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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. #include "mathops.h"

  37. 

  38. #define BITSTREAM_READER_LE

  39. #include "get_bits.h"

  40. #include "bytestream.h"

  41. 

  42. #define SMKTREE_BITS 9

  43. #define SMK_NODE 0x80000000

  44. 

  45. /*

  46.  * Decoder context

  47.  */

  48. typedef struct SmackVContext {

  49.     AVCodecContext *avctx;

  50.     AVFrame pic;

  51. 

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

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

  54. } SmackVContext;

  55. 

  56. /**

  57.  * Context used for code reconstructing

  58.  */

  59. typedef struct HuffContext {

  60.     int length;

  61.     int maxlength;

  62.     int current;

  63.     uint32_t *bits;

  64.     int *lengths;

  65.     int *values;

  66. } HuffContext;

  67. 

  68. /* common parameters used for decode_bigtree */

  69. typedef struct DBCtx {

  70.     VLC *v1, *v2;

  71.     int *recode1, *recode2;

  72.     int escapes[3];

  73.     int *last;

  74.     int lcur;

  75. } DBCtx;

  76. 

  77. /* possible runs of blocks */

  78. static const int block_runs[64] = {

  79.       1,    2,    3,    4,    5,    6,    7,    8,

  80.       9,   10,   11,   12,   13,   14,   15,   16,

  81.      17,   18,   19,   20,   21,   22,   23,   24,

  82.      25,   26,   27,   28,   29,   30,   31,   32,

  83.      33,   34,   35,   36,   37,   38,   39,   40,

  84.      41,   42,   43,   44,   45,   46,   47,   48,

  85.      49,   50,   51,   52,   53,   54,   55,   56,

  86.      57,   58,   59,  128,  256,  512, 1024, 2048 };

  87. 

  88. enum SmkBlockTypes {

  89.     SMK_BLK_MONO = 0,

  90.     SMK_BLK_FULL = 1,

  91.     SMK_BLK_SKIP = 2,

  92.     SMK_BLK_FILL = 3 };

  93. 

  94. /**

  95.  * Decode local frame tree

  96.  */

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

  98. {

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

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

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

  102.             return -1;

  103.         }

  104.         if(length){

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

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

  107.         } else {

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

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

  110.         }

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

  112.         hc->current++;

  113.         if(hc->maxlength < length)

  114.             hc->maxlength = length;

  115.         return 0;

  116.     } else { //Node

  117.         int r;

  118.         length++;

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

  120.         if(r)

  121.             return r;

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

  123.     }

  124. }

  125. 

  126. /**

  127.  * Decode header tree

  128.  */

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

  130. {

  131.     if (hc->current + 1 >= hc->length) {

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

  133.         return -1;

  134.     }

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

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

  137.         b1 = get_bits_count(gb);

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

  139.         b1 = get_bits_count(gb) - b1;

  140.         b2 = get_bits_count(gb);

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

  142.         b2 = get_bits_count(gb) - b2;

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

  144.             return -1;

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

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

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

  148.             val = 0;

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

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

  151.             val = 0;

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

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

  154.             val = 0;

  155.         }

  156. 

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

  158.         return 1;

  159.     } else { //Node

  160.         int r = 0, r_new, t;

  161. 

  162.         t = hc->current++;

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

  164.         if(r < 0)

  165.             return r;

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

  167.         r++;

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

  169.         if (r_new < 0)

  170.             return r_new;

  171.         return r + r_new;

  172.     }

  173. }

  174. 

  175. /**

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

  177.  */

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

  179. {

  180.     int res;

  181.     HuffContext huff;

  182.     HuffContext tmp1, tmp2;

  183.     VLC vlc[2];

  184.     int escapes[3];

  185.     DBCtx ctx;

  186.     int err = 0;

  187. 

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

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

  190.         return -1;

  191.     }

  192. 

  193.     tmp1.length = 256;

  194.     tmp1.maxlength = 0;

  195.     tmp1.current = 0;

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

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

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

  199. 

  200.     tmp2.length = 256;

  201.     tmp2.maxlength = 0;

  202.     tmp2.current = 0;

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

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

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

  206. 

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

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

  209. 

  210.     if(get_bits1(gb)) {

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

  212.         skip_bits1(gb);

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

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

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

  216.         if(res < 0) {

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

  218.             return -1;

  219.         }

  220.     } else {

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

  222.     }

  223.     if(get_bits1(gb)){

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

  225.         skip_bits1(gb);

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

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

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

  229.         if(res < 0) {

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

  231.             return -1;

  232.         }

  233.     } else {

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

  235.     }

  236. 

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

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

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

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

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

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

  243. 

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

  245. 

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

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

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

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

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

  251.     ctx.recode1 = tmp1.values;

  252.     ctx.recode2 = tmp2.values;

  253.     ctx.last = last;

  254. 

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

  256.     huff.maxlength = 0;

  257.     huff.current = 0;

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

  259. 

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

  261.         err = -1;

  262.     skip_bits1(gb);

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

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

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

  266.     if(huff.current > huff.length){

  267.         ctx.last[0] = ctx.last[1] = ctx.last[2] = 1;

  268.         av_log(smk->avctx, AV_LOG_ERROR, "bigtree damaged\n");

  269.         return -1;

  270.     }

  271. 

  272.     *recodes = huff.values;

  273. 

  274.     if(vlc[0].table)

  275.         free_vlc(&vlc[0]);

  276.     if(vlc[1].table)

  277.         free_vlc(&vlc[1]);

  278.     av_free(tmp1.bits);

  279.     av_free(tmp1.lengths);

  280.     av_free(tmp1.values);

  281.     av_free(tmp2.bits);

  282.     av_free(tmp2.lengths);

  283.     av_free(tmp2.values);

  284. 

  285.     return err;

  286. }

  287. 

  288. static int decode_header_trees(SmackVContext *smk) {

  289.     GetBitContext gb;

  290.     int mmap_size, mclr_size, full_size, type_size;

  291. 

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

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

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

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

  296. 

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

  298. 

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

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

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

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

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

  304.     } else {

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

  306.             return -1;

  307.     }

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

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

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

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

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

  313.     } else {

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

  315.             return -1;

  316.     }

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

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

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

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

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

  322.     } else {

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

  324.             return -1;

  325.     }

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

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

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

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

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

  331.     } else {

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

  333.             return -1;

  334.     }

  335. 

  336.     return 0;

  337. }

  338. 

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

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

  341. }

  342. 

  343. /* get code and update history */

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

  345.     register int *table = recode;

  346.     int v;

  347. 

  348.     while(*table & SMK_NODE) {

  349.         if(get_bits1(gb))

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

  351.         table++;

  352.     }

  353.     v = *table;

  354. 

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

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

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

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

  359.     }

  360.     return v;

  361. }

  362. 

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

  364. {

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

  366.     int buf_size = avpkt->size;

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

  368.     uint8_t *out;

  369.     uint32_t *pal;

  370.     GetBitContext gb;

  371.     int blocks, blk, bw, bh;

  372.     int i;

  373.     int stride;

  374. 

  375.     if(buf_size <= 769)

  376.         return 0;

  377. 

  378.     smk->pic.reference = 3;

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

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

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

  382.         return -1;

  383.     }

  384. 

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

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

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

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

  389.     if(smk->pic.key_frame)

  390.         smk->pic.pict_type = AV_PICTURE_TYPE_I;

  391.     else

  392.         smk->pic.pict_type = AV_PICTURE_TYPE_P;

  393. 

  394.     buf++;

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

  396.         *pal++ = 0xFF << 24 | bytestream_get_be24(&buf);

  397.     buf_size -= 769;

  398. 

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

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

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

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

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

  404. 

  405.     blk = 0;

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

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

  408.     blocks = bw * bh;

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

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

  411.     while(blk < blocks) {

  412.         int type, run, mode;

  413.         uint16_t pix;

  414. 

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

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

  417.         switch(type & 3){

  418.         case SMK_BLK_MONO:

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

  420.                 int clr, map;

  421.                 int hi, lo;

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

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

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

  425.                 hi = clr >> 8;

  426.                 lo = clr & 0xFF;

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

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

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

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

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

  432.                     map >>= 4;

  433.                     out += stride;

  434.                 }

  435.                 blk++;

  436.             }

  437.             break;

  438.         case SMK_BLK_FULL:

  439.             mode = 0;

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

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

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

  443.             }

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

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

  446.                 switch(mode){

  447.                 case 0:

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

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

  450.                         AV_WL16(out+2,pix);

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

  452.                         AV_WL16(out,pix);

  453.                         out += stride;

  454.                     }

  455.                     break;

  456.                 case 1:

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

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

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

  460.                     out += stride;

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

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

  463.                     out += stride;

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

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

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

  467.                     out += stride;

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

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

  470.                     out += stride;

  471.                     break;

  472.                 case 2:

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

  474.                         uint16_t pix1, pix2;

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

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

  477.                         AV_WL16(out,pix1);

  478.                         AV_WL16(out+2,pix2);

  479.                         out += stride;

  480.                         AV_WL16(out,pix1);

  481.                         AV_WL16(out+2,pix2);

  482.                         out += stride;

  483.                     }

  484.                     break;

  485.                 }

  486.                 blk++;

  487.             }

  488.             break;

  489.         case SMK_BLK_SKIP:

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

  491.                 blk++;

  492.             break;

  493.         case SMK_BLK_FILL:

  494.             mode = type >> 8;

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

  496.                 uint32_t col;

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

  498.                 col = mode * 0x01010101;

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

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

  501.                     out += stride;

  502.                 }

  503.                 blk++;

  504.             }

  505.             break;

  506.         }

  507. 

  508.     }

  509. 

  510.     *data_size = sizeof(AVFrame);

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

  512. 

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

  514.     return buf_size;

  515. }

  516. 

  517. 

  518. 

  519. /*

  520.  *

  521.  * Init smacker decoder

  522.  *

  523.  */

  524. static av_cold int decode_init(AVCodecContext *avctx)

  525. {

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

  527. 

  528.     c->avctx = avctx;

  529. 

  530.     avctx->pix_fmt = PIX_FMT_PAL8;

  531. 

  532.     avcodec_get_frame_defaults(&c->pic);

  533. 

  534.     /* decode huffman trees from extradata */

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

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

  537.         return -1;

  538.     }

  539. 

  540.     if (decode_header_trees(c))

  541.         return -1;

  542. 

  543.     return 0;

  544. }

  545. 

  546. 

  547. 

  548. /*

  549.  *

  550.  * Uninit smacker decoder

  551.  *

  552.  */

  553. static av_cold int decode_end(AVCodecContext *avctx)

  554. {

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

  556. 

  557.     av_freep(&smk->mmap_tbl);

  558.     av_freep(&smk->mclr_tbl);

  559.     av_freep(&smk->full_tbl);

  560.     av_freep(&smk->type_tbl);

  561. 

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

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

  564. 

  565.     return 0;

  566. }

  567. 

  568. 

  569. typedef struct SmackerAudioContext {

  570.     AVFrame frame;

  571. } SmackerAudioContext;

  572. 

  573. static av_cold int smka_decode_init(AVCodecContext *avctx)

  574. {

  575.     SmackerAudioContext *s = avctx->priv_data;

  576. 

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

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

  579.         return AVERROR(EINVAL);

  580.     }

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

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

  583. 

  584.     avcodec_get_frame_defaults(&s->frame);

  585.     avctx->coded_frame = &s->frame;

  586. 

  587.     return 0;

  588. }

  589. 

  590. /**

  591.  * Decode Smacker audio data

  592.  */

  593. static int smka_decode_frame(AVCodecContext *avctx, void *data,

  594.                              int *got_frame_ptr, AVPacket *avpkt)

  595. {

  596.     SmackerAudioContext *s = avctx->priv_data;

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

  598.     int buf_size = avpkt->size;

  599.     GetBitContext gb;

  600.     HuffContext h[4];

  601.     VLC vlc[4];

  602.     int16_t *samples;

  603.     uint8_t *samples8;

  604.     int val;

  605.     int i, res, ret;

  606.     int unp_size;

  607.     int bits, stereo;

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

  609. 

  610.     if (buf_size <= 4) {

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

  612.         return AVERROR(EINVAL);

  613.     }

  614. 

  615.     unp_size = AV_RL32(buf);

  616. 

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

  618. 

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

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

  621.         *got_frame_ptr = 0;

  622.         return 1;

  623.     }

  624.     stereo = get_bits1(&gb);

  625.     bits = get_bits1(&gb);

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

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

  628.         return AVERROR(EINVAL);

  629.     }

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

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

  632.         return AVERROR(EINVAL);

  633.     }

  634. 

  635.     /* get output buffer */

  636.     s->frame.nb_samples = unp_size / (avctx->channels * (bits + 1));

  637.     if ((ret = avctx->get_buffer(avctx, &s->frame)) < 0) {

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

  639.         return ret;

  640.     }

  641.     samples  = (int16_t *)s->frame.data[0];

  642.     samples8 =            s->frame.data[0];

  643. 

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

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

  646.     // Initialize

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

  648.         h[i].length = 256;

  649.         h[i].maxlength = 0;

  650.         h[i].current = 0;

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

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

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

  654.         skip_bits1(&gb);

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

  656.         skip_bits1(&gb);

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

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

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

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

  661.             if(res < 0) {

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

  663.                 return -1;

  664.             }

  665.         }

  666.     }

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

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

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

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

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

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

  673.             if(get_bits_left(&gb)<0)

  674.                 return -1;

  675.             if(i & stereo) {

  676.                 if(vlc[2].table)

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

  678.                 else

  679.                     res = 0;

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

  681.                 if(vlc[3].table)

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

  683.                 else

  684.                     res = 0;

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

  686.                 pred[1] += sign_extend(val, 16);

  687.                 *samples++ = av_clip_int16(pred[1]);

  688.             } else {

  689.                 if(vlc[0].table)

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

  691.                 else

  692.                     res = 0;

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

  694.                 if(vlc[1].table)

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

  696.                 else

  697.                     res = 0;

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

  699.                 pred[0] += sign_extend(val, 16);

  700.                 *samples++ = av_clip_int16(pred[0]);

  701.             }

  702.         }

  703.     } else { //8-bit data

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

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

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

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

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

  709.             if(get_bits_left(&gb)<0)

  710.                 return -1;

  711.             if(i & stereo){

  712.                 if(vlc[1].table)

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

  714.                 else

  715.                     res = 0;

  716.                 pred[1] += sign_extend(h[1].values[res], 8);

  717.                 *samples8++ = av_clip_uint8(pred[1]);

  718.             } else {

  719.                 if(vlc[0].table)

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

  721.                 else

  722.                     res = 0;

  723.                 pred[0] += sign_extend(h[0].values[res], 8);

  724.                 *samples8++ = av_clip_uint8(pred[0]);

  725.             }

  726.         }

  727.     }

  728. 

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

  730.         if(vlc[i].table)

  731.             free_vlc(&vlc[i]);

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

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

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

  735.     }

  736. 

  737.     *got_frame_ptr   = 1;

  738.     *(AVFrame *)data = s->frame;

  739. 

  740.     return buf_size;

  741. }

  742. 

  743. AVCodec ff_smacker_decoder = {

  744.     .name           = "smackvid",

  745.     .type           = AVMEDIA_TYPE_VIDEO,

  746.     .id             = CODEC_ID_SMACKVIDEO,

  747.     .priv_data_size = sizeof(SmackVContext),

  748.     .init           = decode_init,

  749.     .close          = decode_end,

  750.     .decode         = decode_frame,

  751.     .capabilities   = CODEC_CAP_DR1,

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

  753. };

  754. 

  755. AVCodec ff_smackaud_decoder = {

  756.     .name           = "smackaud",

  757.     .type           = AVMEDIA_TYPE_AUDIO,

  758.     .id             = CODEC_ID_SMACKAUDIO,

  759.     .priv_data_size = sizeof(SmackerAudioContext),

  760.     .init           = smka_decode_init,

  761.     .decode         = smka_decode_frame,

  762.     .capabilities   = CODEC_CAP_DR1,

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

  764. };