libavcodec/anm.c

   1 /*
   2  * Deluxe Paint Animation decoder
   3  * Copyright (c) 2009 Peter Ross
   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  * Deluxe Paint Animation decoder
  25  */
  26
  27 #include "avcodec.h"
  28 #include "bytestream.h"
  29
  30 typedef struct AnmContext {
  31     AVFrame frame;
  32     int palette[AVPALETTE_COUNT];
  33     GetByteContext gb;
  34     int x;  ///< x coordinate position
  35 } AnmContext;
  36
  37 static av_cold int decode_init(AVCodecContext *avctx)
  38 {
  39     AnmContext *s = avctx->priv_data;
  40     int i;
  41
  42     avctx->pix_fmt = AV_PIX_FMT_PAL8;
  43
  44     s->frame.reference = 1;
  45     bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
  46     if (bytestream2_get_bytes_left(&s->gb) < 16 * 8 + 4 * 256)
  47         return AVERROR_INVALIDDATA;
  48
  49     bytestream2_skipu(&s->gb, 16 * 8);
  50     for (i = 0; i < 256; i++)
  51         s->palette[i] = bytestream2_get_le32u(&s->gb);
  52
  53     return 0;
  54 }
  55
  56 /**
  57  * Perform decode operation
  58  * @param dst     pointer to destination image buffer
  59  * @param dst_end pointer to end of destination image buffer
  60  * @param gb GetByteContext (optional, see below)
  61  * @param pixel Fill color (optional, see below)
  62  * @param count Pixel count
  63  * @param x Pointer to x-axis counter
  64  * @param width Image width
  65  * @param linesize Destination image buffer linesize
  66  * @return non-zero if destination buffer is exhausted
  67  *
  68  * a copy operation is achieved when 'gb' is set
  69  * a fill operation is achieved when 'gb' is null and pixel is >= 0
  70  * a skip operation is achieved when 'gb' is null and pixel is < 0
  71  */
  72 static inline int op(uint8_t **dst, const uint8_t *dst_end,
  73                      GetByteContext *gb,
  74                      int pixel, int count,
  75                      int *x, int width, int linesize)
  76 {
  77     int remaining = width - *x;
  78     while(count > 0) {
  79         int striplen = FFMIN(count, remaining);
  80         if (gb) {
  81             if (bytestream2_get_bytes_left(gb) < striplen)
  82                 goto exhausted;
  83             bytestream2_get_bufferu(gb, *dst, striplen);
  84         } else if (pixel >= 0)
  85             memset(*dst, pixel, striplen);
  86         *dst      += striplen;
  87         remaining -= striplen;
  88         count     -= striplen;
  89         if (remaining <= 0) {
  90             *dst      += linesize - width;
  91             remaining  = width;
  92         }
  93         if (linesize > 0) {
  94             if (*dst >= dst_end) goto exhausted;
  95         } else {
  96             if (*dst <= dst_end) goto exhausted;
  97         }
  98     }
  99     *x = width - remaining;
 100     return 0;
 101
 102 exhausted:
 103     *x = width - remaining;
 104     return 1;
 105 }
 106
 107 static int decode_frame(AVCodecContext *avctx,
 108                         void *data, int *got_frame,
 109                         AVPacket *avpkt)
 110 {
 111     AnmContext *s = avctx->priv_data;
 112     const int buf_size = avpkt->size;
 113     uint8_t *dst, *dst_end;
 114     int count, ret;
 115
 116     if ((ret = avctx->reget_buffer(avctx, &s->frame)) < 0){
 117         av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
 118         return ret;
 119     }
 120     dst     = s->frame.data[0];
 121     dst_end = s->frame.data[0] + s->frame.linesize[0]*avctx->height;
 122
 123     bytestream2_init(&s->gb, avpkt->data, buf_size);
 124
 125     if (bytestream2_get_byte(&s->gb) != 0x42) {
 126         av_log_ask_for_sample(avctx, "unknown record type\n");
 127         return buf_size;
 128     }
 129     if (bytestream2_get_byte(&s->gb)) {
 130         av_log_ask_for_sample(avctx, "padding bytes not supported\n");
 131         return buf_size;
 132     }
 133     bytestream2_skip(&s->gb, 2);
 134
 135     s->x = 0;
 136     do {
 137         /* if statements are ordered by probability */
 138 #define OP(gb, pixel, count) \
 139     op(&dst, dst_end, (gb), (pixel), (count), &s->x, avctx->width, s->frame.linesize[0])
 140
 141         int type = bytestream2_get_byte(&s->gb);
 142         count = type & 0x7F;
 143         type >>= 7;
 144         if (count) {
 145             if (OP(type ? NULL : &s->gb, -1, count)) break;
 146         } else if (!type) {
 147             int pixel;
 148             count = bytestream2_get_byte(&s->gb);  /* count==0 gives nop */
 149             pixel = bytestream2_get_byte(&s->gb);
 150             if (OP(NULL, pixel, count)) break;
 151         } else {
 152             int pixel;
 153             type = bytestream2_get_le16(&s->gb);
 154             count = type & 0x3FFF;
 155             type >>= 14;
 156             if (!count) {
 157                 if (type == 0)
 158                     break; // stop
 159                 if (type == 2) {
 160                     av_log_ask_for_sample(avctx, "unknown opcode");
 161                     return AVERROR_PATCHWELCOME;
 162                 }
 163                 continue;
 164             }
 165             pixel = type == 3 ? bytestream2_get_byte(&s->gb) : -1;
 166             if (type == 1) count += 0x4000;
 167             if (OP(type == 2 ? &s->gb : NULL, pixel, count)) break;
 168         }
 169     } while (bytestream2_get_bytes_left(&s->gb) > 0);
 170
 171     memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
 172
 173     *got_frame = 1;
 174     *(AVFrame*)data = s->frame;
 175     return buf_size;
 176 }
 177
 178 static av_cold int decode_end(AVCodecContext *avctx)
 179 {
 180     AnmContext *s = avctx->priv_data;
 181     if (s->frame.data[0])
 182         avctx->release_buffer(avctx, &s->frame);
 183     return 0;
 184 }
 185
 186 AVCodec ff_anm_decoder = {
 187     .name           = "anm",
 188     .type           = AVMEDIA_TYPE_VIDEO,
 189     .id             = AV_CODEC_ID_ANM,
 190     .priv_data_size = sizeof(AnmContext),
 191     .init           = decode_init,
 192     .close          = decode_end,
 193     .decode         = decode_frame,
 194     .capabilities   = CODEC_CAP_DR1,
 195     .long_name      = NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
 196 };