1 files changed, 149 insertions, 0 deletions

diff --git a/xbmc/utils/VC1BitstreamParser.cpp b/xbmc/utils/VC1BitstreamParser.cpp
new file mode 100644
index 0000000..8ac1b6e
--- /dev/null
+++ b/xbmc/utils/VC1BitstreamParser.cpp
@@ -0,0 +1,149 @@
+/*
+ *  Copyright (C) 2017-2018 Team Kodi
+ *  This file is part of Kodi - https://kodi.tv
+ *
+ *  SPDX-License-Identifier: GPL-2.0-or-later
+ *  See LICENSES/README.md for more information.
+ */
+
+#include "VC1BitstreamParser.h"
+
+#include "BitstreamReader.h"
+
+enum
+{
+  VC1_PROFILE_SIMPLE,
+  VC1_PROFILE_MAIN,
+  VC1_PROFILE_RESERVED,
+  VC1_PROFILE_ADVANCED,
+  VC1_PROFILE_NOPROFILE
+};
+
+enum
+{
+  VC1_END_OF_SEQ = 0x0A,
+  VC1_SLICE = 0x0B,
+  VC1_FIELD = 0x0C,
+  VC1_FRAME = 0x0D,
+  VC1_ENTRYPOINT = 0x0E,
+  VC1_SEQUENCE = 0x0F,
+  VC1_SLICE_USER = 0x1B,
+  VC1_FIELD_USER = 0x1C,
+  VC1_FRAME_USER = 0x1D,
+  VC1_ENTRY_POINT_USER = 0x1E,
+  VC1_SEQUENCE_USER = 0x1F
+};
+
+enum
+{
+  VC1_FRAME_PROGRESSIVE = 0x0,
+  VC1_FRAME_INTERLACE = 0x10,
+  VC1_FIELD_INTERLACE = 0x11
+};
+
+CVC1BitstreamParser::CVC1BitstreamParser()
+{
+  Reset();
+}
+
+void CVC1BitstreamParser::Reset()
+{
+  m_Profile = VC1_PROFILE_NOPROFILE;
+}
+
+bool CVC1BitstreamParser::IsRecoveryPoint(const uint8_t *buf, int buf_size)
+{
+  return vc1_parse_frame(buf, buf + buf_size, true);
+};
+
+bool CVC1BitstreamParser::IsIFrame(const uint8_t *buf, int buf_size)
+{
+  return vc1_parse_frame(buf, buf + buf_size, false);
+};
+
+bool CVC1BitstreamParser::vc1_parse_frame(const uint8_t *buf, const uint8_t *buf_end, bool sequence_only)
+{
+  uint32_t state = -1;
+  for (;;)
+  {
+    buf = find_start_code(buf, buf_end, &state);
+    if (buf >= buf_end)
+      break;
+    if (buf[-1] == VC1_SEQUENCE)
+    {
+      if (m_Profile != VC1_PROFILE_NOPROFILE)
+        return false;
+      CBitstreamReader br(buf, buf_end - buf);
+      // Read the profile
+      m_Profile = static_cast<uint8_t>(br.ReadBits(2));
+      if (m_Profile == VC1_PROFILE_ADVANCED)
+      {
+        br.SkipBits(39);
+        m_AdvInterlace = br.ReadBits(1);
+      }
+      else
+      {
+        br.SkipBits(22);
+
+        m_SimpleSkipBits = 2;
+        if (br.ReadBits(1)) //rangered
+          ++m_SimpleSkipBits;
+
+        m_MaxBFrames = br.ReadBits(3);
+
+        br.SkipBits(2); // quantizer
+        if (br.ReadBits(1)) //finterpflag
+          ++m_SimpleSkipBits;
+      }
+      if (sequence_only)
+        return true;
+    }
+    else if (buf[-1] == VC1_FRAME)
+    {
+      CBitstreamReader br(buf, buf_end - buf);
+
+      if (sequence_only)
+        return false;
+      if (m_Profile == VC1_PROFILE_ADVANCED)
+      {
+        uint8_t fcm;
+        if (m_AdvInterlace) {
+          fcm = br.ReadBits(1);
+          if (fcm)
+            fcm = br.ReadBits(1) + 1;
+        }
+        else
+          fcm = VC1_FRAME_PROGRESSIVE;
+        if (fcm == VC1_FIELD_INTERLACE) {
+          uint8_t pic = br.ReadBits(3);
+          return pic == 0x00 || pic == 0x01;
+        }
+        else
+        {
+          uint8_t pic(0);
+          while (pic < 4 && br.ReadBits(1))++pic;
+          return pic == 2;
+        }
+        return false;
+      }
+      else if (m_Profile != VC1_PROFILE_NOPROFILE)
+      {
+        br.SkipBits(m_SimpleSkipBits); // quantizer
+        uint8_t pic(br.ReadBits(1));
+        if (m_MaxBFrames) {
+          if (!pic) {
+            pic = br.ReadBits(1);
+            return pic != 0;
+          }
+          else
+            return false;
+        }
+        else
+          return pic != 0;
+      }
+      else
+        break;
+    }
+  }
+  return false;
+}