VP8 uses a probabilistic bool coder, not a straight bit coder.
This fixes parsing when error-resilient is set.
This commit includes a copy of libvpx's bool coder, BSD licensed.
https://bugzilla.gnome.org/show_bug.cgi?id=652694
--- /dev/null
+/*
+ * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the dboolhuff.LICENSE file in this directory.
+ * See the libvpx original distribution for more information,
+ * including patent information, and author information.
+ */
+
+
+#include "dboolhuff.h"
+
+const unsigned char vp8_norm[256] __attribute__ ((aligned (16))) = {
+0, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
+ 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+ 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0};
+
+int
+vp8dx_start_decode (BOOL_DECODER * br,
+ const unsigned char *source, unsigned int source_sz)
+{
+ br->user_buffer_end = source + source_sz;
+ br->user_buffer = source;
+ br->value = 0;
+ br->count = -8;
+ br->range = 255;
+
+ if (source_sz && !source)
+ return 1;
+
+ /* Populate the buffer */
+ vp8dx_bool_decoder_fill (br);
+
+ return 0;
+}
+
+
+void
+vp8dx_bool_decoder_fill (BOOL_DECODER * br)
+{
+ const unsigned char *bufptr;
+ const unsigned char *bufend;
+ VP8_BD_VALUE value;
+ int count;
+ bufend = br->user_buffer_end;
+ bufptr = br->user_buffer;
+ value = br->value;
+ count = br->count;
+
+ VP8DX_BOOL_DECODER_FILL (count, value, bufptr, bufend);
+
+ br->user_buffer = bufptr;
+ br->value = value;
+ br->count = count;
+}
--- /dev/null
+/*
+ * Copyright (c) 2010 The WebM project authors. All Rights Reserved.
+ *
+ * Use of this source code is governed by a BSD-style license
+ * that can be found in the dboolhuff.LICENSE file in this directory.
+ * See the libvpx original distribution for more information,
+ * including patent information, and author information.
+ */
+
+
+#ifndef DBOOLHUFF_H
+#define DBOOLHUFF_H
+#include <stddef.h>
+#include <limits.h>
+#include <glib.h>
+
+typedef size_t VP8_BD_VALUE;
+
+# define VP8_BD_VALUE_SIZE ((int)sizeof(VP8_BD_VALUE)*CHAR_BIT)
+/*This is meant to be a large, positive constant that can still be efficiently
+ loaded as an immediate (on platforms like ARM, for example).
+ Even relatively modest values like 100 would work fine.*/
+# define VP8_LOTS_OF_BITS (0x40000000)
+
+typedef struct
+{
+ const unsigned char *user_buffer_end;
+ const unsigned char *user_buffer;
+ VP8_BD_VALUE value;
+ int count;
+ unsigned int range;
+} BOOL_DECODER;
+
+extern const unsigned char vp8_norm[256] __attribute__((aligned(16)));
+
+int vp8dx_start_decode(BOOL_DECODER *br,
+ const unsigned char *source,
+ unsigned int source_sz);
+
+void vp8dx_bool_decoder_fill(BOOL_DECODER *br);
+
+/*The refill loop is used in several places, so define it in a macro to make
+ sure they're all consistent.
+ An inline function would be cleaner, but has a significant penalty, because
+ multiple BOOL_DECODER fields must be modified, and the compiler is not smart
+ enough to eliminate the stores to those fields and the subsequent reloads
+ from them when inlining the function.*/
+#define VP8DX_BOOL_DECODER_FILL(_count,_value,_bufptr,_bufend) \
+ do \
+ { \
+ int shift = VP8_BD_VALUE_SIZE - 8 - ((_count) + 8); \
+ int loop_end, x; \
+ size_t bits_left = ((_bufend)-(_bufptr))*CHAR_BIT; \
+ \
+ x = shift + CHAR_BIT - bits_left; \
+ loop_end = 0; \
+ if(x >= 0) \
+ { \
+ (_count) += VP8_LOTS_OF_BITS; \
+ loop_end = x; \
+ if(!bits_left) break; \
+ } \
+ while(shift >= loop_end) \
+ { \
+ (_count) += CHAR_BIT; \
+ (_value) |= (VP8_BD_VALUE)*(_bufptr)++ << shift; \
+ shift -= CHAR_BIT; \
+ } \
+ } \
+ while(0) \
+
+
+static int vp8dx_decode_bool(BOOL_DECODER *br, int probability) {
+ unsigned int bit = 0;
+ VP8_BD_VALUE value;
+ unsigned int split;
+ VP8_BD_VALUE bigsplit;
+ int count;
+ unsigned int range;
+
+ split = 1 + (((br->range - 1) * probability) >> 8);
+
+ if(br->count < 0)
+ vp8dx_bool_decoder_fill(br);
+
+ value = br->value;
+ count = br->count;
+
+ bigsplit = (VP8_BD_VALUE)split << (VP8_BD_VALUE_SIZE - 8);
+
+ range = split;
+
+ if (value >= bigsplit)
+ {
+ range = br->range - split;
+ value = value - bigsplit;
+ bit = 1;
+ }
+
+ {
+ register unsigned int shift = vp8_norm[range];
+ range <<= shift;
+ value <<= shift;
+ count -= shift;
+ }
+ br->value = value;
+ br->count = count;
+ br->range = range;
+
+ return bit;
+}
+
+static G_GNUC_UNUSED int vp8_decode_value(BOOL_DECODER *br, int bits)
+{
+ int z = 0;
+ int bit;
+
+ for (bit = bits - 1; bit >= 0; bit--)
+ {
+ z |= (vp8dx_decode_bool(br, 0x80) << bit);
+ }
+
+ return z;
+}
+
+static G_GNUC_UNUSED int vp8dx_bool_error(BOOL_DECODER *br)
+{
+ /* Check if we have reached the end of the buffer.
+ *
+ * Variable 'count' stores the number of bits in the 'value' buffer, minus
+ * 8. The top byte is part of the algorithm, and the remainder is buffered
+ * to be shifted into it. So if count == 8, the top 16 bits of 'value' are
+ * occupied, 8 for the algorithm and 8 in the buffer.
+ *
+ * When reading a byte from the user's buffer, count is filled with 8 and
+ * one byte is filled into the value buffer. When we reach the end of the
+ * data, count is additionally filled with VP8_LOTS_OF_BITS. So when
+ * count == VP8_LOTS_OF_BITS - 1, the user's data has been exhausted.
+ */
+ if ((br->count > VP8_BD_VALUE_SIZE) && (br->count < VP8_LOTS_OF_BITS))
+ {
+ /* We have tried to decode bits after the end of
+ * stream was encountered.
+ */
+ return 1;
+ }
+
+ /* No error. */
+ return 0;
+}
+#endif
#include <gst/base/gstbitreader.h>
#include <gst/rtp/gstrtppayloads.h>
#include <gst/rtp/gstrtpbuffer.h>
+#include "dboolhuff.h"
#include "gstrtpvp8pay.h"
#define FI_FRAG_UNFRAGMENTED 0x0
guint8 tmp8 = 0;
guint8 *data;
guint8 partitions;
+ guint offset;
+ BOOL_DECODER bc;
reader = gst_bit_reader_new_from_buffer (buffer);
header_size = data[2] << 11 | data[1] << 3 | (data[0] >> 5);
/* Include the uncompressed data blob in the header */
- header_size += keyframe ? 10 : 3;
+ offset = keyframe ? 10 : 3;
+ header_size += offset;
if (!gst_bit_reader_skip (reader, 24))
goto error;
if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 8) || tmp8 != 0x2a)
goto error;
- /* Skip horizontal size code (16 bits) vertical size code (16 bits),
- * color space (1 bit) and clamping type (1 bit) */
- if (!gst_bit_reader_skip (reader, 34))
+ /* Skip horizontal size code (16 bits) vertical size code (16 bits) */
+ if (!gst_bit_reader_skip (reader, 32))
goto error;
}
- /* segmentation_enabled */
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
- goto error;
+ offset = keyframe ? 10 : 3;
+ vp8dx_start_decode (&bc, GST_BUFFER_DATA (buffer) + offset,
+ GST_BUFFER_SIZE (buffer) - offset);
- if (tmp8 != 0) {
- gboolean update_mb_segmentation_map;
- gboolean update_segment_feature_data;
-
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 2))
- goto error;
+ if (keyframe) {
+ /* color space (1 bit) and clamping type (1 bit) */
+ vp8dx_decode_bool (&bc, 0x80);
+ vp8dx_decode_bool (&bc, 0x80);
+ }
- update_mb_segmentation_map = (tmp8 & 0x2) != 0;
- update_segment_feature_data = (tmp8 & 0x1) != 0;
+ /* segmentation_enabled */
+ if (vp8dx_decode_bool (&bc, 0x80)) {
+ guint8 update_mb_segmentation_map = vp8dx_decode_bool (&bc, 0x80);
+ guint8 update_segment_feature_data = vp8dx_decode_bool (&bc, 0x80);
if (update_segment_feature_data) {
/* skip segment feature mode */
- if (!gst_bit_reader_skip (reader, 1))
- goto error;
+ vp8dx_decode_bool (&bc, 0x80);
+ /* quantizer update */
for (i = 0; i < 4; i++) {
- /* quantizer update */
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
- goto error;
-
- if (tmp8 != 0) {
- /* skip quantizer value (7 bits) and sign (1 bit) */
- if (!gst_bit_reader_skip (reader, 8))
- goto error;
- }
+ /* skip flagged quantizer value (7 bits) and sign (1 bit) */
+ if (vp8dx_decode_bool (&bc, 0x80))
+ vp8_decode_value (&bc, 8);
}
+ /* loop filter update */
for (i = 0; i < 4; i++) {
- /* loop filter update */
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
- goto error;
-
- if (tmp8 != 0) {
- /* skip lf update value (6 bits) and sign (1 bit) */
- if (!gst_bit_reader_skip (reader, 7))
- goto error;
- }
+ /* skip flagged lf update value (6 bits) and sign (1 bit) */
+ if (vp8dx_decode_bool (&bc, 0x80))
+ vp8_decode_value (&bc, 7);
}
}
if (update_mb_segmentation_map) {
+ /* segment prob update */
for (i = 0; i < 3; i++) {
- /* segment prob update */
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
- goto error;
-
- if (tmp8 != 0) {
- /* skip segment prob */
- if (!gst_bit_reader_skip (reader, 8))
- goto error;
- }
+ /* skip flagged segment prob */
+ if (vp8dx_decode_bool (&bc, 0x80))
+ vp8_decode_value (&bc, 8);
}
}
}
/* skip filter type (1 bit), loop filter level (6 bits) and
* sharpness level (3 bits) */
- if (!gst_bit_reader_skip (reader, 10))
- goto error;
+ vp8_decode_value (&bc, 1);
+ vp8_decode_value (&bc, 6);
+ vp8_decode_value (&bc, 3);
/* loop_filter_adj_enabled */
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
- goto error;
-
- if (tmp8 != 0) {
- /* loop filter adj enabled */
+ if (vp8dx_decode_bool (&bc, 0x80)) {
- /* mode_ref_lf_delta_update */
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
- goto error;
-
- if (tmp8 != 0) {
- /* mode_ref_lf_data_update */
- int i;
+ /* delta update */
+ if (vp8dx_decode_bool (&bc, 0x80)) {
for (i = 0; i < 8; i++) {
/* 8 updates, 1 bit indicate whether there is one and if follow by a
* 7 bit update */
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 1))
- goto error;
-
- if (tmp8 != 0) {
- /* skip delta magnitude (6 bits) and sign (1 bit) */
- if (!gst_bit_reader_skip (reader, 7))
- goto error;
- }
+ if (vp8dx_decode_bool (&bc, 0x80))
+ vp8_decode_value (&bc, 7);
}
}
}
- if (!gst_bit_reader_get_bits_uint8 (reader, &tmp8, 2))
+ if (vp8dx_bool_error (&bc))
goto error;
+ tmp8 = vp8_decode_value (&bc, 2);
+
partitions = 1 << tmp8;
/* Check if things are still sensible */