lavc: restore copy_block{4,16} functions

[ffmpeg] / libavutil / crc.h

diff --git a/libavutil/crc.h b/libavutil/crc.h
index 6c0baab5ac953019ba0aa4ed00c50a9060e757b1..0540619d20f2a8841daa43b74c5a02a9a2cf990b 100644 (file)
--- a/libavutil/crc.h
+++ b/libavutil/crc.h
@@ -1,20 +1,20 @@
 /*
  * copyright (c) 2006 Michael Niedermayer <michaelni@gmx.at>
  *
- * This file is part of FFmpeg.
+ * This file is part of Libav.
  *
- * FFmpeg is free software; you can redistribute it and/or
+ * Libav 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,
+ * Libav 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
+ * License along with Libav; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
@@ -36,9 +36,39 @@ typedef enum {
     AV_CRC_MAX,         /*< Not part of public API! Do not use outside libavutil. */
 }AVCRCId;
 
+/**
+ * Initialize a CRC table.
+ * @param ctx must be an array of size sizeof(AVCRC)*257 or sizeof(AVCRC)*1024
+ * @param le If 1, the lowest bit represents the coefficient for the highest
+ *           exponent of the corresponding polynomial (both for poly and
+ *           actual CRC).
+ *           If 0, you must swap the CRC parameter and the result of av_crc
+ *           if you need the standard representation (can be simplified in
+ *           most cases to e.g. bswap16):
+ *           av_bswap32(crc << (32-bits))
+ * @param bits number of bits for the CRC
+ * @param poly generator polynomial without the x**bits coefficient, in the
+ *             representation as specified by le
+ * @param ctx_size size of ctx in bytes
+ * @return <0 on failure
+ */
 int av_crc_init(AVCRC *ctx, int le, int bits, uint32_t poly, int ctx_size);
+
+/**
+ * Get an initialized standard CRC table.
+ * @param crc_id ID of a standard CRC
+ * @return a pointer to the CRC table or NULL on failure
+ */
 const AVCRC *av_crc_get_table(AVCRCId crc_id);
-uint32_t av_crc(const AVCRC *ctx, uint32_t start_crc, const uint8_t *buffer, size_t length) av_pure;
 
-#endif /* AVUTIL_CRC_H */
+/**
+ * Calculate the CRC of a block.
+ * @param crc CRC of previous blocks if any or initial value for CRC
+ * @return CRC updated with the data from the given block
+ *
+ * @see av_crc_init() "le" parameter
+ */
+uint32_t av_crc(const AVCRC *ctx, uint32_t crc,
+                const uint8_t *buffer, size_t length) av_pure;
 
+#endif /* AVUTIL_CRC_H */