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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 Libav.

  6.  *

  7.  * Libav 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.  * Libav 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 Libav; 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. 

  36. #define BITSTREAM_READER_LE

  37. #include "avcodec.h"

  38. #include "bitstream.h"

  39. #include "bytestream.h"

  40. #include "internal.h"

  41. #include "mathops.h"

  42. #include "vlc.h"

  43. 

  44. #define SMKTREE_BITS 9

  45. #define SMK_NODE 0x80000000

  46. 

  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(BitstreamContext *bc, HuffContext *hc,

  98.                                uint32_t prefix, int length)

  99. {

  100.     if (!bitstream_read_bit(bc)) { // Leaf

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

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

  103.             return AVERROR_INVALIDDATA;

  104.         }

  105.         if(length){

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

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

  108.         } else {

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

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

  111.         }

  112.         hc->values[hc->current] = bitstream_read(bc, 8);

  113.         hc->current++;

  114.         if(hc->maxlength < length)

  115.             hc->maxlength = length;

  116.         return 0;

  117.     } else { //Node

  118.         int r;

  119.         length++;

  120.         r = smacker_decode_tree(bc, hc, prefix, length);

  121.         if(r)

  122.             return r;

  123.         return smacker_decode_tree(bc, hc, prefix | (1 << (length - 1)), length);

  124.     }

  125. }

  126. 

  127. /**

  128.  * Decode header tree

  129.  */

  130. static int smacker_decode_bigtree(BitstreamContext *bc, HuffContext *hc,

  131.                                   DBCtx *ctx)

  132. {

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

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

  135.         return AVERROR_INVALIDDATA;

  136.     }

  137.     if (!bitstream_read_bit(bc)) { // Leaf

  138.         int val, i1, i2;

  139.         i1 = ctx->v1->table ? bitstream_read_vlc(bc, ctx->v1->table, SMKTREE_BITS, 3) : 0;

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

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

  142.             return AVERROR_INVALIDDATA;

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

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

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

  146.             val = 0;

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

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

  149.             val = 0;

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

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

  152.             val = 0;

  153.         }

  154. 

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

  156.         return 1;

  157.     } else { //Node

  158.         int r = 0, r_new, t;

  159. 

  160.         t = hc->current++;

  161.         r = smacker_decode_bigtree(bc, hc, ctx);

  162.         if(r < 0)

  163.             return r;

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

  165.         r++;

  166.         r_new = smacker_decode_bigtree(bc, hc, ctx);

  167.         if (r_new < 0)

  168.             return r_new;

  169.         return r + r_new;

  170.     }

  171. }

  172. 

  173. /**

  174.  * Store large tree as Libav's vlc codes

  175.  */

  176. static int smacker_decode_header_tree(SmackVContext *smk, BitstreamContext *bc,

  177.                                       int **recodes, int *last, int size)

  178. {

  179.     int res;

  180.     HuffContext huff;

  181.     HuffContext tmp1, tmp2;

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

  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 AVERROR_INVALIDDATA;

  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.     if (!tmp1.bits || !tmp1.lengths || !tmp1.values ||

  206.         !tmp2.bits || !tmp2.lengths || !tmp2.values) {

  207.         err = AVERROR(ENOMEM);

  208.         goto error;

  209.     }

  210. 

  211.     if (bitstream_read_bit(bc)) {

  212.         smacker_decode_tree(bc, &tmp1, 0, 0);

  213.         bitstream_skip(bc, 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.             err = res;

  220.             goto error;

  221.         }

  222.     } else {

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

  224.     }

  225.     if (bitstream_read_bit(bc)) {

  226.         smacker_decode_tree(bc, &tmp2, 0, 0);

  227.         bitstream_skip(bc, 1);

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

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

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

  231.         if(res < 0) {

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

  233.             err = res;

  234.             goto error;

  235.         }

  236.     } else {

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

  238.     }

  239. 

  240.     escapes[0]  = bitstream_read(bc, 8);

  241.     escapes[0] |= bitstream_read(bc, 8) << 8;

  242.     escapes[1]  = bitstream_read(bc, 8);

  243.     escapes[1] |= bitstream_read(bc, 8) << 8;

  244.     escapes[2]  = bitstream_read(bc, 8);

  245.     escapes[2] |= bitstream_read(bc, 8) << 8;

  246. 

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

  248. 

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

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

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

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

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

  254.     ctx.recode1 = tmp1.values;

  255.     ctx.recode2 = tmp2.values;

  256.     ctx.last = last;

  257. 

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

  259.     huff.maxlength = 0;

  260.     huff.current = 0;

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

  262.     if (!huff.values) {

  263.         err = AVERROR(ENOMEM);

  264.         goto error;

  265.     }

  266. 

  267.     if ((res = smacker_decode_bigtree(bc, &huff, &ctx)) < 0)

  268.         err = res;

  269.     bitstream_skip(bc, 1);

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

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

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

  273.     if (ctx.last[0] >= huff.length ||

  274.         ctx.last[1] >= huff.length ||

  275.         ctx.last[2] >= huff.length) {

  276.         av_log(smk->avctx, AV_LOG_ERROR, "Huffman codes out of range\n");

  277.         err = AVERROR_INVALIDDATA;

  278.     }

  279. 

  280.     *recodes = huff.values;

  281. 

  282. error:

  283.     if(vlc[0].table)

  284.         ff_free_vlc(&vlc[0]);

  285.     if(vlc[1].table)

  286.         ff_free_vlc(&vlc[1]);

  287.     av_free(tmp1.bits);

  288.     av_free(tmp1.lengths);

  289.     av_free(tmp1.values);

  290.     av_free(tmp2.bits);

  291.     av_free(tmp2.lengths);

  292.     av_free(tmp2.values);

  293. 

  294.     return err;

  295. }

  296. 

  297. static int decode_header_trees(SmackVContext *smk) {

  298.     BitstreamContext bc;

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

  300. 

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

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

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

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

  305. 

  306.     bitstream_init8(&bc, smk->avctx->extradata + 16, smk->avctx->extradata_size - 16);

  307. 

  308.     if (!bitstream_read_bit(&bc)) {

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

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

  311.         if (!smk->mmap_tbl)

  312.             return AVERROR(ENOMEM);

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

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

  315.     } else {

  316.         if ((ret = smacker_decode_header_tree(smk, &bc, &smk->mmap_tbl, smk->mmap_last, mmap_size)) < 0)

  317.             return ret;

  318.     }

  319.     if (!bitstream_read_bit(&bc)) {

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

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

  322.         if (!smk->mclr_tbl)

  323.             return AVERROR(ENOMEM);

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

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

  326.     } else {

  327.         if ((ret = smacker_decode_header_tree(smk, &bc, &smk->mclr_tbl, smk->mclr_last, mclr_size)) < 0)

  328.             return ret;

  329.     }

  330.     if (!bitstream_read_bit(&bc)) {

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

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

  333.         if (!smk->full_tbl)

  334.             return AVERROR(ENOMEM);

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

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

  337.     } else {

  338.         if ((ret = smacker_decode_header_tree(smk, &bc, &smk->full_tbl, smk->full_last, full_size)) < 0)

  339.             return ret;

  340.     }

  341.     if (!bitstream_read_bit(&bc)) {

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

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

  344.         if (!smk->type_tbl)

  345.             return AVERROR(ENOMEM);

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

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

  348.     } else {

  349.         if ((ret = smacker_decode_header_tree(smk, &bc, &smk->type_tbl, smk->type_last, type_size)) < 0)

  350.             return ret;

  351.     }

  352. 

  353.     return 0;

  354. }

  355. 

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

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

  358. }

  359. 

  360. /* get code and update history */

  361. static av_always_inline int smk_get_code(BitstreamContext *bc, int *recode,

  362.                                          int *last)

  363. {

  364.     register int *table = recode;

  365.     int v;

  366. 

  367.     while(*table & SMK_NODE) {

  368.         if (bitstream_read_bit(bc))

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

  370.         table++;

  371.     }

  372.     v = *table;

  373. 

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

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

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

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

  378.     }

  379.     return v;

  380. }

  381. 

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

  383.                         AVPacket *avpkt)

  384. {

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

  386.     uint8_t *out;

  387.     uint32_t *pal;

  388.     GetByteContext gb2;

  389.     BitstreamContext bc;

  390.     int blocks, blk, bw, bh;

  391.     int i, ret;

  392.     int stride;

  393.     int flags;

  394. 

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

  396.         return 0;

  397. 

  398.     if ((ret = ff_reget_buffer(avctx, smk->pic)) < 0) {

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

  400.         return ret;

  401.     }

  402. 

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

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

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

  406.     flags = bytestream2_get_byteu(&gb2);

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

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

  409.     if(smk->pic->key_frame)

  410.         smk->pic->pict_type = AV_PICTURE_TYPE_I;

  411.     else

  412.         smk->pic->pict_type = AV_PICTURE_TYPE_P;

  413. 

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

  415.         *pal++ = bytestream2_get_be24u(&gb2);

  416. 

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

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

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

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

  421.     bitstream_init8(&bc, avpkt->data + 769, avpkt->size - 769);

  422. 

  423.     blk = 0;

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

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

  426.     blocks = bw * bh;

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

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

  429.     while(blk < blocks) {

  430.         int type, run, mode;

  431.         uint16_t pix;

  432. 

  433.         type = smk_get_code(&bc, smk->type_tbl, smk->type_last);

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

  435.         switch(type & 3){

  436.         case SMK_BLK_MONO:

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

  438.                 int clr, map;

  439.                 int hi, lo;

  440.                 clr = smk_get_code(&bc, smk->mclr_tbl, smk->mclr_last);

  441.                 map = smk_get_code(&bc, smk->mmap_tbl, smk->mmap_last);

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

  443.                 hi = clr >> 8;

  444.                 lo = clr & 0xFF;

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

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

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

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

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

  450.                     map >>= 4;

  451.                     out += stride;

  452.                 }

  453.                 blk++;

  454.             }

  455.             break;

  456.         case SMK_BLK_FULL:

  457.             mode = 0;

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

  459.                 if (bitstream_read_bit(&bc))

  460.                     mode = 1;

  461.                 else if (bitstream_read_bit(&bc))

  462.                     mode = 2;

  463.             }

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

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

  466.                 switch(mode){

  467.                 case 0:

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

  469.                         pix = smk_get_code(&bc, smk->full_tbl, smk->full_last);

  470.                         AV_WL16(out+2,pix);

  471.                         pix = smk_get_code(&bc, smk->full_tbl, smk->full_last);

  472.                         AV_WL16(out,pix);

  473.                         out += stride;

  474.                     }

  475.                     break;

  476.                 case 1:

  477.                     pix = smk_get_code(&bc, smk->full_tbl, smk->full_last);

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

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

  480.                     out += stride;

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

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

  483.                     out += stride;

  484.                     pix = smk_get_code(&bc, smk->full_tbl, smk->full_last);

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

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

  487.                     out += stride;

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

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

  490.                     out += stride;

  491.                     break;

  492.                 case 2:

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

  494.                         uint16_t pix1, pix2;

  495.                         pix2 = smk_get_code(&bc, smk->full_tbl, smk->full_last);

  496.                         pix1 = smk_get_code(&bc, smk->full_tbl, smk->full_last);

  497.                         AV_WL16(out,pix1);

  498.                         AV_WL16(out+2,pix2);

  499.                         out += stride;

  500.                         AV_WL16(out,pix1);

  501.                         AV_WL16(out+2,pix2);

  502.                         out += stride;

  503.                     }

  504.                     break;

  505.                 }

  506.                 blk++;

  507.             }

  508.             break;

  509.         case SMK_BLK_SKIP:

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

  511.                 blk++;

  512.             break;

  513.         case SMK_BLK_FILL:

  514.             mode = type >> 8;

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

  516.                 uint32_t col;

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

  518.                 col = mode * 0x01010101;

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

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

  521.                     out += stride;

  522.                 }

  523.                 blk++;

  524.             }

  525.             break;

  526.         }

  527. 

  528.     }

  529. 

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

  531.         return ret;

  532. 

  533.     *got_frame = 1;

  534. 

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

  536.     return avpkt->size;

  537. }

  538. 

  539. 

  540. static av_cold int decode_end(AVCodecContext *avctx)

  541. {

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

  543. 

  544.     av_freep(&smk->mmap_tbl);

  545.     av_freep(&smk->mclr_tbl);

  546.     av_freep(&smk->full_tbl);

  547.     av_freep(&smk->type_tbl);

  548. 

  549.     av_frame_free(&smk->pic);

  550. 

  551.     return 0;

  552. }

  553. 

  554. 

  555. static av_cold int decode_init(AVCodecContext *avctx)

  556. {

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

  558.     int ret;

  559. 

  560.     c->avctx = avctx;

  561. 

  562.     avctx->pix_fmt = AV_PIX_FMT_PAL8;

  563. 

  564.     c->pic = av_frame_alloc();

  565.     if (!c->pic)

  566.         return AVERROR(ENOMEM);

  567. 

  568.     /* decode huffman trees from extradata */

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

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

  571.         return AVERROR_INVALIDDATA;

  572.     }

  573. 

  574.     if ((ret = decode_header_trees(c))) {

  575.         decode_end(avctx);

  576.         return ret;

  577.     }

  578. 

  579.     return 0;

  580. }

  581. 

  582. 

  583. 

  584. static av_cold int smka_decode_init(AVCodecContext *avctx)

  585. {

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

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

  588.         return AVERROR_INVALIDDATA;

  589.     }

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

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

  592. 

  593.     return 0;

  594. }

  595. 

  596. /**

  597.  * Decode Smacker audio data

  598.  */

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

  600.                              int *got_frame_ptr, AVPacket *avpkt)

  601. {

  602.     AVFrame *frame     = data;

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

  604.     int buf_size = avpkt->size;

  605.     BitstreamContext bc;

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

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

  608.     int16_t *samples;

  609.     uint8_t *samples8;

  610.     int val;

  611.     int i, res, ret;

  612.     int unp_size;

  613.     int bits, stereo;

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

  615. 

  616.     if (buf_size <= 4) {

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

  618.         return AVERROR_INVALIDDATA;

  619.     }

  620. 

  621.     unp_size = AV_RL32(buf);

  622. 

  623.     bitstream_init8(&bc, buf + 4, buf_size - 4);

  624. 

  625.     if (!bitstream_read_bit(&bc)) {

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

  627.         *got_frame_ptr = 0;

  628.         return 1;

  629.     }

  630.     stereo = bitstream_read_bit(&bc);

  631.     bits   = bitstream_read_bit(&bc);

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

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

  634.         return AVERROR_INVALIDDATA;

  635.     }

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

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

  638.         return AVERROR_INVALIDDATA;

  639.     }

  640.     if (unp_size % (avctx->channels * (bits + 1))) {

  641.         av_log(avctx, AV_LOG_ERROR,

  642.                "The buffer does not contain an integer number of samples\n");

  643.         return AVERROR_INVALIDDATA;

  644.     }

  645. 

  646.     /* get output buffer */

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

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

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

  650.         return ret;

  651.     }

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

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

  654. 

  655.     // Initialize

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

  657.         h[i].length = 256;

  658.         h[i].maxlength = 0;

  659.         h[i].current = 0;

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

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

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

  663.         if (!h[i].bits || !h[i].lengths || !h[i].values) {

  664.             ret = AVERROR(ENOMEM);

  665.             goto error;

  666.         }

  667.         bitstream_skip(&bc, 1);

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

  669.             ret = AVERROR_INVALIDDATA;

  670.             goto error;

  671.         }

  672.         bitstream_skip(&bc, 1);

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

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

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

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

  677.             if(res < 0) {

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

  679.                 ret = AVERROR_INVALIDDATA;

  680.                 goto error;

  681.             }

  682.         }

  683.     }

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

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

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

  687.             pred[i] = sign_extend(av_bswap16(bitstream_read(&bc, 16)), 16);

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

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

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

  691.             if(i & stereo) {

  692.                 if(vlc[2].table)

  693.                     res = bitstream_read_vlc(&bc, vlc[2].table, SMKTREE_BITS, 3);

  694.                 else

  695.                     res = 0;

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

  697.                 if(vlc[3].table)

  698.                     res = bitstream_read_vlc(&bc, vlc[3].table, SMKTREE_BITS, 3);

  699.                 else

  700.                     res = 0;

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

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

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

  704.             } else {

  705.                 if(vlc[0].table)

  706.                     res = bitstream_read_vlc(&bc, vlc[0].table, SMKTREE_BITS, 3);

  707.                 else

  708.                     res = 0;

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

  710.                 if(vlc[1].table)

  711.                     res = bitstream_read_vlc(&bc, vlc[1].table, SMKTREE_BITS, 3);

  712.                 else

  713.                     res = 0;

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

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

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

  717.             }

  718.         }

  719.     } else { //8-bit data

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

  721.             pred[i] = bitstream_read(&bc, 8);

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

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

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

  725.             if(i & stereo){

  726.                 if(vlc[1].table)

  727.                     res = bitstream_read_vlc(&bc, vlc[1].table, SMKTREE_BITS, 3);

  728.                 else

  729.                     res = 0;

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

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

  732.             } else {

  733.                 if(vlc[0].table)

  734.                     res = bitstream_read_vlc(&bc, vlc[0].table, SMKTREE_BITS, 3);

  735.                 else

  736.                     res = 0;

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

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

  739.             }

  740.         }

  741.     }

  742. 

  743.     *got_frame_ptr = 1;

  744.     ret = buf_size;

  745. 

  746. error:

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

  748.         if(vlc[i].table)

  749.             ff_free_vlc(&vlc[i]);

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

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

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

  753.     }

  754. 

  755.     return ret;

  756. }

  757. 

  758. AVCodec ff_smacker_decoder = {

  759.     .name           = "smackvid",

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

  761.     .type           = AVMEDIA_TYPE_VIDEO,

  762.     .id             = AV_CODEC_ID_SMACKVIDEO,

  763.     .priv_data_size = sizeof(SmackVContext),

  764.     .init           = decode_init,

  765.     .close          = decode_end,

  766.     .decode         = decode_frame,

  767.     .capabilities   = AV_CODEC_CAP_DR1,

  768. };

  769. 

  770. AVCodec ff_smackaud_decoder = {

  771.     .name           = "smackaud",

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

  773.     .type           = AVMEDIA_TYPE_AUDIO,

  774.     .id             = AV_CODEC_ID_SMACKAUDIO,

  775.     .init           = smka_decode_init,

  776.     .decode         = smka_decode_frame,

  777.     .capabilities   = AV_CODEC_CAP_DR1,

  778. };