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.
8129 Commits
32 Branches
850MB
Tree: fe70f25c58
Branches Tags
${ item.name }
Create branch ${ searchTerm }
from 'fe70f25c58'
${ noResults }
FFmpeg/libavcodec/smacker.c

724 lines
21KB
Raw Blame History 

  1. /*

  2.  * Smacker decoder

  3.  * Copyright (c) 2006 Konstantin Shishkov

  4.  *

  5.  * This file is part of FFmpeg.

  6.  *

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

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

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

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

  11.  *

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

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

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

  15.  * Lesser General Public License for more details.

  16.  *

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

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

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

  20.  *

  21.  */

  22. 

  23. /**

  24.  * @file smacker.c

  25.  * Smacker decoder

  26.  */

  27. 

  28. /*

  29.  * Based on http://wiki.multimedia.cx/index.php?title=Smacker

  30.  */

  31. 

  32. #include <stdio.h>

  33. #include <stdlib.h>

  34. 

  35. #include "common.h"

  36. #include "avcodec.h"

  37. 

  38. #define ALT_BITSTREAM_READER_LE

  39. #include "bitstream.h"

  40. 

  41. #define SMKTREE_BITS 9

  42. #define SMK_NODE 0x80000000

  43. 

  44. /*

  45.  * Decoder context

  46.  */

  47. typedef struct SmackVContext {

  48.     AVCodecContext *avctx;

  49.     AVFrame pic;

  50. 

  51.     int *mmap_tbl, *mclr_tbl, *full_tbl, *type_tbl;

  52.     int mmap_last[3], mclr_last[3], full_last[3], type_last[3];

  53. } SmackVContext;

  54. 

  55. /**

  56.  * Context used for code reconstructing

  57.  */

  58. typedef struct HuffContext {

  59.     int length;

  60.     int maxlength;

  61.     int current;

  62.     uint32_t *bits;

  63.     int *lengths;

  64.     int *values;

  65. } HuffContext;

  66. 

  67. /* common parameters used for decode_bigtree */

  68. typedef struct DBCtx {

  69.     VLC *v1, *v2;

  70.     int *recode1, *recode2;

  71.     int escapes[3];

  72.     int *last;

  73.     int lcur;

  74. } DBCtx;

  75. 

  76. /* possible runs of blocks */

  77. static const int block_runs[64] = {

  78.       1,    2,    3,    4,    5,    6,    7,    8,

  79.       9,   10,   11,   12,   13,   14,   15,   16,

  80.      17,   18,   19,   20,   21,   22,   23,   24,

  81.      25,   26,   27,   28,   29,   30,   31,   32,

  82.      33,   34,   35,   36,   37,   38,   39,   40,

  83.      41,   42,   43,   44,   45,   46,   47,   48,

  84.      49,   50,   51,   52,   53,   54,   55,   56,

  85.      57,   58,   59,  128,  256,  512, 1024, 2048 };

  86. 

  87. enum SmkBlockTypes {

  88.     SMK_BLK_MONO = 0,

  89.     SMK_BLK_FULL = 1,

  90.     SMK_BLK_SKIP = 2,

  91.     SMK_BLK_FILL = 3 };

  92. 

  93. /**

  94.  * Decode local frame tree

  95.  */

  96. static int smacker_decode_tree(GetBitContext *gb, HuffContext *hc, uint32_t prefix, int length)

  97. {

  98.     if(!get_bits1(gb)){ //Leaf

  99.         if(hc->current >= 256){

  100.             av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");

  101.             return -1;

  102.         }

  103.         if(length){

  104.             hc->bits[hc->current] = prefix;

  105.             hc->lengths[hc->current] = length;

  106.         } else {

  107.             hc->bits[hc->current] = 0;

  108.             hc->lengths[hc->current] = 0;

  109.         }

  110.         hc->values[hc->current] = get_bits(gb, 8);

  111.         hc->current++;

  112.         if(hc->maxlength < length)

  113.             hc->maxlength = length;

  114.         return 0;

  115.     } else { //Node

  116.         int r;

  117.         length++;

  118.         r = smacker_decode_tree(gb, hc, prefix, length);

  119.         if(r)

  120.             return r;

  121.         return smacker_decode_tree(gb, hc, prefix | (1 << (length - 1)), length);

  122.     }

  123. }

  124. 

  125. /**

  126.  * Decode header tree

  127.  */

  128. static int smacker_decode_bigtree(GetBitContext *gb, HuffContext *hc, DBCtx *ctx)

  129. {

  130.     if(!get_bits1(gb)){ //Leaf

  131.         int val, i1, i2, b1, b2;

  132.         if(hc->current >= hc->length){

  133.             av_log(NULL, AV_LOG_ERROR, "Tree size exceeded!\n");

  134.             return -1;

  135.         }

  136.         b1 = get_bits_count(gb);

  137.         i1 = get_vlc2(gb, ctx->v1->table, SMKTREE_BITS, 3);

  138.         b1 = get_bits_count(gb) - b1;

  139.         b2 = get_bits_count(gb);

  140.         i2 = get_vlc2(gb, ctx->v2->table, SMKTREE_BITS, 3);

  141.         b2 = get_bits_count(gb) - b2;

  142.         val = ctx->recode1[i1] | (ctx->recode2[i2] << 8);

  143.         if(val == ctx->escapes[0]) {

  144.             ctx->last[0] = hc->current;

  145.             val = 0;

  146.         } else if(val == ctx->escapes[1]) {

  147.             ctx->last[1] = hc->current;

  148.             val = 0;

  149.         } else if(val == ctx->escapes[2]) {

  150.             ctx->last[2] = hc->current;

  151.             val = 0;

  152.         }

  153. 

  154.         hc->values[hc->current++] = val;

  155.         return 1;

  156.     } else { //Node

  157.         int r = 0, t;

  158. 

  159.         t = hc->current++;

  160.         r = smacker_decode_bigtree(gb, hc, ctx);

  161.         if(r < 0)

  162.             return r;

  163.         hc->values[t] = SMK_NODE | r;

  164.         r++;

  165.         r += smacker_decode_bigtree(gb, hc, ctx);

  166.         return r;

  167.     }

  168. }

  169. 

  170. /**

  171.  * Store large tree as FFmpeg's vlc codes

  172.  */

  173. static int smacker_decode_header_tree(SmackVContext *smk, GetBitContext *gb, int **recodes, int *last, int size)

  174. {

  175.     int res;

  176.     HuffContext huff;

  177.     HuffContext tmp1, tmp2;

  178.     VLC vlc[2];

  179.     int escapes[3];

  180.     DBCtx ctx;

  181. 

  182.     if(size >= UINT_MAX>>4){ // (((size + 3) >> 2) + 3) << 2 must not overflow

  183.         av_log(smk->avctx, AV_LOG_ERROR, "size too large\n");

  184.         return -1;

  185.     }

  186. 

  187.     tmp1.length = 256;

  188.     tmp1.maxlength = 0;

  189.     tmp1.current = 0;

  190.     tmp1.bits = av_mallocz(256 * 4);

  191.     tmp1.lengths = av_mallocz(256 * sizeof(int));

  192.     tmp1.values = av_mallocz(256 * sizeof(int));

  193. 

  194.     tmp2.length = 256;

  195.     tmp2.maxlength = 0;

  196.     tmp2.current = 0;

  197.     tmp2.bits = av_mallocz(256 * 4);

  198.     tmp2.lengths = av_mallocz(256 * sizeof(int));

  199.     tmp2.values = av_mallocz(256 * sizeof(int));

  200. 

  201.     memset(&vlc[0], 0, sizeof(VLC));

  202.     memset(&vlc[1], 0, sizeof(VLC));

  203. 

  204.     if(get_bits1(gb)) {

  205.         smacker_decode_tree(gb, &tmp1, 0, 0);

  206.         get_bits1(gb);

  207.         res = init_vlc(&vlc[0], SMKTREE_BITS, tmp1.length,

  208.                     tmp1.lengths, sizeof(int), sizeof(int),

  209.                     tmp1.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);

  210.         if(res < 0) {

  211.             av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");

  212.             return -1;

  213.         }

  214.     } else {

  215.         av_log(smk->avctx, AV_LOG_ERROR, "Skipping low bytes tree\n");

  216.     }

  217.     if(get_bits1(gb)){

  218.         smacker_decode_tree(gb, &tmp2, 0, 0);

  219.         get_bits1(gb);

  220.         res = init_vlc(&vlc[1], SMKTREE_BITS, tmp2.length,

  221.                     tmp2.lengths, sizeof(int), sizeof(int),

  222.                     tmp2.bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);

  223.         if(res < 0) {

  224.             av_log(smk->avctx, AV_LOG_ERROR, "Cannot build VLC table\n");

  225.             return -1;

  226.         }

  227.     } else {

  228.         av_log(smk->avctx, AV_LOG_ERROR, "Skipping high bytes tree\n");

  229.     }

  230. 

  231.     escapes[0]  = get_bits(gb, 8);

  232.     escapes[0] |= get_bits(gb, 8) << 8;

  233.     escapes[1]  = get_bits(gb, 8);

  234.     escapes[1] |= get_bits(gb, 8) << 8;

  235.     escapes[2]  = get_bits(gb, 8);

  236.     escapes[2] |= get_bits(gb, 8) << 8;

  237. 

  238.     last[0] = last[1] = last[2] = -1;

  239. 

  240.     ctx.escapes[0] = escapes[0];

  241.     ctx.escapes[1] = escapes[1];

  242.     ctx.escapes[2] = escapes[2];

  243.     ctx.v1 = &vlc[0];

  244.     ctx.v2 = &vlc[1];

  245.     ctx.recode1 = tmp1.values;

  246.     ctx.recode2 = tmp2.values;

  247.     ctx.last = last;

  248. 

  249.     huff.length = ((size + 3) >> 2) + 3;

  250.     huff.maxlength = 0;

  251.     huff.current = 0;

  252.     huff.values = av_mallocz(huff.length * sizeof(int));

  253. 

  254.     smacker_decode_bigtree(gb, &huff, &ctx);

  255.     get_bits1(gb);

  256.     if(ctx.last[0] == -1) ctx.last[0] = huff.current++;

  257.     if(ctx.last[1] == -1) ctx.last[1] = huff.current++;

  258.     if(ctx.last[2] == -1) ctx.last[2] = huff.current++;

  259. 

  260.     *recodes = huff.values;

  261. 

  262.     if(vlc[0].table)

  263.         free_vlc(&vlc[0]);

  264.     if(vlc[1].table)

  265.         free_vlc(&vlc[1]);

  266.     av_free(tmp1.bits);

  267.     av_free(tmp1.lengths);

  268.     av_free(tmp1.values);

  269.     av_free(tmp2.bits);

  270.     av_free(tmp2.lengths);

  271.     av_free(tmp2.values);

  272. 

  273.     return 0;

  274. }

  275. 

  276. static int decode_header_trees(SmackVContext *smk) {

  277.     GetBitContext gb;

  278.     int mmap_size, mclr_size, full_size, type_size;

  279. 

  280.     mmap_size = AV_RL32(smk->avctx->extradata);

  281.     mclr_size = AV_RL32(smk->avctx->extradata + 4);

  282.     full_size = AV_RL32(smk->avctx->extradata + 8);

  283.     type_size = AV_RL32(smk->avctx->extradata + 12);

  284. 

  285.     init_get_bits(&gb, smk->avctx->extradata + 16, (smk->avctx->extradata_size - 16) * 8);

  286. 

  287.     if(!get_bits1(&gb)) {

  288.         av_log(smk->avctx, AV_LOG_INFO, "Skipping MMAP tree\n");

  289.         smk->mmap_tbl = av_malloc(sizeof(int) * 2);

  290.         smk->mmap_tbl[0] = 0;

  291.         smk->mmap_last[0] = smk->mmap_last[1] = smk->mmap_last[2] = 1;

  292.     } else {

  293.         smacker_decode_header_tree(smk, &gb, &smk->mmap_tbl, smk->mmap_last, mmap_size);

  294.     }

  295.     if(!get_bits(&gb, 1)) {

  296.         av_log(smk->avctx, AV_LOG_INFO, "Skipping MCLR tree\n");

  297.         smk->mclr_tbl = av_malloc(sizeof(int) * 2);

  298.         smk->mclr_tbl[0] = 0;

  299.         smk->mclr_last[0] = smk->mclr_last[1] = smk->mclr_last[2] = 1;

  300.     } else {

  301.         smacker_decode_header_tree(smk, &gb, &smk->mclr_tbl, smk->mclr_last, mclr_size);

  302.     }

  303.     if(!get_bits(&gb, 1)) {

  304.         av_log(smk->avctx, AV_LOG_INFO, "Skipping FULL tree\n");

  305.         smk->full_tbl = av_malloc(sizeof(int) * 2);

  306.         smk->full_tbl[0] = 0;

  307.         smk->full_last[0] = smk->full_last[1] = smk->full_last[2] = 1;

  308.     } else {

  309.         smacker_decode_header_tree(smk, &gb, &smk->full_tbl, smk->full_last, full_size);

  310.     }

  311.     if(!get_bits(&gb, 1)) {

  312.         av_log(smk->avctx, AV_LOG_INFO, "Skipping TYPE tree\n");

  313.         smk->type_tbl = av_malloc(sizeof(int) * 2);

  314.         smk->type_tbl[0] = 0;

  315.         smk->type_last[0] = smk->type_last[1] = smk->type_last[2] = 1;

  316.     } else {

  317.         smacker_decode_header_tree(smk, &gb, &smk->type_tbl, smk->type_last, type_size);

  318.     }

  319. 

  320.     return 0;

  321. }

  322. 

  323. static av_always_inline void last_reset(int *recode, int *last) {

  324.     recode[last[0]] = recode[last[1]] = recode[last[2]] = 0;

  325. }

  326. 

  327. /* get code and update history */

  328. static av_always_inline int smk_get_code(GetBitContext *gb, int *recode, int *last) {

  329.     register int *table = recode;

  330.     int v, b;

  331. 

  332.     b = get_bits_count(gb);

  333.     while(*table & SMK_NODE) {

  334.         if(get_bits1(gb))

  335.             table += (*table) & (~SMK_NODE);

  336.         table++;

  337.     }

  338.     v = *table;

  339.     b = get_bits_count(gb) - b;

  340. 

  341.     if(v != recode[last[0]]) {

  342.         recode[last[2]] = recode[last[1]];

  343.         recode[last[1]] = recode[last[0]];

  344.         recode[last[0]] = v;

  345.     }

  346.     return v;

  347. }

  348. 

  349. static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)

  350. {

  351.     SmackVContext * const smk = (SmackVContext *)avctx->priv_data;

  352.     uint8_t *out;

  353.     uint32_t *pal;

  354.     GetBitContext gb;

  355.     int blocks, blk, bw, bh;

  356.     int i;

  357.     int stride;

  358. 

  359.     if(buf_size == 769)

  360.         return 0;

  361.     if(smk->pic.data[0])

  362.             avctx->release_buffer(avctx, &smk->pic);

  363. 

  364.     smk->pic.reference = 1;

  365.     smk->pic.buffer_hints = FF_BUFFER_HINTS_VALID | FF_BUFFER_HINTS_PRESERVE | FF_BUFFER_HINTS_REUSABLE;

  366.     if(avctx->reget_buffer(avctx, &smk->pic) < 0){

  367.         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");

  368.         return -1;

  369.     }

  370. 

  371.     /* make the palette available on the way out */

  372.     out = buf + 1;

  373.     pal = (uint32_t*)smk->pic.data[1];

  374.     smk->pic.palette_has_changed = buf[0] & 1;

  375.     smk->pic.key_frame = !!(buf[0] & 2);

  376.     if(smk->pic.key_frame)

  377.         smk->pic.pict_type = FF_I_TYPE;

  378.     else

  379.         smk->pic.pict_type = FF_P_TYPE;

  380. 

  381.     for(i = 0; i < 256; i++) {

  382.         int r, g, b;

  383.         r = *out++;

  384.         g = *out++;

  385.         b = *out++;

  386.         *pal++ = (r << 16) | (g << 8) | b;

  387.     }

  388. 

  389.     last_reset(smk->mmap_tbl, smk->mmap_last);

  390.     last_reset(smk->mclr_tbl, smk->mclr_last);

  391.     last_reset(smk->full_tbl, smk->full_last);

  392.     last_reset(smk->type_tbl, smk->type_last);

  393.     init_get_bits(&gb, buf + 769, (buf_size - 769) * 8);

  394. 

  395.     blk = 0;

  396.     bw = avctx->width >> 2;

  397.     bh = avctx->height >> 2;

  398.     blocks = bw * bh;

  399.     out = smk->pic.data[0];

  400.     stride = smk->pic.linesize[0];

  401.     while(blk < blocks) {

  402.         int type, run, mode;

  403.         uint16_t pix;

  404. 

  405.         type = smk_get_code(&gb, smk->type_tbl, smk->type_last);

  406.         run = block_runs[(type >> 2) & 0x3F];

  407.         switch(type & 3){

  408.         case SMK_BLK_MONO:

  409.             while(run-- && blk < blocks){

  410.                 int clr, map;

  411.                 int hi, lo;

  412.                 clr = smk_get_code(&gb, smk->mclr_tbl, smk->mclr_last);

  413.                 map = smk_get_code(&gb, smk->mmap_tbl, smk->mmap_last);

  414.                 out = smk->pic.data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;

  415.                 hi = clr >> 8;

  416.                 lo = clr & 0xFF;

  417.                 for(i = 0; i < 4; i++) {

  418.                     if(map & 1) out[0] = hi; else out[0] = lo;

  419.                     if(map & 2) out[1] = hi; else out[1] = lo;

  420.                     if(map & 4) out[2] = hi; else out[2] = lo;

  421.                     if(map & 8) out[3] = hi; else out[3] = lo;

  422.                     map >>= 4;

  423.                     out += stride;

  424.                 }

  425.                 blk++;

  426.             }

  427.             break;

  428.         case SMK_BLK_FULL:

  429.             mode = 0;

  430.             if(avctx->codec_tag == MKTAG('S', 'M', 'K', '4')) { // In case of Smacker v4 we have three modes

  431.                 if(get_bits1(&gb)) mode = 1;

  432.                 else if(get_bits1(&gb)) mode = 2;

  433.             }

  434.             while(run-- && blk < blocks){

  435.                 out = smk->pic.data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;

  436.                 switch(mode){

  437.                 case 0:

  438.                     for(i = 0; i < 4; i++) {

  439.                         pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);

  440.                         out[2] = pix & 0xFF;

  441.                         out[3] = pix >> 8;

  442.                         pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);

  443.                         out[0] = pix & 0xFF;

  444.                         out[1] = pix >> 8;

  445.                         out += stride;

  446.                     }

  447.                     break;

  448.                 case 1:

  449.                     pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);

  450.                     out[0] = out[1] = pix & 0xFF;

  451.                     out[2] = out[3] = pix >> 8;

  452.                     out += stride;

  453.                     out[0] = out[1] = pix & 0xFF;

  454.                     out[2] = out[3] = pix >> 8;

  455.                     out += stride;

  456.                     pix = smk_get_code(&gb, smk->full_tbl, smk->full_last);

  457.                     out[0] = out[1] = pix & 0xFF;

  458.                     out[2] = out[3] = pix >> 8;

  459.                     out += stride;

  460.                     out[0] = out[1] = pix & 0xFF;

  461.                     out[2] = out[3] = pix >> 8;

  462.                     out += stride;

  463.                     break;

  464.                 case 2:

  465.                     for(i = 0; i < 2; i++) {

  466.                         uint16_t pix1, pix2;

  467.                         pix1 = smk_get_code(&gb, smk->full_tbl, smk->full_last);

  468.                         pix2 = smk_get_code(&gb, smk->full_tbl, smk->full_last);

  469.                         out[0] = pix1 & 0xFF; out[1] = pix1 >> 8;

  470.                         out[2] = pix2 & 0xFF; out[3] = pix2 >> 8;

  471.                         out += stride;

  472.                         out[0] = pix1 & 0xFF; out[1] = pix1 >> 8;

  473.                         out[2] = pix2 & 0xFF; out[3] = pix2 >> 8;

  474.                         out += stride;

  475.                     }

  476.                     break;

  477.                 }

  478.                 blk++;

  479.             }

  480.             break;

  481.         case SMK_BLK_SKIP:

  482.             while(run-- && blk < blocks)

  483.                 blk++;

  484.             break;

  485.         case SMK_BLK_FILL:

  486.             mode = type >> 8;

  487.             while(run-- && blk < blocks){

  488.                 uint32_t col;

  489.                 out = smk->pic.data[0] + (blk / bw) * (stride * 4) + (blk % bw) * 4;

  490.                 col = mode * 0x01010101;

  491.                 for(i = 0; i < 4; i++) {

  492.                     *((uint32_t*)out) = col;

  493.                     out += stride;

  494.                 }

  495.                 blk++;

  496.             }

  497.             break;

  498.         }

  499. 

  500.     }

  501. 

  502.     *data_size = sizeof(AVFrame);

  503.     *(AVFrame*)data = smk->pic;

  504. 

  505.     /* always report that the buffer was completely consumed */

  506.     return buf_size;

  507. }

  508. 

  509. 

  510. 

  511. /*

  512.  *

  513.  * Init smacker decoder

  514.  *

  515.  */

  516. static int decode_init(AVCodecContext *avctx)

  517. {

  518.     SmackVContext * const c = (SmackVContext *)avctx->priv_data;

  519. 

  520.     c->avctx = avctx;

  521.     avctx->has_b_frames = 0;

  522. 

  523.     c->pic.data[0] = NULL;

  524. 

  525.     if (avcodec_check_dimensions(avctx, avctx->width, avctx->height) < 0) {

  526.         return 1;

  527.     }

  528. 

  529.     avctx->pix_fmt = PIX_FMT_PAL8;

  530. 

  531. 

  532.     /* decode huffman trees from extradata */

  533.     if(avctx->extradata_size < 16){

  534.         av_log(avctx, AV_LOG_ERROR, "Extradata missing!\n");

  535.         return -1;

  536.     }

  537. 

  538.     decode_header_trees(c);

  539. 

  540. 

  541.     return 0;

  542. }

  543. 

  544. 

  545. 

  546. /*

  547.  *

  548.  * Uninit smacker decoder

  549.  *

  550.  */

  551. static int decode_end(AVCodecContext *avctx)

  552. {

  553.     SmackVContext * const smk = (SmackVContext *)avctx->priv_data;

  554. 

  555.     av_freep(&smk->mmap_tbl);

  556.     av_freep(&smk->mclr_tbl);

  557.     av_freep(&smk->full_tbl);

  558.     av_freep(&smk->type_tbl);

  559. 

  560.     if (smk->pic.data[0])

  561.         avctx->release_buffer(avctx, &smk->pic);

  562. 

  563.     return 0;

  564. }

  565. 

  566. 

  567. static int smka_decode_init(AVCodecContext *avctx)

  568. {

  569.     return 0;

  570. }

  571. 

  572. /**

  573.  * Decode Smacker audio data

  574.  */

  575. static int smka_decode_frame(AVCodecContext *avctx, void *data, int *data_size, uint8_t *buf, int buf_size)

  576. {

  577.     GetBitContext gb;

  578.     HuffContext h[4];

  579.     VLC vlc[4];

  580.     int16_t *samples = data;

  581.     int val;

  582.     int i, res;

  583.     int unp_size;

  584.     int bits, stereo;

  585.     int pred[2] = {0, 0};

  586. 

  587.     unp_size = AV_RL32(buf);

  588. 

  589.     init_get_bits(&gb, buf + 4, (buf_size - 4) * 8);

  590. 

  591.     if(!get_bits1(&gb)){

  592.         av_log(avctx, AV_LOG_INFO, "Sound: no data\n");

  593.         *data_size = 0;

  594.         return 1;

  595.     }

  596.     stereo = get_bits1(&gb);

  597.     bits = get_bits1(&gb);

  598. 

  599.     memset(vlc, 0, sizeof(VLC) * 4);

  600.     memset(h, 0, sizeof(HuffContext) * 4);

  601.     // Initialize

  602.     for(i = 0; i < (1 << (bits + stereo)); i++) {

  603.         h[i].length = 256;

  604.         h[i].maxlength = 0;

  605.         h[i].current = 0;

  606.         h[i].bits = av_mallocz(256 * 4);

  607.         h[i].lengths = av_mallocz(256 * sizeof(int));

  608.         h[i].values = av_mallocz(256 * sizeof(int));

  609.         get_bits1(&gb);

  610.         smacker_decode_tree(&gb, &h[i], 0, 0);

  611.         get_bits1(&gb);

  612.         if(h[i].current > 1) {

  613.             res = init_vlc(&vlc[i], SMKTREE_BITS, h[i].length,

  614.                     h[i].lengths, sizeof(int), sizeof(int),

  615.                     h[i].bits, sizeof(uint32_t), sizeof(uint32_t), INIT_VLC_LE);

  616.             if(res < 0) {

  617.                 av_log(avctx, AV_LOG_ERROR, "Cannot build VLC table\n");

  618.                 return -1;

  619.             }

  620.         }

  621.     }

  622.     if(bits) { //decode 16-bit data

  623.         pred[0]  = get_bits(&gb, 8);

  624.         pred[0] |= get_bits(&gb, 8);

  625.         *samples++ = pred[0];

  626.         if(stereo) {

  627.             pred[1]  = get_bits(&gb, 8);

  628.             pred[1] |= get_bits(&gb, 8);

  629.             *samples++ = pred[1];

  630.         }

  631.         for(i = 0; i < unp_size / 2; i++) {

  632.             if(i & stereo) {

  633.                 if(vlc[2].table)

  634.                     res = get_vlc2(&gb, vlc[2].table, SMKTREE_BITS, 3);

  635.                 else

  636.                     res = 0;

  637.                 val  = h[2].values[res];

  638.                 if(vlc[3].table)

  639.                     res = get_vlc2(&gb, vlc[3].table, SMKTREE_BITS, 3);

  640.                 else

  641.                     res = 0;

  642.                 val |= h[3].values[res] << 8;

  643.                 pred[1] += (int16_t)val;

  644.                 *samples++ = pred[1];

  645.             } else {

  646.                 if(vlc[0].table)

  647.                     res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);

  648.                 else

  649.                     res = 0;

  650.                 val  = h[0].values[res];

  651.                 if(vlc[1].table)

  652.                     res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);

  653.                 else

  654.                     res = 0;

  655.                 val |= h[1].values[res] << 8;

  656.                 pred[0] += val;

  657.                 *samples++ = pred[0];

  658.             }

  659.         }

  660.     } else { //8-bit data

  661.         pred[0] = get_bits(&gb, 8);

  662.         *samples++ = (pred[0] - 0x80) << 8;

  663.         if(stereo) {

  664.             pred[1] = get_bits(&gb, 8);

  665.             *samples++ = (pred[1] - 0x80) << 8;

  666.         }

  667.         for(i = 0; i < unp_size; i++) {

  668.             if(i & stereo){

  669.                 if(vlc[1].table)

  670.                     res = get_vlc2(&gb, vlc[1].table, SMKTREE_BITS, 3);

  671.                 else

  672.                     res = 0;

  673.                 pred[1] += (int8_t)h[1].values[res];

  674.                 *samples++ = (pred[1] - 0x80) << 8;

  675.             } else {

  676.                 if(vlc[0].table)

  677.                     res = get_vlc2(&gb, vlc[0].table, SMKTREE_BITS, 3);

  678.                 else

  679.                     res = 0;

  680.                 pred[0] += (int8_t)h[0].values[res];

  681.                 *samples++ = (pred[0] - 0x80) << 8;

  682.             }

  683.         }

  684.         unp_size *= 2;

  685.     }

  686. 

  687.     for(i = 0; i < 4; i++) {

  688.         if(vlc[i].table)

  689.             free_vlc(&vlc[i]);

  690.         if(h[i].bits)

  691.             av_free(h[i].bits);

  692.         if(h[i].lengths)

  693.             av_free(h[i].lengths);

  694.         if(h[i].values)

  695.             av_free(h[i].values);

  696.     }

  697. 

  698.     *data_size = unp_size;

  699.     return buf_size;

  700. }

  701. 

  702. AVCodec smacker_decoder = {

  703.     "smackvid",

  704.     CODEC_TYPE_VIDEO,

  705.     CODEC_ID_SMACKVIDEO,

  706.     sizeof(SmackVContext),

  707.     decode_init,

  708.     NULL,

  709.     decode_end,

  710.     decode_frame

  711. };

  712. 

  713. AVCodec smackaud_decoder = {

  714.     "smackaud",

  715.     CODEC_TYPE_AUDIO,

  716.     CODEC_ID_SMACKAUDIO,

  717.     0,

  718.     smka_decode_init,

  719.     NULL,

  720.     NULL,

  721.     smka_decode_frame

  722. };