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vp3.c
2375 lines (2013 loc) · 81.9 KB
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vp3.c
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/*
* Copyright (C) 2003-2004 the ffmpeg project
*
* 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
* On2 VP3 Video Decoder
*
* VP3 Video Decoder by Mike Melanson (mike at multimedia.cx)
* For more information about the VP3 coding process, visit:
* http://wiki.multimedia.cx/index.php?title=On2_VP3
*
* Theora decoder by Alex Beregszaszi
*/
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include "libavutil/imgutils.h"
#include "avcodec.h"
#include "dsputil.h"
#include "get_bits.h"
#include "vp3data.h"
#include "xiph.h"
#include "thread.h"
#define FRAGMENT_PIXELS 8
static av_cold int vp3_decode_end(AVCodecContext *avctx);
//FIXME split things out into their own arrays
typedef struct Vp3Fragment {
int16_t dc;
uint8_t coding_method;
uint8_t qpi;
} Vp3Fragment;
#define SB_NOT_CODED 0
#define SB_PARTIALLY_CODED 1
#define SB_FULLY_CODED 2
// This is the maximum length of a single long bit run that can be encoded
// for superblock coding or block qps. Theora special-cases this to read a
// bit instead of flipping the current bit to allow for runs longer than 4129.
#define MAXIMUM_LONG_BIT_RUN 4129
#define MODE_INTER_NO_MV 0
#define MODE_INTRA 1
#define MODE_INTER_PLUS_MV 2
#define MODE_INTER_LAST_MV 3
#define MODE_INTER_PRIOR_LAST 4
#define MODE_USING_GOLDEN 5
#define MODE_GOLDEN_MV 6
#define MODE_INTER_FOURMV 7
#define CODING_MODE_COUNT 8
/* special internal mode */
#define MODE_COPY 8
/* There are 6 preset schemes, plus a free-form scheme */
static const int ModeAlphabet[6][CODING_MODE_COUNT] =
{
/* scheme 1: Last motion vector dominates */
{ MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
MODE_INTER_PLUS_MV, MODE_INTER_NO_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 2 */
{ MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
MODE_INTER_NO_MV, MODE_INTER_PLUS_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 3 */
{ MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
MODE_INTER_PRIOR_LAST, MODE_INTER_NO_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 4 */
{ MODE_INTER_LAST_MV, MODE_INTER_PLUS_MV,
MODE_INTER_NO_MV, MODE_INTER_PRIOR_LAST,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 5: No motion vector dominates */
{ MODE_INTER_NO_MV, MODE_INTER_LAST_MV,
MODE_INTER_PRIOR_LAST, MODE_INTER_PLUS_MV,
MODE_INTRA, MODE_USING_GOLDEN,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
/* scheme 6 */
{ MODE_INTER_NO_MV, MODE_USING_GOLDEN,
MODE_INTER_LAST_MV, MODE_INTER_PRIOR_LAST,
MODE_INTER_PLUS_MV, MODE_INTRA,
MODE_GOLDEN_MV, MODE_INTER_FOURMV },
};
static const uint8_t hilbert_offset[16][2] = {
{0,0}, {1,0}, {1,1}, {0,1},
{0,2}, {0,3}, {1,3}, {1,2},
{2,2}, {2,3}, {3,3}, {3,2},
{3,1}, {2,1}, {2,0}, {3,0}
};
#define MIN_DEQUANT_VAL 2
typedef struct Vp3DecodeContext {
AVCodecContext *avctx;
int theora, theora_tables;
int version;
int width, height;
int chroma_x_shift, chroma_y_shift;
AVFrame golden_frame;
AVFrame last_frame;
AVFrame current_frame;
int keyframe;
DSPContext dsp;
int flipped_image;
int last_slice_end;
int skip_loop_filter;
int qps[3];
int nqps;
int last_qps[3];
int superblock_count;
int y_superblock_width;
int y_superblock_height;
int y_superblock_count;
int c_superblock_width;
int c_superblock_height;
int c_superblock_count;
int u_superblock_start;
int v_superblock_start;
unsigned char *superblock_coding;
int macroblock_count;
int macroblock_width;
int macroblock_height;
int fragment_count;
int fragment_width[2];
int fragment_height[2];
Vp3Fragment *all_fragments;
int fragment_start[3];
int data_offset[3];
int8_t (*motion_val[2])[2];
ScanTable scantable;
/* tables */
uint16_t coded_dc_scale_factor[64];
uint32_t coded_ac_scale_factor[64];
uint8_t base_matrix[384][64];
uint8_t qr_count[2][3];
uint8_t qr_size [2][3][64];
uint16_t qr_base[2][3][64];
/**
* This is a list of all tokens in bitstream order. Reordering takes place
* by pulling from each level during IDCT. As a consequence, IDCT must be
* in Hilbert order, making the minimum slice height 64 for 4:2:0 and 32
* otherwise. The 32 different tokens with up to 12 bits of extradata are
* collapsed into 3 types, packed as follows:
* (from the low to high bits)
*
* 2 bits: type (0,1,2)
* 0: EOB run, 14 bits for run length (12 needed)
* 1: zero run, 7 bits for run length
* 7 bits for the next coefficient (3 needed)
* 2: coefficient, 14 bits (11 needed)
*
* Coefficients are signed, so are packed in the highest bits for automatic
* sign extension.
*/
int16_t *dct_tokens[3][64];
int16_t *dct_tokens_base;
#define TOKEN_EOB(eob_run) ((eob_run) << 2)
#define TOKEN_ZERO_RUN(coeff, zero_run) (((coeff) << 9) + ((zero_run) << 2) + 1)
#define TOKEN_COEFF(coeff) (((coeff) << 2) + 2)
/**
* number of blocks that contain DCT coefficients at the given level or higher
*/
int num_coded_frags[3][64];
int total_num_coded_frags;
/* this is a list of indexes into the all_fragments array indicating
* which of the fragments are coded */
int *coded_fragment_list[3];
VLC dc_vlc[16];
VLC ac_vlc_1[16];
VLC ac_vlc_2[16];
VLC ac_vlc_3[16];
VLC ac_vlc_4[16];
VLC superblock_run_length_vlc;
VLC fragment_run_length_vlc;
VLC mode_code_vlc;
VLC motion_vector_vlc;
/* these arrays need to be on 16-byte boundaries since SSE2 operations
* index into them */
DECLARE_ALIGNED(16, int16_t, qmat)[3][2][3][64]; //<qmat[qpi][is_inter][plane]
/* This table contains superblock_count * 16 entries. Each set of 16
* numbers corresponds to the fragment indexes 0..15 of the superblock.
* An entry will be -1 to indicate that no entry corresponds to that
* index. */
int *superblock_fragments;
/* This is an array that indicates how a particular macroblock
* is coded. */
unsigned char *macroblock_coding;
uint8_t *edge_emu_buffer;
/* Huffman decode */
int hti;
unsigned int hbits;
int entries;
int huff_code_size;
uint32_t huffman_table[80][32][2];
uint8_t filter_limit_values[64];
DECLARE_ALIGNED(8, int, bounding_values_array)[256+2];
} Vp3DecodeContext;
/************************************************************************
* VP3 specific functions
************************************************************************/
/*
* This function sets up all of the various blocks mappings:
* superblocks <-> fragments, macroblocks <-> fragments,
* superblocks <-> macroblocks
*
* @return 0 is successful; returns 1 if *anything* went wrong.
*/
static int init_block_mapping(Vp3DecodeContext *s)
{
int sb_x, sb_y, plane;
int x, y, i, j = 0;
for (plane = 0; plane < 3; plane++) {
int sb_width = plane ? s->c_superblock_width : s->y_superblock_width;
int sb_height = plane ? s->c_superblock_height : s->y_superblock_height;
int frag_width = s->fragment_width[!!plane];
int frag_height = s->fragment_height[!!plane];
for (sb_y = 0; sb_y < sb_height; sb_y++)
for (sb_x = 0; sb_x < sb_width; sb_x++)
for (i = 0; i < 16; i++) {
x = 4*sb_x + hilbert_offset[i][0];
y = 4*sb_y + hilbert_offset[i][1];
if (x < frag_width && y < frag_height)
s->superblock_fragments[j++] = s->fragment_start[plane] + y*frag_width + x;
else
s->superblock_fragments[j++] = -1;
}
}
return 0; /* successful path out */
}
/*
* This function sets up the dequantization tables used for a particular
* frame.
*/
static void init_dequantizer(Vp3DecodeContext *s, int qpi)
{
int ac_scale_factor = s->coded_ac_scale_factor[s->qps[qpi]];
int dc_scale_factor = s->coded_dc_scale_factor[s->qps[qpi]];
int i, plane, inter, qri, bmi, bmj, qistart;
for(inter=0; inter<2; inter++){
for(plane=0; plane<3; plane++){
int sum=0;
for(qri=0; qri<s->qr_count[inter][plane]; qri++){
sum+= s->qr_size[inter][plane][qri];
if(s->qps[qpi] <= sum)
break;
}
qistart= sum - s->qr_size[inter][plane][qri];
bmi= s->qr_base[inter][plane][qri ];
bmj= s->qr_base[inter][plane][qri+1];
for(i=0; i<64; i++){
int coeff= ( 2*(sum -s->qps[qpi])*s->base_matrix[bmi][i]
- 2*(qistart-s->qps[qpi])*s->base_matrix[bmj][i]
+ s->qr_size[inter][plane][qri])
/ (2*s->qr_size[inter][plane][qri]);
int qmin= 8<<(inter + !i);
int qscale= i ? ac_scale_factor : dc_scale_factor;
s->qmat[qpi][inter][plane][s->dsp.idct_permutation[i]]= av_clip((qscale * coeff)/100 * 4, qmin, 4096);
}
// all DC coefficients use the same quant so as not to interfere with DC prediction
s->qmat[qpi][inter][plane][0] = s->qmat[0][inter][plane][0];
}
}
}
/*
* This function initializes the loop filter boundary limits if the frame's
* quality index is different from the previous frame's.
*
* The filter_limit_values may not be larger than 127.
*/
static void init_loop_filter(Vp3DecodeContext *s)
{
int *bounding_values= s->bounding_values_array+127;
int filter_limit;
int x;
int value;
filter_limit = s->filter_limit_values[s->qps[0]];
/* set up the bounding values */
memset(s->bounding_values_array, 0, 256 * sizeof(int));
for (x = 0; x < filter_limit; x++) {
bounding_values[-x] = -x;
bounding_values[x] = x;
}
for (x = value = filter_limit; x < 128 && value; x++, value--) {
bounding_values[ x] = value;
bounding_values[-x] = -value;
}
if (value)
bounding_values[128] = value;
bounding_values[129] = bounding_values[130] = filter_limit * 0x02020202;
}
/*
* This function unpacks all of the superblock/macroblock/fragment coding
* information from the bitstream.
*/
static int unpack_superblocks(Vp3DecodeContext *s, GetBitContext *gb)
{
int superblock_starts[3] = { 0, s->u_superblock_start, s->v_superblock_start };
int bit = 0;
int current_superblock = 0;
int current_run = 0;
int num_partial_superblocks = 0;
int i, j;
int current_fragment;
int plane;
if (s->keyframe) {
memset(s->superblock_coding, SB_FULLY_CODED, s->superblock_count);
} else {
/* unpack the list of partially-coded superblocks */
bit = get_bits1(gb) ^ 1;
current_run = 0;
while (current_superblock < s->superblock_count && get_bits_left(gb) > 0) {
if (s->theora && current_run == MAXIMUM_LONG_BIT_RUN)
bit = get_bits1(gb);
else
bit ^= 1;
current_run = get_vlc2(gb,
s->superblock_run_length_vlc.table, 6, 2) + 1;
if (current_run == 34)
current_run += get_bits(gb, 12);
if (current_superblock + current_run > s->superblock_count) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid partially coded superblock run length\n");
return -1;
}
memset(s->superblock_coding + current_superblock, bit, current_run);
current_superblock += current_run;
if (bit)
num_partial_superblocks += current_run;
}
/* unpack the list of fully coded superblocks if any of the blocks were
* not marked as partially coded in the previous step */
if (num_partial_superblocks < s->superblock_count) {
int superblocks_decoded = 0;
current_superblock = 0;
bit = get_bits1(gb) ^ 1;
current_run = 0;
while (superblocks_decoded < s->superblock_count - num_partial_superblocks
&& get_bits_left(gb) > 0) {
if (s->theora && current_run == MAXIMUM_LONG_BIT_RUN)
bit = get_bits1(gb);
else
bit ^= 1;
current_run = get_vlc2(gb,
s->superblock_run_length_vlc.table, 6, 2) + 1;
if (current_run == 34)
current_run += get_bits(gb, 12);
for (j = 0; j < current_run; current_superblock++) {
if (current_superblock >= s->superblock_count) {
av_log(s->avctx, AV_LOG_ERROR, "Invalid fully coded superblock run length\n");
return -1;
}
/* skip any superblocks already marked as partially coded */
if (s->superblock_coding[current_superblock] == SB_NOT_CODED) {
s->superblock_coding[current_superblock] = 2*bit;
j++;
}
}
superblocks_decoded += current_run;
}
}
/* if there were partial blocks, initialize bitstream for
* unpacking fragment codings */
if (num_partial_superblocks) {
current_run = 0;
bit = get_bits1(gb);
/* toggle the bit because as soon as the first run length is
* fetched the bit will be toggled again */
bit ^= 1;
}
}
/* figure out which fragments are coded; iterate through each
* superblock (all planes) */
s->total_num_coded_frags = 0;
memset(s->macroblock_coding, MODE_COPY, s->macroblock_count);
for (plane = 0; plane < 3; plane++) {
int sb_start = superblock_starts[plane];
int sb_end = sb_start + (plane ? s->c_superblock_count : s->y_superblock_count);
int num_coded_frags = 0;
for (i = sb_start; i < sb_end && get_bits_left(gb) > 0; i++) {
/* iterate through all 16 fragments in a superblock */
for (j = 0; j < 16; j++) {
/* if the fragment is in bounds, check its coding status */
current_fragment = s->superblock_fragments[i * 16 + j];
if (current_fragment != -1) {
int coded = s->superblock_coding[i];
if (s->superblock_coding[i] == SB_PARTIALLY_CODED) {
/* fragment may or may not be coded; this is the case
* that cares about the fragment coding runs */
if (current_run-- == 0) {
bit ^= 1;
current_run = get_vlc2(gb,
s->fragment_run_length_vlc.table, 5, 2);
}
coded = bit;
}
if (coded) {
/* default mode; actual mode will be decoded in
* the next phase */
s->all_fragments[current_fragment].coding_method =
MODE_INTER_NO_MV;
s->coded_fragment_list[plane][num_coded_frags++] =
current_fragment;
} else {
/* not coded; copy this fragment from the prior frame */
s->all_fragments[current_fragment].coding_method =
MODE_COPY;
}
}
}
}
s->total_num_coded_frags += num_coded_frags;
for (i = 0; i < 64; i++)
s->num_coded_frags[plane][i] = num_coded_frags;
if (plane < 2)
s->coded_fragment_list[plane+1] = s->coded_fragment_list[plane] + num_coded_frags;
}
return 0;
}
/*
* This function unpacks all the coding mode data for individual macroblocks
* from the bitstream.
*/
static int unpack_modes(Vp3DecodeContext *s, GetBitContext *gb)
{
int i, j, k, sb_x, sb_y;
int scheme;
int current_macroblock;
int current_fragment;
int coding_mode;
int custom_mode_alphabet[CODING_MODE_COUNT];
const int *alphabet;
Vp3Fragment *frag;
if (s->keyframe) {
for (i = 0; i < s->fragment_count; i++)
s->all_fragments[i].coding_method = MODE_INTRA;
} else {
/* fetch the mode coding scheme for this frame */
scheme = get_bits(gb, 3);
/* is it a custom coding scheme? */
if (scheme == 0) {
for (i = 0; i < 8; i++)
custom_mode_alphabet[i] = MODE_INTER_NO_MV;
for (i = 0; i < 8; i++)
custom_mode_alphabet[get_bits(gb, 3)] = i;
alphabet = custom_mode_alphabet;
} else
alphabet = ModeAlphabet[scheme-1];
/* iterate through all of the macroblocks that contain 1 or more
* coded fragments */
for (sb_y = 0; sb_y < s->y_superblock_height; sb_y++) {
for (sb_x = 0; sb_x < s->y_superblock_width; sb_x++) {
if (get_bits_left(gb) <= 0)
return -1;
for (j = 0; j < 4; j++) {
int mb_x = 2*sb_x + (j>>1);
int mb_y = 2*sb_y + (((j>>1)+j)&1);
current_macroblock = mb_y * s->macroblock_width + mb_x;
if (mb_x >= s->macroblock_width || mb_y >= s->macroblock_height)
continue;
#define BLOCK_X (2*mb_x + (k&1))
#define BLOCK_Y (2*mb_y + (k>>1))
/* coding modes are only stored if the macroblock has at least one
* luma block coded, otherwise it must be INTER_NO_MV */
for (k = 0; k < 4; k++) {
current_fragment = BLOCK_Y*s->fragment_width[0] + BLOCK_X;
if (s->all_fragments[current_fragment].coding_method != MODE_COPY)
break;
}
if (k == 4) {
s->macroblock_coding[current_macroblock] = MODE_INTER_NO_MV;
continue;
}
/* mode 7 means get 3 bits for each coding mode */
if (scheme == 7)
coding_mode = get_bits(gb, 3);
else
coding_mode = alphabet
[get_vlc2(gb, s->mode_code_vlc.table, 3, 3)];
s->macroblock_coding[current_macroblock] = coding_mode;
for (k = 0; k < 4; k++) {
frag = s->all_fragments + BLOCK_Y*s->fragment_width[0] + BLOCK_X;
if (frag->coding_method != MODE_COPY)
frag->coding_method = coding_mode;
}
#define SET_CHROMA_MODES \
if (frag[s->fragment_start[1]].coding_method != MODE_COPY) \
frag[s->fragment_start[1]].coding_method = coding_mode;\
if (frag[s->fragment_start[2]].coding_method != MODE_COPY) \
frag[s->fragment_start[2]].coding_method = coding_mode;
if (s->chroma_y_shift) {
frag = s->all_fragments + mb_y*s->fragment_width[1] + mb_x;
SET_CHROMA_MODES
} else if (s->chroma_x_shift) {
frag = s->all_fragments + 2*mb_y*s->fragment_width[1] + mb_x;
for (k = 0; k < 2; k++) {
SET_CHROMA_MODES
frag += s->fragment_width[1];
}
} else {
for (k = 0; k < 4; k++) {
frag = s->all_fragments + BLOCK_Y*s->fragment_width[1] + BLOCK_X;
SET_CHROMA_MODES
}
}
}
}
}
}
return 0;
}
/*
* This function unpacks all the motion vectors for the individual
* macroblocks from the bitstream.
*/
static int unpack_vectors(Vp3DecodeContext *s, GetBitContext *gb)
{
int j, k, sb_x, sb_y;
int coding_mode;
int motion_x[4];
int motion_y[4];
int last_motion_x = 0;
int last_motion_y = 0;
int prior_last_motion_x = 0;
int prior_last_motion_y = 0;
int current_macroblock;
int current_fragment;
int frag;
if (s->keyframe)
return 0;
/* coding mode 0 is the VLC scheme; 1 is the fixed code scheme */
coding_mode = get_bits1(gb);
/* iterate through all of the macroblocks that contain 1 or more
* coded fragments */
for (sb_y = 0; sb_y < s->y_superblock_height; sb_y++) {
for (sb_x = 0; sb_x < s->y_superblock_width; sb_x++) {
if (get_bits_left(gb) <= 0)
return -1;
for (j = 0; j < 4; j++) {
int mb_x = 2*sb_x + (j>>1);
int mb_y = 2*sb_y + (((j>>1)+j)&1);
current_macroblock = mb_y * s->macroblock_width + mb_x;
if (mb_x >= s->macroblock_width || mb_y >= s->macroblock_height ||
(s->macroblock_coding[current_macroblock] == MODE_COPY))
continue;
switch (s->macroblock_coding[current_macroblock]) {
case MODE_INTER_PLUS_MV:
case MODE_GOLDEN_MV:
/* all 6 fragments use the same motion vector */
if (coding_mode == 0) {
motion_x[0] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
motion_y[0] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
} else {
motion_x[0] = fixed_motion_vector_table[get_bits(gb, 6)];
motion_y[0] = fixed_motion_vector_table[get_bits(gb, 6)];
}
/* vector maintenance, only on MODE_INTER_PLUS_MV */
if (s->macroblock_coding[current_macroblock] ==
MODE_INTER_PLUS_MV) {
prior_last_motion_x = last_motion_x;
prior_last_motion_y = last_motion_y;
last_motion_x = motion_x[0];
last_motion_y = motion_y[0];
}
break;
case MODE_INTER_FOURMV:
/* vector maintenance */
prior_last_motion_x = last_motion_x;
prior_last_motion_y = last_motion_y;
/* fetch 4 vectors from the bitstream, one for each
* Y fragment, then average for the C fragment vectors */
for (k = 0; k < 4; k++) {
current_fragment = BLOCK_Y*s->fragment_width[0] + BLOCK_X;
if (s->all_fragments[current_fragment].coding_method != MODE_COPY) {
if (coding_mode == 0) {
motion_x[k] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
motion_y[k] = motion_vector_table[get_vlc2(gb, s->motion_vector_vlc.table, 6, 2)];
} else {
motion_x[k] = fixed_motion_vector_table[get_bits(gb, 6)];
motion_y[k] = fixed_motion_vector_table[get_bits(gb, 6)];
}
last_motion_x = motion_x[k];
last_motion_y = motion_y[k];
} else {
motion_x[k] = 0;
motion_y[k] = 0;
}
}
break;
case MODE_INTER_LAST_MV:
/* all 6 fragments use the last motion vector */
motion_x[0] = last_motion_x;
motion_y[0] = last_motion_y;
/* no vector maintenance (last vector remains the
* last vector) */
break;
case MODE_INTER_PRIOR_LAST:
/* all 6 fragments use the motion vector prior to the
* last motion vector */
motion_x[0] = prior_last_motion_x;
motion_y[0] = prior_last_motion_y;
/* vector maintenance */
prior_last_motion_x = last_motion_x;
prior_last_motion_y = last_motion_y;
last_motion_x = motion_x[0];
last_motion_y = motion_y[0];
break;
default:
/* covers intra, inter without MV, golden without MV */
motion_x[0] = 0;
motion_y[0] = 0;
/* no vector maintenance */
break;
}
/* assign the motion vectors to the correct fragments */
for (k = 0; k < 4; k++) {
current_fragment =
BLOCK_Y*s->fragment_width[0] + BLOCK_X;
if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
s->motion_val[0][current_fragment][0] = motion_x[k];
s->motion_val[0][current_fragment][1] = motion_y[k];
} else {
s->motion_val[0][current_fragment][0] = motion_x[0];
s->motion_val[0][current_fragment][1] = motion_y[0];
}
}
if (s->chroma_y_shift) {
if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
motion_x[0] = RSHIFT(motion_x[0] + motion_x[1] + motion_x[2] + motion_x[3], 2);
motion_y[0] = RSHIFT(motion_y[0] + motion_y[1] + motion_y[2] + motion_y[3], 2);
}
motion_x[0] = (motion_x[0]>>1) | (motion_x[0]&1);
motion_y[0] = (motion_y[0]>>1) | (motion_y[0]&1);
frag = mb_y*s->fragment_width[1] + mb_x;
s->motion_val[1][frag][0] = motion_x[0];
s->motion_val[1][frag][1] = motion_y[0];
} else if (s->chroma_x_shift) {
if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
motion_x[0] = RSHIFT(motion_x[0] + motion_x[1], 1);
motion_y[0] = RSHIFT(motion_y[0] + motion_y[1], 1);
motion_x[1] = RSHIFT(motion_x[2] + motion_x[3], 1);
motion_y[1] = RSHIFT(motion_y[2] + motion_y[3], 1);
} else {
motion_x[1] = motion_x[0];
motion_y[1] = motion_y[0];
}
motion_x[0] = (motion_x[0]>>1) | (motion_x[0]&1);
motion_x[1] = (motion_x[1]>>1) | (motion_x[1]&1);
frag = 2*mb_y*s->fragment_width[1] + mb_x;
for (k = 0; k < 2; k++) {
s->motion_val[1][frag][0] = motion_x[k];
s->motion_val[1][frag][1] = motion_y[k];
frag += s->fragment_width[1];
}
} else {
for (k = 0; k < 4; k++) {
frag = BLOCK_Y*s->fragment_width[1] + BLOCK_X;
if (s->macroblock_coding[current_macroblock] == MODE_INTER_FOURMV) {
s->motion_val[1][frag][0] = motion_x[k];
s->motion_val[1][frag][1] = motion_y[k];
} else {
s->motion_val[1][frag][0] = motion_x[0];
s->motion_val[1][frag][1] = motion_y[0];
}
}
}
}
}
}
return 0;
}
static int unpack_block_qpis(Vp3DecodeContext *s, GetBitContext *gb)
{
int qpi, i, j, bit, run_length, blocks_decoded, num_blocks_at_qpi;
int num_blocks = s->total_num_coded_frags;
for (qpi = 0; qpi < s->nqps-1 && num_blocks > 0; qpi++) {
i = blocks_decoded = num_blocks_at_qpi = 0;
bit = get_bits1(gb) ^ 1;
run_length = 0;
do {
if (run_length == MAXIMUM_LONG_BIT_RUN)
bit = get_bits1(gb);
else
bit ^= 1;
run_length = get_vlc2(gb, s->superblock_run_length_vlc.table, 6, 2) + 1;
if (run_length == 34)
run_length += get_bits(gb, 12);
blocks_decoded += run_length;
if (!bit)
num_blocks_at_qpi += run_length;
for (j = 0; j < run_length; i++) {
if (i >= s->total_num_coded_frags)
return -1;
if (s->all_fragments[s->coded_fragment_list[0][i]].qpi == qpi) {
s->all_fragments[s->coded_fragment_list[0][i]].qpi += bit;
j++;
}
}
} while (blocks_decoded < num_blocks && get_bits_left(gb) > 0);
num_blocks -= num_blocks_at_qpi;
}
return 0;
}
/*
* This function is called by unpack_dct_coeffs() to extract the VLCs from
* the bitstream. The VLCs encode tokens which are used to unpack DCT
* data. This function unpacks all the VLCs for either the Y plane or both
* C planes, and is called for DC coefficients or different AC coefficient
* levels (since different coefficient types require different VLC tables.
*
* This function returns a residual eob run. E.g, if a particular token gave
* instructions to EOB the next 5 fragments and there were only 2 fragments
* left in the current fragment range, 3 would be returned so that it could
* be passed into the next call to this same function.
*/
static int unpack_vlcs(Vp3DecodeContext *s, GetBitContext *gb,
VLC *table, int coeff_index,
int plane,
int eob_run)
{
int i, j = 0;
int token;
int zero_run = 0;
DCTELEM coeff = 0;
int bits_to_get;
int blocks_ended;
int coeff_i = 0;
int num_coeffs = s->num_coded_frags[plane][coeff_index];
int16_t *dct_tokens = s->dct_tokens[plane][coeff_index];
/* local references to structure members to avoid repeated deferences */
int *coded_fragment_list = s->coded_fragment_list[plane];
Vp3Fragment *all_fragments = s->all_fragments;
VLC_TYPE (*vlc_table)[2] = table->table;
if (num_coeffs < 0)
av_log(s->avctx, AV_LOG_ERROR, "Invalid number of coefficents at level %d\n", coeff_index);
if (eob_run > num_coeffs) {
coeff_i = blocks_ended = num_coeffs;
eob_run -= num_coeffs;
} else {
coeff_i = blocks_ended = eob_run;
eob_run = 0;
}
// insert fake EOB token to cover the split between planes or zzi
if (blocks_ended)
dct_tokens[j++] = blocks_ended << 2;
while (coeff_i < num_coeffs && get_bits_left(gb) > 0) {
/* decode a VLC into a token */
token = get_vlc2(gb, vlc_table, 11, 3);
/* use the token to get a zero run, a coefficient, and an eob run */
if (token <= 6) {
eob_run = eob_run_base[token];
if (eob_run_get_bits[token])
eob_run += get_bits(gb, eob_run_get_bits[token]);
// record only the number of blocks ended in this plane,
// any spill will be recorded in the next plane.
if (eob_run > num_coeffs - coeff_i) {
dct_tokens[j++] = TOKEN_EOB(num_coeffs - coeff_i);
blocks_ended += num_coeffs - coeff_i;
eob_run -= num_coeffs - coeff_i;
coeff_i = num_coeffs;
} else {
dct_tokens[j++] = TOKEN_EOB(eob_run);
blocks_ended += eob_run;
coeff_i += eob_run;
eob_run = 0;
}
} else {
bits_to_get = coeff_get_bits[token];
if (bits_to_get)
bits_to_get = get_bits(gb, bits_to_get);
coeff = coeff_tables[token][bits_to_get];
zero_run = zero_run_base[token];
if (zero_run_get_bits[token])
zero_run += get_bits(gb, zero_run_get_bits[token]);
if (zero_run) {
dct_tokens[j++] = TOKEN_ZERO_RUN(coeff, zero_run);
} else {
// Save DC into the fragment structure. DC prediction is
// done in raster order, so the actual DC can't be in with
// other tokens. We still need the token in dct_tokens[]
// however, or else the structure collapses on itself.
if (!coeff_index)
all_fragments[coded_fragment_list[coeff_i]].dc = coeff;
dct_tokens[j++] = TOKEN_COEFF(coeff);
}
if (coeff_index + zero_run > 64) {
av_log(s->avctx, AV_LOG_DEBUG, "Invalid zero run of %d with"
" %d coeffs left\n", zero_run, 64-coeff_index);
zero_run = 64 - coeff_index;
}
// zero runs code multiple coefficients,
// so don't try to decode coeffs for those higher levels
for (i = coeff_index+1; i <= coeff_index+zero_run; i++)
s->num_coded_frags[plane][i]--;
coeff_i++;
}
}
if (blocks_ended > s->num_coded_frags[plane][coeff_index])
av_log(s->avctx, AV_LOG_ERROR, "More blocks ended than coded!\n");
// decrement the number of blocks that have higher coeffecients for each
// EOB run at this level
if (blocks_ended)
for (i = coeff_index+1; i < 64; i++)
s->num_coded_frags[plane][i] -= blocks_ended;
// setup the next buffer
if (plane < 2)
s->dct_tokens[plane+1][coeff_index] = dct_tokens + j;
else if (coeff_index < 63)
s->dct_tokens[0][coeff_index+1] = dct_tokens + j;
return eob_run;
}
static void reverse_dc_prediction(Vp3DecodeContext *s,
int first_fragment,
int fragment_width,
int fragment_height);
/*
* This function unpacks all of the DCT coefficient data from the
* bitstream.
*/
static int unpack_dct_coeffs(Vp3DecodeContext *s, GetBitContext *gb)
{
int i;
int dc_y_table;
int dc_c_table;
int ac_y_table;
int ac_c_table;
int residual_eob_run = 0;
VLC *y_tables[64];
VLC *c_tables[64];
s->dct_tokens[0][0] = s->dct_tokens_base;
/* fetch the DC table indexes */
dc_y_table = get_bits(gb, 4);
dc_c_table = get_bits(gb, 4);
/* unpack the Y plane DC coefficients */
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_y_table], 0,
0, residual_eob_run);
/* reverse prediction of the Y-plane DC coefficients */
reverse_dc_prediction(s, 0, s->fragment_width[0], s->fragment_height[0]);
/* unpack the C plane DC coefficients */
residual_eob_run = unpack_vlcs(s, gb, &s->dc_vlc[dc_c_table], 0,
1, residual_eob_run);