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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 "libavutil/channel_layout.h"

  35. #include "avcodec.h"

  36. #include "internal.h"

  37. #include "mathops.h"

  38. 

  39. #define BITSTREAM_READER_LE

  40. #include "get_bits.h"

  41. #include "bytestream.h"

  42. 

  43. #define SMKTREE_BITS 9

  44. #define SMK_NODE 0x80000000

  45. 

  46. /*

  47.  * Decoder context

  48.  */

  49. typedef struct SmackVContext {

  50.     AVCodecContext *avctx;

  51.     AVFrame pic;

  52. 

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

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

  55. } SmackVContext;

  56. 

  57. /**

  58.  * Context used for code reconstructing

  59.  */

  60. typedef struct HuffContext {

  61.     int length;

  62.     int maxlength;

  63.     int current;

  64.     uint32_t *bits;

  65.     int *lengths;

  66.     int *values;

  67. } HuffContext;

  68. 

  69. /* common parameters used for decode_bigtree */

  70. typedef struct DBCtx {

  71.     VLC *v1, *v2;

  72.     int *recode1, *recode2;

  73.     int escapes[3];

  74.     int *last;

  75.     int lcur;

  76. } DBCtx;

  77. 

  78. /* possible runs of blocks */

  79. static const int block_runs[64] = {

  80.       1,    2,    3,    4,    5,    6,    7,    8,

  81.       9,   10,   11,   12,   13,   14,   15,   16,

  82.      17,   18,   19,   20,   21,   22,   23,   24,

  83.      25,   26,   27,   28,   29,   30,   31,   32,

  84.      33,   34,   35,   36,   37,   38,   39,   40,

  85.      41,   42,   43,   44,   45,   46,   47,   48,

  86.      49,   50,   51,   52,   53,   54,   55,   56,

  87.      57,   58,   59,  128,  256,  512, 1024, 2048 };

  88. 

  89. enum SmkBlockTypes {

  90.     SMK_BLK_MONO = 0,

  91.     SMK_BLK_FULL = 1,

  92.     SMK_BLK_SKIP = 2,

  93.     SMK_BLK_FILL = 3 };

  94. 

  95. /**

  96.  * Decode local frame tree

  97.  */

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

  99. {

  100.     if(length > 32 || length > 3*SMKTREE_BITS) {

  101.         av_log(NULL, AV_LOG_ERROR, "length too long\n");

  102.         return AVERROR_INVALIDDATA;

  103.     }

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

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

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

  107.             return AVERROR_INVALIDDATA;

  108.         }

  109.         if(length){

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

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

  112.         } else {

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

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

  115.         }

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

  117.         hc->current++;

  118.         if(hc->maxlength < length)

  119.             hc->maxlength = length;

  120.         return 0;

  121.     } else { //Node

  122.         int r;

  123.         length++;

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

  125.         if(r)

  126.             return r;

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

  128.     }

  129. }

  130. 

  131. /**

  132.  * Decode header tree

  133.  */

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

  135. {

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

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

  138.         return AVERROR_INVALIDDATA;

  139.     }

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

  141.         int val, i1, i2;

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

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

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

  145.             return AVERROR_INVALIDDATA;

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

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

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

  149.             val = 0;

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

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

  152.             val = 0;

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

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

  155.             val = 0;

  156.         }

  157. 

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

  159.         return 1;

  160.     } else { //Node

  161.         int r = 0, r_new, t;

  162. 

  163.         t = hc->current++;

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

  165.         if(r < 0)

  166.             return r;

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

  168.         r++;

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

  170.         if (r_new < 0)

  171.             return r_new;

  172.         return r + r_new;

  173.     }

  174. }

  175. 

  176. /**

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

  178.  */

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

  180. {

  181.     int res;

  182.     HuffContext huff;

  183.     HuffContext tmp1, tmp2;

  184.     VLC vlc[2] = { { 0 } };

  185.     int escapes[3];

  186.     DBCtx ctx;

  187.     int err = 0;

  188. 

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

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

  191.         return AVERROR_INVALIDDATA;

  192.     }

  193. 

  194.     tmp1.length = 256;

  195.     tmp1.maxlength = 0;

  196.     tmp1.current = 0;

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

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

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

  200. 

  201.     tmp2.length = 256;

  202.     tmp2.maxlength = 0;

  203.     tmp2.current = 0;

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

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

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

  207. 

  208.     if(get_bits1(gb)) {

  209.         res = smacker_decode_tree(gb, &tmp1, 0, 0);

  210.         if (res < 0)

  211.             return res;

  212.         skip_bits1(gb);

  213.         if(tmp1.current > 1) {

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

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

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

  217.             if(res < 0) {

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

  219.                 return AVERROR_INVALIDDATA;

  220.             }

  221.         }

  222.     }

  223.     if (!vlc[0].table) {

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

  225.     }

  226.     if(get_bits1(gb)){

  227.         res = smacker_decode_tree(gb, &tmp2, 0, 0);

  228.         if (res < 0)

  229.             return res;

  230.         skip_bits1(gb);

  231.         if(tmp2.current > 1) {

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

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

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

  235.             if(res < 0) {

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

  237.                 return AVERROR_INVALIDDATA;

  238.             }

  239.         }

  240.     }

  241.     if (!vlc[1].table) {

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

  243.     }

  244. 

  245.     escapes[0]  = get_bits(gb, 16);

  246.     escapes[1]  = get_bits(gb, 16);

  247.     escapes[2]  = get_bits(gb, 16);

  248. 

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

  250. 

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

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

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

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

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

  256.     ctx.recode1 = tmp1.values;

  257.     ctx.recode2 = tmp2.values;

  258.     ctx.last = last;

  259. 

  260.     huff.length = ((size + 3) >> 2) + 4;

  261.     huff.maxlength = 0;

  262.     huff.current = 0;

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

  264. 

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

  266.         err = -1;

  267.     skip_bits1(gb);

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

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

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

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

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

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

  274.         return AVERROR_INVALIDDATA;

  275.     }

  276. 

  277.     *recodes = huff.values;

  278. 

  279.     if(vlc[0].table)

  280.         ff_free_vlc(&vlc[0]);

  281.     if(vlc[1].table)

  282.         ff_free_vlc(&vlc[1]);

  283.     av_free(tmp1.bits);

  284.     av_free(tmp1.lengths);

  285.     av_free(tmp1.values);

  286.     av_free(tmp2.bits);

  287.     av_free(tmp2.lengths);

  288.     av_free(tmp2.values);

  289. 

  290.     return err;

  291. }

  292. 

  293. static int decode_header_trees(SmackVContext *smk) {

  294.     GetBitContext gb;

  295.     int mmap_size, mclr_size, full_size, type_size, ret;

  296. 

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

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

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

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

  301. 

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

  303. 

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

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

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

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

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

  309.     } else {

  310.         ret = smacker_decode_header_tree(smk, &gb, &smk->mmap_tbl, smk->mmap_last, mmap_size);

  311.         if (ret < 0)

  312.             return ret;

  313.     }

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

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

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

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

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

  319.     } else {

  320.         ret = smacker_decode_header_tree(smk, &gb, &smk->mclr_tbl, smk->mclr_last, mclr_size);

  321.         if (ret < 0)

  322.             return ret;

  323.     }

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

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

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

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

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

  329.     } else {

  330.         ret = smacker_decode_header_tree(smk, &gb, &smk->full_tbl, smk->full_last, full_size);

  331.         if (ret < 0)

  332.             return ret;

  333.     }

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

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

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

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

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

  339.     } else {

  340.         ret = smacker_decode_header_tree(smk, &gb, &smk->type_tbl, smk->type_last, type_size);

  341.         if (ret < 0)

  342.             return ret;

  343.     }

  344. 

  345.     return 0;

  346. }

  347. 

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

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

  350. }

  351. 

  352. /* get code and update history */

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

  354.     register int *table = recode;

  355.     int v;

  356. 

  357.     while(*table & SMK_NODE) {

  358.         if(get_bits1(gb))

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

  360.         table++;

  361.     }

  362.     v = *table;

  363. 

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

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

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

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

  368.     }

  369.     return v;

  370. }

  371. 

  372. static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame,

  373.                         AVPacket *avpkt)

  374. {

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

  376.     uint8_t *out;

  377.     uint32_t *pal;

  378.     GetByteContext gb2;

  379.     GetBitContext gb;

  380.     int blocks, blk, bw, bh;

  381.     int i, ret;

  382.     int stride;

  383.     int flags;

  384. 

  385.     if (avpkt->size <= 769)

  386.         return AVERROR_INVALIDDATA;

  387. 

  388.     if ((ret = ff_reget_buffer(avctx, &smk->pic)) < 0)

  389.         return ret;

  390. 

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

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

  393.     bytestream2_init(&gb2, avpkt->data, avpkt->size);

  394.     flags = bytestream2_get_byteu(&gb2);

  395.     smk->pic.palette_has_changed = flags & 1;

  396.     smk->pic.key_frame = !!(flags & 2);

  397.     if(smk->pic.key_frame)

  398.         smk->pic.pict_type = AV_PICTURE_TYPE_I;

  399.     else

  400.         smk->pic.pict_type = AV_PICTURE_TYPE_P;

  401. 

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

  403.         *pal++ = 0xFFU << 24 | bytestream2_get_be24u(&gb2);

  404. 

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

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

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

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

  409.     init_get_bits(&gb, avpkt->data + 769, (avpkt->size - 769) * 8);

  410. 

  411.     blk = 0;

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

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

  414.     blocks = bw * bh;

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

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

  417.     while(blk < blocks) {

  418.         int type, run, mode;

  419.         uint16_t pix;

  420. 

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

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

  423.         switch(type & 3){

  424.         case SMK_BLK_MONO:

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

  426.                 int clr, map;

  427.                 int hi, lo;

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

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

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

  431.                 hi = clr >> 8;

  432.                 lo = clr & 0xFF;

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

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

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

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

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

  438.                     map >>= 4;

  439.                     out += stride;

  440.                 }

  441.                 blk++;

  442.             }

  443.             break;

  444.         case SMK_BLK_FULL:

  445.             mode = 0;

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

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

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

  449.             }

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

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

  452.                 switch(mode){

  453.                 case 0:

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

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

  456.                         AV_WL16(out+2,pix);

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

  458.                         AV_WL16(out,pix);

  459.                         out += stride;

  460.                     }

  461.                     break;

  462.                 case 1:

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

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

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

  466.                     out += stride;

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

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

  469.                     out += stride;

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

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

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

  473.                     out += stride;

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

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

  476.                     out += stride;

  477.                     break;

  478.                 case 2:

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

  480.                         uint16_t pix1, pix2;

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

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

  483.                         AV_WL16(out,pix1);

  484.                         AV_WL16(out+2,pix2);

  485.                         out += stride;

  486.                         AV_WL16(out,pix1);

  487.                         AV_WL16(out+2,pix2);

  488.                         out += stride;

  489.                     }

  490.                     break;

  491.                 }

  492.                 blk++;

  493.             }

  494.             break;

  495.         case SMK_BLK_SKIP:

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

  497.                 blk++;

  498.             break;

  499.         case SMK_BLK_FILL:

  500.             mode = type >> 8;

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

  502.                 uint32_t col;

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

  504.                 col = mode * 0x01010101;

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

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

  507.                     out += stride;

  508.                 }

  509.                 blk++;

  510.             }

  511.             break;

  512.         }

  513. 

  514.     }

  515. 

  516.     if ((ret = av_frame_ref(data, &smk->pic)) < 0)

  517.         return ret;

  518. 

  519.     *got_frame = 1;

  520. 

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

  522.     return avpkt->size;

  523. }

  524. 

  525. 

  526. 

  527. /*

  528.  *

  529.  * Init smacker decoder

  530.  *

  531.  */

  532. static av_cold int decode_init(AVCodecContext *avctx)

  533. {

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

  535.     int ret;

  536. 

  537.     c->avctx = avctx;

  538. 

  539.     avctx->pix_fmt = AV_PIX_FMT_PAL8;

  540.     avcodec_get_frame_defaults(&c->pic);

  541. 

  542.     /* decode huffman trees from extradata */

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

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

  545.         return AVERROR(EINVAL);

  546.     }

  547. 

  548.     ret = decode_header_trees(c);

  549.     if (ret < 0)

  550.         return ret;

  551. 

  552.     return 0;

  553. }

  554. 

  555. 

  556. 

  557. /*

  558.  *

  559.  * Uninit smacker decoder

  560.  *

  561.  */

  562. static av_cold int decode_end(AVCodecContext *avctx)

  563. {

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

  565. 

  566.     av_freep(&smk->mmap_tbl);

  567.     av_freep(&smk->mclr_tbl);

  568.     av_freep(&smk->full_tbl);

  569.     av_freep(&smk->type_tbl);

  570. 

  571.     av_frame_unref(&smk->pic);

  572. 

  573.     return 0;

  574. }

  575. 

  576. 

  577. static av_cold int smka_decode_init(AVCodecContext *avctx)

  578. {

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

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

  581.         return AVERROR(EINVAL);

  582.     }

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

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

  585. 

  586.     return 0;

  587. }

  588. 

  589. /**

  590.  * Decode Smacker audio data

  591.  */

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

  593.                              int *got_frame_ptr, AVPacket *avpkt)

  594. {

  595.     AVFrame *frame     = data;

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

  597.     int buf_size = avpkt->size;

  598.     GetBitContext gb;

  599.     HuffContext h[4] = { { 0 } };

  600.     VLC vlc[4]       = { { 0 } };

  601.     int16_t *samples;

  602.     uint8_t *samples8;

  603.     int val;

  604.     int i, res, ret;

  605.     int unp_size;

  606.     int bits, stereo;

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

  608. 

  609.     if (buf_size <= 4) {

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

  611.         return AVERROR(EINVAL);

  612.     }

  613. 

  614.     unp_size = AV_RL32(buf);

  615. 

  616.     if (unp_size > (1U<<24)) {

  617.         av_log(avctx, AV_LOG_ERROR, "packet is too big\n");

  618.         return AVERROR_INVALIDDATA;

  619.     }

  620. 

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

  622. 

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

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

  625.         *got_frame_ptr = 0;

  626.         return 1;

  627.     }

  628.     stereo = get_bits1(&gb);

  629.     bits = get_bits1(&gb);

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

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

  632.         return AVERROR(EINVAL);

  633.     }

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

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

  636.         return AVERROR(EINVAL);

  637.     }

  638. 

  639.     /* get output buffer */

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

  641.     if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)

  642.         return ret;

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

  644.     samples8 =            frame->data[0];

  645. 

  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.         if (smacker_decode_tree(&gb, &h[i], 0, 0) < 0) {

  656.             for (; i >= 0; i--) {

  657.                 if (vlc[i].table)

  658.                     ff_free_vlc(&vlc[i]);

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

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

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

  662.             }

  663.             return AVERROR_INVALIDDATA;

  664.         }

  665.         skip_bits1(&gb);

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

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

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

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

  670.             if(res < 0) {

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

  672.                 return AVERROR_INVALIDDATA;

  673.             }

  674.         }

  675.     }

  676.     /* this codec relies on wraparound instead of clipping audio */

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

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

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

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

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

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

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

  684.                 return AVERROR_INVALIDDATA;

  685.             if(i & stereo) {

  686.                 if(vlc[2].table)

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

  688.                 else

  689.                     res = 0;

  690.                 if (res < 0) {

  691.                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");

  692.                     return AVERROR_INVALIDDATA;

  693.                 }

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

  695.                 if(vlc[3].table)

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

  697.                 else

  698.                     res = 0;

  699.                 if (res < 0) {

  700.                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");

  701.                     return AVERROR_INVALIDDATA;

  702.                 }

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

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

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

  706.             } else {

  707.                 if(vlc[0].table)

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

  709.                 else

  710.                     res = 0;

  711.                 if (res < 0) {

  712.                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");

  713.                     return AVERROR_INVALIDDATA;

  714.                 }

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

  716.                 if(vlc[1].table)

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

  718.                 else

  719.                     res = 0;

  720.                 if (res < 0) {

  721.                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");

  722.                     return AVERROR_INVALIDDATA;

  723.                 }

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

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

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

  727.             }

  728.         }

  729.     } else { //8-bit data

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

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

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

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

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

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

  736.                 return AVERROR_INVALIDDATA;

  737.             if(i & stereo){

  738.                 if(vlc[1].table)

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

  740.                 else

  741.                     res = 0;

  742.                 if (res < 0) {

  743.                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");

  744.                     return AVERROR_INVALIDDATA;

  745.                 }

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

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

  748.             } else {

  749.                 if(vlc[0].table)

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

  751.                 else

  752.                     res = 0;

  753.                 if (res < 0) {

  754.                     av_log(avctx, AV_LOG_ERROR, "invalid vlc\n");

  755.                     return AVERROR_INVALIDDATA;

  756.                 }

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

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

  759.             }

  760.         }

  761.     }

  762. 

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

  764.         if(vlc[i].table)

  765.             ff_free_vlc(&vlc[i]);

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

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

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

  769.     }

  770. 

  771.     *got_frame_ptr = 1;

  772. 

  773.     return buf_size;

  774. }

  775. 

  776. AVCodec ff_smacker_decoder = {

  777.     .name           = "smackvid",

  778.     .type           = AVMEDIA_TYPE_VIDEO,

  779.     .id             = AV_CODEC_ID_SMACKVIDEO,

  780.     .priv_data_size = sizeof(SmackVContext),

  781.     .init           = decode_init,

  782.     .close          = decode_end,

  783.     .decode         = decode_frame,

  784.     .capabilities   = CODEC_CAP_DR1,

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

  786. };

  787. 

  788. AVCodec ff_smackaud_decoder = {

  789.     .name           = "smackaud",

  790.     .type           = AVMEDIA_TYPE_AUDIO,

  791.     .id             = AV_CODEC_ID_SMACKAUDIO,

  792.     .init           = smka_decode_init,

  793.     .decode         = smka_decode_frame,

  794.     .capabilities   = CODEC_CAP_DR1,

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

  796. };