cosmetics: Write NULL pointer equality checks more compactly

[ffmpeg] / libavutil / rc4.h

diff --git a/libavutil/rc4.h b/libavutil/rc4.h
index d3b8e6cb81814ea8d595aa21f1c60ad92ee81bfa..ec3b47cc8a82b57534caa480b990d1ec59d110a9 100644 (file)
--- a/libavutil/rc4.h
+++ b/libavutil/rc4.h
@@ -1,26 +1,50 @@
 /*
  * RC4 encryption/decryption/pseudo-random number generator
  *
- * 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
  */
 
-#ifndef RC4_H
-#define RC4_H
+#ifndef AVUTIL_RC4_H
+#define AVUTIL_RC4_H
 
-void ff_rc4_enc(const uint8_t *key, int keylen, uint8_t *data, int datalen);
+#include <stdint.h>
 
-#endif /* RC4_H */
+struct AVRC4 {
+    uint8_t state[256];
+    int x, y;
+};
+
+/**
+ * @brief Initializes an AVRC4 context.
+ *
+ * @param key_bits must be a multiple of 8
+ * @param decrypt 0 for encryption, 1 for decryption, currently has no effect
+ */
+int av_rc4_init(struct AVRC4 *d, const uint8_t *key, int key_bits, int decrypt);
+
+/**
+ * @brief Encrypts / decrypts using the RC4 algorithm.
+ *
+ * @param count number of bytes
+ * @param dst destination array, can be equal to src
+ * @param src source array, can be equal to dst, may be NULL
+ * @param iv not (yet) used for RC4, should be NULL
+ * @param decrypt 0 for encryption, 1 for decryption, not (yet) used
+ */
+void av_rc4_crypt(struct AVRC4 *d, uint8_t *dst, const uint8_t *src, int count, uint8_t *iv, int decrypt);
+
+#endif /* AVUTIL_RC4_H */