libavcodec/mvha.c

   1 /*
   2  * MidiVid Archive codec
   3  *
   4  * Copyright (c) 2019 Paul B Mahol
   5  *
   6  * This file is part of FFmpeg.
   7  *
   8  * FFmpeg is free software; you can redistribute it and/or
   9  * modify it under the terms of the GNU Lesser General Public
  10  * License as published by the Free Software Foundation; either
  11  * version 2.1 of the License, or (at your option) any later version.
  12  *
  13  * FFmpeg is distributed in the hope that it will be useful,
  14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  16  * Lesser General Public License for more details.
  17  *
  18  * You should have received a copy of the GNU Lesser General Public
  19  * License along with FFmpeg; if not, write to the Free Software
  20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  21  */
  22
  23 #define CACHED_BITSTREAM_READER !ARCH_X86_32
  24 #include "libavutil/intreadwrite.h"
  25
  26 #include "avcodec.h"
  27 #include "codec_internal.h"
  28 #include "decode.h"
  29 #include "get_bits.h"
  30 #include "lossless_videodsp.h"
  31 #include "zlib_wrapper.h"
  32
  33 #include <zlib.h>
  34
  35 typedef struct MVHAContext {
  36     GetBitContext     gb;
  37     int nb_symbols;
  38
  39     uint8_t           symb[256];
  40     uint32_t          prob[256];
  41     VLC               vlc;
  42
  43     FFZStream         zstream;
  44     LLVidDSPContext   llviddsp;
  45 } MVHAContext;
  46
  47 typedef struct Node {
  48     int16_t  sym;
  49     int16_t  n0;
  50     int16_t  l, r;
  51     uint32_t count;
  52 } Node;
  53
  54 static void get_tree_codes(uint32_t *bits, int16_t *lens, uint8_t *xlat,
  55                            Node *nodes, int node,
  56                            uint32_t pfx, int pl, int *pos)
  57 {
  58     int s;
  59
  60     s = nodes[node].sym;
  61     if (s != -1) {
  62         bits[*pos] = (~pfx) & ((1ULL << FFMAX(pl, 1)) - 1);
  63         lens[*pos] = FFMAX(pl, 1);
  64         xlat[*pos] = s + (pl == 0);
  65         (*pos)++;
  66     } else {
  67         pfx <<= 1;
  68         pl++;
  69         get_tree_codes(bits, lens, xlat, nodes, nodes[node].l, pfx, pl,
  70                        pos);
  71         pfx |= 1;
  72         get_tree_codes(bits, lens, xlat, nodes, nodes[node].r, pfx, pl,
  73                        pos);
  74     }
  75 }
  76
  77 static int build_vlc(AVCodecContext *avctx, VLC *vlc)
  78 {
  79     MVHAContext *s = avctx->priv_data;
  80     Node nodes[512];
  81     uint32_t bits[256];
  82     int16_t lens[256];
  83     uint8_t xlat[256];
  84     int cur_node, i, j, pos = 0;
  85
  86     ff_vlc_free(vlc);
  87
  88     for (i = 0; i < s->nb_symbols; i++) {
  89         nodes[i].count = s->prob[i];
  90         nodes[i].sym   = s->symb[i];
  91         nodes[i].n0    = -2;
  92         nodes[i].l     = i;
  93         nodes[i].r     = i;
  94     }
  95
  96     cur_node = s->nb_symbols;
  97     j = 0;
  98     do {
  99         for (i = 0; ; i++) {
 100             int new_node = j;
 101             int first_node = cur_node;
 102             int second_node = cur_node;
 103             unsigned nd, st;
 104
 105             nodes[cur_node].count = -1;
 106
 107             do {
 108                 int val = nodes[new_node].count;
 109                 if (val && (val < nodes[first_node].count)) {
 110                     if (val >= nodes[second_node].count) {
 111                         first_node = new_node;
 112                     } else {
 113                         first_node = second_node;
 114                         second_node = new_node;
 115                     }
 116                 }
 117                 new_node += 1;
 118             } while (new_node != cur_node);
 119
 120             if (first_node == cur_node)
 121                 break;
 122
 123             nd = nodes[second_node].count;
 124             st = nodes[first_node].count;
 125             nodes[second_node].count = 0;
 126             nodes[first_node].count  = 0;
 127             if (nd >= UINT32_MAX - st) {
 128                 av_log(avctx, AV_LOG_ERROR, "count overflow\n");
 129                 return AVERROR_INVALIDDATA;
 130             }
 131             nodes[cur_node].count = nd + st;
 132             nodes[cur_node].sym = -1;
 133             nodes[cur_node].n0 = cur_node;
 134             nodes[cur_node].l = first_node;
 135             nodes[cur_node].r = second_node;
 136             cur_node++;
 137         }
 138         j++;
 139     } while (cur_node - s->nb_symbols == j);
 140
 141     get_tree_codes(bits, lens, xlat, nodes, cur_node - 1, 0, 0, &pos);
 142
 143     return ff_vlc_init_sparse(vlc, 12, pos, lens, 2, 2, bits, 4, 4, xlat, 1, 1, 0);
 144 }
 145
 146 static int decode_frame(AVCodecContext *avctx, AVFrame *frame,
 147                         int *got_frame, AVPacket *avpkt)
 148 {
 149     MVHAContext *s = avctx->priv_data;
 150     uint32_t type, size;
 151     int ret;
 152
 153     if (avpkt->size <= 8)
 154         return AVERROR_INVALIDDATA;
 155
 156     type = AV_RB32(avpkt->data);
 157     size = AV_RL32(avpkt->data + 4);
 158
 159     if (size < 1 || size >= avpkt->size)
 160         return AVERROR_INVALIDDATA;
 161
 162     if (type == MKTAG('L','Z','Y','V')) {
 163         z_stream *const zstream = &s->zstream.zstream;
 164         ret = inflateReset(zstream);
 165         if (ret != Z_OK) {
 166             av_log(avctx, AV_LOG_ERROR, "Inflate reset error: %d\n", ret);
 167             return AVERROR_EXTERNAL;
 168         }
 169
 170         if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
 171             return ret;
 172
 173         zstream->next_in  = avpkt->data + 8;
 174         zstream->avail_in = avpkt->size - 8;
 175
 176         for (int p = 0; p < 3; p++) {
 177             for (int y = 0; y < avctx->height; y++) {
 178                 zstream->next_out  = frame->data[p] + (avctx->height - y - 1) * frame->linesize[p];
 179                 zstream->avail_out = avctx->width >> (p > 0);
 180
 181                 ret = inflate(zstream, Z_SYNC_FLUSH);
 182                 if (ret != Z_OK && ret != Z_STREAM_END) {
 183                     av_log(avctx, AV_LOG_ERROR, "Inflate error: %d\n", ret);
 184                     return AVERROR_EXTERNAL;
 185                 }
 186                 if (zstream->avail_out > 0)
 187                     memset(zstream->next_out, 0, zstream->avail_out);
 188             }
 189         }
 190     } else if (type == MKTAG('H','U','F','Y')) {
 191         GetBitContext *gb = &s->gb;
 192         int first_symbol, symbol;
 193
 194         ret = init_get_bits8(gb, avpkt->data + 8, avpkt->size - 8);
 195         if (ret < 0)
 196             return ret;
 197
 198         skip_bits(gb, 24);
 199
 200         first_symbol = get_bits(gb, 8);
 201         s->nb_symbols = get_bits(gb, 8) + 1;
 202
 203         symbol = first_symbol;
 204         for (int i = 0; i < s->nb_symbols; symbol++) {
 205             int prob;
 206
 207             if (get_bits_left(gb) < 4)
 208                 return AVERROR_INVALIDDATA;
 209
 210             if (get_bits1(gb)) {
 211                 prob = get_bits(gb, 12);
 212             } else {
 213                 prob = get_bits(gb, 3);
 214             }
 215
 216             if (prob) {
 217                 s->symb[i] = symbol;
 218                 s->prob[i] = prob;
 219                 i++;
 220             }
 221         }
 222
 223         if (get_bits_left(gb) < avctx->height * avctx->width)
 224             return AVERROR_INVALIDDATA;
 225
 226         ret = build_vlc(avctx, &s->vlc);
 227         if (ret < 0)
 228             return ret;
 229
 230         if ((ret = ff_get_buffer(avctx, frame, 0)) < 0)
 231             return ret;
 232
 233         for (int p = 0; p < 3; p++) {
 234             int width = avctx->width >> (p > 0);
 235             ptrdiff_t stride = frame->linesize[p];
 236             uint8_t *dst;
 237
 238             dst = frame->data[p] + (avctx->height - 1) * frame->linesize[p];
 239             for (int y = 0; y < avctx->height; y++) {
 240                 if (get_bits_left(gb) < width)
 241                     return AVERROR_INVALIDDATA;
 242                 for (int x = 0; x < width; x++) {
 243                     int v = get_vlc2(gb, s->vlc.table, s->vlc.bits, 3);
 244
 245                     if (v < 0)
 246                         return AVERROR_INVALIDDATA;
 247
 248                     dst[x] = v;
 249                 }
 250                 dst -= stride;
 251             }
 252         }
 253     } else {
 254         return AVERROR_INVALIDDATA;
 255     }
 256
 257     for (int p = 0; p < 3; p++) {
 258         int left, lefttop;
 259         int width = avctx->width >> (p > 0);
 260         ptrdiff_t stride = frame->linesize[p];
 261         uint8_t *dst;
 262
 263         dst = frame->data[p] + (avctx->height - 1) * frame->linesize[p];
 264         s->llviddsp.add_left_pred(dst, dst, width, 0);
 265         if (avctx->height > 1) {
 266             dst -= stride;
 267             lefttop = left = dst[0];
 268             for (int y = 1; y < avctx->height; y++) {
 269                 s->llviddsp.add_median_pred(dst, dst + stride, dst, width, &left, &lefttop);
 270                 lefttop = left = dst[0];
 271                 dst -= stride;
 272             }
 273         }
 274     }
 275
 276     *got_frame = 1;
 277
 278     return avpkt->size;
 279 }
 280
 281 static av_cold int decode_init(AVCodecContext *avctx)
 282 {
 283     MVHAContext *s = avctx->priv_data;
 284
 285     avctx->pix_fmt = AV_PIX_FMT_YUV422P;
 286
 287     ff_llviddsp_init(&s->llviddsp);
 288
 289     return ff_inflate_init(&s->zstream, avctx);
 290 }
 291
 292 static av_cold int decode_close(AVCodecContext *avctx)
 293 {
 294     MVHAContext *s = avctx->priv_data;
 295
 296     ff_inflate_end(&s->zstream);
 297     ff_vlc_free(&s->vlc);
 298
 299     return 0;
 300 }
 301
 302 const FFCodec ff_mvha_decoder = {
 303     .p.name           = "mvha",
 304     CODEC_LONG_NAME("MidiVid Archive Codec"),
 305     .p.type           = AVMEDIA_TYPE_VIDEO,
 306     .p.id             = AV_CODEC_ID_MVHA,
 307     .priv_data_size   = sizeof(MVHAContext),
 308     .init             = decode_init,
 309     .close            = decode_close,
 310     FF_CODEC_DECODE_CB(decode_frame),
 311     .p.capabilities   = AV_CODEC_CAP_DR1,
 312     .caps_internal    = FF_CODEC_CAP_INIT_CLEANUP,
 313 };