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FFmpeg/libavcodec/smacker.c

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  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.  * @file smacker.c

  24.  * Smacker decoder

  25.  */

  26. 

  27. /*

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

  29.  */

  30. 

  31. #include <stdio.h>

  32. #include <stdlib.h>

  33. 

  34. #include "avcodec.h"

  35. 

  36. #define ALT_BITSTREAM_READER_LE

  37. #include "bitstream.h"

  38. 

  39. #define SMKTREE_BITS 9

  40. #define SMK_NODE 0x80000000

  41. 

  42. /*

  43.  * Decoder context

  44.  */

  45. typedef struct SmackVContext {

  46.     AVCodecContext *avctx;

  47.     AVFrame pic;

  48. 

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

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

  51. } SmackVContext;

  52. 

  53. /**

  54.  * Context used for code reconstructing

  55.  */

  56. typedef struct HuffContext {

  57.     int length;

  58.     int maxlength;

  59.     int current;

  60.     uint32_t *bits;

  61.     int *lengths;

  62.     int *values;

  63. } HuffContext;

  64. 

  65. /* common parameters used for decode_bigtree */

  66. typedef struct DBCtx {

  67.     VLC *v1, *v2;

  68.     int *recode1, *recode2;

  69.     int escapes[3];

  70.     int *last;

  71.     int lcur;

  72. } DBCtx;

  73. 

  74. /* possible runs of blocks */

  75. static const int block_runs[64] = {

  76.       1,    2,    3,    4,    5,    6,    7,    8,

  77.       9,   10,   11,   12,   13,   14,   15,   16,

  78.      17,   18,   19,   20,   21,   22,   23,   24,

  79.      25,   26,   27,   28,   29,   30,   31,   32,

  80.      33,   34,   35,   36,   37,   38,   39,   40,

  81.      41,   42,   43,   44,   45,   46,   47,   48,

  82.      49,   50,   51,   52,   53,   54,   55,   56,

  83.      57,   58,   59,  128,  256,  512, 1024, 2048 };

  84. 

  85. enum SmkBlockTypes {

  86.     SMK_BLK_MONO = 0,

  87.     SMK_BLK_FULL = 1,

  88.     SMK_BLK_SKIP = 2,

  89.     SMK_BLK_FILL = 3 };

  90. 

  91. /**

  92.  * Decode local frame tree

  93.  */

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

  95. {

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

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

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

  99.             return -1;

  100.         }

  101.         if(length){

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

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

  104.         } else {

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

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

  107.         }

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

  109.         hc->current++;

  110.         if(hc->maxlength < length)

  111.             hc->maxlength = length;

  112.         return 0;

  113.     } else { //Node

  114.         int r;

  115.         length++;

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

  117.         if(r)

  118.             return r;

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

  120.     }

  121. }

  122. 

  123. /**

  124.  * Decode header tree

  125.  */

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

  127. {

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

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

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

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

  132.             return -1;

  133.         }

  134.         b1 = get_bits_count(gb);

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

  136.         b1 = get_bits_count(gb) - b1;

  137.         b2 = get_bits_count(gb);

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

  139.         b2 = get_bits_count(gb) - b2;

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

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

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

  143.             val = 0;

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

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

  146.             val = 0;

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

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

  149.             val = 0;

  150.         }

  151. 

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

  153.         return 1;

  154.     } else { //Node

  155.         int r = 0, t;

  156. 

  157.         t = hc->current++;

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

  159.         if(r < 0)

  160.             return r;

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

  162.         r++;

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

  164.         return r;

  165.     }

  166. }

  167. 

  168. /**

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

  170.  */

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

  172. {

  173.     int res;

  174.     HuffContext huff;

  175.     HuffContext tmp1, tmp2;

  176.     VLC vlc[2];

  177.     int escapes[3];

  178.     DBCtx ctx;

  179. 

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

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

  182.         return -1;

  183.     }

  184. 

  185.     tmp1.length = 256;

  186.     tmp1.maxlength = 0;

  187.     tmp1.current = 0;

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

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

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

  191. 

  192.     tmp2.length = 256;

  193.     tmp2.maxlength = 0;

  194.     tmp2.current = 0;

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

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

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

  198. 

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

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

  201. 

  202.     if(get_bits1(gb)) {

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

  204.         skip_bits1(gb);

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

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

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

  208.         if(res < 0) {

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

  210.             return -1;

  211.         }

  212.     } else {

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

  214.     }

  215.     if(get_bits1(gb)){

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

  217.         skip_bits1(gb);

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

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

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

  221.         if(res < 0) {

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

  223.             return -1;

  224.         }

  225.     } else {

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

  227.     }

  228. 

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

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

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

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

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

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

  235. 

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

  237. 

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

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

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

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

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

  243.     ctx.recode1 = tmp1.values;

  244.     ctx.recode2 = tmp2.values;

  245.     ctx.last = last;

  246. 

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

  248.     huff.maxlength = 0;

  249.     huff.current = 0;

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

  251. 

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

  253.     skip_bits1(gb);

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

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

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

  257. 

  258.     *recodes = huff.values;

  259. 

  260.     if(vlc[0].table)

  261.         free_vlc(&vlc[0]);

  262.     if(vlc[1].table)

  263.         free_vlc(&vlc[1]);

  264.     av_free(tmp1.bits);

  265.     av_free(tmp1.lengths);

  266.     av_free(tmp1.values);

  267.     av_free(tmp2.bits);

  268.     av_free(tmp2.lengths);

  269.     av_free(tmp2.values);

  270. 

  271.     return 0;

  272. }

  273. 

  274. static int decode_header_trees(SmackVContext *smk) {

  275.     GetBitContext gb;

  276.     int mmap_size, mclr_size, full_size, type_size;

  277. 

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

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

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

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

  282. 

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

  284. 

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

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

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

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

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

  290.     } else {

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

  292.     }

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

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

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

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

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

  298.     } else {

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

  300.     }

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

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

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

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

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

  306.     } else {

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

  308.     }

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

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

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

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

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

  314.     } else {

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

  316.     }

  317. 

  318.     return 0;

  319. }

  320. 

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

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

  323. }

  324. 

  325. /* get code and update history */

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

  327.     register int *table = recode;

  328.     int v, b;

  329. 

  330.     b = get_bits_count(gb);

  331.     while(*table & SMK_NODE) {

  332.         if(get_bits1(gb))

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

  334.         table++;

  335.     }

  336.     v = *table;

  337.     b = get_bits_count(gb) - b;

  338. 

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

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

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

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

  343.     }

  344.     return v;

  345. }

  346. 

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

  348. {

  349.     SmackVContext * const smk = avctx->priv_data;

  350.     uint8_t *out;

  351.     uint32_t *pal;

  352.     GetBitContext gb;

  353.     int blocks, blk, bw, bh;

  354.     int i;

  355.     int stride;

  356. 

  357.     if(buf_size == 769)

  358.         return 0;

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

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

  361. 

  362.     smk->pic.reference = 1;

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

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

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

  366.         return -1;

  367.     }

  368. 

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

  370.     out = buf + 1;

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

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

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

  374.     if(smk->pic.key_frame)

  375.         smk->pic.pict_type = FF_I_TYPE;

  376.     else

  377.         smk->pic.pict_type = FF_P_TYPE;

  378. 

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

  380.         int r, g, b;

  381.         r = *out++;

  382.         g = *out++;

  383.         b = *out++;

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

  385.     }

  386. 

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

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

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

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

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

  392. 

  393.     blk = 0;

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

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

  396.     blocks = bw * bh;

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

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

  399.     while(blk < blocks) {

  400.         int type, run, mode;

  401.         uint16_t pix;

  402. 

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

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

  405.         switch(type & 3){

  406.         case SMK_BLK_MONO:

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

  408.                 int clr, map;

  409.                 int hi, lo;

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

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

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

  413.                 hi = clr >> 8;

  414.                 lo = clr & 0xFF;

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

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

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

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

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

  420.                     map >>= 4;

  421.                     out += stride;

  422.                 }

  423.                 blk++;

  424.             }

  425.             break;

  426.         case SMK_BLK_FULL:

  427.             mode = 0;

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

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

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

  431.             }

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

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

  434.                 switch(mode){

  435.                 case 0:

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

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

  438.                         AV_WL16(out+2,pix);

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

  440.                         AV_WL16(out,pix);

  441.                         out += stride;

  442.                     }

  443.                     break;

  444.                 case 1:

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

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

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

  448.                     out += stride;

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

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

  451.                     out += stride;

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

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

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

  455.                     out += stride;

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

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

  458.                     out += stride;

  459.                     break;

  460.                 case 2:

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

  462.                         uint16_t pix1, pix2;

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

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

  465.                         AV_WL16(out,pix1);

  466.                         AV_WL16(out+2,pix2);

  467.                         out += stride;

  468.                         AV_WL16(out,pix1);

  469.                         AV_WL16(out+2,pix2);

  470.                         out += stride;

  471.                     }

  472.                     break;

  473.                 }

  474.                 blk++;

  475.             }

  476.             break;

  477.         case SMK_BLK_SKIP:

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

  479.                 blk++;

  480.             break;

  481.         case SMK_BLK_FILL:

  482.             mode = type >> 8;

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

  484.                 uint32_t col;

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

  486.                 col = mode * 0x01010101;

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

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

  489.                     out += stride;

  490.                 }

  491.                 blk++;

  492.             }

  493.             break;

  494.         }

  495. 

  496.     }

  497. 

  498.     *data_size = sizeof(AVFrame);

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

  500. 

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

  502.     return buf_size;

  503. }

  504. 

  505. 

  506. 

  507. /*

  508.  *

  509.  * Init smacker decoder

  510.  *

  511.  */

  512. static int decode_init(AVCodecContext *avctx)

  513. {

  514.     SmackVContext * const c = avctx->priv_data;

  515. 

  516.     c->avctx = avctx;

  517. 

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

  519. 

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

  521.         return 1;

  522.     }

  523. 

  524.     avctx->pix_fmt = PIX_FMT_PAL8;

  525. 

  526. 

  527.     /* decode huffman trees from extradata */

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

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

  530.         return -1;

  531.     }

  532. 

  533.     decode_header_trees(c);

  534. 

  535. 

  536.     return 0;

  537. }

  538. 

  539. 

  540. 

  541. /*

  542.  *

  543.  * Uninit smacker decoder

  544.  *

  545.  */

  546. static int decode_end(AVCodecContext *avctx)

  547. {

  548.     SmackVContext * const smk = avctx->priv_data;

  549. 

  550.     av_freep(&smk->mmap_tbl);

  551.     av_freep(&smk->mclr_tbl);

  552.     av_freep(&smk->full_tbl);

  553.     av_freep(&smk->type_tbl);

  554. 

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

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

  557. 

  558.     return 0;

  559. }

  560. 

  561. 

  562. static int smka_decode_init(AVCodecContext *avctx)

  563. {

  564.     return 0;

  565. }

  566. 

  567. /**

  568.  * Decode Smacker audio data

  569.  */

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

  571. {

  572.     GetBitContext gb;

  573.     HuffContext h[4];

  574.     VLC vlc[4];

  575.     int16_t *samples = data;

  576.     int val;

  577.     int i, res;

  578.     int unp_size;

  579.     int bits, stereo;

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

  581. 

  582.     unp_size = AV_RL32(buf);

  583. 

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

  585. 

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

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

  588.         *data_size = 0;

  589.         return 1;

  590.     }

  591.     stereo = get_bits1(&gb);

  592.     bits = get_bits1(&gb);

  593. 

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

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

  596.     // Initialize

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

  598.         h[i].length = 256;

  599.         h[i].maxlength = 0;

  600.         h[i].current = 0;

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

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

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

  604.         skip_bits1(&gb);

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

  606.         skip_bits1(&gb);

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

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

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

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

  611.             if(res < 0) {

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

  613.                 return -1;

  614.             }

  615.         }

  616.     }

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

  618.         for(i = stereo; i >= 0; i--)

  619.             pred[i] = bswap_16(get_bits(&gb, 16));

  620.         for(i = 0; i < stereo; i++)

  621.             *samples++ = pred[i];

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

  623.             if(i & stereo) {

  624.                 if(vlc[2].table)

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

  626.                 else

  627.                     res = 0;

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

  629.                 if(vlc[3].table)

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

  631.                 else

  632.                     res = 0;

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

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

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

  636.             } else {

  637.                 if(vlc[0].table)

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

  639.                 else

  640.                     res = 0;

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

  642.                 if(vlc[1].table)

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

  644.                 else

  645.                     res = 0;

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

  647.                 pred[0] += val;

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

  649.             }

  650.         }

  651.     } else { //8-bit data

  652.         for(i = stereo; i >= 0; i--)

  653.             pred[i] = get_bits(&gb, 8);

  654.         for(i = 0; i < stereo; i++)

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

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

  657.             if(i & stereo){

  658.                 if(vlc[1].table)

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

  660.                 else

  661.                     res = 0;

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

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

  664.             } else {

  665.                 if(vlc[0].table)

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

  667.                 else

  668.                     res = 0;

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

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

  671.             }

  672.         }

  673.         unp_size *= 2;

  674.     }

  675. 

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

  677.         if(vlc[i].table)

  678.             free_vlc(&vlc[i]);

  679.         if(h[i].bits)

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

  681.         if(h[i].lengths)

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

  683.         if(h[i].values)

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

  685.     }

  686. 

  687.     *data_size = unp_size;

  688.     return buf_size;

  689. }

  690. 

  691. AVCodec smacker_decoder = {

  692.     "smackvid",

  693.     CODEC_TYPE_VIDEO,

  694.     CODEC_ID_SMACKVIDEO,

  695.     sizeof(SmackVContext),

  696.     decode_init,

  697.     NULL,

  698.     decode_end,

  699.     decode_frame

  700. };

  701. 

  702. AVCodec smackaud_decoder = {

  703.     "smackaud",

  704.     CODEC_TYPE_AUDIO,

  705.     CODEC_ID_SMACKAUDIO,

  706.     0,

  707.     smka_decode_init,

  708.     NULL,

  709.     NULL,

  710.     smka_decode_frame

  711. };