RFC 6386
VP8 Data Format and Decoding Guide
20. Attachment One: Reference Decoder Source Code
20.1. bit_ops.h
---- Begin code block -------------------------------------- /* * Copyright (c) 2010, 2011, Google Inc. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be * found in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #ifndef BIT_OPS_H #define BIT_OPS_H /* Evaluates to a mask with n bits set */ #define BITS_MASK(n) ((1<<(n))-1) /* Returns len bits, with the LSB at position bit */ #define BITS_GET(val, bit, len) (((val)>>(bit))&BITS_MASK(len)) #endif ---- End code block ----------------------------------------20.2. bool_decoder.h
---- Begin code block -------------------------------------- /* * Copyright (c) 2010, 2011, Google Inc. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be * found in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #ifndef BOOL_DECODER_H #define BOOL_DECODER_H #include <stddef.h>
struct bool_decoder
{
const unsigned char *input; /* next compressed data byte */
size_t input_len; /* length of the input buffer */
unsigned int range; /* identical to encoder's
* range */
unsigned int value; /* contains at least 8
* significant bits */
int bit_count; /* # of bits shifted out of
* value, max 7 */
};
static void
init_bool_decoder(struct bool_decoder *d,
const unsigned char *start_partition,
size_t sz)
{
if (sz >= 2)
{
d->value = (start_partition[0] << 8) /* first 2 input
* bytes */
| start_partition[1];
d->input = start_partition + 2; /* ptr to next byte */
d->input_len = sz - 2;
}
else
{
d->value = 0;
d->input = NULL;
d->input_len = 0;
}
d->range = 255; /* initial range is full */
d->bit_count = 0; /* have not yet shifted out any bits */
}
static int bool_get(struct bool_decoder *d, int probability)
{
/* range and split are identical to the corresponding values
used by the encoder when this bool was written */
unsigned int split = 1 + (((d->range - 1) * probability) >> 8);
unsigned int SPLIT = split << 8;
int retval; /* will be 0 or 1 */
if (d->value >= SPLIT) /* encoded a one */
{
retval = 1;
d->range -= split; /* reduce range */
d->value -= SPLIT; /* subtract off left endpoint of
* interval */
}
else /* encoded a zero */
{
retval = 0;
d->range = split; /* reduce range, no change in left
* endpoint */
}
while (d->range < 128) /* shift out irrelevant value bits */
{
d->value <<= 1;
d->range <<= 1;
if (++d->bit_count == 8) /* shift in new bits 8 at a time */
{
d->bit_count = 0;
if (d->input_len)
{
d->value |= *d->input++;
d->input_len--;
}
}
}
return retval;
}
static int bool_get_bit(struct bool_decoder *br)
{
return bool_get(br, 128);
}
static int bool_get_uint(struct bool_decoder *br, int bits)
{
int z = 0;
int bit;
for (bit = bits - 1; bit >= 0; bit--)
{
z |= (bool_get_bit(br) << bit);
}
return z;
}
static int bool_get_int(struct bool_decoder *br, int bits)
{
int z = 0;
int bit;
for (bit = bits - 1; bit >= 0; bit--)
{
z |= (bool_get_bit(br) << bit);
}
return bool_get_bit(br) ? -z : z;
}
static int bool_maybe_get_int(struct bool_decoder *br, int bits)
{
return bool_get_bit(br) ? bool_get_int(br, bits) : 0;
}
static int
bool_read_tree(struct bool_decoder *bool,
const int *t,
const unsigned char *p)
{
int i = 0;
while ((i = t[ i + bool_get(bool, p[i>>1])]) > 0);
return -i;
}
#endif
---- End code block ----------------------------------------
20.3. dequant_data.h
---- Begin code block -------------------------------------- /* * Copyright (c) 2010, 2011, Google Inc. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be * found in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ static const int dc_q_lookup[128] = { 4, 5, 6, 7, 8, 9, 10, 10, 11, 12, 13, 14, 15, 16, 17, 17, 18, 19, 20, 20, 21, 21, 22, 22, 23, 23, 24, 25, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 59, 60, 61, 62, 63, 64, 65, 66, 67, 68, 69, 70, 71, 72, 73, 74, 75, 76, 76, 77, 78, 79, 80, 81, 82, 83, 84, 85, 86, 87, 88, 89, 91, 93, 95, 96, 98, 100, 101, 102, 104, 106, 108, 110, 112, 114, 116, 118, 122, 124, 126, 128, 130, 132, 134, 136, 138, 140, 143, 145, 148, 151, 154, 157 }; static const int ac_q_lookup[128] = { 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25, 26, 27, 28, 29, 30, 31, 32, 33, 34, 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 56, 57, 58, 60, 62, 64, 66, 68, 70, 72, 74, 76, 78, 80, 82, 84, 86, 88, 90, 92, 94, 96, 98, 100, 102, 104, 106, 108, 110, 112, 114, 116, 119, 122, 125, 128, 131, 134, 137, 140, 143, 146, 149, 152,
155, 158, 161, 164, 167, 170, 173, 177,
181, 185, 189, 193, 197, 201, 205, 209,
213, 217, 221, 225, 229, 234, 239, 245,
249, 254, 259, 264, 269, 274, 279, 284
};
---- End code block ----------------------------------------
20.4. dixie.c
---- Begin code block --------------------------------------
/*
* Copyright (c) 2010, 2011, Google Inc. All rights reserved.
*
* Use of this source code is governed by a BSD-style license
* that can be found in the LICENSE file in the root of the source
* tree. An additional intellectual property rights grant can be
* found in the file PATENTS. All contributing project authors may
* be found in the AUTHORS file in the root of the source tree.
*/
#include "vpx_codec_internal.h"
#include "bit_ops.h"
#include "dixie.h"
#include "vp8_prob_data.h"
#include "dequant_data.h"
#include "modemv.h"
#include "tokens.h"
#include "predict.h"
#include "dixie_loopfilter.h"
#include <string.h>
#include <assert.h>
enum
{
FRAME_HEADER_SZ = 3,
KEYFRAME_HEADER_SZ = 7
};
#define ARRAY_COPY(a,b) {\
assert(sizeof(a)==sizeof(b));memcpy(a,b,sizeof(a));}
static void
decode_entropy_header(struct vp8_decoder_ctx *ctx,
struct bool_decoder *bool,
struct vp8_entropy_hdr *hdr)
{
int i, j, k, l;
/* Read coefficient probability updates */
for (i = 0; i < BLOCK_TYPES; i++)
for (j = 0; j < COEFF_BANDS; j++)
for (k = 0; k < PREV_COEFF_CONTEXTS; k++)
for (l = 0; l < ENTROPY_NODES; l++)
if (bool_get(bool,
k_coeff_entropy_update_probs
[i][j][k][l]))
hdr->coeff_probs[i][j][k][l] =
bool_get_uint(bool, 8);
/* Read coefficient skip mode probability */
hdr->coeff_skip_enabled = bool_get_bit(bool);
if (hdr->coeff_skip_enabled)
hdr->coeff_skip_prob = bool_get_uint(bool, 8);
/* Parse interframe probability updates */
if (!ctx->frame_hdr.is_keyframe)
{
hdr->prob_inter = bool_get_uint(bool, 8);
hdr->prob_last = bool_get_uint(bool, 8);
hdr->prob_gf = bool_get_uint(bool, 8);
if (bool_get_bit(bool))
for (i = 0; i < 4; i++)
hdr->y_mode_probs[i] = bool_get_uint(bool, 8);
if (bool_get_bit(bool))
for (i = 0; i < 3; i++)
hdr->uv_mode_probs[i] = bool_get_uint(bool, 8);
for (i = 0; i < 2; i++)
for (j = 0; j < MV_PROB_CNT; j++)
if (bool_get(bool, k_mv_entropy_update_probs[i][j]))
{
int x = bool_get_uint(bool, 7);
hdr->mv_probs[i][j] = x ? x << 1 : 1;
}
}
}
static void
decode_reference_header(struct vp8_decoder_ctx *ctx,
struct bool_decoder *bool,
struct vp8_reference_hdr *hdr)
{
unsigned int key = ctx->frame_hdr.is_keyframe;
hdr->refresh_gf = key ? 1 : bool_get_bit(bool);
hdr->refresh_arf = key ? 1 : bool_get_bit(bool);
hdr->copy_gf = key ? 0 : !hdr->refresh_gf
? bool_get_uint(bool, 2) : 0;
hdr->copy_arf = key ? 0 : !hdr->refresh_arf
? bool_get_uint(bool, 2) : 0;
hdr->sign_bias[GOLDEN_FRAME] = key ? 0 : bool_get_bit(bool);
hdr->sign_bias[ALTREF_FRAME] = key ? 0 : bool_get_bit(bool);
hdr->refresh_entropy = bool_get_bit(bool);
hdr->refresh_last = key ? 1 : bool_get_bit(bool);
}
static void
decode_quantizer_header(struct vp8_decoder_ctx *ctx,
struct bool_decoder *bool,
struct vp8_quant_hdr *hdr)
{
int update;
int last_q = hdr->q_index;
hdr->q_index = bool_get_uint(bool, 7);
update = last_q != hdr->q_index;
update |= (hdr->y1_dc_delta_q = bool_maybe_get_int(bool, 4));
update |= (hdr->y2_dc_delta_q = bool_maybe_get_int(bool, 4));
update |= (hdr->y2_ac_delta_q = bool_maybe_get_int(bool, 4));
update |= (hdr->uv_dc_delta_q = bool_maybe_get_int(bool, 4));
update |= (hdr->uv_ac_delta_q = bool_maybe_get_int(bool, 4));
hdr->delta_update = update;
}
static void
decode_and_init_token_partitions(struct vp8_decoder_ctx *ctx,
struct bool_decoder *bool,
const unsigned char *data,
unsigned int sz,
struct vp8_token_hdr *hdr)
{
int i;
hdr->partitions = 1 << bool_get_uint(bool, 2);
if (sz < 3 *(hdr->partitions - 1))
vpx_internal_error(&ctx->error, VPX_CODEC_CORRUPT_FRAME,
"Truncated packet found parsing partition"
" lengths.");
sz -= 3 * (hdr->partitions - 1);
for (i = 0; i < hdr->partitions; i++)
{
if (i < hdr->partitions - 1)
{
hdr->partition_sz[i] = (data[2] << 16)
| (data[1] << 8) | data[0];
data += 3;
}
else
hdr->partition_sz[i] = sz;
if (sz < hdr->partition_sz[i])
vpx_internal_error(&ctx->error, VPX_CODEC_CORRUPT_FRAME,
"Truncated partition %d", i);
sz -= hdr->partition_sz[i];
}
for (i = 0; i < ctx->token_hdr.partitions; i++)
{
init_bool_decoder(&ctx->tokens[i].bool, data,
ctx->token_hdr.partition_sz[i]);
data += ctx->token_hdr.partition_sz[i];
}
}
static void
decode_loopfilter_header(struct vp8_decoder_ctx *ctx,
struct bool_decoder *bool,
struct vp8_loopfilter_hdr *hdr)
{
if (ctx->frame_hdr.is_keyframe)
memset(hdr, 0, sizeof(*hdr));
hdr->use_simple = bool_get_bit(bool);
hdr->level = bool_get_uint(bool, 6);
hdr->sharpness = bool_get_uint(bool, 3);
hdr->delta_enabled = bool_get_bit(bool);
if (hdr->delta_enabled && bool_get_bit(bool))
{
int i;
for (i = 0; i < BLOCK_CONTEXTS; i++)
hdr->ref_delta[i] = bool_maybe_get_int(bool, 6);
for (i = 0; i < BLOCK_CONTEXTS; i++)
hdr->mode_delta[i] = bool_maybe_get_int(bool, 6);
}
}
static void
decode_segmentation_header(struct vp8_decoder_ctx *ctx,
struct bool_decoder *bool,
struct vp8_segment_hdr *hdr)
{
if (ctx->frame_hdr.is_keyframe)
memset(hdr, 0, sizeof(*hdr));
hdr->enabled = bool_get_bit(bool);
if (hdr->enabled)
{
int i;
hdr->update_map = bool_get_bit(bool);
hdr->update_data = bool_get_bit(bool);
if (hdr->update_data)
{
hdr->abs = bool_get_bit(bool);
for (i = 0; i < MAX_MB_SEGMENTS; i++)
hdr->quant_idx[i] = bool_maybe_get_int(bool, 7);
for (i = 0; i < MAX_MB_SEGMENTS; i++)
hdr->lf_level[i] = bool_maybe_get_int(bool, 6);
}
if (hdr->update_map)
{
for (i = 0; i < MB_FEATURE_TREE_PROBS; i++)
hdr->tree_probs[i] = bool_get_bit(bool)
? bool_get_uint(bool, 8)
: 255;
}
}
else
{
hdr->update_map = 0;
hdr->update_data = 0;
}
}
static void
dequant_global_init(struct dequant_factors dqf[MAX_MB_SEGMENTS])
{
int i;
for (i = 0; i < MAX_MB_SEGMENTS; i++)
dqf[i].quant_idx = -1;
}
static int
clamp_q(int q)
{
if (q < 0) return 0;
else if (q > 127) return 127;
return q;
}
static int
dc_q(int q)
{
return dc_q_lookup[clamp_q(q)];
}
static int
ac_q(int q)
{
return ac_q_lookup[clamp_q(q)];
}
static void
dequant_init(struct dequant_factors factors[MAX_MB_SEGMENTS],
const struct vp8_segment_hdr *seg,
const struct vp8_quant_hdr *quant_hdr)
{
int i, q;
struct dequant_factors *dqf = factors;
for (i = 0; i < (seg->enabled ? MAX_MB_SEGMENTS : 1); i++)
{
q = quant_hdr->q_index;
if (seg->enabled)
q = (!seg->abs) ? q + seg->quant_idx[i]
: seg->quant_idx[i];
if (dqf->quant_idx != q || quant_hdr->delta_update)
{
dqf->factor[TOKEN_BLOCK_Y1][0] =
dc_q(q + quant_hdr->y1_dc_delta_q);
dqf->factor[TOKEN_BLOCK_Y1][1] =
ac_q(q);
dqf->factor[TOKEN_BLOCK_UV][0] =
dc_q(q + quant_hdr->uv_dc_delta_q);
dqf->factor[TOKEN_BLOCK_UV][1] =
ac_q(q + quant_hdr->uv_ac_delta_q);
dqf->factor[TOKEN_BLOCK_Y2][0] =
dc_q(q + quant_hdr->y2_dc_delta_q) * 2;
dqf->factor[TOKEN_BLOCK_Y2][1] =
ac_q(q + quant_hdr->y2_ac_delta_q) * 155 / 100;
if (dqf->factor[TOKEN_BLOCK_Y2][1] < 8)
dqf->factor[TOKEN_BLOCK_Y2][1] = 8;
if (dqf->factor[TOKEN_BLOCK_UV][0] > 132)
dqf->factor[TOKEN_BLOCK_UV][0] = 132;
dqf->quant_idx = q;
}
dqf++;
}
}
static void
decode_frame(struct vp8_decoder_ctx *ctx,
const unsigned char *data,
unsigned int sz)
{
vpx_codec_err_t res;
struct bool_decoder bool;
int i, row, partition;
ctx->saved_entropy_valid = 0;
if ((res = vp8_parse_frame_header(data, sz, &ctx->frame_hdr)))
vpx_internal_error(&ctx->error, res,
"Failed to parse frame header");
if (ctx->frame_hdr.is_experimental)
vpx_internal_error(&ctx->error, VPX_CODEC_UNSUP_BITSTREAM,
"Experimental bitstreams not supported.");
data += FRAME_HEADER_SZ;
sz -= FRAME_HEADER_SZ;
if (ctx->frame_hdr.is_keyframe)
{
data += KEYFRAME_HEADER_SZ;
sz -= KEYFRAME_HEADER_SZ;
ctx->mb_cols = (ctx->frame_hdr.kf.w + 15) / 16;
ctx->mb_rows = (ctx->frame_hdr.kf.h + 15) / 16;
}
/* Start the bitreader for the header/entropy partition */
init_bool_decoder(&bool, data, ctx->frame_hdr.part0_sz);
/* Skip the colorspace and clamping bits */
if (ctx->frame_hdr.is_keyframe)
if (bool_get_uint(&bool, 2))
vpx_internal_error(
&ctx->error, VPX_CODEC_UNSUP_BITSTREAM,
"Reserved bits not supported.");
decode_segmentation_header(ctx, &bool, &ctx->segment_hdr);
decode_loopfilter_header(ctx, &bool, &ctx->loopfilter_hdr);
decode_and_init_token_partitions(ctx,
&bool,
data + ctx->frame_hdr.part0_sz,
sz - ctx->frame_hdr.part0_sz,
&ctx->token_hdr);
decode_quantizer_header(ctx, &bool, &ctx->quant_hdr);
decode_reference_header(ctx, &bool, &ctx->reference_hdr);
/* Set keyframe entropy defaults. These get updated on keyframes
* regardless of the refresh_entropy setting.
*/
if (ctx->frame_hdr.is_keyframe)
{
ARRAY_COPY(ctx->entropy_hdr.coeff_probs,
k_default_coeff_probs);
ARRAY_COPY(ctx->entropy_hdr.mv_probs,
k_default_mv_probs);
ARRAY_COPY(ctx->entropy_hdr.y_mode_probs,
k_default_y_mode_probs);
ARRAY_COPY(ctx->entropy_hdr.uv_mode_probs,
k_default_uv_mode_probs);
}
if (!ctx->reference_hdr.refresh_entropy)
{
ctx->saved_entropy = ctx->entropy_hdr;
ctx->saved_entropy_valid = 1;
}
decode_entropy_header(ctx, &bool, &ctx->entropy_hdr);
vp8_dixie_modemv_init(ctx);
vp8_dixie_tokens_init(ctx);
vp8_dixie_predict_init(ctx);
dequant_init(ctx->dequant_factors, &ctx->segment_hdr,
&ctx->quant_hdr);
for (row = 0, partition = 0; row < ctx->mb_rows; row++)
{
vp8_dixie_modemv_process_row(
ctx, &bool, row, 0, ctx->mb_cols);
vp8_dixie_tokens_process_row(ctx, partition, row, 0,
ctx->mb_cols);
vp8_dixie_predict_process_row(ctx, row, 0, ctx->mb_cols);
if (ctx->loopfilter_hdr.level && row)
vp8_dixie_loopfilter_process_row(ctx, row - 1, 0,
ctx->mb_cols);
if (++partition == ctx->token_hdr.partitions)
partition = 0;
}
if (ctx->loopfilter_hdr.level)
vp8_dixie_loopfilter_process_row(
ctx, row - 1, 0, ctx->mb_cols);
ctx->frame_cnt++;
if (!ctx->reference_hdr.refresh_entropy)
{
ctx->entropy_hdr = ctx->saved_entropy;
ctx->saved_entropy_valid = 0;
}
/* Handle reference frame updates */
if (ctx->reference_hdr.copy_arf == 1)
{
vp8_dixie_release_ref_frame(ctx->ref_frames[ALTREF_FRAME]);
ctx->ref_frames[ALTREF_FRAME] =
vp8_dixie_ref_frame(ctx->ref_frames[LAST_FRAME]);
}
else if (ctx->reference_hdr.copy_arf == 2)
{
vp8_dixie_release_ref_frame(ctx->ref_frames[ALTREF_FRAME]);
ctx->ref_frames[ALTREF_FRAME] =
vp8_dixie_ref_frame(ctx->ref_frames[GOLDEN_FRAME]);
}
if (ctx->reference_hdr.copy_gf == 1)
{
vp8_dixie_release_ref_frame(ctx->ref_frames[GOLDEN_FRAME]);
ctx->ref_frames[GOLDEN_FRAME] =
vp8_dixie_ref_frame(ctx->ref_frames[LAST_FRAME]);
}
else if (ctx->reference_hdr.copy_gf == 2)
{
vp8_dixie_release_ref_frame(ctx->ref_frames[GOLDEN_FRAME]);
ctx->ref_frames[GOLDEN_FRAME] =
vp8_dixie_ref_frame(ctx->ref_frames[ALTREF_FRAME]);
}
if (ctx->reference_hdr.refresh_gf)
{
vp8_dixie_release_ref_frame(ctx->ref_frames[GOLDEN_FRAME]);
ctx->ref_frames[GOLDEN_FRAME] =
vp8_dixie_ref_frame(ctx->ref_frames[CURRENT_FRAME]);
}
if (ctx->reference_hdr.refresh_arf)
{
vp8_dixie_release_ref_frame(ctx->ref_frames[ALTREF_FRAME]);
ctx->ref_frames[ALTREF_FRAME] =
vp8_dixie_ref_frame(ctx->ref_frames[CURRENT_FRAME]);
}
if (ctx->reference_hdr.refresh_last)
{
vp8_dixie_release_ref_frame(ctx->ref_frames[LAST_FRAME]);
ctx->ref_frames[LAST_FRAME] =
vp8_dixie_ref_frame(ctx->ref_frames[CURRENT_FRAME]);
}
}
void
vp8_dixie_decode_init(struct vp8_decoder_ctx *ctx)
{
dequant_global_init(ctx->dequant_factors);
}
#define CHECK_FOR_UPDATE(lval,rval,update_flag) do {\
unsigned int old = lval; \
update_flag |= (old != (lval = rval)); \
} while (0)
vpx_codec_err_t
vp8_parse_frame_header(const unsigned char *data,
unsigned int sz,
struct vp8_frame_hdr *hdr)
{
unsigned long raw;
if (sz < 10)
return VPX_CODEC_CORRUPT_FRAME;
/* The frame header is defined as a three-byte little endian
* value
*/
raw = data[0] | (data[1] << 8) | (data[2] << 16);
hdr->is_keyframe = !BITS_GET(raw, 0, 1);
hdr->version = BITS_GET(raw, 1, 2);
hdr->is_experimental = BITS_GET(raw, 3, 1);
hdr->is_shown = BITS_GET(raw, 4, 1);
hdr->part0_sz = BITS_GET(raw, 5, 19);
if (sz <= hdr->part0_sz + (hdr->is_keyframe ? 10 : 3))
return VPX_CODEC_CORRUPT_FRAME;
hdr->frame_size_updated = 0;
if (hdr->is_keyframe)
{
unsigned int update = 0;
/* Keyframe header consists of a three-byte sync code
* followed by the width and height and associated scaling
* factors.
*/
if (data[3] != 0x9d || data[4] != 0x01 || data[5] != 0x2a)
return VPX_CODEC_UNSUP_BITSTREAM;
raw = data[6] | (data[7] << 8)
| (data[8] << 16) | (data[9] << 24);
CHECK_FOR_UPDATE(hdr->kf.w, BITS_GET(raw, 0, 14),
update);
CHECK_FOR_UPDATE(hdr->kf.scale_w, BITS_GET(raw, 14, 2),
update);
CHECK_FOR_UPDATE(hdr->kf.h, BITS_GET(raw, 16, 14),
update);
CHECK_FOR_UPDATE(hdr->kf.scale_h, BITS_GET(raw, 30, 2),
update);
hdr->frame_size_updated = update;
if (!hdr->kf.w || !hdr->kf.h)
return VPX_CODEC_UNSUP_BITSTREAM;
}
return VPX_CODEC_OK;
}
vpx_codec_err_t
vp8_dixie_decode_frame(struct vp8_decoder_ctx *ctx,
const unsigned char *data,
unsigned int sz)
{
volatile struct vp8_decoder_ctx *ctx_ = ctx;
ctx->error.error_code = VPX_CODEC_OK;
ctx->error.has_detail = 0;
if (!setjmp(ctx->error.jmp))
decode_frame(ctx, data, sz);
return ctx_->error.error_code;
}
void
vp8_dixie_decode_destroy(struct vp8_decoder_ctx *ctx)
{
vp8_dixie_predict_destroy(ctx);
vp8_dixie_tokens_destroy(ctx);
vp8_dixie_modemv_destroy(ctx);
}
---- End code block ----------------------------------------
20.5. dixie.h
---- Begin code block -------------------------------------- /* * Copyright (c) 2010, 2011, Google Inc. All rights reserved. * * Use of this source code is governed by a BSD-style license * that can be found in the LICENSE file in the root of the source * tree. An additional intellectual property rights grant can be * found in the file PATENTS. All contributing project authors may * be found in the AUTHORS file in the root of the source tree. */ #ifndef DIXIE_H #define DIXIE_H #include "vpx_codec_internal.h" #include "bool_decoder.h" struct vp8_frame_hdr { unsigned int is_keyframe; /* Frame is a keyframe */ unsigned int is_experimental; /* Frame is a keyframe */ unsigned int version; /* Bitstream version */ unsigned int is_shown; /* Frame is to be displayed. */ unsigned int part0_sz; /* Partition 0 length, in bytes */ struct vp8_kf_hdr { unsigned int w; /* Width */ unsigned int h; /* Height */ unsigned int scale_w; /* Scaling factor, Width */ unsigned int scale_h; /* Scaling factor, Height */ } kf; unsigned int frame_size_updated; /* Flag to indicate a resolution * update. */ }; enum { MB_FEATURE_TREE_PROBS = 3, MAX_MB_SEGMENTS = 4 };
struct vp8_segment_hdr
{
unsigned int enabled;
unsigned int update_data;
unsigned int update_map;
unsigned int abs; /* 0=deltas, 1=absolute values */
unsigned int tree_probs[MB_FEATURE_TREE_PROBS];
int lf_level[MAX_MB_SEGMENTS];
int quant_idx[MAX_MB_SEGMENTS];
};
enum
{
BLOCK_CONTEXTS = 4
};
struct vp8_loopfilter_hdr
{
unsigned int use_simple;
unsigned int level;
unsigned int sharpness;
unsigned int delta_enabled;
int ref_delta[BLOCK_CONTEXTS];
int mode_delta[BLOCK_CONTEXTS];
};
enum
{
MAX_PARTITIONS = 8
};
struct vp8_token_hdr
{
unsigned int partitions;
unsigned int partition_sz[MAX_PARTITIONS];
};
struct vp8_quant_hdr
{
unsigned int q_index;
int delta_update;
int y1_dc_delta_q;
int y2_dc_delta_q;
int y2_ac_delta_q;
int uv_dc_delta_q;
int uv_ac_delta_q;
};
struct vp8_reference_hdr
{
unsigned int refresh_last;
unsigned int refresh_gf;
unsigned int refresh_arf;
unsigned int copy_gf;
unsigned int copy_arf;
unsigned int sign_bias[4];
unsigned int refresh_entropy;
};
enum
{
BLOCK_TYPES = 4,
PREV_COEFF_CONTEXTS = 3,
COEFF_BANDS = 8,
ENTROPY_NODES = 11,
};
typedef unsigned char coeff_probs_table_t[BLOCK_TYPES][COEFF_BANDS]
[PREV_COEFF_CONTEXTS]
[ENTROPY_NODES];
enum
{
MV_PROB_CNT = 2 + 8 - 1 + 10 /* from entropymv.h */
};
typedef unsigned char mv_component_probs_t[MV_PROB_CNT];
struct vp8_entropy_hdr
{
coeff_probs_table_t coeff_probs;
mv_component_probs_t mv_probs[2];
unsigned int coeff_skip_enabled;
unsigned char coeff_skip_prob;
unsigned char y_mode_probs[4];
unsigned char uv_mode_probs[3];
unsigned char prob_inter;
unsigned char prob_last;
unsigned char prob_gf;
};
enum reference_frame
{
CURRENT_FRAME,
LAST_FRAME,
GOLDEN_FRAME,
ALTREF_FRAME,
NUM_REF_FRAMES
};
enum prediction_mode
{
/* 16x16 intra modes */
DC_PRED, V_PRED, H_PRED, TM_PRED, B_PRED,
/* 16x16 inter modes */
NEARESTMV, NEARMV, ZEROMV, NEWMV, SPLITMV,
MB_MODE_COUNT,
/* 4x4 intra modes */
B_DC_PRED = 0, B_TM_PRED, B_VE_PRED, B_HE_PRED, B_LD_PRED,
B_RD_PRED, B_VR_PRED, B_VL_PRED, B_HD_PRED, B_HU_PRED,
/* 4x4 inter modes */
LEFT4X4, ABOVE4X4, ZERO4X4, NEW4X4,
B_MODE_COUNT
};
enum splitmv_partitioning
{
SPLITMV_16X8,
SPLITMV_8X16,
SPLITMV_8X8,
SPLITMV_4X4
};
typedef short filter_t[6];
typedef union mv
{
struct
{
int16_t x, y;
} d;
uint32_t raw;
} mv_t;
struct mb_base_info
{
unsigned char y_mode : 4;
unsigned char uv_mode : 4;
unsigned char segment_id : 2;
unsigned char ref_frame : 2;
unsigned char skip_coeff : 1;
unsigned char need_mc_border : 1;
enum splitmv_partitioning partitioning : 2;
union mv mv;
unsigned int eob_mask;
};
struct mb_info
{
struct mb_base_info base;
union
{
union mv mvs[16];
enum prediction_mode modes[16];
} split;
};
/* A "token entropy context" has 4 Y values, 2 U, 2 V, and 1 Y2 */
typedef int token_entropy_ctx_t[4 + 2 + 2 + 1];
struct token_decoder
{
struct bool_decoder bool;
token_entropy_ctx_t left_token_entropy_ctx;
short *coeffs;
};
enum token_block_type
{
TOKEN_BLOCK_Y1,
TOKEN_BLOCK_UV,
TOKEN_BLOCK_Y2,
TOKEN_BLOCK_TYPES,
};
struct dequant_factors
{
int quant_idx;
short factor[TOKEN_BLOCK_TYPES][2]; /* [ Y1, UV, Y2 ]
* [ DC, AC ] */
};
struct ref_cnt_img
{
vpx_image_t img;
unsigned int ref_cnt;
};
struct vp8_decoder_ctx
{
struct vpx_internal_error_info error;
unsigned int frame_cnt;
struct vp8_frame_hdr frame_hdr;
struct vp8_segment_hdr segment_hdr;
struct vp8_loopfilter_hdr loopfilter_hdr;
struct vp8_token_hdr token_hdr;
struct vp8_quant_hdr quant_hdr;
struct vp8_reference_hdr reference_hdr;
struct vp8_entropy_hdr entropy_hdr;
struct vp8_entropy_hdr saved_entropy;
unsigned int saved_entropy_valid;
unsigned int mb_rows;
unsigned int mb_cols;
struct mb_info *mb_info_storage;
struct mb_info **mb_info_rows_storage;
struct mb_info **mb_info_rows;
token_entropy_ctx_t *above_token_entropy_ctx;
struct token_decoder tokens[MAX_PARTITIONS];
struct dequant_factors dequant_factors[MAX_MB_SEGMENTS];
struct ref_cnt_img frame_strg[NUM_REF_FRAMES];
struct ref_cnt_img *ref_frames[NUM_REF_FRAMES];
ptrdiff_t ref_frame_offsets[4];
const filter_t *subpixel_filters;
};
void
vp8_dixie_decode_init(struct vp8_decoder_ctx *ctx);
void
vp8_dixie_decode_destroy(struct vp8_decoder_ctx *ctx);
vpx_codec_err_t
vp8_parse_frame_header(const unsigned char *data,
unsigned int sz,
struct vp8_frame_hdr *hdr);
vpx_codec_err_t
vp8_dixie_decode_frame(struct vp8_decoder_ctx *ctx,
const unsigned char *data,
unsigned int sz);
#define CLAMP_255(x) ((x)<0?0:((x)>255?255:(x)))
#endif
---- End code block ----------------------------------------
(next page on part 7)
