FFmpeg
loco.c
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1 /*
2  * LOCO codec
3  * Copyright (c) 2005 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  * LOCO codec.
25  */
26 
27 #include "avcodec.h"
28 #include "get_bits.h"
29 #include "golomb.h"
30 #include "internal.h"
31 #include "mathops.h"
32 
33 enum LOCO_MODE {
34  LOCO_UNKN = 0,
35  LOCO_CYUY2 = -1,
36  LOCO_CRGB = -2,
37  LOCO_CRGBA = -3,
38  LOCO_CYV12 = -4,
39  LOCO_YUY2 = 1,
40  LOCO_UYVY = 2,
41  LOCO_RGB = 3,
42  LOCO_RGBA = 4,
43  LOCO_YV12 = 5,
44 };
45 
46 typedef struct LOCOContext {
47  AVCodecContext *avctx;
48  int lossy;
49  enum LOCO_MODE mode;
50 } LOCOContext;
51 
52 typedef struct RICEContext {
53  GetBitContext gb;
54  int save, run, run2; /* internal rice decoder state */
55  int sum, count; /* sum and count for getting rice parameter */
56  int lossy;
57 } RICEContext;
58 
59 static int loco_get_rice_param(RICEContext *r)
60 {
61  int cnt = 0;
62  int val = r->count;
63 
64  while (r->sum > val && cnt < 9) {
65  val <<= 1;
66  cnt++;
67  }
68 
69  return cnt;
70 }
71 
72 static inline void loco_update_rice_param(RICEContext *r, int val)
73 {
74  r->sum += val;
75  r->count++;
76 
77  if (r->count == 16) {
78  r->sum >>= 1;
79  r->count >>= 1;
80  }
81 }
82 
83 static inline int loco_get_rice(RICEContext *r)
84 {
85  unsigned v;
86  if (r->run > 0) { /* we have zero run */
87  r->run--;
88  loco_update_rice_param(r, 0);
89  return 0;
90  }
91  if (get_bits_left(&r->gb) < 1)
92  return INT_MIN;
93  v = get_ur_golomb_jpegls(&r->gb, loco_get_rice_param(r), INT_MAX, 0);
94  loco_update_rice_param(r, (v + 1) >> 1);
95  if (!v) {
96  if (r->save >= 0) {
97  r->run = get_ur_golomb_jpegls(&r->gb, 2, INT_MAX, 0);
98  if (r->run > 1)
99  r->save += r->run + 1;
100  else
101  r->save -= 3;
102  } else
103  r->run2++;
104  } else {
105  v = ((v >> 1) + r->lossy) ^ -(v & 1);
106  if (r->run2 > 0) {
107  if (r->run2 > 2)
108  r->save += r->run2;
109  else
110  r->save -= 3;
111  r->run2 = 0;
112  }
113  }
114 
115  return v;
116 }
117 
118 /* LOCO main predictor - LOCO-I/JPEG-LS predictor */
119 static inline int loco_predict(uint8_t* data, int stride)
120 {
121  int a, b, c;
122 
123  a = data[-stride];
124  b = data[-1];
125  c = data[-stride - 1];
126 
127  return mid_pred(a, a + b - c, b);
128 }
129 
130 static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height,
131  int stride, const uint8_t *buf, int buf_size)
132 {
133  RICEContext rc;
134  unsigned val;
135  int ret;
136  int i, j;
137 
138  if(buf_size<=0)
139  return -1;
140 
141  if ((ret = init_get_bits8(&rc.gb, buf, buf_size)) < 0)
142  return ret;
143 
144  rc.save = 0;
145  rc.run = 0;
146  rc.run2 = 0;
147  rc.lossy = l->lossy;
148 
149  rc.sum = 8;
150  rc.count = 1;
151 
152  /* restore top left pixel */
153  val = loco_get_rice(&rc);
154  data[0] = 128 + val;
155  /* restore top line */
156  for (i = 1; i < width; i++) {
157  val = loco_get_rice(&rc);
158  if (val == INT_MIN)
159  return AVERROR_INVALIDDATA;
160  data[i] = data[i - 1] + val;
161  }
162  data += stride;
163  for (j = 1; j < height; j++) {
164  /* restore left column */
165  val = loco_get_rice(&rc);
166  if (val == INT_MIN)
167  return AVERROR_INVALIDDATA;
168  data[0] = data[-stride] + val;
169  /* restore all other pixels */
170  for (i = 1; i < width; i++) {
171  val = loco_get_rice(&rc);
172  if (val == INT_MIN)
173  return -1;
174  data[i] = loco_predict(&data[i], stride) + val;
175  }
176  data += stride;
177  }
178 
179  return (get_bits_count(&rc.gb) + 7) >> 3;
180 }
181 
182 static void rotate_faulty_loco(uint8_t *data, int width, int height, int stride)
183 {
184  int y;
185 
186  for (y=1; y<height; y++) {
187  if (width>=y) {
188  memmove(data + y*stride,
189  data + y*(stride + 1),
190  (width-y));
191  if (y+1 < height)
192  memmove(data + y*stride + (width-y),
193  data + (y+1)*stride, y);
194  }
195  }
196 }
197 
198 static int decode_frame(AVCodecContext *avctx,
199  void *data, int *got_frame,
200  AVPacket *avpkt)
201 {
202  LOCOContext * const l = avctx->priv_data;
203  const uint8_t *buf = avpkt->data;
204  int buf_size = avpkt->size;
205  AVFrame * const p = data;
206  int decoded, ret;
207 
208  if ((ret = ff_get_buffer(avctx, p, 0)) < 0)
209  return ret;
210  p->key_frame = 1;
211 
212 #define ADVANCE_BY_DECODED do { \
213  if (decoded < 0 || decoded >= buf_size) goto buf_too_small; \
214  buf += decoded; buf_size -= decoded; \
215 } while(0)
216  switch(l->mode) {
217  case LOCO_CYUY2: case LOCO_YUY2: case LOCO_UYVY:
218  decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
219  p->linesize[0], buf, buf_size);
220  ADVANCE_BY_DECODED;
221  decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height,
222  p->linesize[1], buf, buf_size);
223  ADVANCE_BY_DECODED;
224  decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height,
225  p->linesize[2], buf, buf_size);
226  break;
227  case LOCO_CYV12: case LOCO_YV12:
228  decoded = loco_decode_plane(l, p->data[0], avctx->width, avctx->height,
229  p->linesize[0], buf, buf_size);
230  ADVANCE_BY_DECODED;
231  decoded = loco_decode_plane(l, p->data[2], avctx->width / 2, avctx->height / 2,
232  p->linesize[2], buf, buf_size);
233  ADVANCE_BY_DECODED;
234  decoded = loco_decode_plane(l, p->data[1], avctx->width / 2, avctx->height / 2,
235  p->linesize[1], buf, buf_size);
236  break;
237  case LOCO_CRGB: case LOCO_RGB:
238  decoded = loco_decode_plane(l, p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height,
239  -p->linesize[1], buf, buf_size);
240  ADVANCE_BY_DECODED;
241  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
242  -p->linesize[0], buf, buf_size);
243  ADVANCE_BY_DECODED;
244  decoded = loco_decode_plane(l, p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height,
245  -p->linesize[2], buf, buf_size);
246  if (avctx->width & 1) {
247  rotate_faulty_loco(p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[0]);
248  rotate_faulty_loco(p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[1]);
249  rotate_faulty_loco(p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height, -p->linesize[2]);
250  }
251  break;
252  case LOCO_CRGBA:
253  case LOCO_RGBA:
254  decoded = loco_decode_plane(l, p->data[1] + p->linesize[1]*(avctx->height-1), avctx->width, avctx->height,
255  -p->linesize[1], buf, buf_size);
256  ADVANCE_BY_DECODED;
257  decoded = loco_decode_plane(l, p->data[0] + p->linesize[0]*(avctx->height-1), avctx->width, avctx->height,
258  -p->linesize[0], buf, buf_size);
259  ADVANCE_BY_DECODED;
260  decoded = loco_decode_plane(l, p->data[2] + p->linesize[2]*(avctx->height-1), avctx->width, avctx->height,
261  -p->linesize[2], buf, buf_size);
262  ADVANCE_BY_DECODED;
263  decoded = loco_decode_plane(l, p->data[3] + p->linesize[3]*(avctx->height-1), avctx->width, avctx->height,
264  -p->linesize[3], buf, buf_size);
265  break;
266  default:
267  av_assert0(0);
268  }
269 
270  if (decoded < 0 || decoded > buf_size)
271  goto buf_too_small;
272  buf_size -= decoded;
273 
274  *got_frame = 1;
275 
276  return avpkt->size - buf_size;
277 buf_too_small:
278  av_log(avctx, AV_LOG_ERROR, "Input data too small.\n");
279  return AVERROR(EINVAL);
280 }
281 
282 static av_cold int decode_init(AVCodecContext *avctx)
283 {
284  LOCOContext * const l = avctx->priv_data;
285  int version;
286 
287  l->avctx = avctx;
288  if (avctx->extradata_size < 12) {
289  av_log(avctx, AV_LOG_ERROR, "Extradata size must be >= 12 instead of %i\n",
290  avctx->extradata_size);
291  return AVERROR_INVALIDDATA;
292  }
293  version = AV_RL32(avctx->extradata);
294  switch (version) {
295  case 1:
296  l->lossy = 0;
297  break;
298  case 2:
299  l->lossy = AV_RL32(avctx->extradata + 8);
300  break;
301  default:
302  l->lossy = AV_RL32(avctx->extradata + 8);
303  avpriv_request_sample(avctx, "LOCO codec version %i", version);
304  }
305 
306  if (l->lossy > 65536U) {
307  av_log(avctx, AV_LOG_ERROR, "lossy %i is too large\n", l->lossy);
308  return AVERROR_INVALIDDATA;
309  }
310 
311  l->mode = AV_RL32(avctx->extradata + 4);
312  switch (l->mode) {
313  case LOCO_CYUY2:
314  case LOCO_YUY2:
315  case LOCO_UYVY:
316  avctx->pix_fmt = AV_PIX_FMT_YUV422P;
317  break;
318  case LOCO_CRGB:
319  case LOCO_RGB:
320  avctx->pix_fmt = AV_PIX_FMT_GBRP;
321  break;
322  case LOCO_CYV12:
323  case LOCO_YV12:
324  avctx->pix_fmt = AV_PIX_FMT_YUV420P;
325  break;
326  case LOCO_CRGBA:
327  case LOCO_RGBA:
328  avctx->pix_fmt = AV_PIX_FMT_GBRAP;
329  break;
330  default:
331  av_log(avctx, AV_LOG_INFO, "Unknown colorspace, index = %i\n", l->mode);
332  return AVERROR_INVALIDDATA;
333  }
334  if (avctx->debug & FF_DEBUG_PICT_INFO)
335  av_log(avctx, AV_LOG_INFO, "lossy:%i, version:%i, mode: %i\n", l->lossy, version, l->mode);
336 
337  return 0;
338 }
339 
340 const AVCodec ff_loco_decoder = {
341  .name = "loco",
342  .long_name = NULL_IF_CONFIG_SMALL("LOCO"),
343  .type = AVMEDIA_TYPE_VIDEO,
344  .id = AV_CODEC_ID_LOCO,
345  .priv_data_size = sizeof(LOCOContext),
346  .init = decode_init,
347  .decode = decode_frame,
348  .capabilities = AV_CODEC_CAP_DR1,
349  .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE,
350 };
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
LOCOContext
Definition: loco.c:46
get_bits_left
static int get_bits_left(GetBitContext *gb)
Definition: get_bits.h:850
r
const char * r
Definition: vf_curves.c:116
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
LOCO_YUY2
@ LOCO_YUY2
Definition: loco.c:39
LOCO_UNKN
@ LOCO_UNKN
Definition: loco.c:34
AV_CODEC_ID_LOCO
@ AV_CODEC_ID_LOCO
Definition: codec_id.h:122
get_bits_count
static int get_bits_count(const GetBitContext *s)
Definition: get_bits.h:220
AVFrame
This structure describes decoded (raw) audio or video data.
Definition: frame.h:317
internal.h
AVPacket::data
uint8_t * data
Definition: packet.h:373
b
#define b
Definition: input.c:40
data
const char data[16]
Definition: mxf.c:143
LOCOContext::avctx
AVCodecContext * avctx
Definition: loco.c:47
loco_get_rice
static int loco_get_rice(RICEContext *r)
Definition: loco.c:83
FF_DEBUG_PICT_INFO
#define FF_DEBUG_PICT_INFO
Definition: avcodec.h:1303
AVFrame::data
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:338
decode_frame
static int decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: loco.c:198
init
static int init
Definition: av_tx.c:47
golomb.h
exp golomb vlc stuff
ff_loco_decoder
const AVCodec ff_loco_decoder
Definition: loco.c:340
AV_PIX_FMT_GBRAP
@ AV_PIX_FMT_GBRAP
planar GBRA 4:4:4:4 32bpp
Definition: pixfmt.h:205
U
#define U(x)
Definition: vp56_arith.h:37
LOCO_CYV12
@ LOCO_CYV12
Definition: loco.c:38
LOCO_MODE
LOCO_MODE
Definition: loco.c:33
GetBitContext
Definition: get_bits.h:62
AVFrame::key_frame
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:409
val
static double val(void *priv, double ch)
Definition: aeval.c:76
RICEContext::sum
int sum
Definition: loco.c:55
RICEContext
Definition: loco.c:52
AV_LOG_ERROR
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:180
get_ur_golomb_jpegls
static int get_ur_golomb_jpegls(GetBitContext *gb, int k, int limit, int esc_len)
read unsigned golomb rice code (jpegls).
Definition: golomb.h:430
av_cold
#define av_cold
Definition: attributes.h:90
init_get_bits8
static int init_get_bits8(GetBitContext *s, const uint8_t *buffer, int byte_size)
Initialize GetBitContext.
Definition: get_bits.h:678
LOCO_YV12
@ LOCO_YV12
Definition: loco.c:43
decode
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:71
ADVANCE_BY_DECODED
#define ADVANCE_BY_DECODED
AVCodecContext::extradata_size
int extradata_size
Definition: avcodec.h:485
width
#define width
LOCO_CRGB
@ LOCO_CRGB
Definition: loco.c:36
av_assert0
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
get_bits.h
RICEContext::lossy
int lossy
Definition: loco.c:56
AV_PIX_FMT_YUV420P
@ AV_PIX_FMT_YUV420P
planar YUV 4:2:0, 12bpp, (1 Cr & Cb sample per 2x2 Y samples)
Definition: pixfmt.h:66
loco_predict
static int loco_predict(uint8_t *data, int stride)
Definition: loco.c:119
LOCOContext::mode
enum LOCO_MODE mode
Definition: loco.c:49
mathops.h
LOCO_CYUY2
@ LOCO_CYUY2
Definition: loco.c:35
rotate_faulty_loco
static void rotate_faulty_loco(uint8_t *data, int width, int height, int stride)
Definition: loco.c:182
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
ff_get_buffer
int ff_get_buffer(AVCodecContext *avctx, AVFrame *frame, int flags)
Get a buffer for a frame.
Definition: decode.c:1652
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
RICEContext::run2
int run2
Definition: loco.c:54
height
#define height
loco_get_rice_param
static int loco_get_rice_param(RICEContext *r)
Definition: loco.c:59
a
The reader does not expect b to be semantically here and if the code is changed by maybe adding a a division or other the signedness will almost certainly be mistaken To avoid this confusion a new type was SUINT is the C unsigned type but it holds a signed int to use the same example SUINT a
Definition: undefined.txt:41
loco_decode_plane
static int loco_decode_plane(LOCOContext *l, uint8_t *data, int width, int height, int stride, const uint8_t *buf, int buf_size)
Definition: loco.c:130
version
version
Definition: libkvazaar.c:313
AV_LOG_INFO
#define AV_LOG_INFO
Standard information.
Definition: log.h:191
RICEContext::count
int count
Definition: loco.c:55
i
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:271
AVCodecContext::extradata
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:484
LOCOContext::lossy
int lossy
Definition: loco.c:48
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
mid_pred
#define mid_pred
Definition: mathops.h:97
ret
ret
Definition: filter_design.txt:187
loco_update_rice_param
static void loco_update_rice_param(RICEContext *r, int val)
Definition: loco.c:72
RICEContext::run
int run
Definition: loco.c:54
AV_RL32
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:92
LOCO_UYVY
@ LOCO_UYVY
Definition: loco.c:40
AVCodecContext
main external API structure.
Definition: avcodec.h:383
LOCO_RGB
@ LOCO_RGB
Definition: loco.c:41
RICEContext::gb
GetBitContext gb
Definition: loco.c:53
AVCodecContext::debug
int debug
debug
Definition: avcodec.h:1302
AV_PIX_FMT_GBRP
@ AV_PIX_FMT_GBRP
planar GBR 4:4:4 24bpp
Definition: pixfmt.h:158
AVMEDIA_TYPE_VIDEO
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
AV_PIX_FMT_YUV422P
@ AV_PIX_FMT_YUV422P
planar YUV 4:2:2, 16bpp, (1 Cr & Cb sample per 2x1 Y samples)
Definition: pixfmt.h:70
avpriv_request_sample
#define avpriv_request_sample(...)
Definition: tableprint_vlc.h:37
AVCodecContext::priv_data
void * priv_data
Definition: avcodec.h:410
AVPacket
This structure stores compressed data.
Definition: packet.h:350
decode_init
static av_cold int decode_init(AVCodecContext *avctx)
Definition: loco.c:282
LOCO_CRGBA
@ LOCO_CRGBA
Definition: loco.c:37
AVCodecContext::width
int width
picture width / height.
Definition: avcodec.h:556
AVFrame::linesize
int linesize[AV_NUM_DATA_POINTERS]
For video, a positive or negative value, which is typically indicating the size in bytes of each pict...
Definition: frame.h:362
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
RICEContext::save
int save
Definition: loco.c:54
LOCO_RGBA
@ LOCO_RGBA
Definition: loco.c:42
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