[FFmpeg-devel] [PATCH 4/4] libavcodec/svq: Remove ff_svq1_packet_checksum()

Michael Niedermayer michael at niedermayer.cc
Wed Feb 19 01:59:19 EET 2020


Signed-off-by: Michael Niedermayer <michael at niedermayer.cc>
---
 libavcodec/Makefile  |  4 +--
 libavcodec/svq1.h    |  3 --
 libavcodec/svq13.c   | 69 --------------------------------------------
 libavcodec/svq1dec.c |  6 ++--
 libavcodec/svq3.c    |  5 +++-
 5 files changed, 9 insertions(+), 78 deletions(-)
 delete mode 100644 libavcodec/svq13.c

diff --git a/libavcodec/Makefile b/libavcodec/Makefile
index 46da42570f..71eeb60901 100644
--- a/libavcodec/Makefile
+++ b/libavcodec/Makefile
@@ -610,10 +610,10 @@ OBJS-$(CONFIG_SUNRAST_ENCODER)         += sunrastenc.o
 OBJS-$(CONFIG_LIBRSVG_DECODER)         += librsvgdec.o
 OBJS-$(CONFIG_SBC_DECODER)             += sbcdec.o sbcdec_data.o sbc.o
 OBJS-$(CONFIG_SBC_ENCODER)             += sbcenc.o sbc.o sbcdsp.o sbcdsp_data.o
-OBJS-$(CONFIG_SVQ1_DECODER)            += svq1dec.o svq1.o svq13.o h263data.o
+OBJS-$(CONFIG_SVQ1_DECODER)            += svq1dec.o svq1.o h263data.o
 OBJS-$(CONFIG_SVQ1_ENCODER)            += svq1enc.o svq1.o  h263data.o  \
                                           h263.o ituh263enc.o
-OBJS-$(CONFIG_SVQ3_DECODER)            += svq3.o svq13.o mpegutils.o h264data.o
+OBJS-$(CONFIG_SVQ3_DECODER)            += svq3.o mpegutils.o h264data.o
 OBJS-$(CONFIG_TEXT_DECODER)            += textdec.o ass.o
 OBJS-$(CONFIG_TEXT_ENCODER)            += srtenc.o ass_split.o
 OBJS-$(CONFIG_TAK_DECODER)             += takdec.o tak.o takdsp.o
diff --git a/libavcodec/svq1.h b/libavcodec/svq1.h
index 63c0479329..0ebc73a933 100644
--- a/libavcodec/svq1.h
+++ b/libavcodec/svq1.h
@@ -42,9 +42,6 @@
 #define SVQ1_BLOCK_INTER_4V     2
 #define SVQ1_BLOCK_INTRA        3
 
-uint16_t ff_svq1_packet_checksum(const uint8_t *data,
-                                 const int length, int value);
-
 extern const int8_t *const ff_svq1_inter_codebooks[6];
 extern const int8_t *const ff_svq1_intra_codebooks[6];
 
diff --git a/libavcodec/svq13.c b/libavcodec/svq13.c
deleted file mode 100644
index b821a446d6..0000000000
--- a/libavcodec/svq13.c
+++ /dev/null
@@ -1,69 +0,0 @@
-/*
- * SVQ1/SVQ3 decoder common code
- *
- * This file is part of FFmpeg.
- *
- * FFmpeg is free software; you can redistribute it and/or
- * modify it under the terms of the GNU Lesser General Public
- * License as published by the Free Software Foundation; either
- * version 2.1 of the License, or (at your option) any later version.
- *
- * FFmpeg is distributed in the hope that it will be useful,
- * but WITHOUT ANY WARRANTY; without even the implied warranty of
- * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
- * Lesser General Public License for more details.
- *
- * You should have received a copy of the GNU Lesser General Public
- * License along with FFmpeg; if not, write to the Free Software
- * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
- */
-
-#include <stdint.h>
-
-#include "svq1.h"
-
-static const uint16_t checksum_table[256] = {
-    0x0000, 0x1021, 0x2042, 0x3063, 0x4084, 0x50A5, 0x60C6, 0x70E7,
-    0x8108, 0x9129, 0xA14A, 0xB16B, 0xC18C, 0xD1AD, 0xE1CE, 0xF1EF,
-    0x1231, 0x0210, 0x3273, 0x2252, 0x52B5, 0x4294, 0x72F7, 0x62D6,
-    0x9339, 0x8318, 0xB37B, 0xA35A, 0xD3BD, 0xC39C, 0xF3FF, 0xE3DE,
-    0x2462, 0x3443, 0x0420, 0x1401, 0x64E6, 0x74C7, 0x44A4, 0x5485,
-    0xA56A, 0xB54B, 0x8528, 0x9509, 0xE5EE, 0xF5CF, 0xC5AC, 0xD58D,
-    0x3653, 0x2672, 0x1611, 0x0630, 0x76D7, 0x66F6, 0x5695, 0x46B4,
-    0xB75B, 0xA77A, 0x9719, 0x8738, 0xF7DF, 0xE7FE, 0xD79D, 0xC7BC,
-    0x48C4, 0x58E5, 0x6886, 0x78A7, 0x0840, 0x1861, 0x2802, 0x3823,
-    0xC9CC, 0xD9ED, 0xE98E, 0xF9AF, 0x8948, 0x9969, 0xA90A, 0xB92B,
-    0x5AF5, 0x4AD4, 0x7AB7, 0x6A96, 0x1A71, 0x0A50, 0x3A33, 0x2A12,
-    0xDBFD, 0xCBDC, 0xFBBF, 0xEB9E, 0x9B79, 0x8B58, 0xBB3B, 0xAB1A,
-    0x6CA6, 0x7C87, 0x4CE4, 0x5CC5, 0x2C22, 0x3C03, 0x0C60, 0x1C41,
-    0xEDAE, 0xFD8F, 0xCDEC, 0xDDCD, 0xAD2A, 0xBD0B, 0x8D68, 0x9D49,
-    0x7E97, 0x6EB6, 0x5ED5, 0x4EF4, 0x3E13, 0x2E32, 0x1E51, 0x0E70,
-    0xFF9F, 0xEFBE, 0xDFDD, 0xCFFC, 0xBF1B, 0xAF3A, 0x9F59, 0x8F78,
-    0x9188, 0x81A9, 0xB1CA, 0xA1EB, 0xD10C, 0xC12D, 0xF14E, 0xE16F,
-    0x1080, 0x00A1, 0x30C2, 0x20E3, 0x5004, 0x4025, 0x7046, 0x6067,
-    0x83B9, 0x9398, 0xA3FB, 0xB3DA, 0xC33D, 0xD31C, 0xE37F, 0xF35E,
-    0x02B1, 0x1290, 0x22F3, 0x32D2, 0x4235, 0x5214, 0x6277, 0x7256,
-    0xB5EA, 0xA5CB, 0x95A8, 0x8589, 0xF56E, 0xE54F, 0xD52C, 0xC50D,
-    0x34E2, 0x24C3, 0x14A0, 0x0481, 0x7466, 0x6447, 0x5424, 0x4405,
-    0xA7DB, 0xB7FA, 0x8799, 0x97B8, 0xE75F, 0xF77E, 0xC71D, 0xD73C,
-    0x26D3, 0x36F2, 0x0691, 0x16B0, 0x6657, 0x7676, 0x4615, 0x5634,
-    0xD94C, 0xC96D, 0xF90E, 0xE92F, 0x99C8, 0x89E9, 0xB98A, 0xA9AB,
-    0x5844, 0x4865, 0x7806, 0x6827, 0x18C0, 0x08E1, 0x3882, 0x28A3,
-    0xCB7D, 0xDB5C, 0xEB3F, 0xFB1E, 0x8BF9, 0x9BD8, 0xABBB, 0xBB9A,
-    0x4A75, 0x5A54, 0x6A37, 0x7A16, 0x0AF1, 0x1AD0, 0x2AB3, 0x3A92,
-    0xFD2E, 0xED0F, 0xDD6C, 0xCD4D, 0xBDAA, 0xAD8B, 0x9DE8, 0x8DC9,
-    0x7C26, 0x6C07, 0x5C64, 0x4C45, 0x3CA2, 0x2C83, 0x1CE0, 0x0CC1,
-    0xEF1F, 0xFF3E, 0xCF5D, 0xDF7C, 0xAF9B, 0xBFBA, 0x8FD9, 0x9FF8,
-    0x6E17, 0x7E36, 0x4E55, 0x5E74, 0x2E93, 0x3EB2, 0x0ED1, 0x1EF0
-};
-
-uint16_t ff_svq1_packet_checksum (const uint8_t *data,
-                                  const int length, int value)
-{
-    int i;
-
-    for (i = 0; i < length; i++)
-        value = checksum_table[data[i] ^ (value >> 8)] ^ ((value & 0xFF) << 8);
-
-    return value;
-}
diff --git a/libavcodec/svq1dec.c b/libavcodec/svq1dec.c
index b61ae348d2..25bd3d0253 100644
--- a/libavcodec/svq1dec.c
+++ b/libavcodec/svq1dec.c
@@ -32,6 +32,8 @@
  *   http://www.pcisys.net/~melanson/codecs/
  */
 
+#include "libavutil/crc.h"
+
 #include "avcodec.h"
 #include "get_bits.h"
 #include "h263.h"
@@ -546,9 +548,7 @@ static int svq1_decode_frame_header(AVCodecContext *avctx, AVFrame *frame)
         if (s->frame_code == 0x50 || s->frame_code == 0x60) {
             int csum = get_bits(bitbuf, 16);
 
-            csum = ff_svq1_packet_checksum(bitbuf->buffer,
-                                           bitbuf->size_in_bits >> 3,
-                                           csum);
+            csum = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_CCITT), av_bswap16(csum), bitbuf->buffer, bitbuf->size_in_bits >> 3));
 
             ff_dlog(avctx, "%s checksum (%02x) for packet data\n",
                     (csum == 0) ? "correct" : "incorrect", csum);
diff --git a/libavcodec/svq3.c b/libavcodec/svq3.c
index 9cea9ac840..c8db08a32f 100644
--- a/libavcodec/svq3.c
+++ b/libavcodec/svq3.c
@@ -43,6 +43,8 @@
 #include <inttypes.h>
 
 #include "libavutil/attributes.h"
+#include "libavutil/crc.h"
+
 #include "internal.h"
 #include "avcodec.h"
 #include "mpegutils.h"
@@ -1293,7 +1295,8 @@ static av_cold int svq3_decode_init(AVCodecContext *avctx)
                 ret = -1;
                 goto fail;
             }
-            s->watermark_key = ff_svq1_packet_checksum(buf, buf_len, 0);
+            s->watermark_key = av_bswap16(av_crc(av_crc_get_table(AV_CRC_16_CCITT), 0, buf, buf_len));
+
             s->watermark_key = s->watermark_key << 16 | s->watermark_key;
             av_log(avctx, AV_LOG_DEBUG,
                    "watermark key %#"PRIx32"\n", s->watermark_key);
-- 
2.17.1



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