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>

Changelog

@@ -37,6 +37,7 @@ version <next>:
 - Hap decoder and encoder
 - DirectDraw Surface image/texture decoder
 - rewritten ASF demuxer
+- Go2Meeting decoding support
 
 
 version 11:

doc/general.texi

@@ -607,6 +607,8 @@ following image formats are supported:
     @tab Sorenson H.263 used in Flash
 @item Forward Uncompressed   @tab     @tab  X
 @item Fraps                  @tab     @tab  X
+@item Go2Meeting             @tab     @tab  X
+    @tab fourcc: G2M2, G2M3
 @item Go2Webinar             @tab     @tab  X
     @tab fourcc: G2M4
 @item H.261                  @tab  X  @tab  X

libavcodec/Makefile

@@ -214,7 +214,7 @@ OBJS-$(CONFIG_FLIC_DECODER)            += flicvideo.o
 OBJS-$(CONFIG_FOURXM_DECODER)          += 4xm.o
 OBJS-$(CONFIG_FRAPS_DECODER)           += fraps.o
 OBJS-$(CONFIG_FRWU_DECODER)            += frwu.o
-OBJS-$(CONFIG_G2M_DECODER)             += g2meet.o
+OBJS-$(CONFIG_G2M_DECODER)             += g2meet.o elsdec.o
 OBJS-$(CONFIG_G723_1_DECODER)          += g723_1.o acelp_vectors.o \
                                           celp_filters.o
 OBJS-$(CONFIG_GIF_DECODER)             += gifdec.o lzw.o

libavcodec/elsdec.h

+/*
+ * 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 */

libavcodec/version.h

@@ -29,8 +29,8 @@
 #include "libavutil/version.h"
 
 #define LIBAVCODEC_VERSION_MAJOR 56
-#define LIBAVCODEC_VERSION_MINOR 29
-#define LIBAVCODEC_VERSION_MICRO  1
+#define LIBAVCODEC_VERSION_MINOR 31
+#define LIBAVCODEC_VERSION_MICRO  0
 
 #define LIBAVCODEC_VERSION_INT  AV_VERSION_INT(LIBAVCODEC_VERSION_MAJOR, \
                                                LIBAVCODEC_VERSION_MINOR, \