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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. 

  36. #define BITSTREAM_READER_LE

  37. #include "avcodec.h"

  38. #include "bytestream.h"

  39. #include "get_bits.h"

  40. #include "internal.h"

  41. #include "mathops.h"

  42. 

  43. #define SMKTREE_BITS 9

  44. #define SMK_NODE 0x80000000

  45. 

  46. #define SMKTREE_DECODE_MAX_RECURSION 32

  47. #define SMKTREE_DECODE_BIG_MAX_RECURSION 500

  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 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. } 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 (length > SMKTREE_DECODE_MAX_RECURSION || length > 3 * SMKTREE_BITS) {

  99.         av_log(NULL, AV_LOG_ERROR, "Maximum tree recursion level exceeded.\n");

  100.         return AVERROR_INVALIDDATA;

  101.     }

  102. 

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

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

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

  106.             return AVERROR_INVALIDDATA;

  107.         }

  108.         if(length){

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

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

  111.         } else {

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

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

  114.         }

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

  116.         hc->current++;

  117.         return 0;

  118.     } else { //Node

  119.         int r;

  120.         length++;

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

  122.         if(r)

  123.             return r;

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

  125.     }

  126. }

  127. 

  128. /**

  129.  * Decode header tree

  130.  */

  131. static int smacker_decode_bigtree(GetBitContext *gb, HuffContext *hc,

  132.                                   DBCtx *ctx, int length)

  133. {

  134.     // Larger length can cause segmentation faults due to too deep recursion.

  135.     if (length > SMKTREE_DECODE_BIG_MAX_RECURSION) {

  136.         av_log(NULL, AV_LOG_ERROR, "Maximum bigtree recursion level exceeded.\n");

  137.         return AVERROR_INVALIDDATA;

  138.     }

  139. 

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

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

  142.         return AVERROR_INVALIDDATA;

  143.     }

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

  145.         int val, i1, i2;

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

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

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

  149.             return AVERROR_INVALIDDATA;

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

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

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

  153.             val = 0;

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

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

  156.             val = 0;

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

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

  159.             val = 0;

  160.         }

  161. 

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

  163.         return 1;

  164.     } else { //Node

  165.         int r = 0, r_new, t;

  166. 

  167.         t = hc->current++;

  168.         r = smacker_decode_bigtree(gb, hc, ctx, length + 1);

  169.         if(r < 0)

  170.             return r;

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

  172.         r++;

  173.         r_new = smacker_decode_bigtree(gb, hc, ctx, length + 1);

  174.         if (r_new < 0)

  175.             return r_new;

  176.         return r + r_new;

  177.     }

  178. }

  179. 

  180. /**

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

  182.  */

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

  184. {

  185.     HuffContext huff;

  186.     HuffContext h[2] = { 0 };

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

  188.     int escapes[3];

  189.     DBCtx ctx;

  190.     int err;

  191. 

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

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

  194.         return AVERROR_INVALIDDATA;

  195.     }

  196. 

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

  198.         h[i].length  = 256;

  199.         h[i].current = 0;

  200.         h[i].bits    = av_malloc(256 * sizeof(h[i].bits[0]));

  201.         h[i].lengths = av_malloc(256 * sizeof(h[i].lengths[0]));

  202.         h[i].values  = av_malloc(256 * sizeof(h[i].values[0]));

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

  204.             err = AVERROR(ENOMEM);

  205.             goto error;

  206.         }

  207.         if (!get_bits1(gb)) {

  208.             h[i].values[0] = 0;

  209.             av_log(smk->avctx, AV_LOG_ERROR, "Skipping %s bytes tree\n",

  210.                    i ? "high" : "low");

  211.             continue;

  212.         }

  213.         err = smacker_decode_tree(gb, &h[i], 0, 0);

  214.         if (err < 0)

  215.             goto error;

  216.         skip_bits1(gb);

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

  218.             err = init_vlc(&vlc[i], SMKTREE_BITS, h[i].current,

  219.                            INIT_VLC_DEFAULT_SIZES(h[i].lengths),

  220.                            INIT_VLC_DEFAULT_SIZES(h[i].bits),

  221.                            INIT_VLC_LE);

  222.             if (err < 0) {

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

  224.                 goto error;

  225.             }

  226.         }

  227.     }

  228. 

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

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

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

  232. 

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

  234. 

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

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

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

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

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

  240.     ctx.recode1 = h[0].values;

  241.     ctx.recode2 = h[1].values;

  242.     ctx.last = last;

  243. 

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

  245.     huff.current = 0;

  246.     huff.values = av_malloc_array(huff.length + 3, sizeof(huff.values[0]));

  247.     if (!huff.values) {

  248.         err = AVERROR(ENOMEM);

  249.         goto error;

  250.     }

  251.     *recodes = huff.values;

  252. 

  253.     err = smacker_decode_bigtree(gb, &huff, &ctx, 0);

  254.     if (err < 0)

  255.         goto error;

  256.     skip_bits1(gb);

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

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

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

  260. 

  261.     err = 0;

  262. error:

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

  264.         if (vlc[i].table)

  265.             ff_free_vlc(&vlc[i]);

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

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

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

  269.     }

  270. 

  271.     return err;

  272. }

  273. 

  274. static int decode_header_trees(SmackVContext *smk) {

  275.     GetBitContext gb;

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

  277.     int skip = 0;

  278. 

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

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

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

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

  283. 

  284.     ret = init_get_bits8(&gb, smk->avctx->extradata + 16, smk->avctx->extradata_size - 16);

  285.     if (ret < 0)

  286.         return ret;

  287. 

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

  289.         skip ++;

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

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

  292.         if (!smk->mmap_tbl)

  293.             return AVERROR(ENOMEM);

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

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

  296.     } else {

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

  298.         if (ret < 0)

  299.             return ret;

  300.     }

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

  302.         skip ++;

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

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

  305.         if (!smk->mclr_tbl)

  306.             return AVERROR(ENOMEM);

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

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

  309.     } else {

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

  311.         if (ret < 0)

  312.             return ret;

  313.     }

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

  315.         skip ++;

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

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

  318.         if (!smk->full_tbl)

  319.             return AVERROR(ENOMEM);

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

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

  322.     } else {

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

  324.         if (ret < 0)

  325.             return ret;

  326.     }

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

  328.         skip ++;

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

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

  331.         if (!smk->type_tbl)

  332.             return AVERROR(ENOMEM);

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

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

  335.     } else {

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

  337.         if (ret < 0)

  338.             return ret;

  339.     }

  340.     if (skip == 4)

  341.         return AVERROR_INVALIDDATA;

  342. 

  343.     return 0;

  344. }

  345. 

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

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

  348. }

  349. 

  350. /* get code and update history */

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

  352.     register int *table = recode;

  353.     int v;

  354. 

  355.     while(*table & SMK_NODE) {

  356.         if (get_bits_left(gb) < 1)

  357.             return AVERROR_INVALIDDATA;

  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)) < 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.     if ((ret = init_get_bits8(&gb, avpkt->data + 769, avpkt->size - 769)) < 0)

  410.         return ret;

  411. 

  412.     blk = 0;

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

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

  415.     blocks = bw * bh;

  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.         if (type < 0)

  423.             return type;

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

  425.         switch(type & 3){

  426.         case SMK_BLK_MONO:

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

  428.                 int clr, map;

  429.                 int hi, lo;

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

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

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

  433.                 hi = clr >> 8;

  434.                 lo = clr & 0xFF;

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

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

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

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

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

  440.                     map >>= 4;

  441.                     out += stride;

  442.                 }

  443.                 blk++;

  444.             }

  445.             break;

  446.         case SMK_BLK_FULL:

  447.             mode = 0;

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

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

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

  451.             }

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

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

  454.                 switch(mode){

  455.                 case 0:

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

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

  458.                         AV_WL16(out+2,pix);

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

  460.                         AV_WL16(out,pix);

  461.                         out += stride;

  462.                     }

  463.                     break;

  464.                 case 1:

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

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

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

  468.                     out += stride;

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

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

  471.                     out += stride;

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

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

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

  475.                     out += stride;

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

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

  478.                     break;

  479.                 case 2:

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

  481.                         uint16_t pix1, pix2;

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

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

  484.                         AV_WL16(out,pix1);

  485.                         AV_WL16(out+2,pix2);

  486.                         out += stride;

  487.                         AV_WL16(out,pix1);

  488.                         AV_WL16(out+2,pix2);

  489.                         out += stride;

  490.                     }

  491.                     break;

  492.                 }

  493.                 blk++;

  494.             }

  495.             break;

  496.         case SMK_BLK_SKIP:

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

  498.                 blk++;

  499.             break;

  500.         case SMK_BLK_FILL:

  501.             mode = type >> 8;

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

  503.                 uint32_t col;

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

  505.                 col = mode * 0x01010101U;

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

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

  508.                     out += stride;

  509.                 }

  510.                 blk++;

  511.             }

  512.             break;

  513.         }

  514. 

  515.     }

  516. 

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

  518.         return ret;

  519. 

  520.     *got_frame = 1;

  521. 

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

  523.     return avpkt->size;

  524. }

  525. 

  526. 

  527. static av_cold int decode_end(AVCodecContext *avctx)

  528. {

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

  530. 

  531.     av_freep(&smk->mmap_tbl);

  532.     av_freep(&smk->mclr_tbl);

  533.     av_freep(&smk->full_tbl);

  534.     av_freep(&smk->type_tbl);

  535. 

  536.     av_frame_free(&smk->pic);

  537. 

  538.     return 0;

  539. }

  540. 

  541. 

  542. static av_cold int decode_init(AVCodecContext *avctx)

  543. {

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

  545.     int ret;

  546. 

  547.     c->avctx = avctx;

  548. 

  549.     avctx->pix_fmt = AV_PIX_FMT_PAL8;

  550. 

  551.     c->pic = av_frame_alloc();

  552.     if (!c->pic)

  553.         return AVERROR(ENOMEM);

  554. 

  555.     /* decode huffman trees from extradata */

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

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

  558.         return AVERROR(EINVAL);

  559.     }

  560. 

  561.     ret = decode_header_trees(c);

  562.     if (ret < 0) {

  563.         return ret;

  564.     }

  565. 

  566.     return 0;

  567. }

  568. 

  569. 

  570. static av_cold int smka_decode_init(AVCodecContext *avctx)

  571. {

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

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

  574.         return AVERROR_INVALIDDATA;

  575.     }

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

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

  578. 

  579.     return 0;

  580. }

  581. 

  582. /**

  583.  * Decode Smacker audio data

  584.  */

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

  586.                              int *got_frame_ptr, AVPacket *avpkt)

  587. {

  588.     AVFrame *frame     = data;

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

  590.     int buf_size = avpkt->size;

  591.     GetBitContext gb;

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

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

  594.     int16_t *samples;

  595.     uint8_t *samples8;

  596.     int val;

  597.     int i, res, ret;

  598.     int unp_size;

  599.     int bits, stereo;

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

  601. 

  602.     if (buf_size <= 4) {

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

  604.         return AVERROR_INVALIDDATA;

  605.     }

  606. 

  607.     unp_size = AV_RL32(buf);

  608. 

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

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

  611.         return AVERROR_INVALIDDATA;

  612.     }

  613. 

  614.     if ((ret = init_get_bits8(&gb, buf + 4, buf_size - 4)) < 0)

  615.         return ret;

  616. 

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

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

  619.         *got_frame_ptr = 0;

  620.         return 1;

  621.     }

  622.     stereo = get_bits1(&gb);

  623.     bits = get_bits1(&gb);

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

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

  626.         return AVERROR_INVALIDDATA;

  627.     }

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

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

  630.         return AVERROR_INVALIDDATA;

  631.     }

  632. 

  633.     /* get output buffer */

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

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

  636.         av_log(avctx, AV_LOG_ERROR,

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

  638.         return AVERROR_INVALIDDATA;

  639.     }

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

  641.         return ret;

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

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

  644. 

  645.     // Initialize

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

  647.         h[i].length = 256;

  648.         h[i].current = 0;

  649.         h[i].bits    = av_malloc(256 * sizeof(h[i].bits));

  650.         h[i].lengths = av_malloc(256 * sizeof(h[i].lengths));

  651.         h[i].values  = av_malloc(256 * sizeof(h[i].values));

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

  653.             ret = AVERROR(ENOMEM);

  654.             goto error;

  655.         }

  656.         skip_bits1(&gb);

  657.         if ((ret = smacker_decode_tree(&gb, &h[i], 0, 0)) < 0)

  658.             goto error;

  659.         skip_bits1(&gb);

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

  661.             ret = init_vlc(&vlc[i], SMKTREE_BITS, h[i].current,

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

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

  664.             if (ret < 0) {

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

  666.                 goto error;

  667.             }

  668.         }

  669.     }

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

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

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

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

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

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

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

  677.             if (get_bits_left(&gb) < 0) {

  678.                 ret = AVERROR_INVALIDDATA;

  679.                 goto error;

  680.             }

  681.             if(i & stereo) {

  682.                 if(vlc[2].table)

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

  684.                 else

  685.                     res = 0;

  686.                 if (res < 0) {

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

  688.                     ret = AVERROR_INVALIDDATA;

  689.                     goto error;

  690.                 }

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

  692.                 if(vlc[3].table)

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

  694.                 else

  695.                     res = 0;

  696.                 if (res < 0) {

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

  698.                     ret = AVERROR_INVALIDDATA;

  699.                     goto error;

  700.                 }

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

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

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

  704.             } else {

  705.                 if(vlc[0].table)

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

  707.                 else

  708.                     res = 0;

  709.                 if (res < 0) {

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

  711.                     ret = AVERROR_INVALIDDATA;

  712.                     goto error;

  713.                 }

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

  715.                 if(vlc[1].table)

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

  717.                 else

  718.                     res = 0;

  719.                 if (res < 0) {

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

  721.                     ret = AVERROR_INVALIDDATA;

  722.                     goto error;

  723.                 }

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

  725.                 pred[0] += (unsigned)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.                 ret = AVERROR_INVALIDDATA;

  737.                 goto error;

  738.             }

  739.             if(i & stereo){

  740.                 if(vlc[1].table)

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

  742.                 else

  743.                     res = 0;

  744.                 if (res < 0) {

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

  746.                     ret = AVERROR_INVALIDDATA;

  747.                     goto error;

  748.                 }

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

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

  751.             } else {

  752.                 if(vlc[0].table)

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

  754.                 else

  755.                     res = 0;

  756.                 if (res < 0) {

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

  758.                     ret = AVERROR_INVALIDDATA;

  759.                     goto error;

  760.                 }

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

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

  763.             }

  764.         }

  765.     }

  766. 

  767.     *got_frame_ptr = 1;

  768.     ret = buf_size;

  769. 

  770. error:

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

  772.         if(vlc[i].table)

  773.             ff_free_vlc(&vlc[i]);

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

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

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

  777.     }

  778. 

  779.     return ret;

  780. }

  781. 

  782. AVCodec ff_smacker_decoder = {

  783.     .name           = "smackvid",

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

  785.     .type           = AVMEDIA_TYPE_VIDEO,

  786.     .id             = AV_CODEC_ID_SMACKVIDEO,

  787.     .priv_data_size = sizeof(SmackVContext),

  788.     .init           = decode_init,

  789.     .close          = decode_end,

  790.     .decode         = decode_frame,

  791.     .capabilities   = AV_CODEC_CAP_DR1,

  792.     .caps_internal  = FF_CODEC_CAP_INIT_CLEANUP,

  793. };

  794. 

  795. AVCodec ff_smackaud_decoder = {

  796.     .name           = "smackaud",

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

  798.     .type           = AVMEDIA_TYPE_AUDIO,

  799.     .id             = AV_CODEC_ID_SMACKAUDIO,

  800.     .init           = smka_decode_init,

  801.     .decode         = smka_decode_frame,

  802.     .capabilities   = AV_CODEC_CAP_DR1,

  803. };