summaryrefslogtreecommitdiffstats
path: root/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c
diff options
context:
space:
mode:
Diffstat (limited to 'media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c')
-rw-r--r--media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c103
1 files changed, 103 insertions, 0 deletions
diff --git a/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c b/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c
new file mode 100644
index 0000000..96593d1
--- /dev/null
+++ b/media/libstagefright/codecs/on2/h264dec/omxdl/reference/vc/m4p2/src/omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c
@@ -0,0 +1,103 @@
+/**
+ *
+ * File Name: omxVCM4P2_DecodeVLCZigzag_IntraACVLC.c
+ * OpenMAX DL: v1.0.2
+ * Revision: 9641
+ * Date: Thursday, February 7, 2008
+ *
+ * (c) Copyright 2007-2008 ARM Limited. All Rights Reserved.
+ *
+ *
+ *
+ * Description:
+ * Contains modules for zigzag scanning and VLC decoding
+ * for intra block.
+ *
+ */
+
+#include "omxtypes.h"
+#include "armOMX.h"
+#include "omxVC.h"
+
+#include "armVC.h"
+#include "armCOMM.h"
+
+
+
+/**
+ * Function: omxVCM4P2_DecodeVLCZigzag_IntraACVLC (6.2.5.2.2)
+ *
+ * Description:
+ * Performs VLC decoding and inverse zigzag scan of AC and DC coefficients
+ * for one intra block. Two versions of the function (DCVLC and ACVLC) are
+ * provided in order to support the two different methods of processing DC
+ * coefficients, as described in [ISO14496-2], subclause 7.4.1.4, Intra DC
+ * Coefficient Decoding for the Case of Switched VLC Encoding.
+ *
+ * Input Arguments:
+ *
+ * ppBitStream - pointer to the pointer to the current byte in the
+ * bitstream buffer
+ * pBitOffset - pointer to the bit position in the current byte referenced
+ * by *ppBitStream. The parameter *pBitOffset is valid in the
+ * range [0-7]. Bit Position in one byte: |Most Least| *pBitOffset
+ * |0 1 2 3 4 5 6 7|
+ * predDir - AC prediction direction; used to select the zigzag scan
+ * pattern; takes one of the following values: OMX_VC_NONE - AC
+ * prediction not used; performs classical zigzag scan.
+ * OMX_VC_HORIZONTAL - Horizontal prediction; performs
+ * alternate-vertical zigzag scan; OMX_VC_VERTICAL - Vertical
+ * prediction; performs alternate-horizontal zigzag scan.
+ * shortVideoHeader - binary flag indicating presence of
+ * short_video_header; escape modes 0-3 are used if
+ * shortVideoHeader==0, and escape mode 4 is used when
+ * shortVideoHeader==1.
+ * videoComp - video component type (luminance or chrominance) of the
+ * current block
+ *
+ * Output Arguments:
+ *
+ * ppBitStream - *ppBitStream is updated after the block is decoded such
+ * that it points to the current byte in the bit stream buffer
+ * pBitOffset - *pBitOffset is updated such that it points to the current
+ * bit position in the byte pointed by *ppBitStream
+ * pDst - pointer to the coefficient buffer of current block; must be
+ * 4-byte aligned.
+ *
+ * Return Value:
+ *
+ * OMX_Sts_NoErr - no error
+ * OMX_Sts_BadArgErr - bad arguments At least one of the following
+ * pointers is NULL: ppBitStream, *ppBitStream, pBitOffset, pDst,
+ * or At least one of the following conditions is true:
+ * *pBitOffset exceeds [0,7], preDir exceeds [0,2], or pDst is
+ * not 4-byte aligned
+ * OMX_Sts_Err In DecodeVLCZigzag_IntraDCVLC, dc_size > 12 At least one of
+ * mark bits equals zero Illegal stream encountered; code cannot
+ * be located in VLC table Forbidden code encountered in the VLC
+ * FLC table The number of coefficients is greater than 64
+ *
+ */
+
+
+OMXResult omxVCM4P2_DecodeVLCZigzag_IntraACVLC(
+ const OMX_U8 ** ppBitStream,
+ OMX_INT * pBitOffset,
+ OMX_S16 * pDst,
+ OMX_U8 predDir,
+ OMX_INT shortVideoHeader
+)
+{
+ OMX_U8 start = 0;
+
+ return armVCM4P2_DecodeVLCZigzag_Intra(
+ ppBitStream,
+ pBitOffset,
+ pDst,
+ predDir,
+ shortVideoHeader,
+ start);
+}
+
+/* End of file */
+