FFmpeg
motionpixels.c
Go to the documentation of this file.
1 /*
2  * Motion Pixels Video Decoder
3  * Copyright (c) 2008 Gregory Montoir (cyx@users.sourceforge.net)
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 "get_bits.h"
24 #include "bswapdsp.h"
25 #include "internal.h"
26 
27 #define MAX_HUFF_CODES 16
28 
29 #include "motionpixels_tablegen.h"
30 
31 typedef struct HuffCode {
32  int code;
35 } HuffCode;
36 
37 typedef struct MotionPixelsContext {
43  int codes_count, current_codes_count;
47  YuvPixel *vpt, *hpt;
48  uint8_t gradient_scale[3];
52 
54 {
55  MotionPixelsContext *mp = avctx->priv_data;
56 
57  av_freep(&mp->changes_map);
58  av_freep(&mp->vpt);
59  av_freep(&mp->hpt);
60  av_freep(&mp->bswapbuf);
61  av_frame_free(&mp->frame);
62 
63  return 0;
64 }
65 
67 {
68  MotionPixelsContext *mp = avctx->priv_data;
69  int w4 = (avctx->width + 3) & ~3;
70  int h4 = (avctx->height + 3) & ~3;
71 
72  if(avctx->extradata_size < 2){
73  av_log(avctx, AV_LOG_ERROR, "extradata too small\n");
74  return AVERROR_INVALIDDATA;
75  }
76 
78  mp->avctx = avctx;
79  ff_bswapdsp_init(&mp->bdsp);
80  mp->changes_map = av_mallocz_array(avctx->width, h4);
81  mp->offset_bits_len = av_log2(avctx->width * avctx->height) + 1;
82  mp->vpt = av_mallocz_array(avctx->height, sizeof(YuvPixel));
83  mp->hpt = av_mallocz_array(h4 / 4, w4 / 4 * sizeof(YuvPixel));
84  if (!mp->changes_map || !mp->vpt || !mp->hpt) {
85  av_freep(&mp->changes_map);
86  av_freep(&mp->vpt);
87  av_freep(&mp->hpt);
88  return AVERROR(ENOMEM);
89  }
90  avctx->pix_fmt = AV_PIX_FMT_RGB555;
91 
92  mp->frame = av_frame_alloc();
93  if (!mp->frame) {
94  mp_decode_end(avctx);
95  return AVERROR(ENOMEM);
96  }
97 
98  return 0;
99 }
100 
101 static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
102 {
103  uint16_t *pixels;
104  int offset, w, h, color = 0, x, y, i;
105 
106  while (count--) {
107  offset = get_bits_long(gb, mp->offset_bits_len);
108  w = get_bits(gb, bits_len) + 1;
109  h = get_bits(gb, bits_len) + 1;
110  if (read_color)
111  color = get_bits(gb, 15);
112  x = offset % mp->avctx->width;
113  y = offset / mp->avctx->width;
114  if (y >= mp->avctx->height)
115  continue;
116  w = FFMIN(w, mp->avctx->width - x);
117  h = FFMIN(h, mp->avctx->height - y);
118  pixels = (uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];
119  while (h--) {
120  mp->changes_map[offset] = w;
121  if (read_color)
122  for (i = 0; i < w; ++i)
123  pixels[i] = color;
124  offset += mp->avctx->width;
125  pixels += mp->frame->linesize[0] / 2;
126  }
127  }
128 }
129 
130 static int mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
131 {
132  while (get_bits1(gb)) {
133  ++size;
134  if (size > mp->max_codes_bits) {
135  av_log(mp->avctx, AV_LOG_ERROR, "invalid code size %d/%d\n", size, mp->max_codes_bits);
136  return AVERROR_INVALIDDATA;
137  }
138  code <<= 1;
139  if (mp_get_code(mp, gb, size, code + 1) < 0)
140  return AVERROR_INVALIDDATA;
141  }
142  if (mp->current_codes_count >= MAX_HUFF_CODES) {
143  av_log(mp->avctx, AV_LOG_ERROR, "too many codes\n");
144  return AVERROR_INVALIDDATA;
145  }
146 
147  mp->codes[mp->current_codes_count ].code = code;
148  mp->codes[mp->current_codes_count++].size = size;
149  return 0;
150 }
151 
153 {
154  if (mp->codes_count == 1) {
155  mp->codes[0].delta = get_bits(gb, 4);
156  } else {
157  int i;
158  int ret;
159 
160  mp->max_codes_bits = get_bits(gb, 4);
161  for (i = 0; i < mp->codes_count; ++i)
162  mp->codes[i].delta = get_bits(gb, 4);
163  mp->current_codes_count = 0;
164  if ((ret = mp_get_code(mp, gb, 0, 0)) < 0)
165  return ret;
166  if (mp->current_codes_count < mp->codes_count) {
167  av_log(mp->avctx, AV_LOG_ERROR, "too few codes\n");
168  return AVERROR_INVALIDDATA;
169  }
170  }
171  return 0;
172 }
173 
174 static int mp_gradient(MotionPixelsContext *mp, int component, int v)
175 {
176  int delta;
177 
178  delta = (v - 7) * mp->gradient_scale[component];
179  mp->gradient_scale[component] = (v == 0 || v == 14) ? 2 : 1;
180  return delta;
181 }
182 
184 {
185  int color;
186 
187  color = *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2];
188  return mp_rgb_yuv_table[color];
189 }
190 
191 static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
192 {
193  int color;
194 
195  color = mp_yuv_to_rgb(p->y, p->v, p->u, 1);
196  *(uint16_t *)&mp->frame->data[0][y * mp->frame->linesize[0] + x * 2] = color;
197 }
198 
200 {
201  int i;
202 
203  i = (mp->codes_count == 1) ? 0 : get_vlc2(gb, mp->vlc.table, mp->max_codes_bits, 1);
204  if (i < 0)
205  return i;
206  return mp->codes[i].delta;
207 }
208 
210 {
211  YuvPixel p;
212  const int y0 = y * mp->avctx->width;
213  int w, i, x = 0;
214 
215  p = mp->vpt[y];
216  if (mp->changes_map[y0 + x] == 0) {
217  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
218  ++x;
219  }
220  while (x < mp->avctx->width) {
221  w = mp->changes_map[y0 + x];
222  if (w != 0) {
223  if ((y & 3) == 0) {
224  if (mp->changes_map[y0 + x + mp->avctx->width] < w ||
225  mp->changes_map[y0 + x + mp->avctx->width * 2] < w ||
226  mp->changes_map[y0 + x + mp->avctx->width * 3] < w) {
227  for (i = (x + 3) & ~3; i < x + w; i += 4) {
228  mp->hpt[((y / 4) * mp->avctx->width + i) / 4] = mp_get_yuv_from_rgb(mp, i, y);
229  }
230  }
231  }
232  x += w;
233  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
234  p = mp_get_yuv_from_rgb(mp, x - 1, y);
235  } else {
236  p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
237  p.y = av_clip_uintp2(p.y, 5);
238  if ((x & 3) == 0) {
239  if ((y & 3) == 0) {
240  p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
241  p.v = av_clip_intp2(p.v, 5);
242  p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
243  p.u = av_clip_intp2(p.u, 5);
244  mp->hpt[((y / 4) * mp->avctx->width + x) / 4] = p;
245  } else {
246  p.v = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].v;
247  p.u = mp->hpt[((y / 4) * mp->avctx->width + x) / 4].u;
248  }
249  }
250  mp_set_rgb_from_yuv(mp, x, y, &p);
251  ++x;
252  }
253  }
254 }
255 
257 {
258  YuvPixel p;
259  int y, y0;
260 
261  av_assert1(mp->changes_map[0]);
262 
263  for (y = 0; y < mp->avctx->height; ++y) {
264  if (mp->changes_map[y * mp->avctx->width] != 0) {
265  memset(mp->gradient_scale, 1, sizeof(mp->gradient_scale));
266  p = mp_get_yuv_from_rgb(mp, 0, y);
267  } else {
268  p.y += mp_gradient(mp, 0, mp_get_vlc(mp, gb));
269  p.y = av_clip_uintp2(p.y, 5);
270  if ((y & 3) == 0) {
271  p.v += mp_gradient(mp, 1, mp_get_vlc(mp, gb));
272  p.v = av_clip_intp2(p.v, 5);
273  p.u += mp_gradient(mp, 2, mp_get_vlc(mp, gb));
274  p.u = av_clip_intp2(p.u, 5);
275  }
276  mp->vpt[y] = p;
277  mp_set_rgb_from_yuv(mp, 0, y, &p);
278  }
279  }
280  for (y0 = 0; y0 < 2; ++y0)
281  for (y = y0; y < mp->avctx->height; y += 2)
282  mp_decode_line(mp, gb, y);
283 }
284 
285 static int mp_decode_frame(AVCodecContext *avctx,
286  void *data, int *got_frame,
287  AVPacket *avpkt)
288 {
289  const uint8_t *buf = avpkt->data;
290  int buf_size = avpkt->size;
291  MotionPixelsContext *mp = avctx->priv_data;
292  GetBitContext gb;
293  int i, count1, count2, sz, ret;
294 
295  if ((ret = ff_reget_buffer(avctx, mp->frame)) < 0)
296  return ret;
297 
298  /* le32 bitstream msb first */
299  av_fast_padded_malloc(&mp->bswapbuf, &mp->bswapbuf_size, buf_size);
300  if (!mp->bswapbuf)
301  return AVERROR(ENOMEM);
302  mp->bdsp.bswap_buf((uint32_t *) mp->bswapbuf, (const uint32_t *) buf,
303  buf_size / 4);
304  if (buf_size & 3)
305  memcpy(mp->bswapbuf + (buf_size & ~3), buf + (buf_size & ~3), buf_size & 3);
306  init_get_bits(&gb, mp->bswapbuf, buf_size * 8);
307 
308  memset(mp->changes_map, 0, avctx->width * avctx->height);
309  for (i = !(avctx->extradata[1] & 2); i < 2; ++i) {
310  count1 = get_bits(&gb, 12);
311  count2 = get_bits(&gb, 12);
312  mp_read_changes_map(mp, &gb, count1, 8, i);
313  mp_read_changes_map(mp, &gb, count2, 4, i);
314  }
315 
316  mp->codes_count = get_bits(&gb, 4);
317  if (mp->codes_count == 0)
318  goto end;
319 
320  if (mp->changes_map[0] == 0) {
321  *(uint16_t *)mp->frame->data[0] = get_bits(&gb, 15);
322  mp->changes_map[0] = 1;
323  }
324  if (mp_read_codes_table(mp, &gb) < 0)
325  goto end;
326 
327  sz = get_bits(&gb, 18);
328  if (avctx->extradata[0] != 5)
329  sz += get_bits(&gb, 18);
330  if (sz == 0)
331  goto end;
332 
333  if (mp->max_codes_bits <= 0)
334  goto end;
335  if (init_vlc(&mp->vlc, mp->max_codes_bits, mp->codes_count, &mp->codes[0].size, sizeof(HuffCode), 1, &mp->codes[0].code, sizeof(HuffCode), 4, 0))
336  goto end;
337  mp_decode_frame_helper(mp, &gb);
338  ff_free_vlc(&mp->vlc);
339 
340 end:
341  if ((ret = av_frame_ref(data, mp->frame)) < 0)
342  return ret;
343  *got_frame = 1;
344  return buf_size;
345 }
346 
348  .name = "motionpixels",
349  .long_name = NULL_IF_CONFIG_SMALL("Motion Pixels video"),
350  .type = AVMEDIA_TYPE_VIDEO,
352  .priv_data_size = sizeof(MotionPixelsContext),
353  .init = mp_decode_init,
354  .close = mp_decode_end,
356  .capabilities = AV_CODEC_CAP_DR1,
357 };
#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:295
ptrdiff_t const GLvoid * data
Definition: opengl_enc.c:100
uint8_t size
Definition: motionpixels.c:33
static unsigned int get_bits(GetBitContext *s, int n)
Read 1-25 bits.
Definition: get_bits.h:379
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
AVCodec ff_motionpixels_decoder
Definition: motionpixels.c:347
int size
Definition: avcodec.h:1478
int av_log2(unsigned v)
Definition: intmath.c:26
enum AVPixelFormat pix_fmt
Pixel format, see AV_PIX_FMT_xxx.
Definition: avcodec.h:1775
void av_fast_padded_malloc(void *ptr, unsigned int *size, size_t min_size)
Same behaviour av_fast_malloc but the buffer has additional AV_INPUT_BUFFER_PADDING_SIZE at the end w...
Definition: utils.c:70
AVCodec.
Definition: avcodec.h:3481
static void decode(AVCodecContext *dec_ctx, AVPacket *pkt, AVFrame *frame, FILE *outfile)
Definition: decode_audio.c:42
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: decode.c:2011
uint8_t delta
Definition: motionpixels.c:34
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:189
static const uint32_t color[16+AV_CLASS_CATEGORY_NB]
Definition: log.c:92
void(* bswap_buf)(uint32_t *dst, const uint32_t *src, int w)
Definition: bswapdsp.h:25
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 offset
static av_cold int end(AVCodecContext *avctx)
Definition: avrndec.c:90
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
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1666
static YuvPixel mp_get_yuv_from_rgb(MotionPixelsContext *mp, int x, int y)
Definition: motionpixels.c:183
uint8_t * data
Definition: avcodec.h:1477
bitstream reader API header.
ptrdiff_t size
Definition: opengl_enc.c:100
#define av_log(a,...)
#define i(width, name, range_min, range_max)
Definition: cbs_h2645.c:259
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define init_vlc(vlc, nb_bits, nb_codes,bits, bits_wrap, bits_size,codes, codes_wrap, codes_size,flags)
Definition: vlc.h:38
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:202
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:186
const char * name
Name of the codec implementation.
Definition: avcodec.h:3488
GLsizei count
Definition: opengl_enc.c:108
BswapDSPContext bdsp
Definition: motionpixels.c:40
Definition: vlc.h:26
#define av_assert1(cond)
assert() equivalent, that does not lie in speed critical code.
Definition: avassert.h:53
#define FFMIN(a, b)
Definition: common.h:96
static int mp_yuv_to_rgb(int y, int v, int u, int clip_rgb)
int width
picture width / height.
Definition: avcodec.h:1738
uint8_t w
Definition: llviddspenc.c:38
AVCodecContext * avctx
Definition: motionpixels.c:38
static int mp_get_code(MotionPixelsContext *mp, GetBitContext *gb, int size, int code)
Definition: motionpixels.c:130
static int mp_decode_frame(AVCodecContext *avctx, void *data, int *got_frame, AVPacket *avpkt)
Definition: motionpixels.c:285
static av_always_inline int get_vlc2(GetBitContext *s, VLC_TYPE(*table)[2], int bits, int max_depth)
Parse a vlc code.
Definition: get_bits.h:797
static av_cold void motionpixels_tableinit(void)
uint8_t * changes_map
Definition: motionpixels.c:41
static void mp_decode_frame_helper(MotionPixelsContext *mp, GetBitContext *gb)
Definition: motionpixels.c:256
static av_cold int mp_decode_init(AVCodecContext *avctx)
Definition: motionpixels.c:66
Libavcodec external API header.
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:326
main external API structure.
Definition: avcodec.h:1565
HuffCode codes[MAX_HUFF_CODES]
Definition: motionpixels.c:45
void * buf
Definition: avisynth_c.h:766
int extradata_size
Definition: avcodec.h:1667
static unsigned int get_bits1(GetBitContext *s)
Definition: get_bits.h:498
static int init_get_bits(GetBitContext *s, const uint8_t *buffer, int bit_size)
Initialize GetBitContext.
Definition: get_bits.h:659
static int mp_gradient(MotionPixelsContext *mp, int component, int v)
Definition: motionpixels.c:174
static unsigned int get_bits_long(GetBitContext *s, int n)
Read 0-32 bits.
Definition: get_bits.h:546
static int mp_get_vlc(MotionPixelsContext *mp, GetBitContext *gb)
Definition: motionpixels.c:199
uint8_t gradient_scale[3]
Definition: motionpixels.c:48
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:309
static void mp_decode_line(MotionPixelsContext *mp, GetBitContext *gb, int y)
Definition: motionpixels.c:209
common internal api header.
static void mp_read_changes_map(MotionPixelsContext *mp, GetBitContext *gb, int count, int bits_len, int read_color)
Definition: motionpixels.c:101
#define AV_PIX_FMT_RGB555
Definition: pixfmt.h:375
#define MAX_HUFF_CODES
Definition: motionpixels.c:27
av_cold void ff_bswapdsp_init(BswapDSPContext *c)
Definition: bswapdsp.c:49
void * priv_data
Definition: avcodec.h:1592
int pixels
Definition: avisynth_c.h:390
static void mp_set_rgb_from_yuv(MotionPixelsContext *mp, int x, int y, const YuvPixel *p)
Definition: motionpixels.c:191
static av_cold int mp_decode_end(AVCodecContext *avctx)
Definition: motionpixels.c:53
VLC_TYPE(* table)[2]
code, bits
Definition: vlc.h:28
static int mp_read_codes_table(MotionPixelsContext *mp, GetBitContext *gb)
Definition: motionpixels.c:152
static YuvPixel mp_rgb_yuv_table[1<< 15]
#define av_freep(p)
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
This structure stores compressed data.
Definition: avcodec.h:1454
void ff_free_vlc(VLC *vlc)
Definition: bitstream.c:359
#define AV_CODEC_CAP_DR1
Codec uses get_buffer() for allocating buffers and supports custom allocators.
Definition: avcodec.h:981
void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.c:191