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-rw-r--r--libavcodec/startcode.c57
1 files changed, 57 insertions, 0 deletions
diff --git a/libavcodec/startcode.c b/libavcodec/startcode.c
new file mode 100644
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--- /dev/null
+++ b/libavcodec/startcode.c
@@ -0,0 +1,57 @@
+/*
+ * Copyright (c) 2003-2010 Michael Niedermayer <michaelni@gmx.at>
+ *
+ * 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
+ */
+
+/**
+ * @file
+ * Accelerated start code search function for start codes common to
+ * MPEG-1/2/4 video, VC-1, H.264/5
+ * @author Michael Niedermayer <michaelni@gmx.at>
+ */
+
+#include "startcode.h"
+#include "config.h"
+
+int ff_startcode_find_candidate_c(const uint8_t *buf, int size)
+{
+ int i = 0;
+#if HAVE_FAST_UNALIGNED
+ /* we check i < size instead of i + 3 / 7 because it is
+ * simpler and there must be FF_INPUT_BUFFER_PADDING_SIZE
+ * bytes at the end.
+ */
+# if HAVE_FAST_64BIT
+ while (i < size &&
+ !((~*(const uint64_t *)(buf + i) &
+ (*(const uint64_t *)(buf + i) - 0x0101010101010101ULL)) &
+ 0x8080808080808080ULL))
+ i += 8;
+# else
+ while (i < size &&
+ !((~*(const uint32_t *)(buf + i) &
+ (*(const uint32_t *)(buf + i) - 0x01010101U)) &
+ 0x80808080U))
+ i += 4;
+# endif
+#endif
+ for (; i < size; i++)
+ if (!buf[i])
+ break;
+ return i;
+}