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anm.c
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1 /*
2  * Deluxe Paint Animation decoder
3  * Copyright (c) 2009 Peter Ross
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  * Deluxe Paint Animation decoder
25  */
26 
27 #include "avcodec.h"
28 #include "bytestream.h"
29 
30 typedef struct AnmContext {
34  int x; ///< x coordinate position
35 } AnmContext;
36 
38 {
39  AnmContext *s = avctx->priv_data;
40  int i;
41 
42  avctx->pix_fmt = AV_PIX_FMT_PAL8;
43 
45  s->frame.reference = 3;
46  bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
47  if (bytestream2_get_bytes_left(&s->gb) < 16 * 8 + 4 * 256)
48  return AVERROR_INVALIDDATA;
49 
50  bytestream2_skipu(&s->gb, 16 * 8);
51  for (i = 0; i < 256; i++)
52  s->palette[i] = bytestream2_get_le32u(&s->gb);
53 
54  return 0;
55 }
56 
57 /**
58  * Perform decode operation
59  * @param dst pointer to destination image buffer
60  * @param dst_end pointer to end of destination image buffer
61  * @param gb GetByteContext (optional, see below)
62  * @param pixel Fill color (optional, see below)
63  * @param count Pixel count
64  * @param x Pointer to x-axis counter
65  * @param width Image width
66  * @param linesize Destination image buffer linesize
67  * @return non-zero if destination buffer is exhausted
68  *
69  * a copy operation is achieved when 'gb' is set
70  * a fill operation is achieved when 'gb' is null and pixel is >= 0
71  * a skip operation is achieved when 'gb' is null and pixel is < 0
72  */
73 static inline int op(uint8_t **dst, const uint8_t *dst_end,
74  GetByteContext *gb,
75  int pixel, int count,
76  int *x, int width, int linesize)
77 {
78  int remaining = width - *x;
79  while(count > 0) {
80  int striplen = FFMIN(count, remaining);
81  if (gb) {
82  if (bytestream2_get_bytes_left(gb) < striplen)
83  goto exhausted;
84  bytestream2_get_bufferu(gb, *dst, striplen);
85  } else if (pixel >= 0)
86  memset(*dst, pixel, striplen);
87  *dst += striplen;
88  remaining -= striplen;
89  count -= striplen;
90  if (remaining <= 0) {
91  *dst += linesize - width;
92  remaining = width;
93  }
94  if (linesize > 0) {
95  if (*dst >= dst_end) goto exhausted;
96  } else {
97  if (*dst <= dst_end) goto exhausted;
98  }
99  }
100  *x = width - remaining;
101  return 0;
102 
103 exhausted:
104  *x = width - remaining;
105  return 1;
106 }
107 
108 static int decode_frame(AVCodecContext *avctx,
109  void *data, int *got_frame,
110  AVPacket *avpkt)
111 {
112  AnmContext *s = avctx->priv_data;
113  const int buf_size = avpkt->size;
114  uint8_t *dst, *dst_end;
115  int count, ret;
116 
117  if ((ret = avctx->reget_buffer(avctx, &s->frame)) < 0){
118  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
119  return ret;
120  }
121  dst = s->frame.data[0];
122  dst_end = s->frame.data[0] + s->frame.linesize[0]*avctx->height;
123 
124  bytestream2_init(&s->gb, avpkt->data, buf_size);
125 
126  if (bytestream2_get_byte(&s->gb) != 0x42) {
127  av_log_ask_for_sample(avctx, "unknown record type\n");
128  return AVERROR_INVALIDDATA;
129  }
130  if (bytestream2_get_byte(&s->gb)) {
131  av_log_ask_for_sample(avctx, "padding bytes not supported\n");
132  return AVERROR_PATCHWELCOME;
133  }
134  bytestream2_skip(&s->gb, 2);
135 
136  s->x = 0;
137  do {
138  /* if statements are ordered by probability */
139 #define OP(gb, pixel, count) \
140  op(&dst, dst_end, (gb), (pixel), (count), &s->x, avctx->width, s->frame.linesize[0])
141 
142  int type = bytestream2_get_byte(&s->gb);
143  count = type & 0x7F;
144  type >>= 7;
145  if (count) {
146  if (OP(type ? NULL : &s->gb, -1, count)) break;
147  } else if (!type) {
148  int pixel;
149  count = bytestream2_get_byte(&s->gb); /* count==0 gives nop */
150  pixel = bytestream2_get_byte(&s->gb);
151  if (OP(NULL, pixel, count)) break;
152  } else {
153  int pixel;
154  type = bytestream2_get_le16(&s->gb);
155  count = type & 0x3FFF;
156  type >>= 14;
157  if (!count) {
158  if (type == 0)
159  break; // stop
160  if (type == 2) {
161  av_log_ask_for_sample(avctx, "unknown opcode");
162  return AVERROR_PATCHWELCOME;
163  }
164  continue;
165  }
166  pixel = type == 3 ? bytestream2_get_byte(&s->gb) : -1;
167  if (type == 1) count += 0x4000;
168  if (OP(type == 2 ? &s->gb : NULL, pixel, count)) break;
169  }
170  } while (bytestream2_get_bytes_left(&s->gb) > 0);
171 
172  memcpy(s->frame.data[1], s->palette, AVPALETTE_SIZE);
173 
174  *got_frame = 1;
175  *(AVFrame*)data = s->frame;
176  return buf_size;
177 }
178 
180 {
181  AnmContext *s = avctx->priv_data;
182  if (s->frame.data[0])
183  avctx->release_buffer(avctx, &s->frame);
184  return 0;
185 }
186 
188  .name = "anm",
189  .type = AVMEDIA_TYPE_VIDEO,
190  .id = AV_CODEC_ID_ANM,
191  .priv_data_size = sizeof(AnmContext),
192  .init = decode_init,
193  .close = decode_end,
194  .decode = decode_frame,
195  .capabilities = CODEC_CAP_DR1,
196  .long_name = NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
197 };