On 12/23/2017 3:01 PM, Aurelien Jacobs wrote:
> ---
> libavutil/crc.c | 26 ++++++++++++++++++++++++++
> libavutil/crc.h | 1 +
> libavutil/tests/crc.c | 7 ++++---
> tests/ref/fate/crc | 1 +
> 4 files changed, 32 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)
The polynomial 0x1D seems to be used in a couple standards, including
one defined by the European Broadcasting Union, so instead of _SBC which
is a codec using the CRC, I'd use _EBU for the enum constant.
This is public API, so once introduced it can't easily be changed.
> 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)));
> }
> diff --git a/tests/ref/fate/crc b/tests/ref/fate/crc
> index 8aa0dd2448..7b59a3cc07 100644
> --- a/tests/ref/fate/crc
> +++ b/tests/ref/fate/crc
> @@ -4,3 +4,4 @@ crc 00864CFB = 326039
> crc 0000A001 = BFD8
> crc 00008005 = BB1F
> crc 00000007 = E3
> +crc 0000001D = D6
>
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