Libav
a64multienc.c
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1 /*
2  * a64 video encoder - multicolor modes
3  * Copyright (c) 2009 Tobias Bindhammer
4  *
5  * This file is part of Libav.
6  *
7  * Libav 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  * Libav 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 Libav; if not, write to the Free Software
19  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
20  */
21 
27 #include "a64enc.h"
28 #include "a64colors.h"
29 #include "a64tables.h"
30 #include "elbg.h"
31 #include "internal.h"
32 #include "libavutil/common.h"
33 #include "libavutil/intreadwrite.h"
34 
35 #define DITHERSTEPS 8
36 #define CHARSET_CHARS 256
37 #define INTERLACED 1
38 #define CROP_SCREENS 1
39 
40 /* gray gradient */
41 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
42 
43 /* other possible gradients - to be tested */
44 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
45 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
46 
47 static void to_meta_with_crop(AVCodecContext *avctx,
48  const AVFrame *p, int *dest)
49 {
50  int blockx, blocky, x, y;
51  int luma = 0;
52  int height = FFMIN(avctx->height, C64YRES);
53  int width = FFMIN(avctx->width , C64XRES);
54  uint8_t *src = p->data[0];
55 
56  for (blocky = 0; blocky < C64YRES; blocky += 8) {
57  for (blockx = 0; blockx < C64XRES; blockx += 8) {
58  for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
59  for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
60  if(x < width && y < height) {
61  /* build average over 2 pixels */
62  luma = (src[(x + 0 + y * p->linesize[0])] +
63  src[(x + 1 + y * p->linesize[0])]) / 2;
64  /* write blocks as linear data now so they are suitable for elbg */
65  dest[0] = luma;
66  }
67  dest++;
68  }
69  }
70  }
71  }
72 }
73 
74 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
75  uint8_t *colrammap)
76 {
77  A64Context *c = avctx->priv_data;
78  uint8_t row1, row2;
79  int charpos, x, y;
80  int a, b;
81  uint8_t pix;
82  int lowdiff, highdiff;
83  int *best_cb = c->mc_best_cb;
84  static uint8_t index1[256];
85  static uint8_t index2[256];
86  static uint8_t dither[256];
87  int i;
88  int distance;
89 
90  /* generate lookup-tables for dither and index before looping */
91  i = 0;
92  for (a=0; a < 256; a++) {
93  if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
94  distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
95  for(b = 0; b <= distance; b++) {
96  dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
97  }
98  i++;
99  }
100  if(i >= c->mc_pal_size - 1) dither[a] = 0;
101  index1[a] = i;
102  index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
103  }
104 
105  /* and render charset */
106  for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
107  lowdiff = 0;
108  highdiff = 0;
109  for (y = 0; y < 8; y++) {
110  row1 = 0; row2 = 0;
111  for (x = 0; x < 4; x++) {
112  pix = best_cb[y * 4 + x];
113 
114  /* accumulate error for brightest/darkest color */
115  if (index1[pix] >= 3)
116  highdiff += pix - c->mc_luma_vals[3];
117  if (index1[pix] < 1)
118  lowdiff += c->mc_luma_vals[1] - pix;
119 
120  row1 <<= 2;
121 
122  if (INTERLACED) {
123  row2 <<= 2;
124  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
125  row1 |= 3-(index2[pix] & 3);
126  else
127  row1 |= 3-(index1[pix] & 3);
128 
129  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
130  row2 |= 3-(index2[pix] & 3);
131  else
132  row2 |= 3-(index1[pix] & 3);
133  }
134  else {
135  if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
136  row1 |= 3-(index2[pix] & 3);
137  else
138  row1 |= 3-(index1[pix] & 3);
139  }
140  }
141  charset[y+0x000] = row1;
142  if (INTERLACED) charset[y+0x800] = row2;
143  }
144  /* do we need to adjust pixels? */
145  if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
146  if (lowdiff > highdiff) {
147  for (x = 0; x < 32; x++)
148  best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
149  } else {
150  for (x = 0; x < 32; x++)
151  best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
152  }
153  charpos--; /* redo now adjusted char */
154  /* no adjustment needed, all fine */
155  } else {
156  /* advance pointers */
157  best_cb += 32;
158  charset += 8;
159 
160  /* remember colorram value */
161  colrammap[charpos] = (highdiff > 0);
162  }
163  }
164 }
165 
167 {
168  A64Context *c = avctx->priv_data;
170  av_free(c->mc_best_cb);
171  av_free(c->mc_charset);
172  av_free(c->mc_charmap);
173  av_free(c->mc_colram);
174  return 0;
175 }
176 
178 {
179  A64Context *c = avctx->priv_data;
180  int a;
181  av_lfg_init(&c->randctx, 1);
182 
183  if (avctx->global_quality < 1) {
184  c->mc_lifetime = 4;
185  } else {
186  c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
187  }
188 
189  av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
190 
191  c->mc_frame_counter = 0;
192  c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
193  c->mc_pal_size = 4 + c->mc_use_5col;
194 
195  /* precalc luma values for later use */
196  for (a = 0; a < c->mc_pal_size; a++) {
197  c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
198  a64_palette[mc_colors[a]][1] * 0.59 +
199  a64_palette[mc_colors[a]][2] * 0.11;
200  }
201 
202  if (!(c->mc_meta_charset = av_malloc(32000 * c->mc_lifetime * sizeof(int))) ||
203  !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
204  !(c->mc_charmap = av_mallocz(1000 * c->mc_lifetime * sizeof(int))) ||
205  !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
206  !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
207  av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
208  return AVERROR(ENOMEM);
209  }
210 
211  /* set up extradata */
212  if (!(avctx->extradata = av_mallocz(8 * 4 + AV_INPUT_BUFFER_PADDING_SIZE))) {
213  av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
214  return AVERROR(ENOMEM);
215  }
216  avctx->extradata_size = 8 * 4;
217  AV_WB32(avctx->extradata, c->mc_lifetime);
218  AV_WB32(avctx->extradata + 16, INTERLACED);
219 
220 #if FF_API_CODED_FRAME
223  avctx->coded_frame->key_frame = 1;
225 #endif
226  if (!avctx->codec_tag)
227  avctx->codec_tag = AV_RL32("a64m");
228 
230 
231  return 0;
232 }
233 
234 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
235 {
236  int a;
237  uint8_t temp;
238  /* only needs to be done in 5col mode */
239  /* XXX could be squeezed to 0x80 bytes */
240  for (a = 0; a < 256; a++) {
241  temp = colram[charmap[a + 0x000]] << 0;
242  temp |= colram[charmap[a + 0x100]] << 1;
243  temp |= colram[charmap[a + 0x200]] << 2;
244  if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
245  buf[a] = temp << 2;
246  }
247 }
248 
250  const AVFrame *pict, int *got_packet)
251 {
252  A64Context *c = avctx->priv_data;
253 
254  int frame;
255  int x, y;
256  int b_height;
257  int b_width;
258 
259  int req_size, ret;
260  uint8_t *buf;
261 
262  int *charmap = c->mc_charmap;
263  uint8_t *colram = c->mc_colram;
264  uint8_t *charset = c->mc_charset;
265  int *meta = c->mc_meta_charset;
266  int *best_cb = c->mc_best_cb;
267 
268  int charset_size = 0x800 * (INTERLACED + 1);
269  int colram_size = 0x100 * c->mc_use_5col;
270  int screen_size;
271 
272  if(CROP_SCREENS) {
273  b_height = FFMIN(avctx->height,C64YRES) >> 3;
274  b_width = FFMIN(avctx->width ,C64XRES) >> 3;
275  screen_size = b_width * b_height;
276  } else {
277  b_height = C64YRES >> 3;
278  b_width = C64XRES >> 3;
279  screen_size = 0x400;
280  }
281 
282  /* no data, means end encoding asap */
283  if (!pict) {
284  /* all done, end encoding */
285  if (!c->mc_lifetime) return 0;
286  /* no more frames in queue, prepare to flush remaining frames */
287  if (!c->mc_frame_counter) {
288  c->mc_lifetime = 0;
289  }
290  /* still frames in queue so limit lifetime to remaining frames */
291  else c->mc_lifetime = c->mc_frame_counter;
292  /* still new data available */
293  } else {
294  /* fill up mc_meta_charset with data until lifetime exceeds */
295  if (c->mc_frame_counter < c->mc_lifetime) {
296 #if FF_API_CODED_FRAME
299  avctx->coded_frame->key_frame = 1;
301 #endif
302  to_meta_with_crop(avctx, pict, meta + 32000 * c->mc_frame_counter);
303  c->mc_frame_counter++;
304  if (c->next_pts == AV_NOPTS_VALUE)
305  c->next_pts = pict->pts;
306  /* lifetime is not reached so wait for next frame first */
307  return 0;
308  }
309  }
310 
311  /* lifetime reached so now convert X frames at once */
312  if (c->mc_frame_counter == c->mc_lifetime) {
313  req_size = 0;
314  /* any frames to encode? */
315  if (c->mc_lifetime) {
316  req_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
317  if ((ret = ff_alloc_packet(pkt, req_size)) < 0) {
318  av_log(avctx, AV_LOG_ERROR, "Error getting output packet of size %d.\n", req_size);
319  return ret;
320  }
321  buf = pkt->data;
322 
323  /* calc optimal new charset + charmaps */
324  ret = ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
325  CHARSET_CHARS, 50, charmap, &c->randctx);
326  if (ret < 0)
327  return ret;
328  ret = ff_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
329  CHARSET_CHARS, 50, charmap, &c->randctx);
330  if (ret < 0)
331  return ret;
332 
333  /* create colorram map and a c64 readable charset */
334  render_charset(avctx, charset, colram);
335 
336  /* copy charset to buf */
337  memcpy(buf, charset, charset_size);
338 
339  /* advance pointers */
340  buf += charset_size;
341  charset += charset_size;
342  }
343 
344  /* write x frames to buf */
345  for (frame = 0; frame < c->mc_lifetime; frame++) {
346  /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
347  for (y = 0; y < b_height; y++) {
348  for (x = 0; x < b_width; x++) {
349  buf[y * b_width + x] = charmap[y * b_width + x];
350  }
351  }
352  /* advance pointers */
353  buf += screen_size;
354  req_size += screen_size;
355 
356  /* compress and copy colram to buf */
357  if (c->mc_use_5col) {
358  a64_compress_colram(buf, charmap, colram);
359  /* advance pointers */
360  buf += colram_size;
361  req_size += colram_size;
362  }
363 
364  /* advance to next charmap */
365  charmap += 1000;
366  }
367 
368  AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
369  AV_WB32(avctx->extradata + 8, charset_size);
370  AV_WB32(avctx->extradata + 12, screen_size + colram_size);
371 
372  /* reset counter */
373  c->mc_frame_counter = 0;
374 
375  pkt->pts = pkt->dts = c->next_pts;
377 
378  pkt->size = req_size;
379  pkt->flags |= AV_PKT_FLAG_KEY;
380  *got_packet = !!req_size;
381  }
382  return 0;
383 }
384 
386  .name = "a64multi",
387  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
388  .type = AVMEDIA_TYPE_VIDEO,
389  .id = AV_CODEC_ID_A64_MULTI,
390  .priv_data_size = sizeof(A64Context),
392  .encode2 = a64multi_encode_frame,
393  .close = a64multi_close_encoder,
395  .capabilities = AV_CODEC_CAP_DELAY,
396 };
397 
399  .name = "a64multi5",
400  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
401  .type = AVMEDIA_TYPE_VIDEO,
403  .priv_data_size = sizeof(A64Context),
405  .encode2 = a64multi_encode_frame,
406  .close = a64multi_close_encoder,
408  .capabilities = AV_CODEC_CAP_DELAY,
409 };
const struct AVCodec * codec
Definition: avcodec.h:1418
void * av_malloc(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:62
This structure describes decoded (raw) audio or video data.
Definition: frame.h:140
#define INTERLACED
Definition: a64multienc.c:37
AVCodec ff_a64multi_encoder
Definition: a64multienc.c:385
int size
Definition: avcodec.h:1347
av_log(ac->avr, AV_LOG_TRACE, "%d samples - audio_convert: %s to %s (%s)\, len, av_get_sample_fmt_name(ac->in_fmt), av_get_sample_fmt_name(ac->out_fmt), use_generic ? ac->func_descr_generic :ac->func_descr)
AVCodec.
Definition: avcodec.h:3120
#define AV_WB32(p, val)
Definition: intreadwrite.h:246
int mc_luma_vals[5]
Definition: a64enc.h:45
#define AV_CODEC_CAP_DELAY
Encoder or decoder requires flushing with NULL input at the end in order to give the complete and cor...
Definition: avcodec.h:863
uint8_t
#define av_cold
Definition: attributes.h:66
#define C64XRES
Definition: a64enc.h:33
#define b
Definition: input.c:52
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:211
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1523
int mc_use_5col
Definition: a64enc.h:40
uint8_t * data
Definition: avcodec.h:1346
int ff_init_elbg(int *points, int dim, int numpoints, int *codebook, int numCB, int max_steps, int *closest_cb, AVLFG *rand_state)
Initialize the **codebook vector for the elbg algorithm.
Definition: elbg.c:326
int * mc_best_cb
Definition: a64enc.h:44
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1378
#define src
Definition: vp8dsp.c:254
enum AVCodecID id
Definition: avcodec.h:3134
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:124
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:190
#define AVERROR(e)
Definition: error.h:43
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:148
#define CROP_SCREENS
Definition: a64multienc.c:38
a64 video encoder - tables used by a64 encoders
const char * name
Name of the codec implementation.
Definition: avcodec.h:3127
#define DITHERSTEPS
Definition: a64multienc.c:35
#define FFMAX(a, b)
Definition: common.h:64
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1352
static float distance(float x, float y, int band)
int * mc_meta_charset
Definition: a64enc.h:42
#define CHARSET_CHARS
Definition: a64multienc.c:36
enum AVPictureType pict_type
Picture type of the frame.
Definition: frame.h:201
#define FFMIN(a, b)
Definition: common.h:66
unsigned mc_frame_counter
Definition: a64enc.h:41
static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
Definition: a64multienc.c:234
#define C64YRES
Definition: a64enc.h:34
int width
picture width / height.
Definition: avcodec.h:1580
uint8_t * mc_charset
Definition: a64enc.h:46
int ff_alloc_packet(AVPacket *avpkt, int size)
Check AVPacket size and/or allocate data.
Definition: utils.c:1211
#define AV_RL32
Definition: intreadwrite.h:146
int mc_pal_size
Definition: a64enc.h:49
static const uint16_t dither[8][8]
Definition: vf_gradfun.c:46
static int width
Definition: utils.c:156
#define AV_LOG_INFO
Standard information.
Definition: log.h:135
static void render_charset(AVCodecContext *avctx, uint8_t *charset, uint8_t *colrammap)
Definition: a64multienc.c:74
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:158
main external API structure.
Definition: avcodec.h:1409
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> (&#39;D&#39;<<24) + (&#39;C&#39;<<16) + (&#39;B&#39;<<8) + &#39;A&#39;).
Definition: avcodec.h:1441
int extradata_size
Definition: avcodec.h:1524
static void to_meta_with_crop(AVCodecContext *avctx, const AVFrame *p, int *dest)
Definition: a64multienc.c:47
a64 video encoder - c64 colors in rgb
static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *pict, int *got_packet)
Definition: a64multienc.c:249
static const int mc_colors[5]
Definition: a64multienc.c:41
a64 video encoder - basic headers
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:30
int ff_do_elbg(int *points, int dim, int numpoints, int *codebook, int numCB, int max_steps, int *closest_cb, AVLFG *rand_state)
Implementation of the Enhanced LBG Algorithm Based on the paper "Neural Networks 14:1219-1237" that c...
Definition: elbg.c:360
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:257
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1489
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:146
int64_t next_pts
Definition: a64enc.h:52
int height
Definition: gxfenc.c:72
AVCodec ff_a64multi5_encoder
Definition: a64multienc.c:398
Y , 8bpp.
Definition: pixfmt.h:67
static av_cold int a64multi_encode_init(AVCodecContext *avctx)
Definition: a64multienc.c:177
#define FF_DISABLE_DEPRECATION_WARNINGS
Definition: internal.h:77
common internal api header.
common internal and external API header
int * mc_charmap
Definition: a64enc.h:43
attribute_deprecated AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2797
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:582
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:638
void * priv_data
Definition: avcodec.h:1451
static const uint8_t a64_palette[16][3]
Definition: a64colors.h:33
#define FF_ENABLE_DEPRECATION_WARNINGS
Definition: internal.h:78
static const uint8_t interlaced_dither_patterns[9][8][4]
Definition: a64tables.h:93
AVLFG randctx
Definition: a64enc.h:38
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:196
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:214
static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
Definition: a64multienc.c:166
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1345
uint8_t * mc_colram
Definition: a64enc.h:47
int mc_lifetime
Definition: a64enc.h:39
AVPixelFormat
Pixel format.
Definition: pixfmt.h:57
This structure stores compressed data.
Definition: avcodec.h:1323
void * av_mallocz(size_t size)
Allocate a block of size bytes with alignment suitable for all memory accesses (including vectors if ...
Definition: mem.c:211
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1339
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:235
static const uint8_t multi_dither_patterns[9][4][4]
dither patterns used vor rendering the multicolor charset
Definition: a64tables.h:36