FFmpeg
dxa.c
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1 /*
2  * Feeble Files/ScummVM DXA decoder
3  * Copyright (c) 2007 Konstantin Shishkov
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  * DXA Video decoder
25  */
26 
27 #include <stdio.h>
28 #include <stdlib.h>
29 
30 #include "libavutil/common.h"
31 #include "libavutil/intreadwrite.h"
32 #include "bytestream.h"
33 #include "avcodec.h"
34 #include "internal.h"
35 
36 #include <zlib.h>
37 
38 /*
39  * Decoder context
40  */
41 typedef struct DxaDecContext {
43 
44  int dsize;
45 #define DECOMP_BUF_PADDING 16
46  uint8_t *decomp_buf;
47  uint32_t pal[256];
49 
50 static const int shift1[6] = { 0, 8, 8, 8, 4, 4 };
51 static const int shift2[6] = { 0, 0, 8, 4, 0, 4 };
52 
53 static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t* dst,
54  int stride, uint8_t *src, int srcsize, uint8_t *ref)
55 {
56  uint8_t *code, *data, *mv, *msk, *tmp, *tmp2;
57  uint8_t *src_end = src + srcsize;
58  int i, j, k;
59  int type, x, y, d, d2;
60  uint32_t mask;
61 
62  if (12ULL + ((avctx->width * avctx->height) >> 4) + AV_RB32(src + 0) + AV_RB32(src + 4) > srcsize)
63  return AVERROR_INVALIDDATA;
64 
65  code = src + 12;
66  data = code + ((avctx->width * avctx->height) >> 4);
67  mv = data + AV_RB32(src + 0);
68  msk = mv + AV_RB32(src + 4);
69 
70  for(j = 0; j < avctx->height; j += 4){
71  for(i = 0; i < avctx->width; i += 4){
72  if (data > src_end || mv > src_end || msk > src_end)
73  return AVERROR_INVALIDDATA;
74  tmp = dst + i;
75  tmp2 = ref + i;
76  type = *code++;
77  switch(type){
78  case 4: // motion compensation
79  x = (*mv) >> 4; if(x & 8) x = 8 - x;
80  y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
81  if (i < -x || avctx->width - i - 4 < x ||
82  j < -y || avctx->height - j - 4 < y) {
83  av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);
84  return AVERROR_INVALIDDATA;
85  }
86  tmp2 += x + y*stride;
87  case 0: // skip
88  case 5: // skip in method 12
89  for(y = 0; y < 4; y++){
90  memcpy(tmp, tmp2, 4);
91  tmp += stride;
92  tmp2 += stride;
93  }
94  break;
95  case 1: // masked change
96  case 10: // masked change with only half of pixels changed
97  case 11: // cases 10-15 are for method 12 only
98  case 12:
99  case 13:
100  case 14:
101  case 15:
102  if(type == 1){
103  mask = AV_RB16(msk);
104  msk += 2;
105  }else{
106  type -= 10;
107  mask = ((msk[0] & 0xF0) << shift1[type]) | ((msk[0] & 0xF) << shift2[type]);
108  msk++;
109  }
110  for(y = 0; y < 4; y++){
111  for(x = 0; x < 4; x++){
112  tmp[x] = (mask & 0x8000) ? *data++ : tmp2[x];
113  mask <<= 1;
114  }
115  tmp += stride;
116  tmp2 += stride;
117  }
118  break;
119  case 2: // fill block
120  for(y = 0; y < 4; y++){
121  memset(tmp, data[0], 4);
122  tmp += stride;
123  }
124  data++;
125  break;
126  case 3: // raw block
127  for(y = 0; y < 4; y++){
128  memcpy(tmp, data, 4);
129  data += 4;
130  tmp += stride;
131  }
132  break;
133  case 8: // subblocks - method 13 only
134  mask = *msk++;
135  for(k = 0; k < 4; k++){
136  d = ((k & 1) << 1) + ((k & 2) * stride);
137  d2 = ((k & 1) << 1) + ((k & 2) * stride);
138  tmp2 = ref + i + d2;
139  switch(mask & 0xC0){
140  case 0x80: // motion compensation
141  x = (*mv) >> 4; if(x & 8) x = 8 - x;
142  y = (*mv++) & 0xF; if(y & 8) y = 8 - y;
143  if (i + 2*(k & 1) < -x || avctx->width - i - 2*(k & 1) - 2 < x ||
144  j + (k & 2) < -y || avctx->height - j - (k & 2) - 2 < y) {
145  av_log(avctx, AV_LOG_ERROR, "MV %d %d out of bounds\n", x,y);
146  return AVERROR_INVALIDDATA;
147  }
148  tmp2 += x + y*stride;
149  case 0x00: // skip
150  tmp[d + 0 ] = tmp2[0];
151  tmp[d + 1 ] = tmp2[1];
152  tmp[d + 0 + stride] = tmp2[0 + stride];
153  tmp[d + 1 + stride] = tmp2[1 + stride];
154  break;
155  case 0x40: // fill
156  tmp[d + 0 ] = data[0];
157  tmp[d + 1 ] = data[0];
158  tmp[d + 0 + stride] = data[0];
159  tmp[d + 1 + stride] = data[0];
160  data++;
161  break;
162  case 0xC0: // raw
163  tmp[d + 0 ] = *data++;
164  tmp[d + 1 ] = *data++;
165  tmp[d + 0 + stride] = *data++;
166  tmp[d + 1 + stride] = *data++;
167  break;
168  }
169  mask <<= 2;
170  }
171  break;
172  case 32: // vector quantization - 2 colors
173  mask = AV_RB16(msk);
174  msk += 2;
175  for(y = 0; y < 4; y++){
176  for(x = 0; x < 4; x++){
177  tmp[x] = data[mask & 1];
178  mask >>= 1;
179  }
180  tmp += stride;
181  tmp2 += stride;
182  }
183  data += 2;
184  break;
185  case 33: // vector quantization - 3 or 4 colors
186  case 34:
187  mask = AV_RB32(msk);
188  msk += 4;
189  for(y = 0; y < 4; y++){
190  for(x = 0; x < 4; x++){
191  tmp[x] = data[mask & 3];
192  mask >>= 2;
193  }
194  tmp += stride;
195  tmp2 += stride;
196  }
197  data += type - 30;
198  break;
199  default:
200  av_log(avctx, AV_LOG_ERROR, "Unknown opcode %d\n", type);
201  return AVERROR_INVALIDDATA;
202  }
203  }
204  dst += stride * 4;
205  ref += stride * 4;
206  }
207  return 0;
208 }
209 
210 static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
211 {
212  AVFrame *frame = data;
213  DxaDecContext * const c = avctx->priv_data;
214  uint8_t *outptr, *srcptr, *tmpptr;
215  unsigned long dsize;
216  int i, j, compr, ret;
217  int stride;
218  int pc = 0;
219  GetByteContext gb;
220 
221  bytestream2_init(&gb, avpkt->data, avpkt->size);
222 
223  /* make the palette available on the way out */
224  if (bytestream2_peek_le32(&gb) == MKTAG('C','M','A','P')) {
225  bytestream2_skip(&gb, 4);
226  for(i = 0; i < 256; i++){
227  c->pal[i] = 0xFFU << 24 | bytestream2_get_be24(&gb);
228  }
229  pc = 1;
230  }
231 
232  if ((ret = ff_get_buffer(avctx, frame, AV_GET_BUFFER_FLAG_REF)) < 0)
233  return ret;
234  memcpy(frame->data[1], c->pal, AVPALETTE_SIZE);
235  frame->palette_has_changed = pc;
236 
237  outptr = frame->data[0];
238  srcptr = c->decomp_buf;
239  tmpptr = c->prev->data[0];
240  stride = frame->linesize[0];
241 
242  if (bytestream2_get_le32(&gb) == MKTAG('N','U','L','L'))
243  compr = -1;
244  else
245  compr = bytestream2_get_byte(&gb);
246 
247  dsize = c->dsize;
248  if (compr != 4 && compr != -1) {
249  bytestream2_skip(&gb, 4);
250  if (uncompress(c->decomp_buf, &dsize, avpkt->data + bytestream2_tell(&gb),
251  bytestream2_get_bytes_left(&gb)) != Z_OK) {
252  av_log(avctx, AV_LOG_ERROR, "Uncompress failed!\n");
253  return AVERROR_UNKNOWN;
254  }
255  memset(c->decomp_buf + dsize, 0, DECOMP_BUF_PADDING);
256  }
257 
258  if (avctx->debug & FF_DEBUG_PICT_INFO)
259  av_log(avctx, AV_LOG_DEBUG, "compr:%2d, dsize:%d\n", compr, (int)dsize);
260 
261  switch(compr){
262  case -1:
263  frame->key_frame = 0;
264  frame->pict_type = AV_PICTURE_TYPE_P;
265  if (c->prev->data[0])
266  memcpy(frame->data[0], c->prev->data[0], frame->linesize[0] * avctx->height);
267  else{ // Should happen only when first frame is 'NULL'
268  memset(frame->data[0], 0, frame->linesize[0] * avctx->height);
269  frame->key_frame = 1;
270  frame->pict_type = AV_PICTURE_TYPE_I;
271  }
272  break;
273  case 2:
274  case 4:
275  frame->key_frame = 1;
276  frame->pict_type = AV_PICTURE_TYPE_I;
277  for (j = 0; j < avctx->height; j++) {
278  memcpy(outptr, srcptr, avctx->width);
279  outptr += stride;
280  srcptr += avctx->width;
281  }
282  break;
283  case 3:
284  case 5:
285  if (!tmpptr) {
286  av_log(avctx, AV_LOG_ERROR, "Missing reference frame.\n");
287  if (!(avctx->flags2 & AV_CODEC_FLAG2_SHOW_ALL))
288  return AVERROR_INVALIDDATA;
289  }
290  frame->key_frame = 0;
291  frame->pict_type = AV_PICTURE_TYPE_P;
292  for (j = 0; j < avctx->height; j++) {
293  if(tmpptr){
294  for(i = 0; i < avctx->width; i++)
295  outptr[i] = srcptr[i] ^ tmpptr[i];
296  tmpptr += stride;
297  }else
298  memcpy(outptr, srcptr, avctx->width);
299  outptr += stride;
300  srcptr += avctx->width;
301  }
302  break;
303  case 12: // ScummVM coding
304  case 13:
305  frame->key_frame = 0;
306  frame->pict_type = AV_PICTURE_TYPE_P;
307  if (!c->prev->data[0]) {
308  av_log(avctx, AV_LOG_ERROR, "Missing reference frame\n");
309  return AVERROR_INVALIDDATA;
310  }
311  decode_13(avctx, c, frame->data[0], frame->linesize[0], srcptr, dsize, c->prev->data[0]);
312  break;
313  default:
314  av_log(avctx, AV_LOG_ERROR, "Unknown/unsupported compression type %d\n", compr);
315  return AVERROR_INVALIDDATA;
316  }
317 
318  av_frame_unref(c->prev);
319  if ((ret = av_frame_ref(c->prev, frame)) < 0)
320  return ret;
321 
322  *got_frame = 1;
323 
324  /* always report that the buffer was completely consumed */
325  return avpkt->size;
326 }
327 
329 {
330  DxaDecContext * const c = avctx->priv_data;
331 
332  if (avctx->width%4 || avctx->height%4) {
333  avpriv_request_sample(avctx, "dimensions are not a multiple of 4");
334  return AVERROR_INVALIDDATA;
335  }
336 
337  c->prev = av_frame_alloc();
338  if (!c->prev)
339  return AVERROR(ENOMEM);
340 
341  avctx->pix_fmt = AV_PIX_FMT_PAL8;
342 
343  c->dsize = avctx->width * avctx->height * 2;
344  c->decomp_buf = av_malloc(c->dsize + DECOMP_BUF_PADDING);
345  if (!c->decomp_buf) {
346  av_log(avctx, AV_LOG_ERROR, "Can't allocate decompression buffer.\n");
347  return AVERROR(ENOMEM);
348  }
349 
350  return 0;
351 }
352 
354 {
355  DxaDecContext * const c = avctx->priv_data;
356 
357  av_freep(&c->decomp_buf);
358  av_frame_free(&c->prev);
359 
360  return 0;
361 }
362 
364  .name = "dxa",
365  .long_name = NULL_IF_CONFIG_SMALL("Feeble Files/ScummVM DXA"),
366  .type = AVMEDIA_TYPE_VIDEO,
367  .id = AV_CODEC_ID_DXA,
368  .priv_data_size = sizeof(DxaDecContext),
369  .init = decode_init,
370  .close = decode_end,
371  .decode = decode_frame,
372  .capabilities = AV_CODEC_CAP_DR1,
374 };
AVCodec
AVCodec.
Definition: codec.h:202
stride
int stride
Definition: mace.c:144
FF_CODEC_CAP_INIT_THREADSAFE
#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:42
init
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
AVERROR
Filter the word “frame” indicates either a video frame or a group of audio as stored in an AVFrame structure Format for each input and each output the list of supported formats For video that means pixel format For audio that means channel sample they are references to shared objects When the negotiation mechanism computes the intersection of the formats supported at each end of a all references to both lists are replaced with a reference to the intersection And when a single format is eventually chosen for a link amongst the remaining all references to the list are updated That means that if a filter requires that its input and output have the same format amongst a supported all it has to do is use a reference to the same list of formats query_formats can leave some formats unset and return AVERROR(EAGAIN) to cause the negotiation mechanism toagain later. That can be used by filters with complex requirements to use the format negotiated on one link to set the formats supported on another. Frame references ownership and permissions
GetByteContext
Definition: bytestream.h:33
mv
static const int8_t mv[256][2]
Definition: 4xm.c:79
av_frame_free
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:112
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:310
tmp
static uint8_t tmp[11]
Definition: aes_ctr.c:26
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
data
const char data[16]
Definition: mxf.c:143
AVERROR_UNKNOWN
#define AVERROR_UNKNOWN
Unknown error, typically from an external library.
Definition: error.h:73
FF_DEBUG_PICT_INFO
#define FF_DEBUG_PICT_INFO
Definition: avcodec.h:1303
av_malloc
#define av_malloc(s)
Definition: tableprint_vlc.h:31
bytestream2_skip
static av_always_inline void bytestream2_skip(GetByteContext *g, unsigned int size)
Definition: bytestream.h:168
U
#define U(x)
Definition: vp56_arith.h:37
decode_end
static av_cold int decode_end(AVCodecContext *avctx)
Definition: dxa.c:353
type
it s the only field you need to keep assuming you have a context There is some magic you don t need to care about around this just let it vf type
Definition: writing_filters.txt:86
av_frame_alloc
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:99
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
av_cold
#define av_cold
Definition: attributes.h:90
mask
static const uint16_t mask[17]
Definition: lzw.c:38
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
width
#define width
intreadwrite.h
AV_GET_BUFFER_FLAG_REF
#define AV_GET_BUFFER_FLAG_REF
The decoder will keep a reference to the frame and may reuse it later.
Definition: avcodec.h:361
AV_LOG_DEBUG
#define AV_LOG_DEBUG
Stuff which is only useful for libav* developers.
Definition: log.h:201
DECOMP_BUF_PADDING
#define DECOMP_BUF_PADDING
Definition: dxa.c:45
AVPALETTE_SIZE
#define AVPALETTE_SIZE
Definition: pixfmt.h:32
AV_PICTURE_TYPE_I
@ AV_PICTURE_TYPE_I
Intra.
Definition: avutil.h:274
src
#define src
Definition: vp8dsp.c:255
ff_dxa_decoder
const AVCodec ff_dxa_decoder
Definition: dxa.c:363
c
Undefined Behavior In the C some operations are like signed integer dereferencing freed accessing outside allocated Undefined Behavior must not occur in a C it is not safe even if the output of undefined operations is unused The unsafety may seem nit picking but Optimizing compilers have in fact optimized code on the assumption that no undefined Behavior occurs Optimizing code based on wrong assumptions can and has in some cases lead to effects beyond the output of computations The signed integer overflow problem in speed critical code Code which is highly optimized and works with signed integers sometimes has the problem that often the output of the computation does not c
Definition: undefined.txt:32
bytestream2_get_bytes_left
static av_always_inline int bytestream2_get_bytes_left(GetByteContext *g)
Definition: bytestream.h:158
bytestream2_tell
static av_always_inline int bytestream2_tell(GetByteContext *g)
Definition: bytestream.h:192
shift1
static const int shift1[6]
Definition: dxa.c:50
AVCodecContext::flags2
int flags2
AV_CODEC_FLAG2_*.
Definition: avcodec.h:470
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1651
AV_CODEC_CAP_DR1
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() or get_encode_buffer() for allocating buffers and supports custom allocators.
Definition: codec.h:52
AVPacket::size
int size
Definition: packet.h:374
NULL_IF_CONFIG_SMALL
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
av_frame_ref
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:327
DxaDecContext::dsize
int dsize
Definition: dxa.c:44
AV_RB32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_RB32
Definition: bytestream.h:96
height
#define height
decode_13
static int decode_13(AVCodecContext *avctx, DxaDecContext *c, uint8_t *dst, int stride, uint8_t *src, int srcsize, uint8_t *ref)
Definition: dxa.c:53
AV_CODEC_ID_DXA
@ AV_CODEC_ID_DXA
Definition: codec_id.h:148
shift2
static const int shift2[6]
Definition: dxa.c:51
DxaDecContext::pal
uint32_t pal[256]
Definition: dxa.c:47
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
code
and forward the test the status of outputs and forward it to the corresponding return FFERROR_NOT_READY If the filters stores internally one or a few frame for some it can consider them to be part of the FIFO and delay acknowledging a status change accordingly Example code
Definition: filter_design.txt:178
AV_CODEC_FLAG2_SHOW_ALL
#define AV_CODEC_FLAG2_SHOW_ALL
Show all frames before the first keyframe.
Definition: avcodec.h:315
FF_CODEC_CAP_INIT_CLEANUP
#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:50
common.h
av_frame_unref
void av_frame_unref(AVFrame *frame)
Unreference all the buffers referenced by frame and reset the frame fields.
Definition: frame.c:437
AVCodec::name
const char * name
Name of the codec implementation.
Definition: codec.h:209
AVCodecContext::height
int height
Definition: avcodec.h:556
AVCodecContext::pix_fmt
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:593
avcodec.h
AV_PIX_FMT_PAL8
@ AV_PIX_FMT_PAL8
8 bits with AV_PIX_FMT_RGB32 palette
Definition: pixfmt.h:77
ret
ret
Definition: filter_design.txt:187
frame
these buffered frames must be flushed immediately if a new input produces new the filter must not call request_frame to get more It must just process the frame or queue it The task of requesting more frames is left to the filter s request_frame method or the application If a filter has several the filter must be ready for frames arriving randomly on any input any filter with several inputs will most likely require some kind of queuing mechanism It is perfectly acceptable to have a limited queue and to drop frames when the inputs are too unbalanced request_frame For filters that do not use the this method is called when a frame is wanted on an output For a it should directly call filter_frame on the corresponding output For a if there are queued frames already one of these frames should be pushed If the filter should request a frame on one of its repeatedly until at least one frame has been pushed Return or at least make progress towards producing a frame
Definition: filter_design.txt:264
DxaDecContext::prev
AVFrame * prev
Definition: dxa.c:42
AVCodecContext
main external API structure.
Definition: avcodec.h:383
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: dxa.c:210
ref
static int ref[MAX_W *MAX_W]
Definition: jpeg2000dwt.c:107
AVCodecContext::debug
int debug
debug
Definition: avcodec.h:1302
AV_PICTURE_TYPE_P
@ AV_PICTURE_TYPE_P
Predicted.
Definition: avutil.h:275
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:37
DxaDecContext
Definition: dxa.c:41
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
AVPacket
This structure stores compressed data.
Definition: packet.h:350
DxaDecContext::decomp_buf
uint8_t * decomp_buf
Definition: dxa.c:46
av_freep
#define av_freep(p)
Definition: tableprint_vlc.h:35
d
d
Definition: ffmpeg_filter.c:156
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:556
bytestream.h
bytestream2_init
static av_always_inline void bytestream2_init(GetByteContext *g, const uint8_t *buf, int buf_size)
Definition: bytestream.h:137
av_log
#define av_log(a,...)
Definition: tableprint_vlc.h:28
AVERROR_INVALIDDATA
#define AVERROR_INVALIDDATA
Invalid data found when processing input.
Definition: error.h:61
MKTAG
#define MKTAG(a, b, c, d)
Definition: macros.h:55
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: dxa.c:328
AV_RB16
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_WL32 unsigned int_TMPL AV_WL24 unsigned int_TMPL AV_WL16 uint64_t_TMPL AV_WB64 unsigned int_TMPL AV_WB32 unsigned int_TMPL AV_WB24 unsigned int_TMPL AV_RB16
Definition: bytestream.h:98