falkTX
/
FFmpeg
mirror of https://github.com/falkTX/FFmpeg.git
1
0
Fork 0
Code Issues 0 Releases 338 Wiki Activity
You can not select more than 25 topics Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
20536 Commits
32 Branches
283MB
Tree: b01c7b756e
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from 'b01c7b756e'
${ noResults }
FFmpeg/libavcodec/vp6.c

644 lines
21KB
Raw Blame History 

  1. /**

  2.  * @file libavcodec/vp6.c

  3.  * VP6 compatible video decoder

  4.  *

  5.  * Copyright (C) 2006  Aurelien Jacobs <aurel@gnuage.org>

  6.  *

  7.  * The VP6F decoder accepts an optional 1 byte extradata. It is composed of:

  8.  *  - upper 4bits: difference between encoded width and visible width

  9.  *  - lower 4bits: difference between encoded height and visible height

  10.  *

  11.  * This file is part of FFmpeg.

  12.  *

  13.  * FFmpeg is free software; you can redistribute it and/or

  14.  * modify it under the terms of the GNU Lesser General Public

  15.  * License as published by the Free Software Foundation; either

  16.  * version 2.1 of the License, or (at your option) any later version.

  17.  *

  18.  * FFmpeg is distributed in the hope that it will be useful,

  19.  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  20.  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  21.  * Lesser General Public License for more details.

  22.  *

  23.  * You should have received a copy of the GNU Lesser General Public

  24.  * License along with FFmpeg; if not, write to the Free Software

  25.  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA

  26.  */

  27. 

  28. #include <stdlib.h>

  29. 

  30. #include "avcodec.h"

  31. #include "dsputil.h"

  32. #include "get_bits.h"

  33. #include "huffman.h"

  34. 

  35. #include "vp56.h"

  36. #include "vp56data.h"

  37. #include "vp6data.h"

  38. 

  39. 

  40. static void vp6_parse_coeff(VP56Context *s);

  41. static void vp6_parse_coeff_huffman(VP56Context *s);

  42. 

  43. static int vp6_parse_header(VP56Context *s, const uint8_t *buf, int buf_size,

  44.                             int *golden_frame)

  45. {

  46.     VP56RangeCoder *c = &s->c;

  47.     int parse_filter_info = 0;

  48.     int coeff_offset = 0;

  49.     int vrt_shift = 0;

  50.     int sub_version;

  51.     int rows, cols;

  52.     int res = 1;

  53.     int separated_coeff = buf[0] & 1;

  54. 

  55.     s->framep[VP56_FRAME_CURRENT]->key_frame = !(buf[0] & 0x80);

  56.     vp56_init_dequant(s, (buf[0] >> 1) & 0x3F);

  57. 

  58.     if (s->framep[VP56_FRAME_CURRENT]->key_frame) {

  59.         sub_version = buf[1] >> 3;

  60.         if (sub_version > 8)

  61.             return 0;

  62.         s->filter_header = buf[1] & 0x06;

  63.         if (buf[1] & 1) {

  64.             av_log(s->avctx, AV_LOG_ERROR, "interlacing not supported\n");

  65.             return 0;

  66.         }

  67.         if (separated_coeff || !s->filter_header) {

  68.             coeff_offset = AV_RB16(buf+2) - 2;

  69.             buf += 2;

  70.             buf_size -= 2;

  71.         }

  72. 

  73.         rows = buf[2];  /* number of stored macroblock rows */

  74.         cols = buf[3];  /* number of stored macroblock cols */

  75.         /* buf[4] is number of displayed macroblock rows */

  76.         /* buf[5] is number of displayed macroblock cols */

  77. 

  78.         if (!s->macroblocks || /* first frame */

  79.             16*cols != s->avctx->coded_width ||

  80.             16*rows != s->avctx->coded_height) {

  81.             avcodec_set_dimensions(s->avctx, 16*cols, 16*rows);

  82.             if (s->avctx->extradata_size == 1) {

  83.                 s->avctx->width  -= s->avctx->extradata[0] >> 4;

  84.                 s->avctx->height -= s->avctx->extradata[0] & 0x0F;

  85.             }

  86.             res = 2;

  87.         }

  88. 

  89.         vp56_init_range_decoder(c, buf+6, buf_size-6);

  90.         vp56_rac_gets(c, 2);

  91. 

  92.         parse_filter_info = s->filter_header;

  93.         if (sub_version < 8)

  94.             vrt_shift = 5;

  95.         s->sub_version = sub_version;

  96.     } else {

  97.         if (!s->sub_version)

  98.             return 0;

  99. 

  100.         if (separated_coeff || !s->filter_header) {

  101.             coeff_offset = AV_RB16(buf+1) - 2;

  102.             buf += 2;

  103.             buf_size -= 2;

  104.         }

  105.         vp56_init_range_decoder(c, buf+1, buf_size-1);

  106. 

  107.         *golden_frame = vp56_rac_get(c);

  108.         if (s->filter_header) {

  109.             s->deblock_filtering = vp56_rac_get(c);

  110.             if (s->deblock_filtering)

  111.                 vp56_rac_get(c);

  112.             if (s->sub_version > 7)

  113.                 parse_filter_info = vp56_rac_get(c);

  114.         }

  115.     }

  116. 

  117.     if (parse_filter_info) {

  118.         if (vp56_rac_get(c)) {

  119.             s->filter_mode = 2;

  120.             s->sample_variance_threshold = vp56_rac_gets(c, 5) << vrt_shift;

  121.             s->max_vector_length = 2 << vp56_rac_gets(c, 3);

  122.         } else if (vp56_rac_get(c)) {

  123.             s->filter_mode = 1;

  124.         } else {

  125.             s->filter_mode = 0;

  126.         }

  127.         if (s->sub_version > 7)

  128.             s->filter_selection = vp56_rac_gets(c, 4);

  129.         else

  130.             s->filter_selection = 16;

  131.     }

  132. 

  133.     s->use_huffman = vp56_rac_get(c);

  134. 

  135.     s->parse_coeff = vp6_parse_coeff;

  136.     if (coeff_offset) {

  137.         buf      += coeff_offset;

  138.         buf_size -= coeff_offset;

  139.         if (buf_size < 0)

  140.             return 0;

  141.         if (s->use_huffman) {

  142.             s->parse_coeff = vp6_parse_coeff_huffman;

  143.             init_get_bits(&s->gb, buf, buf_size<<3);

  144.         } else {

  145.             vp56_init_range_decoder(&s->cc, buf, buf_size);

  146.             s->ccp = &s->cc;

  147.         }

  148.     } else {

  149.         s->ccp = &s->c;

  150.     }

  151. 

  152.     return res;

  153. }

  154. 

  155. static void vp6_coeff_order_table_init(VP56Context *s)

  156. {

  157.     int i, pos, idx = 1;

  158. 

  159.     s->modelp->coeff_index_to_pos[0] = 0;

  160.     for (i=0; i<16; i++)

  161.         for (pos=1; pos<64; pos++)

  162.             if (s->modelp->coeff_reorder[pos] == i)

  163.                 s->modelp->coeff_index_to_pos[idx++] = pos;

  164. }

  165. 

  166. static void vp6_default_models_init(VP56Context *s)

  167. {

  168.     VP56Model *model = s->modelp;

  169. 

  170.     model->vector_dct[0] = 0xA2;

  171.     model->vector_dct[1] = 0xA4;

  172.     model->vector_sig[0] = 0x80;

  173.     model->vector_sig[1] = 0x80;

  174. 

  175.     memcpy(model->mb_types_stats, vp56_def_mb_types_stats, sizeof(model->mb_types_stats));

  176.     memcpy(model->vector_fdv, vp6_def_fdv_vector_model, sizeof(model->vector_fdv));

  177.     memcpy(model->vector_pdv, vp6_def_pdv_vector_model, sizeof(model->vector_pdv));

  178.     memcpy(model->coeff_runv, vp6_def_runv_coeff_model, sizeof(model->coeff_runv));

  179.     memcpy(model->coeff_reorder, vp6_def_coeff_reorder, sizeof(model->coeff_reorder));

  180. 

  181.     vp6_coeff_order_table_init(s);

  182. }

  183. 

  184. static void vp6_parse_vector_models(VP56Context *s)

  185. {

  186.     VP56RangeCoder *c = &s->c;

  187.     VP56Model *model = s->modelp;

  188.     int comp, node;

  189. 

  190.     for (comp=0; comp<2; comp++) {

  191.         if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][0]))

  192.             model->vector_dct[comp] = vp56_rac_gets_nn(c, 7);

  193.         if (vp56_rac_get_prob(c, vp6_sig_dct_pct[comp][1]))

  194.             model->vector_sig[comp] = vp56_rac_gets_nn(c, 7);

  195.     }

  196. 

  197.     for (comp=0; comp<2; comp++)

  198.         for (node=0; node<7; node++)

  199.             if (vp56_rac_get_prob(c, vp6_pdv_pct[comp][node]))

  200.                 model->vector_pdv[comp][node] = vp56_rac_gets_nn(c, 7);

  201. 

  202.     for (comp=0; comp<2; comp++)

  203.         for (node=0; node<8; node++)

  204.             if (vp56_rac_get_prob(c, vp6_fdv_pct[comp][node]))

  205.                 model->vector_fdv[comp][node] = vp56_rac_gets_nn(c, 7);

  206. }

  207. 

  208. /* nodes must ascend by count, but with descending symbol order */

  209. static int vp6_huff_cmp(const void *va, const void *vb)

  210. {

  211.     const Node *a = va, *b = vb;

  212.     return (a->count - b->count)*16 + (b->sym - a->sym);

  213. }

  214. 

  215. static void vp6_build_huff_tree(VP56Context *s, uint8_t coeff_model[],

  216.                                 const uint8_t *map, unsigned size, VLC *vlc)

  217. {

  218.     Node nodes[2*size], *tmp = &nodes[size];

  219.     int a, b, i;

  220. 

  221.     /* first compute probabilities from model */

  222.     tmp[0].count = 256;

  223.     for (i=0; i<size-1; i++) {

  224.         a = tmp[i].count *        coeff_model[i]  >> 8;

  225.         b = tmp[i].count * (255 - coeff_model[i]) >> 8;

  226.         nodes[map[2*i  ]].count = a + !a;

  227.         nodes[map[2*i+1]].count = b + !b;

  228.     }

  229. 

  230.     /* then build the huffman tree accodring to probabilities */

  231.     ff_huff_build_tree(s->avctx, vlc, size, nodes, vp6_huff_cmp,

  232.                        FF_HUFFMAN_FLAG_HNODE_FIRST);

  233. }

  234. 

  235. static void vp6_parse_coeff_models(VP56Context *s)

  236. {

  237.     VP56RangeCoder *c = &s->c;

  238.     VP56Model *model = s->modelp;

  239.     int def_prob[11];

  240.     int node, cg, ctx, pos;

  241.     int ct;    /* code type */

  242.     int pt;    /* plane type (0 for Y, 1 for U or V) */

  243. 

  244.     memset(def_prob, 0x80, sizeof(def_prob));

  245. 

  246.     for (pt=0; pt<2; pt++)

  247.         for (node=0; node<11; node++)

  248.             if (vp56_rac_get_prob(c, vp6_dccv_pct[pt][node])) {

  249.                 def_prob[node] = vp56_rac_gets_nn(c, 7);

  250.                 model->coeff_dccv[pt][node] = def_prob[node];

  251.             } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {

  252.                 model->coeff_dccv[pt][node] = def_prob[node];

  253.             }

  254. 

  255.     if (vp56_rac_get(c)) {

  256.         for (pos=1; pos<64; pos++)

  257.             if (vp56_rac_get_prob(c, vp6_coeff_reorder_pct[pos]))

  258.                 model->coeff_reorder[pos] = vp56_rac_gets(c, 4);

  259.         vp6_coeff_order_table_init(s);

  260.     }

  261. 

  262.     for (cg=0; cg<2; cg++)

  263.         for (node=0; node<14; node++)

  264.             if (vp56_rac_get_prob(c, vp6_runv_pct[cg][node]))

  265.                 model->coeff_runv[cg][node] = vp56_rac_gets_nn(c, 7);

  266. 

  267.     for (ct=0; ct<3; ct++)

  268.         for (pt=0; pt<2; pt++)

  269.             for (cg=0; cg<6; cg++)

  270.                 for (node=0; node<11; node++)

  271.                     if (vp56_rac_get_prob(c, vp6_ract_pct[ct][pt][cg][node])) {

  272.                         def_prob[node] = vp56_rac_gets_nn(c, 7);

  273.                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];

  274.                     } else if (s->framep[VP56_FRAME_CURRENT]->key_frame) {

  275.                         model->coeff_ract[pt][ct][cg][node] = def_prob[node];

  276.                     }

  277. 

  278.     if (s->use_huffman) {

  279.         for (pt=0; pt<2; pt++) {

  280.             vp6_build_huff_tree(s, model->coeff_dccv[pt],

  281.                                 vp6_huff_coeff_map, 12, &s->dccv_vlc[pt]);

  282.             vp6_build_huff_tree(s, model->coeff_runv[pt],

  283.                                 vp6_huff_run_map, 9, &s->runv_vlc[pt]);

  284.             for (ct=0; ct<3; ct++)

  285.                 for (cg = 0; cg < 6; cg++)

  286.                     vp6_build_huff_tree(s, model->coeff_ract[pt][ct][cg],

  287.                                         vp6_huff_coeff_map, 12,

  288.                                         &s->ract_vlc[pt][ct][cg]);

  289.         }

  290.         memset(s->nb_null, 0, sizeof(s->nb_null));

  291.     } else {

  292.     /* coeff_dcct is a linear combination of coeff_dccv */

  293.     for (pt=0; pt<2; pt++)

  294.         for (ctx=0; ctx<3; ctx++)

  295.             for (node=0; node<5; node++)

  296.                 model->coeff_dcct[pt][ctx][node] = av_clip(((model->coeff_dccv[pt][node] * vp6_dccv_lc[ctx][node][0] + 128) >> 8) + vp6_dccv_lc[ctx][node][1], 1, 255);

  297.     }

  298. }

  299. 

  300. static void vp6_parse_vector_adjustment(VP56Context *s, VP56mv *vect)

  301. {

  302.     VP56RangeCoder *c = &s->c;

  303.     VP56Model *model = s->modelp;

  304.     int comp;

  305. 

  306.     *vect = (VP56mv) {0,0};

  307.     if (s->vector_candidate_pos < 2)

  308.         *vect = s->vector_candidate[0];

  309. 

  310.     for (comp=0; comp<2; comp++) {

  311.         int i, delta = 0;

  312. 

  313.         if (vp56_rac_get_prob(c, model->vector_dct[comp])) {

  314.             static const uint8_t prob_order[] = {0, 1, 2, 7, 6, 5, 4};

  315.             for (i=0; i<sizeof(prob_order); i++) {

  316.                 int j = prob_order[i];

  317.                 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][j])<<j;

  318.             }

  319.             if (delta & 0xF0)

  320.                 delta |= vp56_rac_get_prob(c, model->vector_fdv[comp][3])<<3;

  321.             else

  322.                 delta |= 8;

  323.         } else {

  324.             delta = vp56_rac_get_tree(c, vp56_pva_tree,

  325.                                       model->vector_pdv[comp]);

  326.         }

  327. 

  328.         if (delta && vp56_rac_get_prob(c, model->vector_sig[comp]))

  329.             delta = -delta;

  330. 

  331.         if (!comp)

  332.             vect->x += delta;

  333.         else

  334.             vect->y += delta;

  335.     }

  336. }

  337. 

  338. /**

  339.  * Read number of consecutive blocks with null DC or AC.

  340.  * This value is < 74.

  341.  */

  342. static unsigned vp6_get_nb_null(VP56Context *s)

  343. {

  344.     unsigned val = get_bits(&s->gb, 2);

  345.     if (val == 2)

  346.         val += get_bits(&s->gb, 2);

  347.     else if (val == 3) {

  348.         val = get_bits1(&s->gb) << 2;

  349.         val = 6+val + get_bits(&s->gb, 2+val);

  350.     }

  351.     return val;

  352. }

  353. 

  354. static void vp6_parse_coeff_huffman(VP56Context *s)

  355. {

  356.     VP56Model *model = s->modelp;

  357.     uint8_t *permute = s->scantable.permutated;

  358.     VLC *vlc_coeff;

  359.     int coeff, sign, coeff_idx;

  360.     int b, cg, idx;

  361.     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */

  362. 

  363.     for (b=0; b<6; b++) {

  364.         int ct = 0;    /* code type */

  365.         if (b > 3) pt = 1;

  366.         vlc_coeff = &s->dccv_vlc[pt];

  367. 

  368.         for (coeff_idx=0; coeff_idx<64; ) {

  369.             int run = 1;

  370.             if (coeff_idx<2 && s->nb_null[coeff_idx][pt]) {

  371.                 s->nb_null[coeff_idx][pt]--;

  372.                 if (coeff_idx)

  373.                     break;

  374.             } else {

  375.                 if (get_bits_count(&s->gb) >= s->gb.size_in_bits)

  376.                     return;

  377.                 coeff = get_vlc2(&s->gb, vlc_coeff->table, 9, 3);

  378.                 if (coeff == 0) {

  379.                     if (coeff_idx) {

  380.                         int pt = (coeff_idx >= 6);

  381.                         run += get_vlc2(&s->gb, s->runv_vlc[pt].table, 9, 3);

  382.                         if (run >= 9)

  383.                             run += get_bits(&s->gb, 6);

  384.                     } else

  385.                         s->nb_null[0][pt] = vp6_get_nb_null(s);

  386.                     ct = 0;

  387.                 } else if (coeff == 11) {  /* end of block */

  388.                     if (coeff_idx == 1)    /* first AC coeff ? */

  389.                         s->nb_null[1][pt] = vp6_get_nb_null(s);

  390.                     break;

  391.                 } else {

  392.                     int coeff2 = vp56_coeff_bias[coeff];

  393.                     if (coeff > 4)

  394.                         coeff2 += get_bits(&s->gb, coeff <= 9 ? coeff - 4 : 11);

  395.                     ct = 1 + (coeff2 > 1);

  396.                     sign = get_bits1(&s->gb);

  397.                     coeff2 = (coeff2 ^ -sign) + sign;

  398.                     if (coeff_idx)

  399.                         coeff2 *= s->dequant_ac;

  400.                     idx = model->coeff_index_to_pos[coeff_idx];

  401.                     s->block_coeff[b][permute[idx]] = coeff2;

  402.                 }

  403.             }

  404.             coeff_idx+=run;

  405.             cg = FFMIN(vp6_coeff_groups[coeff_idx], 3);

  406.             vlc_coeff = &s->ract_vlc[pt][ct][cg];

  407.         }

  408.     }

  409. }

  410. 

  411. static void vp6_parse_coeff(VP56Context *s)

  412. {

  413.     VP56RangeCoder *c = s->ccp;

  414.     VP56Model *model = s->modelp;

  415.     uint8_t *permute = s->scantable.permutated;

  416.     uint8_t *model1, *model2, *model3;

  417.     int coeff, sign, coeff_idx;

  418.     int b, i, cg, idx, ctx;

  419.     int pt = 0;    /* plane type (0 for Y, 1 for U or V) */

  420. 

  421.     for (b=0; b<6; b++) {

  422.         int ct = 1;    /* code type */

  423.         int run = 1;

  424. 

  425.         if (b > 3) pt = 1;

  426. 

  427.         ctx = s->left_block[vp56_b6to4[b]].not_null_dc

  428.               + s->above_blocks[s->above_block_idx[b]].not_null_dc;

  429.         model1 = model->coeff_dccv[pt];

  430.         model2 = model->coeff_dcct[pt][ctx];

  431. 

  432.         for (coeff_idx=0; coeff_idx<64; ) {

  433.             if ((coeff_idx>1 && ct==0) || vp56_rac_get_prob(c, model2[0])) {

  434.                 /* parse a coeff */

  435.                 if (vp56_rac_get_prob(c, model2[2])) {

  436.                     if (vp56_rac_get_prob(c, model2[3])) {

  437.                         idx = vp56_rac_get_tree(c, vp56_pc_tree, model1);

  438.                         coeff = vp56_coeff_bias[idx+5];

  439.                         for (i=vp56_coeff_bit_length[idx]; i>=0; i--)

  440.                             coeff += vp56_rac_get_prob(c, vp56_coeff_parse_table[idx][i]) << i;

  441.                     } else {

  442.                         if (vp56_rac_get_prob(c, model2[4]))

  443.                             coeff = 3 + vp56_rac_get_prob(c, model1[5]);

  444.                         else

  445.                             coeff = 2;

  446.                     }

  447.                     ct = 2;

  448.                 } else {

  449.                     ct = 1;

  450.                     coeff = 1;

  451.                 }

  452.                 sign = vp56_rac_get(c);

  453.                 coeff = (coeff ^ -sign) + sign;

  454.                 if (coeff_idx)

  455.                     coeff *= s->dequant_ac;

  456.                 idx = model->coeff_index_to_pos[coeff_idx];

  457.                 s->block_coeff[b][permute[idx]] = coeff;

  458.                 run = 1;

  459.             } else {

  460.                 /* parse a run */

  461.                 ct = 0;

  462.                 if (coeff_idx > 0) {

  463.                     if (!vp56_rac_get_prob(c, model2[1]))

  464.                         break;

  465. 

  466.                     model3 = model->coeff_runv[coeff_idx >= 6];

  467.                     run = vp56_rac_get_tree(c, vp6_pcr_tree, model3);

  468.                     if (!run)

  469.                         for (run=9, i=0; i<6; i++)

  470.                             run += vp56_rac_get_prob(c, model3[i+8]) << i;

  471.                 }

  472.             }

  473. 

  474.             cg = vp6_coeff_groups[coeff_idx+=run];

  475.             model1 = model2 = model->coeff_ract[pt][ct][cg];

  476.         }

  477. 

  478.         s->left_block[vp56_b6to4[b]].not_null_dc =

  479.         s->above_blocks[s->above_block_idx[b]].not_null_dc = !!s->block_coeff[b][0];

  480.     }

  481. }

  482. 

  483. static int vp6_adjust(int v, int t)

  484. {

  485.     int V = v, s = v >> 31;

  486.     V ^= s;

  487.     V -= s;

  488.     if (V-t-1 >= (unsigned)(t-1))

  489.         return v;

  490.     V = 2*t - V;

  491.     V += s;

  492.     V ^= s;

  493.     return V;

  494. }

  495. 

  496. static int vp6_block_variance(uint8_t *src, int stride)

  497. {

  498.     int sum = 0, square_sum = 0;

  499.     int y, x;

  500. 

  501.     for (y=0; y<8; y+=2) {

  502.         for (x=0; x<8; x+=2) {

  503.             sum += src[x];

  504.             square_sum += src[x]*src[x];

  505.         }

  506.         src += 2*stride;

  507.     }

  508.     return (16*square_sum - sum*sum) >> 8;

  509. }

  510. 

  511. static void vp6_filter_hv4(uint8_t *dst, uint8_t *src, int stride,

  512.                            int delta, const int16_t *weights)

  513. {

  514.     int x, y;

  515. 

  516.     for (y=0; y<8; y++) {

  517.         for (x=0; x<8; x++) {

  518.             dst[x] = av_clip_uint8((  src[x-delta  ] * weights[0]

  519.                                  + src[x        ] * weights[1]

  520.                                  + src[x+delta  ] * weights[2]

  521.                                  + src[x+2*delta] * weights[3] + 64) >> 7);

  522.         }

  523.         src += stride;

  524.         dst += stride;

  525.     }

  526. }

  527. 

  528. static void vp6_filter_diag2(VP56Context *s, uint8_t *dst, uint8_t *src,

  529.                              int stride, int h_weight, int v_weight)

  530. {

  531.     uint8_t *tmp = s->edge_emu_buffer+16;

  532.     s->dsp.put_h264_chroma_pixels_tab[0](tmp, src, stride, 9, h_weight, 0);

  533.     s->dsp.put_h264_chroma_pixels_tab[0](dst, tmp, stride, 8, 0, v_weight);

  534. }

  535. 

  536. static void vp6_filter(VP56Context *s, uint8_t *dst, uint8_t *src,

  537.                        int offset1, int offset2, int stride,

  538.                        VP56mv mv, int mask, int select, int luma)

  539. {

  540.     int filter4 = 0;

  541.     int x8 = mv.x & mask;

  542.     int y8 = mv.y & mask;

  543. 

  544.     if (luma) {

  545.         x8 *= 2;

  546.         y8 *= 2;

  547.         filter4 = s->filter_mode;

  548.         if (filter4 == 2) {

  549.             if (s->max_vector_length &&

  550.                 (FFABS(mv.x) > s->max_vector_length ||

  551.                  FFABS(mv.y) > s->max_vector_length)) {

  552.                 filter4 = 0;

  553.             } else if (s->sample_variance_threshold

  554.                        && (vp6_block_variance(src+offset1, stride)

  555.                            < s->sample_variance_threshold)) {

  556.                 filter4 = 0;

  557.             }

  558.         }

  559.     }

  560. 

  561.     if ((y8 && (offset2-offset1)*s->flip<0) || (!y8 && offset1 > offset2)) {

  562.         offset1 = offset2;

  563.     }

  564. 

  565.     if (filter4) {

  566.         if (!y8) {                      /* left or right combine */

  567.             vp6_filter_hv4(dst, src+offset1, stride, 1,

  568.                            vp6_block_copy_filter[select][x8]);

  569.         } else if (!x8) {               /* above or below combine */

  570.             vp6_filter_hv4(dst, src+offset1, stride, stride,

  571.                            vp6_block_copy_filter[select][y8]);

  572.         } else {

  573.             s->dsp.vp6_filter_diag4(dst, src+offset1+((mv.x^mv.y)>>31), stride,

  574.                              vp6_block_copy_filter[select][x8],

  575.                              vp6_block_copy_filter[select][y8]);

  576.         }

  577.     } else {

  578.         if (!x8 || !y8) {

  579.             s->dsp.put_h264_chroma_pixels_tab[0](dst, src+offset1, stride, 8, x8, y8);

  580.         } else {

  581.             vp6_filter_diag2(s, dst, src+offset1 + ((mv.x^mv.y)>>31), stride, x8, y8);

  582.         }

  583.     }

  584. }

  585. 

  586. static av_cold int vp6_decode_init(AVCodecContext *avctx)

  587. {

  588.     VP56Context *s = avctx->priv_data;

  589. 

  590.     vp56_init(avctx, avctx->codec->id == CODEC_ID_VP6,

  591.                      avctx->codec->id == CODEC_ID_VP6A);

  592.     s->vp56_coord_div = vp6_coord_div;

  593.     s->parse_vector_adjustment = vp6_parse_vector_adjustment;

  594.     s->adjust = vp6_adjust;

  595.     s->filter = vp6_filter;

  596.     s->default_models_init = vp6_default_models_init;

  597.     s->parse_vector_models = vp6_parse_vector_models;

  598.     s->parse_coeff_models = vp6_parse_coeff_models;

  599.     s->parse_header = vp6_parse_header;

  600. 

  601.     return 0;

  602. }

  603. 

  604. AVCodec vp6_decoder = {

  605.     "vp6",

  606.     CODEC_TYPE_VIDEO,

  607.     CODEC_ID_VP6,

  608.     sizeof(VP56Context),

  609.     vp6_decode_init,

  610.     NULL,

  611.     vp56_free,

  612.     vp56_decode_frame,

  613.     CODEC_CAP_DR1,

  614.     .long_name = NULL_IF_CONFIG_SMALL("On2 VP6"),

  615. };

  616. 

  617. /* flash version, not flipped upside-down */

  618. AVCodec vp6f_decoder = {

  619.     "vp6f",

  620.     CODEC_TYPE_VIDEO,

  621.     CODEC_ID_VP6F,

  622.     sizeof(VP56Context),

  623.     vp6_decode_init,

  624.     NULL,

  625.     vp56_free,

  626.     vp56_decode_frame,

  627.     CODEC_CAP_DR1,

  628.     .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version)"),

  629. };

  630. 

  631. /* flash version, not flipped upside-down, with alpha channel */

  632. AVCodec vp6a_decoder = {

  633.     "vp6a",

  634.     CODEC_TYPE_VIDEO,

  635.     CODEC_ID_VP6A,

  636.     sizeof(VP56Context),

  637.     vp6_decode_init,

  638.     NULL,

  639.     vp56_free,

  640.     vp56_decode_frame,

  641.     CODEC_CAP_DR1,

  642.     .long_name = NULL_IF_CONFIG_SMALL("On2 VP6 (Flash version, with alpha channel)"),

  643. };