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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 libavcodec/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 "get_bits.h"

  38. #include "bytestream.h"

  39. 

  40. #define SMKTREE_BITS 9

  41. #define SMK_NODE 0x80000000

  42. 

  43. /*

  44.  * Decoder context

  45.  */

  46. typedef struct SmackVContext {

  47.     AVCodecContext *avctx;

  48.     AVFrame pic;

  49. 

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

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

  52. } SmackVContext;

  53. 

  54. /**

  55.  * Context used for code reconstructing

  56.  */

  57. typedef struct HuffContext {

  58.     int length;

  59.     int maxlength;

  60.     int current;

  61.     uint32_t *bits;

  62.     int *lengths;

  63.     int *values;

  64. } HuffContext;

  65. 

  66. /* common parameters used for decode_bigtree */

  67. typedef struct DBCtx {

  68.     VLC *v1, *v2;

  69.     int *recode1, *recode2;

  70.     int escapes[3];

  71.     int *last;

  72.     int lcur;

  73. } DBCtx;

  74. 

  75. /* possible runs of blocks */

  76. static const int block_runs[64] = {

  77.       1,    2,    3,    4,    5,    6,    7,    8,

  78.       9,   10,   11,   12,   13,   14,   15,   16,

  79.      17,   18,   19,   20,   21,   22,   23,   24,

  80.      25,   26,   27,   28,   29,   30,   31,   32,

  81.      33,   34,   35,   36,   37,   38,   39,   40,

  82.      41,   42,   43,   44,   45,   46,   47,   48,

  83.      49,   50,   51,   52,   53,   54,   55,   56,

  84.      57,   58,   59,  128,  256,  512, 1024, 2048 };

  85. 

  86. enum SmkBlockTypes {

  87.     SMK_BLK_MONO = 0,

  88.     SMK_BLK_FULL = 1,

  89.     SMK_BLK_SKIP = 2,

  90.     SMK_BLK_FILL = 3 };

  91. 

  92. /**

  93.  * Decode local frame tree

  94.  */

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

  96. {

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

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

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

  100.             return -1;

  101.         }

  102.         if(length){

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

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

  105.         } else {

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

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

  108.         }

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

  110.         hc->current++;

  111.         if(hc->maxlength < length)

  112.             hc->maxlength = length;

  113.         return 0;

  114.     } else { //Node

  115.         int r;

  116.         length++;

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

  118.         if(r)

  119.             return r;

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

  121.     }

  122. }

  123. 

  124. /**

  125.  * Decode header tree

  126.  */

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

  128. {

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

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

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

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

  133.             return -1;

  134.         }

  135.         b1 = get_bits_count(gb);

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

  137.         b1 = get_bits_count(gb) - b1;

  138.         b2 = get_bits_count(gb);

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

  140.         b2 = get_bits_count(gb) - b2;

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

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

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

  144.             val = 0;

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

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

  147.             val = 0;

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

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

  150.             val = 0;

  151.         }

  152. 

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

  154.         return 1;

  155.     } else { //Node

  156.         int r = 0, t;

  157. 

  158.         t = hc->current++;

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

  160.         if(r < 0)

  161.             return r;

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

  163.         r++;

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

  165.         return r;

  166.     }

  167. }

  168. 

  169. /**

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

  171.  */

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

  173. {

  174.     int res;

  175.     HuffContext huff;

  176.     HuffContext tmp1, tmp2;

  177.     VLC vlc[2];

  178.     int escapes[3];

  179.     DBCtx ctx;

  180. 

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

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

  183.         return -1;

  184.     }

  185. 

  186.     tmp1.length = 256;

  187.     tmp1.maxlength = 0;

  188.     tmp1.current = 0;

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

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

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

  192. 

  193.     tmp2.length = 256;

  194.     tmp2.maxlength = 0;

  195.     tmp2.current = 0;

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

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

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

  199. 

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

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

  202. 

  203.     if(get_bits1(gb)) {

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

  205.         skip_bits1(gb);

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

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

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

  209.         if(res < 0) {

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

  211.             return -1;

  212.         }

  213.     } else {

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

  215.     }

  216.     if(get_bits1(gb)){

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

  218.         skip_bits1(gb);

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

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

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

  222.         if(res < 0) {

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

  224.             return -1;

  225.         }

  226.     } else {

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

  228.     }

  229. 

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

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

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

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

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

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

  236. 

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

  238. 

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

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

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

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

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

  244.     ctx.recode1 = tmp1.values;

  245.     ctx.recode2 = tmp2.values;

  246.     ctx.last = last;

  247. 

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

  249.     huff.maxlength = 0;

  250.     huff.current = 0;

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

  252. 

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

  254.     skip_bits1(gb);

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

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

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

  258. 

  259.     *recodes = huff.values;

  260. 

  261.     if(vlc[0].table)

  262.         free_vlc(&vlc[0]);

  263.     if(vlc[1].table)

  264.         free_vlc(&vlc[1]);

  265.     av_free(tmp1.bits);

  266.     av_free(tmp1.lengths);

  267.     av_free(tmp1.values);

  268.     av_free(tmp2.bits);

  269.     av_free(tmp2.lengths);

  270.     av_free(tmp2.values);

  271. 

  272.     return 0;

  273. }

  274. 

  275. static int decode_header_trees(SmackVContext *smk) {

  276.     GetBitContext gb;

  277.     int mmap_size, mclr_size, full_size, type_size;

  278. 

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

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

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

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

  283. 

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

  285. 

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

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

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

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

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

  291.     } else {

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

  293.     }

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

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

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

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

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

  299.     } else {

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

  301.     }

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

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

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

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

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

  307.     } else {

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

  309.     }

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

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

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

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

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

  315.     } else {

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

  317.     }

  318. 

  319.     return 0;

  320. }

  321. 

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

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

  324. }

  325. 

  326. /* get code and update history */

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

  328.     register int *table = recode;

  329.     int v, b;

  330. 

  331.     b = get_bits_count(gb);

  332.     while(*table & SMK_NODE) {

  333.         if(get_bits1(gb))

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

  335.         table++;

  336.     }

  337.     v = *table;

  338.     b = get_bits_count(gb) - b;

  339. 

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

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

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

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

  344.     }

  345.     return v;

  346. }

  347. 

  348. static int decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)

  349. {

  350.     const uint8_t *buf = avpkt->data;

  351.     int buf_size = avpkt->size;

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

  353.     uint8_t *out;

  354.     uint32_t *pal;

  355.     GetBitContext gb;

  356.     int blocks, blk, bw, bh;

  357.     int i;

  358.     int stride;

  359. 

  360.     if(buf_size <= 769)

  361.         return 0;

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

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

  364. 

  365.     smk->pic.reference = 1;

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

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

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

  369.         return -1;

  370.     }

  371. 

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

  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.     buf++;

  382.     for(i = 0; i < 256; i++)

  383.         *pal++ = bytestream_get_be24(&buf);

  384.     buf_size -= 769;

  385. 

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

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

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

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

  390.     init_get_bits(&gb, buf, buf_size * 8);

  391. 

  392.     blk = 0;

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

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

  395.     blocks = bw * bh;

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

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

  398.     while(blk < blocks) {

  399.         int type, run, mode;

  400.         uint16_t pix;

  401. 

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

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

  404.         switch(type & 3){

  405.         case SMK_BLK_MONO:

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

  407.                 int clr, map;

  408.                 int hi, lo;

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

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

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

  412.                 hi = clr >> 8;

  413.                 lo = clr & 0xFF;

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

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

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

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

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

  419.                     map >>= 4;

  420.                     out += stride;

  421.                 }

  422.                 blk++;

  423.             }

  424.             break;

  425.         case SMK_BLK_FULL:

  426.             mode = 0;

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

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

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

  430.             }

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

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

  433.                 switch(mode){

  434.                 case 0:

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

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

  437.                         AV_WL16(out+2,pix);

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

  439.                         AV_WL16(out,pix);

  440.                         out += stride;

  441.                     }

  442.                     break;

  443.                 case 1:

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

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

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

  447.                     out += stride;

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

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

  450.                     out += stride;

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

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

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

  454.                     out += stride;

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

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

  457.                     out += stride;

  458.                     break;

  459.                 case 2:

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

  461.                         uint16_t pix1, pix2;

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

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

  464.                         AV_WL16(out,pix1);

  465.                         AV_WL16(out+2,pix2);

  466.                         out += stride;

  467.                         AV_WL16(out,pix1);

  468.                         AV_WL16(out+2,pix2);

  469.                         out += stride;

  470.                     }

  471.                     break;

  472.                 }

  473.                 blk++;

  474.             }

  475.             break;

  476.         case SMK_BLK_SKIP:

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

  478.                 blk++;

  479.             break;

  480.         case SMK_BLK_FILL:

  481.             mode = type >> 8;

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

  483.                 uint32_t col;

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

  485.                 col = mode * 0x01010101;

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

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

  488.                     out += stride;

  489.                 }

  490.                 blk++;

  491.             }

  492.             break;

  493.         }

  494. 

  495.     }

  496. 

  497.     *data_size = sizeof(AVFrame);

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

  499. 

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

  501.     return buf_size;

  502. }

  503. 

  504. 

  505. 

  506. /*

  507.  *

  508.  * Init smacker decoder

  509.  *

  510.  */

  511. static av_cold int decode_init(AVCodecContext *avctx)

  512. {

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

  514. 

  515.     c->avctx = avctx;

  516. 

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

  518.         return 1;

  519.     }

  520. 

  521.     avctx->pix_fmt = PIX_FMT_PAL8;

  522. 

  523. 

  524.     /* decode huffman trees from extradata */

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

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

  527.         return -1;

  528.     }

  529. 

  530.     decode_header_trees(c);

  531. 

  532. 

  533.     return 0;

  534. }

  535. 

  536. 

  537. 

  538. /*

  539.  *

  540.  * Uninit smacker decoder

  541.  *

  542.  */

  543. static av_cold int decode_end(AVCodecContext *avctx)

  544. {

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

  546. 

  547.     av_freep(&smk->mmap_tbl);

  548.     av_freep(&smk->mclr_tbl);

  549.     av_freep(&smk->full_tbl);

  550.     av_freep(&smk->type_tbl);

  551. 

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

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

  554. 

  555.     return 0;

  556. }

  557. 

  558. 

  559. static av_cold int smka_decode_init(AVCodecContext *avctx)

  560. {

  561.     avctx->channel_layout = (avctx->channels==2) ? CH_LAYOUT_STEREO : CH_LAYOUT_MONO;

  562.     return 0;

  563. }

  564. 

  565. /**

  566.  * Decode Smacker audio data

  567.  */

  568. static int smka_decode_frame(AVCodecContext *avctx, void *data, int *data_size, AVPacket *avpkt)

  569. {

  570.     const uint8_t *buf = avpkt->data;

  571.     int buf_size = avpkt->size;

  572.     GetBitContext gb;

  573.     HuffContext h[4];

  574.     VLC vlc[4];

  575.     int16_t *samples = data;

  576.     int8_t *samples8 = data;

  577.     int val;

  578.     int i, res;

  579.     int unp_size;

  580.     int bits, stereo;

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

  582. 

  583.     unp_size = AV_RL32(buf);

  584. 

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

  586. 

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

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

  589.         *data_size = 0;

  590.         return 1;

  591.     }

  592.     stereo = get_bits1(&gb);

  593.     bits = get_bits1(&gb);

  594.     if (unp_size & 0xC0000000 || unp_size > *data_size) {

  595.         av_log(avctx, AV_LOG_ERROR, "Frame is too large to fit in buffer\n");

  596.         return -1;

  597.     }

  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.         skip_bits1(&gb);

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

  611.         skip_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.         for(i = stereo; i >= 0; i--)

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

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

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

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

  628.             if(i & stereo) {

  629.                 if(vlc[2].table)

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

  631.                 else

  632.                     res = 0;

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

  634.                 if(vlc[3].table)

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

  636.                 else

  637.                     res = 0;

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

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

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

  641.             } else {

  642.                 if(vlc[0].table)

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

  644.                 else

  645.                     res = 0;

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

  647.                 if(vlc[1].table)

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

  649.                 else

  650.                     res = 0;

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

  652.                 pred[0] += val;

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

  654.             }

  655.         }

  656.     } else { //8-bit data

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

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

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

  660.             *samples8++ = pred[i];

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

  662.             if(i & stereo){

  663.                 if(vlc[1].table)

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

  665.                 else

  666.                     res = 0;

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

  668.                 *samples8++ = pred[1];

  669.             } else {

  670.                 if(vlc[0].table)

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

  672.                 else

  673.                     res = 0;

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

  675.                 *samples8++ = pred[0];

  676.             }

  677.         }

  678.     }

  679. 

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

  681.         if(vlc[i].table)

  682.             free_vlc(&vlc[i]);

  683.         if(h[i].bits)

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

  685.         if(h[i].lengths)

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

  687.         if(h[i].values)

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

  689.     }

  690. 

  691.     *data_size = unp_size;

  692.     return buf_size;

  693. }

  694. 

  695. AVCodec smacker_decoder = {

  696.     "smackvid",

  697.     CODEC_TYPE_VIDEO,

  698.     CODEC_ID_SMACKVIDEO,

  699.     sizeof(SmackVContext),

  700.     decode_init,

  701.     NULL,

  702.     decode_end,

  703.     decode_frame,

  704.     CODEC_CAP_DR1,

  705.     .long_name = NULL_IF_CONFIG_SMALL("Smacker video"),

  706. };

  707. 

  708. AVCodec smackaud_decoder = {

  709.     "smackaud",

  710.     CODEC_TYPE_AUDIO,

  711.     CODEC_ID_SMACKAUDIO,

  712.     0,

  713.     smka_decode_init,

  714.     NULL,

  715.     NULL,

  716.     smka_decode_frame,

  717.     .long_name = NULL_IF_CONFIG_SMALL("Smacker audio"),

  718. };