F5BAE0 },
         { AV_CRC_24_IEEE   , 0x864CFB  , 0xB704CE   },
         { AV_CRC_16_ANSI_LE, 0xA001    , 0xBFD8     },
         { AV_CRC_16_ANSI   , 0x8005    , 0x1FBB     },
-        { AV_CRC_8_ATM     , 0x07      , 0xE3       }
+        { AV_CRC_8_ATM     , 0x07      , 0xE3       },
+        { AV_CRC_8_SBC     , 0x1D      , 0xD6       },
     };
     const AVCRC *ctx;
 
     for (i = 0; i < sizeof(buf); i++)
         buf[i] = i + i * i;
 
-    for (i = 0; i < 6; i++) {
+    for (i = 0; i < 7; i++) {
         ctx = av_crc_get_table(p[i][0]);
         printf("crc %08X = %X\n", p[i][1], av_crc(ctx, 0, buf, sizeof(buf)));
     }
-- 
2.15.1



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