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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

  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. #include "libavutil/audioconvert.h"

  36. 

  37. #define ALT_BITSTREAM_READER_LE

  38. #include "get_bits.h"

  39. #include "bytestream.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 (hc->current + 1 >= hc->length) {

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

  132.         return -1;

  133.     }

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

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

  136.         b1 = get_bits_count(gb);

  137.         i1 = ctx->v1->table ? get_vlc2(gb, ctx->v1->table, SMKTREE_BITS, 3) : 0;

  138.         b1 = get_bits_count(gb) - b1;

  139.         b2 = get_bits_count(gb);

  140.         i2 = ctx->v2->table ? get_vlc2(gb, ctx->v2->table, SMKTREE_BITS, 3) : 0;

  141.         b2 = get_bits_count(gb) - b2;

  142.         if (i1 < 0 || i2 < 0)

  143.             return -1;

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

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

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

  147.             val = 0;

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

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

  150.             val = 0;

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

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

  153.             val = 0;

  154.         }

  155. 

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

  157.         return 1;

  158.     } else { //Node

  159.         int r = 0, r_new, t;

  160. 

  161.         t = hc->current++;

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

  163.         if(r < 0)

  164.             return r;

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

  166.         r++;

  167.         r_new = smacker_decode_bigtree(gb, hc, ctx);

  168.         if (r_new < 0)

  169.             return r_new;

  170.         return r + r_new;

  171.     }

  172. }

  173. 

  174. /**

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

  176.  */

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

  178. {

  179.     int res;

  180.     HuffContext huff;

  181.     HuffContext tmp1, tmp2;

  182.     VLC vlc[2];

  183.     int escapes[3];

  184.     DBCtx ctx;

  185.     int err = 0;

  186. 

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

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

  189.         return -1;

  190.     }

  191. 

  192.     tmp1.length = 256;

  193.     tmp1.maxlength = 0;

  194.     tmp1.current = 0;

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

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

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

  198. 

  199.     tmp2.length = 256;

  200.     tmp2.maxlength = 0;

  201.     tmp2.current = 0;

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

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

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

  205. 

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

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

  208. 

  209.     if(get_bits1(gb)) {

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

  211.         skip_bits1(gb);

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

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

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

  215.         if(res < 0) {

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

  217.             return -1;

  218.         }

  219.     } else {

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

  221.     }

  222.     if(get_bits1(gb)){

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

  224.         skip_bits1(gb);

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

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

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

  228.         if(res < 0) {

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

  230.             return -1;

  231.         }

  232.     } else {

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

  234.     }

  235. 

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

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

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

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

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

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

  242. 

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

  244. 

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

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

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

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

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

  250.     ctx.recode1 = tmp1.values;

  251.     ctx.recode2 = tmp2.values;

  252.     ctx.last = last;

  253. 

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

  255.     huff.maxlength = 0;

  256.     huff.current = 0;

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

  258. 

  259.     if (smacker_decode_bigtree(gb, &huff, &ctx) < 0)

  260.         err = -1;

  261.     skip_bits1(gb);

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

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

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

  265. 

  266.     *recodes = huff.values;

  267. 

  268.     if(vlc[0].table)

  269.         free_vlc(&vlc[0]);

  270.     if(vlc[1].table)

  271.         free_vlc(&vlc[1]);

  272.     av_free(tmp1.bits);

  273.     av_free(tmp1.lengths);

  274.     av_free(tmp1.values);

  275.     av_free(tmp2.bits);

  276.     av_free(tmp2.lengths);

  277.     av_free(tmp2.values);

  278. 

  279.     return err;

  280. }

  281. 

  282. static int decode_header_trees(SmackVContext *smk) {

  283.     GetBitContext gb;

  284.     int mmap_size, mclr_size, full_size, type_size;

  285. 

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

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

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

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

  290. 

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

  292. 

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

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

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

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

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

  298.     } else {

  299.         if (smacker_decode_header_tree(smk, &gb, &smk->mmap_tbl, smk->mmap_last, mmap_size))

  300.             return -1;

  301.     }

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

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

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

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

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

  307.     } else {

  308.         if (smacker_decode_header_tree(smk, &gb, &smk->mclr_tbl, smk->mclr_last, mclr_size))

  309.             return -1;

  310.     }

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

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

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

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

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

  316.     } else {

  317.         if (smacker_decode_header_tree(smk, &gb, &smk->full_tbl, smk->full_last, full_size))

  318.             return -1;

  319.     }

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

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

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

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

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

  325.     } else {

  326.         if (smacker_decode_header_tree(smk, &gb, &smk->type_tbl, smk->type_last, type_size))

  327.             return -1;

  328.     }

  329. 

  330.     return 0;

  331. }

  332. 

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

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

  335. }

  336. 

  337. /* get code and update history */

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

  339.     register int *table = recode;

  340.     int v, b;

  341. 

  342.     b = get_bits_count(gb);

  343.     while(*table & SMK_NODE) {

  344.         if(get_bits1(gb))

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

  346.         table++;

  347.     }

  348.     v = *table;

  349.     b = get_bits_count(gb) - b;

  350. 

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

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

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

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

  355.     }

  356.     return v;

  357. }

  358. 

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

  360. {

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

  362.     int buf_size = avpkt->size;

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

  364.     uint8_t *out;

  365.     uint32_t *pal;

  366.     GetBitContext gb;

  367.     int blocks, blk, bw, bh;

  368.     int i;

  369.     int stride;

  370. 

  371.     if(buf_size <= 769)

  372.         return 0;

  373. 

  374.     smk->pic.reference = 1;

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

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

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

  378.         return -1;

  379.     }

  380. 

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

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

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

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

  385.     if(smk->pic.key_frame)

  386.         smk->pic.pict_type = AV_PICTURE_TYPE_I;

  387.     else

  388.         smk->pic.pict_type = AV_PICTURE_TYPE_P;

  389. 

  390.     buf++;

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

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

  393.     buf_size -= 769;

  394. 

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

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

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

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

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

  400. 

  401.     blk = 0;

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

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

  404.     blocks = bw * bh;

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

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

  407.     while(blk < blocks) {

  408.         int type, run, mode;

  409.         uint16_t pix;

  410. 

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

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

  413.         switch(type & 3){

  414.         case SMK_BLK_MONO:

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

  416.                 int clr, map;

  417.                 int hi, lo;

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

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

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

  421.                 hi = clr >> 8;

  422.                 lo = clr & 0xFF;

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

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

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

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

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

  428.                     map >>= 4;

  429.                     out += stride;

  430.                 }

  431.                 blk++;

  432.             }

  433.             break;

  434.         case SMK_BLK_FULL:

  435.             mode = 0;

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

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

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

  439.             }

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

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

  442.                 switch(mode){

  443.                 case 0:

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

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

  446.                         AV_WL16(out+2,pix);

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

  448.                         AV_WL16(out,pix);

  449.                         out += stride;

  450.                     }

  451.                     break;

  452.                 case 1:

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

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

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

  456.                     out += stride;

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

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

  459.                     out += stride;

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

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

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

  463.                     out += stride;

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

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

  466.                     out += stride;

  467.                     break;

  468.                 case 2:

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

  470.                         uint16_t pix1, pix2;

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

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

  473.                         AV_WL16(out,pix1);

  474.                         AV_WL16(out+2,pix2);

  475.                         out += stride;

  476.                         AV_WL16(out,pix1);

  477.                         AV_WL16(out+2,pix2);

  478.                         out += stride;

  479.                     }

  480.                     break;

  481.                 }

  482.                 blk++;

  483.             }

  484.             break;

  485.         case SMK_BLK_SKIP:

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

  487.                 blk++;

  488.             break;

  489.         case SMK_BLK_FILL:

  490.             mode = type >> 8;

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

  492.                 uint32_t col;

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

  494.                 col = mode * 0x01010101;

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

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

  497.                     out += stride;

  498.                 }

  499.                 blk++;

  500.             }

  501.             break;

  502.         }

  503. 

  504.     }

  505. 

  506.     *data_size = sizeof(AVFrame);

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

  508. 

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

  510.     return buf_size;

  511. }

  512. 

  513. 

  514. 

  515. /*

  516.  *

  517.  * Init smacker decoder

  518.  *

  519.  */

  520. static av_cold int decode_init(AVCodecContext *avctx)

  521. {

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

  523. 

  524.     c->avctx = avctx;

  525. 

  526.     avctx->pix_fmt = PIX_FMT_PAL8;

  527. 

  528.     avcodec_get_frame_defaults(&c->pic);

  529. 

  530.     /* decode huffman trees from extradata */

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

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

  533.         return -1;

  534.     }

  535. 

  536.     if (decode_header_trees(c))

  537.         return -1;

  538. 

  539.     return 0;

  540. }

  541. 

  542. 

  543. 

  544. /*

  545.  *

  546.  * Uninit smacker decoder

  547.  *

  548.  */

  549. static av_cold int decode_end(AVCodecContext *avctx)

  550. {

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

  552. 

  553.     av_freep(&smk->mmap_tbl);

  554.     av_freep(&smk->mclr_tbl);

  555.     av_freep(&smk->full_tbl);

  556.     av_freep(&smk->type_tbl);

  557. 

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

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

  560. 

  561.     return 0;

  562. }

  563. 

  564. 

  565. static av_cold int smka_decode_init(AVCodecContext *avctx)

  566. {

  567.     if (avctx->channels < 1 || avctx->channels > 2) {

  568.         av_log(avctx, AV_LOG_ERROR, "invalid number of channels\n");

  569.         return AVERROR(EINVAL);

  570.     }

  571.     avctx->channel_layout = (avctx->channels==2) ? AV_CH_LAYOUT_STEREO : AV_CH_LAYOUT_MONO;

  572.     avctx->sample_fmt = avctx->bits_per_coded_sample == 8 ? AV_SAMPLE_FMT_U8 : AV_SAMPLE_FMT_S16;

  573.     return 0;

  574. }

  575. 

  576. /**

  577.  * Decode Smacker audio data

  578.  */

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

  580. {

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

  582.     int buf_size = avpkt->size;

  583.     GetBitContext gb;

  584.     HuffContext h[4];

  585.     VLC vlc[4];

  586.     int16_t *samples = data;

  587.     int8_t *samples8 = data;

  588.     int val;

  589.     int i, res;

  590.     int unp_size;

  591.     int bits, stereo;

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

  593. 

  594.     if (buf_size <= 4) {

  595.         av_log(avctx, AV_LOG_ERROR, "packet is too small\n");

  596.         return AVERROR(EINVAL);

  597.     }

  598. 

  599.     unp_size = AV_RL32(buf);

  600. 

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

  602. 

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

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

  605.         *data_size = 0;

  606.         return 1;

  607.     }

  608.     stereo = get_bits1(&gb);

  609.     bits = get_bits1(&gb);

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

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

  612.         return -1;

  613.     }

  614.     if (stereo ^ (avctx->channels != 1)) {

  615.         av_log(avctx, AV_LOG_ERROR, "channels mismatch\n");

  616.         return AVERROR(EINVAL);

  617.     }

  618.     if (bits && avctx->sample_fmt == AV_SAMPLE_FMT_U8) {

  619.         av_log(avctx, AV_LOG_ERROR, "sample format mismatch\n");

  620.         return AVERROR(EINVAL);

  621.     }

  622. 

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

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

  625.     // Initialize

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

  627.         h[i].length = 256;

  628.         h[i].maxlength = 0;

  629.         h[i].current = 0;

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

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

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

  633.         skip_bits1(&gb);

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

  635.         skip_bits1(&gb);

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

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

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

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

  640.             if(res < 0) {

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

  642.                 return -1;

  643.             }

  644.         }

  645.     }

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

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

  648.             pred[i] = av_bswap16(get_bits(&gb, 16));

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

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

  651.         for(; i < unp_size / 2; i++) {

  652.             if(i & stereo) {

  653.                 if(vlc[2].table)

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

  655.                 else

  656.                     res = 0;

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

  658.                 if(vlc[3].table)

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

  660.                 else

  661.                     res = 0;

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

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

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

  665.             } else {

  666.                 if(vlc[0].table)

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

  668.                 else

  669.                     res = 0;

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

  671.                 if(vlc[1].table)

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

  673.                 else

  674.                     res = 0;

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

  676.                 pred[0] += val;

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

  678.             }

  679.         }

  680.     } else { //8-bit data

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

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

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

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

  685.         for(; i < unp_size; i++) {

  686.             if(i & stereo){

  687.                 if(vlc[1].table)

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

  689.                 else

  690.                     res = 0;

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

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

  693.             } else {

  694.                 if(vlc[0].table)

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

  696.                 else

  697.                     res = 0;

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

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

  700.             }

  701.         }

  702.     }

  703. 

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

  705.         if(vlc[i].table)

  706.             free_vlc(&vlc[i]);

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

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

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

  710.     }

  711. 

  712.     *data_size = unp_size;

  713.     return buf_size;

  714. }

  715. 

  716. AVCodec ff_smacker_decoder = {

  717.     "smackvid",

  718.     AVMEDIA_TYPE_VIDEO,

  719.     CODEC_ID_SMACKVIDEO,

  720.     sizeof(SmackVContext),

  721.     decode_init,

  722.     NULL,

  723.     decode_end,

  724.     decode_frame,

  725.     CODEC_CAP_DR1,

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

  727. };

  728. 

  729. AVCodec ff_smackaud_decoder = {

  730.     "smackaud",

  731.     AVMEDIA_TYPE_AUDIO,

  732.     CODEC_ID_SMACKAUDIO,

  733.     0,

  734.     smka_decode_init,

  735.     NULL,

  736.     NULL,

  737.     smka_decode_frame,

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

  739. };