Go2Meeting decoder

ELS and ePIC decoder courtesy of Maxim Poliakovski,
cleanup and integration by Diego Biurrun.

Signed-off-by: Diego Biurrun <diego@biurrun.de>
Signed-off-by: Luca Barbato <lu_zero@gentoo.org>

1 files changed, 60 insertions, 0 deletions

diff --git a/libavcodec/elsdec.h b/libavcodec/elsdec.h
new file mode 100644
index 0000000000..515b49aa71
--- /dev/null
+++ b/libavcodec/elsdec.h
@@ -0,0 +1,60 @@
+/*
+ * ELS (Entropy Logarithmic-Scale) decoder
+ *
+ * Copyright (c) 2013 Maxim Poliakovski
+ *
+ * This file is part of Libav.
+ *
+ * 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.
+ *
+ * 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 Libav; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+ */
+
+/**
+ * @file
+ * Entropy Logarithmic-Scale binary arithmetic coder
+ */
+
+#ifndef AVCODEC_ELSDEC_H
+#define AVCODEC_ELSDEC_H
+
+#include <stdint.h>
+#include <sys/types.h>
+
+#define ELS_EXPGOLOMB_LEN   10
+
+typedef struct ElsDecCtx {
+    const uint8_t *in_buf;
+    unsigned x;
+    size_t data_size;
+    int j, t, diff, err;
+} ElsDecCtx;
+
+typedef struct ElsRungNode {
+    uint8_t  rung;
+    uint16_t next_index;
+} ElsRungNode;
+
+typedef struct ElsUnsignedRung {
+    uint8_t      prefix_rung[ELS_EXPGOLOMB_LEN + 1];
+    ElsRungNode  *rem_rung_list;
+    size_t       rung_list_size;
+    uint16_t     avail_index;
+} ElsUnsignedRung;
+
+void ff_els_decoder_init(ElsDecCtx *ctx, const uint8_t *in, size_t data_size);
+void ff_els_decoder_uninit(ElsUnsignedRung *rung);
+int  ff_els_decode_bit(ElsDecCtx *ctx, unsigned char *rung);
+unsigned ff_els_decode_unsigned(ElsDecCtx *ctx, ElsUnsignedRung *ur);
+
+#endif /* AVCODEC_ELSDEC_H */