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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 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  * a64 video encoder - multicolor modes
25  */
26 
27 #include "a64colors.h"
28 #include "a64tables.h"
29 #include "elbg.h"
30 #include "internal.h"
31 #include "libavutil/avassert.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 #define C64XRES 320
41 #define C64YRES 200
42 
43 typedef struct A64Context {
44  /* variables for multicolor modes */
48  unsigned mc_frame_counter;
50  int *mc_charmap;
51  int *mc_best_cb;
52  int mc_luma_vals[5];
57 
58  /* pts of the next packet that will be output */
59  int64_t next_pts;
60 } A64Context;
61 
62 /* gray gradient */
63 static const int mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
64 
65 /* other possible gradients - to be tested */
66 //static const int mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
67 //static const int mc_colors[5]={0x0,0x9,0x8,0xa,0x3};
68 
69 static void to_meta_with_crop(AVCodecContext *avctx, const AVFrame *p, int *dest)
70 {
71  int blockx, blocky, x, y;
72  int luma = 0;
73  int height = FFMIN(avctx->height, C64YRES);
74  int width = FFMIN(avctx->width , C64XRES);
75  uint8_t *src = p->data[0];
76 
77  for (blocky = 0; blocky < C64YRES; blocky += 8) {
78  for (blockx = 0; blockx < C64XRES; blockx += 8) {
79  for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
80  for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
81  if(x < width && y < height) {
82  if (x + 1 < width) {
83  /* build average over 2 pixels */
84  luma = (src[(x + 0 + y * p->linesize[0])] +
85  src[(x + 1 + y * p->linesize[0])]) / 2;
86  } else {
87  luma = src[(x + y * p->linesize[0])];
88  }
89  /* write blocks as linear data now so they are suitable for elbg */
90  dest[0] = luma;
91  }
92  dest++;
93  }
94  }
95  }
96  }
97 }
98 
99 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
100  uint8_t *colrammap)
101 {
102  A64Context *c = avctx->priv_data;
103  uint8_t row1, row2;
104  int charpos, x, y;
105  int a, b;
106  uint8_t pix;
107  int lowdiff, highdiff;
108  int *best_cb = c->mc_best_cb;
109  static uint8_t index1[256];
110  static uint8_t index2[256];
111  static uint8_t dither[256];
112  int i;
113  int distance;
114 
115  /* generate lookup-tables for dither and index before looping */
116  i = 0;
117  for (a=0; a < 256; a++) {
118  if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
119  distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
120  for(b = 0; b <= distance; b++) {
121  dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
122  }
123  i++;
124  }
125  if(i >= c->mc_pal_size - 1) dither[a] = 0;
126  index1[a] = i;
127  index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
128  }
129 
130  /* and render charset */
131  for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
132  lowdiff = 0;
133  highdiff = 0;
134  for (y = 0; y < 8; y++) {
135  row1 = 0; row2 = 0;
136  for (x = 0; x < 4; x++) {
137  pix = best_cb[y * 4 + x];
138 
139  /* accumulate error for brightest/darkest color */
140  if (index1[pix] >= 3)
141  highdiff += pix - c->mc_luma_vals[3];
142  if (index1[pix] < 1)
143  lowdiff += c->mc_luma_vals[1] - pix;
144 
145  row1 <<= 2;
146 
147  if (INTERLACED) {
148  row2 <<= 2;
149  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
150  row1 |= 3-(index2[pix] & 3);
151  else
152  row1 |= 3-(index1[pix] & 3);
153 
154  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
155  row2 |= 3-(index2[pix] & 3);
156  else
157  row2 |= 3-(index1[pix] & 3);
158  }
159  else {
160  if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
161  row1 |= 3-(index2[pix] & 3);
162  else
163  row1 |= 3-(index1[pix] & 3);
164  }
165  }
166  charset[y+0x000] = row1;
167  if (INTERLACED) charset[y+0x800] = row2;
168  }
169  /* do we need to adjust pixels? */
170  if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
171  if (lowdiff > highdiff) {
172  for (x = 0; x < 32; x++)
173  best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
174  } else {
175  for (x = 0; x < 32; x++)
176  best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
177  }
178  charpos--; /* redo now adjusted char */
179  /* no adjustment needed, all fine */
180  } else {
181  /* advance pointers */
182  best_cb += 32;
183  charset += 8;
184 
185  /* remember colorram value */
186  colrammap[charpos] = (highdiff > 0);
187  }
188  }
189 }
190 
192 {
193  A64Context *c = avctx->priv_data;
195  av_freep(&c->mc_best_cb);
196  av_freep(&c->mc_charset);
197  av_freep(&c->mc_charmap);
198  av_freep(&c->mc_colram);
199  return 0;
200 }
201 
203 {
204  A64Context *c = avctx->priv_data;
205  int a;
206  av_lfg_init(&c->randctx, 1);
207 
208  if (avctx->global_quality < 1) {
209  c->mc_lifetime = 4;
210  } else {
211  c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
212  }
213 
214  av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
215 
216  c->mc_frame_counter = 0;
217  c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
218  c->mc_pal_size = 4 + c->mc_use_5col;
219 
220  /* precalc luma values for later use */
221  for (a = 0; a < c->mc_pal_size; a++) {
222  c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
223  a64_palette[mc_colors[a]][1] * 0.59 +
224  a64_palette[mc_colors[a]][2] * 0.11;
225  }
226 
227  if (!(c->mc_meta_charset = av_mallocz_array(c->mc_lifetime, 32000 * sizeof(int))) ||
228  !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
229  !(c->mc_charmap = av_mallocz_array(c->mc_lifetime, 1000 * sizeof(int))) ||
230  !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
231  !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
232  av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
233  return AVERROR(ENOMEM);
234  }
235 
236  /* set up extradata */
237  if (!(avctx->extradata = av_mallocz(8 * 4 + FF_INPUT_BUFFER_PADDING_SIZE))) {
238  av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
239  return AVERROR(ENOMEM);
240  }
241  avctx->extradata_size = 8 * 4;
242  AV_WB32(avctx->extradata, c->mc_lifetime);
243  AV_WB32(avctx->extradata + 16, INTERLACED);
244 
245  if (!avctx->codec_tag)
246  avctx->codec_tag = AV_RL32("a64m");
247 
249 
250  return 0;
251 }
252 
253 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
254 {
255  int a;
256  uint8_t temp;
257  /* only needs to be done in 5col mode */
258  /* XXX could be squeezed to 0x80 bytes */
259  for (a = 0; a < 256; a++) {
260  temp = colram[charmap[a + 0x000]] << 0;
261  temp |= colram[charmap[a + 0x100]] << 1;
262  temp |= colram[charmap[a + 0x200]] << 2;
263  if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
264  buf[a] = temp << 2;
265  }
266 }
267 
269  const AVFrame *p, int *got_packet)
270 {
271  A64Context *c = avctx->priv_data;
272 
273  int frame;
274  int x, y;
275  int b_height;
276  int b_width;
277 
278  int req_size, ret;
279  uint8_t *buf = NULL;
280 
281  int *charmap = c->mc_charmap;
282  uint8_t *colram = c->mc_colram;
283  uint8_t *charset = c->mc_charset;
284  int *meta = c->mc_meta_charset;
285  int *best_cb = c->mc_best_cb;
286 
287  int charset_size = 0x800 * (INTERLACED + 1);
288  int colram_size = 0x100 * c->mc_use_5col;
289  int screen_size;
290 
291  if(CROP_SCREENS) {
292  b_height = FFMIN(avctx->height,C64YRES) >> 3;
293  b_width = FFMIN(avctx->width ,C64XRES) >> 3;
294  screen_size = b_width * b_height;
295  } else {
296  b_height = C64YRES >> 3;
297  b_width = C64XRES >> 3;
298  screen_size = 0x400;
299  }
300 
301  /* no data, means end encoding asap */
302  if (!p) {
303  /* all done, end encoding */
304  if (!c->mc_lifetime) return 0;
305  /* no more frames in queue, prepare to flush remaining frames */
306  if (!c->mc_frame_counter) {
307  c->mc_lifetime = 0;
308  }
309  /* still frames in queue so limit lifetime to remaining frames */
310  else c->mc_lifetime = c->mc_frame_counter;
311  /* still new data available */
312  } else {
313  /* fill up mc_meta_charset with data until lifetime exceeds */
314  if (c->mc_frame_counter < c->mc_lifetime) {
315  to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
316  c->mc_frame_counter++;
317  if (c->next_pts == AV_NOPTS_VALUE)
318  c->next_pts = p->pts;
319  /* lifetime is not reached so wait for next frame first */
320  return 0;
321  }
322  }
323 
324  /* lifetime reached so now convert X frames at once */
325  if (c->mc_frame_counter == c->mc_lifetime) {
326  req_size = 0;
327  /* any frames to encode? */
328  if (c->mc_lifetime) {
329  int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
330  if ((ret = ff_alloc_packet2(avctx, pkt, alloc_size)) < 0)
331  return ret;
332  buf = pkt->data;
333 
334  /* calc optimal new charset + charmaps */
335  ret = avpriv_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
336  CHARSET_CHARS, 50, charmap, &c->randctx);
337  if (ret < 0)
338  return ret;
339  ret = avpriv_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
340  CHARSET_CHARS, 50, charmap, &c->randctx);
341  if (ret < 0)
342  return ret;
343 
344  /* create colorram map and a c64 readable charset */
345  render_charset(avctx, charset, colram);
346 
347  /* copy charset to buf */
348  memcpy(buf, charset, charset_size);
349 
350  /* advance pointers */
351  buf += charset_size;
352  req_size += charset_size;
353  }
354 
355  /* write x frames to buf */
356  for (frame = 0; frame < c->mc_lifetime; frame++) {
357  /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
358  for (y = 0; y < b_height; y++) {
359  for (x = 0; x < b_width; x++) {
360  buf[y * b_width + x] = charmap[y * b_width + x];
361  }
362  }
363  /* advance pointers */
364  buf += screen_size;
365  req_size += screen_size;
366 
367  /* compress and copy colram to buf */
368  if (c->mc_use_5col) {
369  a64_compress_colram(buf, charmap, colram);
370  /* advance pointers */
371  buf += colram_size;
372  req_size += colram_size;
373  }
374 
375  /* advance to next charmap */
376  charmap += 1000;
377  }
378 
379  AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
380  AV_WB32(avctx->extradata + 8, charset_size);
381  AV_WB32(avctx->extradata + 12, screen_size + colram_size);
382 
383  /* reset counter */
384  c->mc_frame_counter = 0;
385 
386  pkt->pts = pkt->dts = c->next_pts;
388 
389  av_assert0(pkt->size >= req_size);
390  pkt->size = req_size;
391  pkt->flags |= AV_PKT_FLAG_KEY;
392  *got_packet = !!req_size;
393  }
394  return 0;
395 }
396 
397 #if CONFIG_A64MULTI_ENCODER
398 AVCodec ff_a64multi_encoder = {
399  .name = "a64multi",
400  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
401  .type = AVMEDIA_TYPE_VIDEO,
402  .id = AV_CODEC_ID_A64_MULTI,
403  .priv_data_size = sizeof(A64Context),
405  .encode2 = a64multi_encode_frame,
406  .close = a64multi_close_encoder,
407  .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
408  .capabilities = CODEC_CAP_DELAY,
409 };
410 #endif
411 #if CONFIG_A64MULTI5_ENCODER
412 AVCodec ff_a64multi5_encoder = {
413  .name = "a64multi5",
414  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
415  .type = AVMEDIA_TYPE_VIDEO,
417  .priv_data_size = sizeof(A64Context),
419  .encode2 = a64multi_encode_frame,
420  .close = a64multi_close_encoder,
421  .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
422  .capabilities = CODEC_CAP_DELAY,
423 };
424 #endif
Definition: lfg.h:25
#define NULL
Definition: coverity.c:32
int ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size)
Check AVPacket size and/or allocate data.
Definition: utils.c:1754
const struct AVCodec * codec
Definition: avcodec.h:1261
#define C64XRES
Definition: a64multienc.c:40
This structure describes decoded (raw) audio or video data.
Definition: frame.h:171
#define INTERLACED
Definition: a64multienc.c:37
else temp
Definition: vf_mcdeint.c:257
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
uint8_t * mc_palette
Definition: a64multienc.c:55
int size
Definition: avcodec.h:1174
const char * b
Definition: vf_curves.c:109
static AVPacket pkt
AVCodec.
Definition: avcodec.h:3206
int mc_luma_vals[5]
Definition: a64multienc.c:52
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
uint8_t
#define av_cold
Definition: attributes.h:74
#define av_malloc(s)
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:257
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1366
int avpriv_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:371
int mc_use_5col
Definition: a64multienc.c:47
static AVFrame * frame
uint8_t * data
Definition: avcodec.h:1173
int * mc_best_cb
Definition: a64multienc.c:51
#define av_log(a,...)
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1219
enum AVCodecID id
Definition: avcodec.h:3220
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#define 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:829
#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:175
#define CROP_SCREENS
Definition: a64multienc.c:38
static const uint8_t dither[8][8]
Definition: vf_fspp.c:57
simple assert() macros that are a bit more flexible than ISO C assert().
a64 video encoder - tables used by a64 encoders
const char * name
Name of the codec implementation.
Definition: avcodec.h:3213
#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:1179
#define C64YRES
Definition: a64multienc.c:41
static float distance(float x, float y, int band)
#define FF_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:635
int * mc_meta_charset
Definition: a64multienc.c:49
static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *p, int *got_packet)
Definition: a64multienc.c:268
#define CHARSET_CHARS
Definition: a64multienc.c:36
#define FFMIN(a, b)
Definition: common.h:66
float y
unsigned mc_frame_counter
Definition: a64multienc.c:48
static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
Definition: a64multienc.c:253
ret
Definition: avfilter.c:974
int width
picture width / height.
Definition: avcodec.h:1430
uint8_t * mc_charset
Definition: a64multienc.c:53
int mc_pal_size
Definition: a64multienc.c:56
#define AV_LOG_INFO
Standard information.
Definition: log.h:187
static void render_charset(AVCodecContext *avctx, uint8_t *charset, uint8_t *colrammap)
Definition: a64multienc.c:99
int avpriv_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:337
AVS_Value src
Definition: avisynth_c.h:482
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:199
main external API structure.
Definition: avcodec.h:1252
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:1284
void * buf
Definition: avisynth_c.h:553
int extradata_size
Definition: avcodec.h:1367
BYTE int const BYTE int int int height
Definition: avisynth_c.h:676
static void to_meta_with_crop(AVCodecContext *avctx, const AVFrame *p, int *dest)
Definition: a64multienc.c:69
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
a64 video encoder - c64 colors in rgb
static const int mc_colors[5]
Definition: a64multienc.c:63
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:30
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1332
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:182
int64_t next_pts
Definition: a64multienc.c:59
Y , 8bpp.
Definition: pixfmt.h:71
static av_cold int a64multi_encode_init(AVCodecContext *avctx)
Definition: a64multienc.c:202
common internal api header.
common internal and external API header
int * mc_charmap
Definition: a64multienc.c:50
static double c[64]
void * priv_data
Definition: avcodec.h:1294
static const uint8_t a64_palette[16][3]
Definition: a64colors.h:33
static const uint8_t interlaced_dither_patterns[9][8][4]
Definition: a64tables.h:93
AVLFG randctx
Definition: a64multienc.c:45
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:227
static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
Definition: a64multienc.c:191
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1172
static void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.h:228
#define av_freep(p)
uint8_t * mc_colram
Definition: a64multienc.c:54
int mc_lifetime
Definition: a64multienc.c:46
uint64_t_TMPL AV_WL64 unsigned int_TMPL AV_RL32
Definition: bytestream.h:85
AVPixelFormat
Pixel format.
Definition: pixfmt.h:61
This structure stores compressed data.
Definition: avcodec.h:1150
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:250
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1166
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
static const uint8_t multi_dither_patterns[9][4][4]
dither patterns used vor rendering the multicolor charset
Definition: a64tables.h:36
static int width