FFmpeg  4.4.5
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  return AVERROR(ENOMEM);
68 
69  return 0;
70 }
71 
72 static inline int copy_block(AVCodecContext *avctx, uint8_t *to,
73  uint8_t *from, int offset, int height, int stride)
74 {
75  int i;
76  int width = height;
77  int from_x = offset % WIDTH;
78  int from_y = offset / WIDTH;
79  int overflow = from_x + width - WIDTH;
80 
81  if (!from) {
82  /* silently ignoring predictive blocks in first frame */
83  return 0;
84  }
85 
86  if (from_y + height > HEIGHT) {
87  av_log(avctx, AV_LOG_ERROR, "invalid offset %d during C93 decoding\n",
88  offset);
89  return AVERROR_INVALIDDATA;
90  }
91 
92  if (overflow > 0) {
93  width -= overflow;
94  for (i = 0; i < height; i++) {
95  memcpy(&to[i*stride+width], &from[(from_y+i)*stride], overflow);
96  }
97  }
98 
99  for (i = 0; i < height; i++) {
100  memcpy(&to[i*stride], &from[(from_y+i)*stride+from_x], width);
101  }
102 
103  return 0;
104 }
105 
106 static inline void draw_n_color(uint8_t *out, int stride, int width,
107  int height, int bpp, uint8_t cols[4], uint8_t grps[4], uint32_t col)
108 {
109  int x, y;
110  for (y = 0; y < height; y++) {
111  if (grps)
112  cols[0] = grps[3 * (y >> 1)];
113  for (x = 0; x < width; x++) {
114  if (grps)
115  cols[1]= grps[(x >> 1) + 1];
116  out[x + y*stride] = cols[col & ((1 << bpp) - 1)];
117  col >>= bpp;
118  }
119  }
120 }
121 
122 static int decode_frame(AVCodecContext *avctx, void *data,
123  int *got_frame, AVPacket *avpkt)
124 {
125  const uint8_t *buf = avpkt->data;
126  int buf_size = avpkt->size;
127  C93DecoderContext * const c93 = avctx->priv_data;
128  AVFrame * const newpic = c93->pictures[c93->currentpic];
129  AVFrame * const oldpic = c93->pictures[c93->currentpic^1];
130  GetByteContext gb;
131  uint8_t *out;
132  int stride, ret, i, x, y, b, bt = 0;
133 
134  if ((ret = ff_set_dimensions(avctx, WIDTH, HEIGHT)) < 0)
135  return ret;
136 
137  c93->currentpic ^= 1;
138 
139  if ((ret = ff_reget_buffer(avctx, newpic, 0)) < 0)
140  return ret;
141 
142  stride = newpic->linesize[0];
143 
144  bytestream2_init(&gb, buf, buf_size);
145  b = bytestream2_get_byte(&gb);
146  if (b & C93_FIRST_FRAME) {
147  newpic->pict_type = AV_PICTURE_TYPE_I;
148  newpic->key_frame = 1;
149  } else {
150  newpic->pict_type = AV_PICTURE_TYPE_P;
151  newpic->key_frame = 0;
152  }
153 
154  for (y = 0; y < HEIGHT; y += 8) {
155  out = newpic->data[0] + y * stride;
156  for (x = 0; x < WIDTH; x += 8) {
157  uint8_t *copy_from = oldpic->data[0];
158  unsigned int offset, j;
159  uint8_t cols[4], grps[4];
160  C93BlockType block_type;
161 
162  if (!bt)
163  bt = bytestream2_get_byte(&gb);
164 
165  block_type= bt & 0x0F;
166  switch (block_type) {
167  case C93_8X8_FROM_PREV:
168  offset = bytestream2_get_le16(&gb);
169  if ((ret = copy_block(avctx, out, copy_from, offset, 8, stride)) < 0)
170  return ret;
171  break;
172 
173  case C93_4X4_FROM_CURR:
174  copy_from = newpic->data[0];
175  case C93_4X4_FROM_PREV:
176  for (j = 0; j < 8; j += 4) {
177  for (i = 0; i < 8; i += 4) {
178  int offset = bytestream2_get_le16(&gb);
179  int from_x = offset % WIDTH;
180  int from_y = offset / WIDTH;
181  if (block_type == C93_4X4_FROM_CURR && from_y == y+j &&
182  (FFABS(from_x - x-i) < 4 || FFABS(from_x - x-i) > WIDTH-4)) {
183  avpriv_request_sample(avctx, "block overlap %d %d %d %d", from_x, x+i, from_y, y+j);
184  return AVERROR_INVALIDDATA;
185  }
186  if ((ret = copy_block(avctx, &out[j*stride+i],
187  copy_from, offset, 4, stride)) < 0)
188  return ret;
189  }
190  }
191  break;
192 
193  case C93_8X8_2COLOR:
194  bytestream2_get_buffer(&gb, cols, 2);
195  for (i = 0; i < 8; i++) {
196  draw_n_color(out + i*stride, stride, 8, 1, 1, cols,
197  NULL, bytestream2_get_byte(&gb));
198  }
199 
200  break;
201 
202  case C93_4X4_2COLOR:
203  case C93_4X4_4COLOR:
204  case C93_4X4_4COLOR_GRP:
205  for (j = 0; j < 8; j += 4) {
206  for (i = 0; i < 8; i += 4) {
207  if (block_type == C93_4X4_2COLOR) {
208  bytestream2_get_buffer(&gb, cols, 2);
209  draw_n_color(out + i + j*stride, stride, 4, 4,
210  1, cols, NULL, bytestream2_get_le16(&gb));
211  } else if (block_type == C93_4X4_4COLOR) {
212  bytestream2_get_buffer(&gb, cols, 4);
213  draw_n_color(out + i + j*stride, stride, 4, 4,
214  2, cols, NULL, bytestream2_get_le32(&gb));
215  } else {
216  bytestream2_get_buffer(&gb, grps, 4);
217  draw_n_color(out + i + j*stride, stride, 4, 4,
218  1, cols, grps, bytestream2_get_le16(&gb));
219  }
220  }
221  }
222  break;
223 
224  case C93_NOOP:
225  break;
226 
227  case C93_8X8_INTRA:
228  for (j = 0; j < 8; j++)
229  bytestream2_get_buffer(&gb, out + j*stride, 8);
230  break;
231 
232  default:
233  av_log(avctx, AV_LOG_ERROR, "unexpected type %x at %dx%d\n",
234  block_type, x, y);
235  return AVERROR_INVALIDDATA;
236  }
237  bt >>= 4;
238  out += 8;
239  }
240  }
241 
242  if (b & C93_HAS_PALETTE) {
243  uint32_t *palette = (uint32_t *) newpic->data[1];
244  for (i = 0; i < 256; i++) {
245  palette[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
246  }
247  newpic->palette_has_changed = 1;
248  } else {
249  if (oldpic->data[1])
250  memcpy(newpic->data[1], oldpic->data[1], 256 * 4);
251  }
252 
253  if ((ret = av_frame_ref(data, newpic)) < 0)
254  return ret;
255  *got_frame = 1;
256 
257  return buf_size;
258 }
259 
261  .name = "c93",
262  .long_name = NULL_IF_CONFIG_SMALL("Interplay C93"),
263  .type = AVMEDIA_TYPE_VIDEO,
264  .id = AV_CODEC_ID_C93,
265  .priv_data_size = sizeof(C93DecoderContext),
266  .init = decode_init,
267  .close = decode_end,
268  .decode = decode_frame,
269  .capabilities = AV_CODEC_CAP_DR1,
271 };
#define av_cold
Definition: attributes.h:88
uint8_t
Libavcodec external API header.
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
static av_always_inline unsigned int bytestream2_get_buffer(GetByteContext *g, uint8_t *dst, unsigned int size)
Definition: bytestream.h:267
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
#define s(width, name)
Definition: cbs_vp9.c:257
#define FFABS(a)
Absolute value, Note, INT_MIN / INT64_MIN result in undefined behavior as they are not representable ...
Definition: common.h:72
#define NULL
Definition: coverity.c:32
int ff_reget_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Identical in function to ff_get_buffer(), except it reuses the existing buffer if available.
Definition: decode.c:2007
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
@ AV_CODEC_ID_C93
Definition: codec_id.h:151
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:59
#define AVERROR(e)
Definition: error.h:43
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:443
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:203
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:190
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
for(j=16;j >0;--j)
int i
Definition: input.c:407
static int copy_from(IpvideoContext *s, AVFrame *src, AVFrame *dst, int delta_x, int delta_y)
#define C93_FIRST_FRAME
Definition: c93.c:47
#define WIDTH
Definition: c93.c:43
C93BlockType
Definition: c93.c:31
@ C93_NOOP
Definition: c93.c:39
@ C93_4X4_FROM_PREV
Definition: c93.c:33
@ C93_4X4_FROM_CURR
Definition: c93.c:34
@ C93_8X8_INTRA
Definition: c93.c:40
@ C93_8X8_FROM_PREV
Definition: c93.c:32
@ C93_8X8_2COLOR
Definition: c93.c:35
@ C93_4X4_4COLOR
Definition: c93.c:38
@ C93_4X4_4COLOR_GRP
Definition: c93.c:37
@ C93_4X4_2COLOR
Definition: c93.c:36
static int copy_block(AVCodecContext *avctx, uint8_t *to, uint8_t *from, int offset, int height, int stride)
Definition: c93.c:72
static av_cold int decode_init(AVCodecContext *avctx)
Definition: c93.c:59
static av_cold int decode_end(AVCodecContext *avctx)
Definition: c93.c:49
AVCodec ff_c93_decoder
Definition: c93.c:260
#define C93_HAS_PALETTE
Definition: c93.c:46
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: c93.c:122
#define HEIGHT
Definition: c93.c:44
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:106
#define FF_CODEC_CAP_INIT_THREADSAFE
The codec does not modify any global variables in the init function, allowing to call the init functi...
Definition: internal.h:41
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: internal.h:49
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:84
const char * from
Definition: jacosubdec.c:65
const char * to
Definition: webvttdec.c:34
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
int stride
Definition: mace.c:144
const char data[16]
Definition: mxf.c:142
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
main external API structure.
Definition: avcodec.h:536
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:746
void * priv_data
Definition: avcodec.h:563
AVCodec.
Definition: codec.h:197
const char * name
Name of the codec implementation.
Definition: codec.h:204
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:396
int palette_has_changed
Tell user application that palette has changed from previous frame.
Definition: frame.h:475
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:349
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:401
This structure stores compressed data.
Definition: packet.h:346
int size
Definition: packet.h:370
uint8_t * data
Definition: packet.h:369
int currentpic
Definition: c93.c:28
AVFrame * pictures[2]
Definition: c93.c:27
#define avpriv_request_sample(...)
#define av_log(a,...)
FILE * out
Definition: movenc.c:54
#define height
#define width
const char * b
Definition: vf_curves.c:118
static const uint8_t offset[127][2]
Definition: vf_spp.c:107