FFmpeg
 All Data Structures Namespaces Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
anm.c
Go to the documentation of this file.
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 #include "internal.h"
30 
31 typedef struct AnmContext {
35  int x; ///< x coordinate position
36 } AnmContext;
37 
39 {
40  AnmContext *s = avctx->priv_data;
41  int i;
42 
43  avctx->pix_fmt = AV_PIX_FMT_PAL8;
44 
45  s->frame = av_frame_alloc();
46  if (!s->frame)
47  return AVERROR(ENOMEM);
48 
49  bytestream2_init(&s->gb, avctx->extradata, avctx->extradata_size);
50  if (bytestream2_get_bytes_left(&s->gb) < 16 * 8 + 4 * 256)
51  return AVERROR_INVALIDDATA;
52 
53  bytestream2_skipu(&s->gb, 16 * 8);
54  for (i = 0; i < 256; i++)
55  s->palette[i] = bytestream2_get_le32u(&s->gb);
56 
57  return 0;
58 }
59 
60 /**
61  * Perform decode operation
62  * @param dst pointer to destination image buffer
63  * @param dst_end pointer to end of destination image buffer
64  * @param gb GetByteContext (optional, see below)
65  * @param pixel Fill color (optional, see below)
66  * @param count Pixel count
67  * @param x Pointer to x-axis counter
68  * @param width Image width
69  * @param linesize Destination image buffer linesize
70  * @return non-zero if destination buffer is exhausted
71  *
72  * a copy operation is achieved when 'gb' is set
73  * a fill operation is achieved when 'gb' is null and pixel is >= 0
74  * a skip operation is achieved when 'gb' is null and pixel is < 0
75  */
76 static inline int op(uint8_t **dst, const uint8_t *dst_end,
77  GetByteContext *gb,
78  int pixel, int count,
79  int *x, int width, int linesize)
80 {
81  int remaining = width - *x;
82  while(count > 0) {
83  int striplen = FFMIN(count, remaining);
84  if (gb) {
85  if (bytestream2_get_bytes_left(gb) < striplen)
86  goto exhausted;
87  bytestream2_get_bufferu(gb, *dst, striplen);
88  } else if (pixel >= 0)
89  memset(*dst, pixel, striplen);
90  *dst += striplen;
91  remaining -= striplen;
92  count -= striplen;
93  if (remaining <= 0) {
94  *dst += linesize - width;
95  remaining = width;
96  }
97  if (linesize > 0) {
98  if (*dst >= dst_end) goto exhausted;
99  } else {
100  if (*dst <= dst_end) goto exhausted;
101  }
102  }
103  *x = width - remaining;
104  return 0;
105 
106 exhausted:
107  *x = width - remaining;
108  return 1;
109 }
110 
111 static int decode_frame(AVCodecContext *avctx,
112  void *data, int *got_frame,
113  AVPacket *avpkt)
114 {
115  AnmContext *s = avctx->priv_data;
116  const int buf_size = avpkt->size;
117  uint8_t *dst, *dst_end;
118  int count, ret;
119 
120  if ((ret = ff_reget_buffer(avctx, s->frame)) < 0)
121  return ret;
122  dst = s->frame->data[0];
123  dst_end = s->frame->data[0] + s->frame->linesize[0]*avctx->height;
124 
125  bytestream2_init(&s->gb, avpkt->data, buf_size);
126 
127  if (bytestream2_get_byte(&s->gb) != 0x42) {
128  avpriv_request_sample(avctx, "Unknown record type");
129  return AVERROR_INVALIDDATA;
130  }
131  if (bytestream2_get_byte(&s->gb)) {
132  avpriv_request_sample(avctx, "Padding bytes");
133  return AVERROR_PATCHWELCOME;
134  }
135  bytestream2_skip(&s->gb, 2);
136 
137  s->x = 0;
138  do {
139  /* if statements are ordered by probability */
140 #define OP(gb, pixel, count) \
141  op(&dst, dst_end, (gb), (pixel), (count), &s->x, avctx->width, s->frame->linesize[0])
142 
143  int type = bytestream2_get_byte(&s->gb);
144  count = type & 0x7F;
145  type >>= 7;
146  if (count) {
147  if (OP(type ? NULL : &s->gb, -1, count)) break;
148  } else if (!type) {
149  int pixel;
150  count = bytestream2_get_byte(&s->gb); /* count==0 gives nop */
151  pixel = bytestream2_get_byte(&s->gb);
152  if (OP(NULL, pixel, count)) break;
153  } else {
154  int pixel;
155  type = bytestream2_get_le16(&s->gb);
156  count = type & 0x3FFF;
157  type >>= 14;
158  if (!count) {
159  if (type == 0)
160  break; // stop
161  if (type == 2) {
162  avpriv_request_sample(avctx, "Unknown opcode");
163  return AVERROR_PATCHWELCOME;
164  }
165  continue;
166  }
167  pixel = type == 3 ? bytestream2_get_byte(&s->gb) : -1;
168  if (type == 1) count += 0x4000;
169  if (OP(type == 2 ? &s->gb : NULL, pixel, count)) break;
170  }
171  } while (bytestream2_get_bytes_left(&s->gb) > 0);
172 
173  memcpy(s->frame->data[1], s->palette, AVPALETTE_SIZE);
174 
175  *got_frame = 1;
176  if ((ret = av_frame_ref(data, s->frame)) < 0)
177  return ret;
178 
179  return buf_size;
180 }
181 
183 {
184  AnmContext *s = avctx->priv_data;
185 
186  av_frame_free(&s->frame);
187  return 0;
188 }
189 
191  .name = "anm",
192  .long_name = NULL_IF_CONFIG_SMALL("Deluxe Paint Animation"),
193  .type = AVMEDIA_TYPE_VIDEO,
194  .id = AV_CODEC_ID_ANM,
195  .priv_data_size = sizeof(AnmContext),
196  .init = decode_init,
197  .close = decode_end,
198  .decode = decode_frame,
199  .capabilities = CODEC_CAP_DR1,
200 };