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-rw-r--r--kopete/protocols/msn/webcam/libmimic/bitstring.c88
1 files changed, 88 insertions, 0 deletions
diff --git a/kopete/protocols/msn/webcam/libmimic/bitstring.c b/kopete/protocols/msn/webcam/libmimic/bitstring.c
new file mode 100644
index 00000000..2aef7284
--- /dev/null
+++ b/kopete/protocols/msn/webcam/libmimic/bitstring.c
@@ -0,0 +1,88 @@
+/* Copyright (C) 2005 Ole André Vadla Ravnås <oleavr@gmail.com>
+ *
+ * This library 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.
+ *
+ * This library 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 this library; if not, write to the Free Software
+ * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ */
+
+#include "mimic-private.h"
+
+/*
+ * _read_bits
+ *
+ * Internal helper-function used to read num_bits
+ * from stream.
+ */
+guint32 _read_bits(MimCtx *ctx, gint num_bits)
+{
+ guint32 bits;
+
+ if (ctx->cur_chunk_len >= 16) {
+ guchar *input_buf = (guchar *) ctx->data_buffer + ctx->data_index;
+
+ if (!ctx->read_odd) {
+ ctx->read_odd = TRUE;
+
+ ctx->cur_chunk = (input_buf[3] << 24) |
+ (input_buf[2] << 16) |
+ (input_buf[1] << 8) |
+ input_buf[0];
+
+ } else {
+ ctx->read_odd = FALSE;
+
+ ctx->cur_chunk = (input_buf[1] << 24) |
+ (input_buf[0] << 16) |
+ (input_buf[7] << 8) |
+ input_buf[6];
+
+ ctx->data_index += 4;
+ }
+
+ ctx->cur_chunk_len -= 16;
+ }
+
+ bits = (ctx->cur_chunk << ctx->cur_chunk_len) >> (32 - num_bits);
+ ctx->cur_chunk_len += num_bits;
+
+ return bits;
+}
+
+/*
+ * _write_bits
+ *
+ * Internal helper-function used to write "length"
+ * bits of "bits" to stream.
+ */
+void _write_bits(MimCtx *ctx, guint32 bits, gint length)
+{
+ /* Left-align the bit string within its 32-bit container. */
+ bits <<= (32 - length);
+
+ /* Append the bit string (one or more of the trailing bits might not fit, but that's ok). */
+ ctx->cur_chunk |= bits >> ctx->cur_chunk_len;
+ ctx->cur_chunk_len += length;
+
+ /* Is it full? */
+ if (ctx->cur_chunk_len >= 32) {
+
+ /* Add the full 32-bit chunk to the stream and update counter. */
+ ctx->chunk_ptr[0] = GUINT32_TO_LE(ctx->cur_chunk);
+ ctx->chunk_ptr++;
+ ctx->cur_chunk_len -= 32;
+
+ /* Add any trailing bits that didn't fit. */
+ ctx->cur_chunk = bits << (length - ctx->cur_chunk_len);
+ }
+}
+