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c93.c
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1 /*
2  * Interplay C93 video decoder
3  * Copyright (c) 2007 Anssi Hannula <anssi.hannula@gmail.com>
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 #include "avcodec.h"
23 #include "bytestream.h"
24 #include "internal.h"
25 
26 typedef struct C93DecoderContext {
30 
31 typedef enum {
39  C93_NOOP = 0x0E,
40  C93_8X8_INTRA = 0x0F,
41 } C93BlockType;
42 
43 #define WIDTH 320
44 #define HEIGHT 192
45 
46 #define C93_HAS_PALETTE 0x01
47 #define C93_FIRST_FRAME 0x02
48 
49 static av_cold int decode_end(AVCodecContext *avctx)
50 {
51  C93DecoderContext * const c93 = avctx->priv_data;
52 
53  av_frame_free(&c93->pictures[0]);
54  av_frame_free(&c93->pictures[1]);
55 
56  return 0;
57 }
58 
60 {
61  C93DecoderContext *s = avctx->priv_data;
62  avctx->pix_fmt = AV_PIX_FMT_PAL8;
63 
64  s->pictures[0] = av_frame_alloc();
65  s->pictures[1] = av_frame_alloc();
66  if (!s->pictures[0] || !s->pictures[1]) {
67  decode_end(avctx);
68  return AVERROR(ENOMEM);
69  }
70 
71  return 0;
72 }
73 
74 static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
75  uint8_t *from, int offset, int height, int stride)
76 {
77  int i;
78  int width = height;
79  int from_x = offset % WIDTH;
80  int from_y = offset / WIDTH;
81  int overflow = from_x + width - WIDTH;
82 
83  if (!from) {
84  /* silently ignoring predictive blocks in first frame */
85  return 0;
86  }
87 
88  if (from_y + height > HEIGHT) {
89  av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
90  offset);
91  return AVERROR_INVALIDDATA;
92  }
93 
94  if (overflow > 0) {
95  width -= overflow;
96  for (i = 0; i < height; i++) {
97  memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
98  }
99  }
100 
101  for (i = 0; i < height; i++) {
102  memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
103  }
104 
105  return 0;
106 }
107 
108 static inline void draw_n_color(uint8_t *out, int stride, int width,
109  int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
110 {
111  int x, y;
112  for (y = 0; y < height; y++) {
113  if (grps)
114  cols[0] = grps[3 * (y >> 1)];
115  for (x = 0; x < width; x++) {
116  if (grps)
117  cols[1]= grps[(x >> 1) + 1];
118  out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
119  col >>= bpp;
120  }
121  }
122 }
123 
124 static int decode_frame(AVCodecContext *avctx, void *data,
125  int *got_frame, AVPacket *avpkt)
126 {
127  const uint8_t *buf = avpkt->data;
128  int buf_size = avpkt->size;
129  C93DecoderContext * const c93 = avctx->priv_data;
130  AVFrame * const newpic = c93->pictures[c93->currentpic];
131  AVFrame * const oldpic = c93->pictures[c93->currentpic^1];
132  GetByteContext gb;
133  uint8_t *out;
134  int stride, ret, i, x, y, b, bt = 0;
135 
136  if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0)
137  return ret;
138 
139  c93->currentpic ^= 1;
140 
141  if ((ret = ff_reget_buffer(avctx, newpic)) < 0)
142  return ret;
143 
144  stride = newpic->linesize[0];
145 
146  bytestream2_init(&gb, buf, buf_size);
147  b = bytestream2_get_byte(&gb);
148  if (b & C93_FIRST_FRAME) {
149  newpic->pict_type = AV_PICTURE_TYPE_I;
150  newpic->key_frame = 1;
151  } else {
152  newpic->pict_type = AV_PICTURE_TYPE_P;
153  newpic->key_frame = 0;
154  }
155 
156  for (y = 0; y < HEIGHT; y += 8) {
157  out = newpic->data[0] + y * stride;
158  for (x = 0; x < WIDTH; x += 8) {
159  uint8_t *copy_from = oldpic->data[0];
160  unsigned int offset, j;
161  uint8_t cols[4], grps[4];
162  C93BlockType block_type;
163 
164  if (!bt)
165  bt = bytestream2_get_byte(&gb);
166 
167  block_type= bt & 0x0F;
168  switch (block_type) {
169  case C93_8X8_FROM_PREV:
170  offset = bytestream2_get_le16(&gb);
171  if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0)
172  return ret;
173  break;
174 
175  case C93_4X4_FROM_CURR:
176  copy_from = newpic->data[0];
177  case C93_4X4_FROM_PREV:
178  for (j = 0; j < 8; j += 4) {
179  for (i = 0; i < 8; i += 4) {
180  int offset = bytestream2_get_le16(&gb);
181  int from_x = offset % WIDTH;
182  int from_y = offset / WIDTH;
183  if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
184  (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) {
185  avpriv_request_sample(avctx, "block overlap %d %d %d %d", from_x, x+i, from_y, y+j);
186  return AVERROR_INVALIDDATA;
187  }
188  if ((ret = copy_block(avctx, &out[j*stride+i],
189  copy_from, offset, 4, stride)) < 0)
190  return ret;
191  }
192  }
193  break;
194 
195  case C93_8X8_2COLOR:
196  bytestream2_get_buffer(&gb, cols, 2);
197  for (i = 0; i < 8; i++) {
198  draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
199  NULL, bytestream2_get_byte(&gb));
200  }
201 
202  break;
203 
204  case C93_4X4_2COLOR:
205  case C93_4X4_4COLOR:
206  case C93_4X4_4COLOR_GRP:
207  for (j = 0; j < 8; j += 4) {
208  for (i = 0; i < 8; i += 4) {
209  if (block_type == C93_4X4_2COLOR) {
210  bytestream2_get_buffer(&gb, cols, 2);
211  draw_n_color(out + i + j*stride, stride, 4, 4,
212  1, cols, NULL, bytestream2_get_le16(&gb));
213  } else if (block_type == C93_4X4_4COLOR) {
214  bytestream2_get_buffer(&gb, cols, 4);
215  draw_n_color(out + i + j*stride, stride, 4, 4,
216  2, cols, NULL, bytestream2_get_le32(&gb));
217  } else {
218  bytestream2_get_buffer(&gb, grps, 4);
219  draw_n_color(out + i + j*stride, stride, 4, 4,
220  1, cols, grps, bytestream2_get_le16(&gb));
221  }
222  }
223  }
224  break;
225 
226  case C93_NOOP:
227  break;
228 
229  case C93_8X8_INTRA:
230  for (j = 0; j < 8; j++)
231  bytestream2_get_buffer(&gb, out + j*stride, 8);
232  break;
233 
234  default:
235  av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
236  block_type, x, y);
237  return AVERROR_INVALIDDATA;
238  }
239  bt >>= 4;
240  out += 8;
241  }
242  }
243 
244  if (b & C93_HAS_PALETTE) {
245  uint32_t *palette = (uint32_t *) newpic->data[1];
246  for (i = 0; i < 256; i++) {
247  palette[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
248  }
249  newpic->palette_has_changed = 1;
250  } else {
251  if (oldpic->data[1])
252  memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
253  }
254 
255  if ((ret = av_frame_ref(data, newpic)) < 0)
256  return ret;
257  *got_frame = 1;
258 
259  return buf_size;
260 }
261 
263  .name = "c93",
264  .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
265  .type = AVMEDIA_TYPE_VIDEO,
266  .id = AV_CODEC_ID_C93,
267  .priv_data_size = sizeof(C93DecoderContext),
268  .init = decode_init,
269  .close = decode_end,
270  .decode = decode_frame,
271  .capabilities = AV_CODEC_CAP_DR1,
272 };
#define NULL
Definition: coverity.c:32
#define WIDTH
Definition: c93.c:43
const char * s
Definition: avisynth_c.h:631
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
This structure describes decoded (raw) audio or video data.
Definition: frame.h:180
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:101
int ff_set_dimensions(AVCodecContext *s, int width, int height)
Check that the provided frame dimensions are valid and set them on the codec context.
Definition: utils.c:210
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
int size
Definition: avcodec.h:1578
const char * b
Definition: vf_curves.c:109
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1870
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:133
AVCodec.
Definition: avcodec.h:3535
AVCodec ff_c93_decoder
Definition: c93.c:262
static void draw_n_color(uint8_t *out, int stride, int width, int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
Definition: c93.c:108
static av_cold int decode_init(AVCodecContext *avctx)
Definition: c93.c:59
void void avpriv_request_sample(void *avc, const char *msg,...) av_printf_format(2
Log a generic warning message about a missing feature.
uint8_t
#define av_cold
Definition: attributes.h:82
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:140
8 bit with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:73
int av_frame_ref(AVFrame *dst, const AVFrame *src)
Set up a new reference to the data described by the source frame.
Definition: frame.c:374
const char * from
Definition: jacosubdec.c:65
uint8_t * data
Definition: avcodec.h:1577
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: c93.c:124
#define av_log(a,...)
const char * to
Definition: webvttdec.c:34
static av_cold int decode_end(AVCodecContext *avctx)
Definition: c93.c:49
#define U(x)
Definition: vp56_arith.h:37
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define C93_HAS_PALETTE
Definition: c93.c:46
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:153
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:176
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:263
const char * name
Name of the codec implementation.
Definition: avcodec.h:3542
static const uint8_t offset[127][2]
Definition: vf_spp.c:92
#define C93_FIRST_FRAME
Definition: c93.c:47
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame)
Identical in function to av_frame_make_writable(), except it uses ff_get_buffer() to allocate the buf...
Definition: utils.c:977
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:254
#define width
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
static int copy_from(IpvideoContext *s, AVFrame *src, AVFrame *dst, int delta_x, int delta_y)
FILE * out
Definition: movenc-test.c:54
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:211
main external API structure.
Definition: avcodec.h:1642
void * buf
Definition: avisynth_c.h:553
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:324
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:194
static int decode(AVCodecContext *avctx, void *data, int *got_sub, AVPacket *avpkt)
Definition: ccaption_dec.c:722
int palette
Definition: v4l.c:61
GLint GLenum GLboolean GLsizei stride
Definition: opengl_enc.c:105
common internal api header.
void * priv_data
Definition: avcodec.h:1684
C93BlockType
Definition: c93.c:31
static int copy_block(AVCodecContext *avctx, uint8_t *to, uint8_t *from, int offset, int height, int stride)
Definition: c93.c:74
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:249
AVFrame * pictures[2]
Definition: c93.c:27
#define HEIGHT
Definition: c93.c:44
#define stride
#define height
Definition: c93.c:39
This structure stores compressed data.
Definition: avcodec.h:1554
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:953
int currentpic
Definition: c93.c:28
for(j=16;j >0;--j)
Predicted.
Definition: avutil.h:267