Libav
yop.c
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1 /*
2  * Psygnosis YOP decoder
3  *
4  * Copyright (C) 2010 Mohamed Naufal Basheer <naufal11@gmail.com>
5  * derived from the code by
6  * Copyright (C) 2009 Thomas P. Higdon <thomas.p.higdon@gmail.com>
7  *
8  * This file is part of Libav.
9  *
10  * Libav is free software; you can redistribute it and/or
11  * modify it under the terms of the GNU Lesser General Public
12  * License as published by the Free Software Foundation; either
13  * version 2.1 of the License, or (at your option) any later version.
14  *
15  * Libav is distributed in the hope that it will be useful,
16  * but WITHOUT ANY WARRANTY; without even the implied warranty of
17  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18  * Lesser General Public License for more details.
19  *
20  * You should have received a copy of the GNU Lesser General Public
21  * License along with Libav; if not, write to the Free Software
22  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
23  */
24 
25 #include <string.h>
26 
27 #include "libavutil/imgutils.h"
28 #include "libavutil/internal.h"
29 #include "libavutil/intreadwrite.h"
30 
31 #include "avcodec.h"
32 #include "internal.h"
33 
34 typedef struct YopDecContext {
36 
38  int first_color[2];
40 
47 
48 // These tables are taken directly from:
49 // http://wiki.multimedia.cx/index.php?title=Psygnosis_YOP
50 
57 static const uint8_t paint_lut[15][4] =
58  {{1, 2, 3, 4}, {1, 2, 0, 3},
59  {1, 2, 1, 3}, {1, 2, 2, 3},
60  {1, 0, 2, 3}, {1, 0, 0, 2},
61  {1, 0, 1, 2}, {1, 1, 2, 3},
62  {0, 1, 2, 3}, {0, 1, 0, 2},
63  {1, 1, 0, 2}, {0, 1, 1, 2},
64  {0, 0, 1, 2}, {0, 0, 0, 1},
65  {1, 1, 1, 2},
66  };
67 
72 static const int8_t motion_vector[16][2] =
73  {{-4, -4}, {-2, -4},
74  { 0, -4}, { 2, -4},
75  {-4, -2}, {-4, 0},
76  {-3, -3}, {-1, -3},
77  { 1, -3}, { 3, -3},
78  {-3, -1}, {-2, -2},
79  { 0, -2}, { 2, -2},
80  { 4, -2}, {-2, 0},
81  };
82 
84 {
85  YopDecContext *s = avctx->priv_data;
86  s->avctx = avctx;
87 
88  if (avctx->width & 1 || avctx->height & 1 ||
89  av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
90  av_log(avctx, AV_LOG_ERROR, "YOP has invalid dimensions\n");
91  return AVERROR_INVALIDDATA;
92  }
93 
94  if (avctx->extradata_size < 3) {
95  av_log(avctx, AV_LOG_ERROR, "Missing or incomplete extradata.\n");
96  return AVERROR_INVALIDDATA;
97  }
98 
99  avctx->pix_fmt = AV_PIX_FMT_PAL8;
100 
101  s->num_pal_colors = avctx->extradata[0];
102  s->first_color[0] = avctx->extradata[1];
103  s->first_color[1] = avctx->extradata[2];
104 
105  if (s->num_pal_colors + s->first_color[0] > 256 ||
106  s->num_pal_colors + s->first_color[1] > 256) {
107  av_log(avctx, AV_LOG_ERROR,
108  "YOP: palette parameters invalid, header probably corrupt\n");
109  return AVERROR_INVALIDDATA;
110  }
111 
112  return 0;
113 }
114 
120 static int yop_paint_block(YopDecContext *s, int linesize, int tag)
121 {
122  if (s->src_end - s->srcptr < paint_lut[tag][3]) {
123  av_log(s->avctx, AV_LOG_ERROR, "Packet too small.\n");
124  return AVERROR_INVALIDDATA;
125  }
126 
127  s->dstptr[0] = s->srcptr[0];
128  s->dstptr[1] = s->srcptr[paint_lut[tag][0]];
129  s->dstptr[linesize] = s->srcptr[paint_lut[tag][1]];
130  s->dstptr[linesize + 1] = s->srcptr[paint_lut[tag][2]];
131 
132  // The number of src bytes consumed is in the last part of the lut entry.
133  s->srcptr += paint_lut[tag][3];
134  return 0;
135 }
136 
141 static int yop_copy_previous_block(YopDecContext *s, int linesize, int copy_tag)
142 {
143  uint8_t *bufptr;
144 
145  // Calculate position for the copy source
146  bufptr = s->dstptr + motion_vector[copy_tag][0] +
147  linesize * motion_vector[copy_tag][1];
148  if (bufptr < s->dstbuf) {
150  "YOP: cannot decode, file probably corrupt\n");
151  return AVERROR_INVALIDDATA;
152  }
153 
154  s->dstptr[0] = bufptr[0];
155  s->dstptr[1] = bufptr[1];
156  s->dstptr[linesize] = bufptr[linesize];
157  s->dstptr[linesize + 1] = bufptr[linesize + 1];
158 
159  return 0;
160 }
161 
167 {
168  int ret;
169 
170  if (s->low_nibble) {
171  ret = *s->low_nibble & 0xf;
172  s->low_nibble = NULL;
173  }else {
174  s->low_nibble = s->srcptr++;
175  ret = *s->low_nibble >> 4;
176  }
177  return ret;
178 }
179 
180 static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame,
181  AVPacket *avpkt)
182 {
183  YopDecContext *s = avctx->priv_data;
184  AVFrame *frame = data;
185  int tag, firstcolor, is_odd_frame;
186  int ret, i, x, y;
187  uint32_t *palette;
188 
189  if (avpkt->size < 4 + 3 * s->num_pal_colors) {
190  av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
191  return AVERROR_INVALIDDATA;
192  }
193 
194  ret = ff_get_buffer(avctx, frame, 0);
195  if (ret < 0) {
196  av_log(avctx, AV_LOG_ERROR, "get_buffer() failed\n");
197  return ret;
198  }
199 
200  if (!avctx->frame_number)
201  memset(frame->data[1], 0, AVPALETTE_SIZE);
202 
203  s->dstbuf = frame->data[0];
204  s->dstptr = frame->data[0];
205  s->srcptr = avpkt->data + 4;
206  s->src_end = avpkt->data + avpkt->size;
207  s->low_nibble = NULL;
208 
209  is_odd_frame = avpkt->data[0];
210  firstcolor = s->first_color[is_odd_frame];
211  palette = (uint32_t *)frame->data[1];
212 
213  for (i = 0; i < s->num_pal_colors; i++, s->srcptr += 3)
214  palette[i + firstcolor] = (s->srcptr[0] << 18) |
215  (s->srcptr[1] << 10) |
216  (s->srcptr[2] << 2);
217 
218  frame->palette_has_changed = 1;
219 
220  for (y = 0; y < avctx->height; y += 2) {
221  for (x = 0; x < avctx->width; x += 2) {
222  if (s->srcptr - avpkt->data >= avpkt->size) {
223  av_log(avctx, AV_LOG_ERROR, "Packet too small.\n");
224  return AVERROR_INVALIDDATA;
225  }
226 
227  tag = yop_get_next_nibble(s);
228 
229  if (tag != 0xf) {
230  ret = yop_paint_block(s, frame->linesize[0], tag);
231  if (ret < 0)
232  return ret;
233  } else {
234  tag = yop_get_next_nibble(s);
235  ret = yop_copy_previous_block(s, frame->linesize[0], tag);
236  if (ret < 0)
237  return ret;
238  }
239  s->dstptr += 2;
240  }
241  s->dstptr += 2*frame->linesize[0] - x;
242  }
243 
244  *got_frame = 1;
245  return avpkt->size;
246 }
247 
249  .name = "yop",
250  .long_name = NULL_IF_CONFIG_SMALL("Psygnosis YOP Video"),
251  .type = AVMEDIA_TYPE_VIDEO,
252  .id = AV_CODEC_ID_YOP,
253  .priv_data_size = sizeof(YopDecContext),
256  .capabilities = AV_CODEC_CAP_DR1,
257 };
uint8_t * srcptr
Definition: yop.c:42
static int copy_tag(AVIOContext *in, AVIOContext *out, int32_t tag_name)
Definition: ismindex.c:107
#define AVPALETTE_SIZE
Definition: avcodec.h:3402
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:54
This structure describes decoded (raw) audio or video data.
Definition: frame.h:140
misc image utilities
static uint8_t yop_get_next_nibble(YopDecContext *s)
Return the next nibble in sequence, consuming a new byte on the input only if necessary.
Definition: yop.c:166
int size
Definition: avcodec.h:1347
av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (%s)\, len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt), use_generic ? ac->func_descr_generic :ac->func_descr)
uint8_t * src_end
Definition: yop.c:43
int frame_data_length
Definition: yop.c:39
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1621
AVCodec.
Definition: avcodec.h:3120
uint8_t * dstptr
Definition: yop.c:44
uint8_t
#define av_cold
Definition: attributes.h:66
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:70
static int yop_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: yop.c:180
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1523
const char data[16]
Definition: mxf.c:70
uint8_t * data
Definition: avcodec.h:1346
uint32_t tag
Definition: movenc.c:854
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:124
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:148
uint8_t * low_nibble
Definition: yop.c:41
static const int8_t motion_vector[16][2]
Lookup table for copying macroblocks.
Definition: yop.c:72
const char * name
Name of the codec implementation.
Definition: avcodec.h:3127
common internal API header
int av_image_check_size(unsigned int w, unsigned int h, int log_offset, void *log_ctx)
Check if the given dimension of an image is valid, meaning that all bytes of the image can be address...
Definition: imgutils.c:223
int width
picture width / height.
Definition: avcodec.h:1580
static int decode(AVCodecContext *avctx, AVFrame *frame, int *got_frame, AVPacket *pkt)
Definition: avconv.c:1288
static const uint8_t paint_lut[15][4]
Lookup table for painting macroblocks.
Definition: yop.c:57
AVCodec ff_yop_decoder
Definition: yop.c:248
NULL
Definition: eval.c:55
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:158
main external API structure.
Definition: avcodec.h:1409
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: utils.c:589
int extradata_size
Definition: avcodec.h:1524
static int yop_paint_block(YopDecContext *s, int linesize, int tag)
Paint a macroblock using the pattern in paint_lut.
Definition: yop.c:120
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:273
int num_pal_colors
Definition: yop.c:37
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:146
int first_color[2]
Definition: yop.c:38
static int yop_copy_previous_block(YopDecContext *s, int linesize, int copy_tag)
Copy a previously painted macroblock to the current_block.
Definition: yop.c:141
common internal api header.
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:582
void * priv_data
Definition: avcodec.h:1451
static av_cold int yop_decode_init(AVCodecContext *avctx)
Definition: yop.c:83
AVCodecContext * avctx
Definition: yop.c:35
int frame_number
Frame counter, set by libavcodec.
Definition: avcodec.h:2183
uint8_t * dstbuf
Definition: yop.c:45
This structure stores compressed data.
Definition: avcodec.h:1323
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:838
for(j=16;j >0;--j)