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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,
70  const AVFrame *p, int *dest)
71 {
72  int blockx, blocky, x, y;
73  int luma = 0;
74  int height = FFMIN(avctx->height, C64YRES);
75  int width = FFMIN(avctx->width , C64XRES);
76  uint8_t *src = p->data[0];
77 
78  for (blocky = 0; blocky < C64YRES; blocky += 8) {
79  for (blockx = 0; blockx < C64XRES; blockx += 8) {
80  for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
81  for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
82  if(x < width && y < height) {
83  if (x + 1 < width) {
84  /* build average over 2 pixels */
85  luma = (src[(x + 0 + y * p->linesize[0])] +
86  src[(x + 1 + y * p->linesize[0])]) / 2;
87  } else {
88  luma = src[(x + y * p->linesize[0])];
89  }
90  /* write blocks as linear data now so they are suitable for elbg */
91  dest[0] = luma;
92  }
93  dest++;
94  }
95  }
96  }
97  }
98 }
99 
100 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
101  uint8_t *colrammap)
102 {
103  A64Context *c = avctx->priv_data;
104  uint8_t row1, row2;
105  int charpos, x, y;
106  int a, b;
107  uint8_t pix;
108  int lowdiff, highdiff;
109  int *best_cb = c->mc_best_cb;
110  static uint8_t index1[256];
111  static uint8_t index2[256];
112  static uint8_t dither[256];
113  int i;
114  int distance;
115 
116  /* generate lookup-tables for dither and index before looping */
117  i = 0;
118  for (a=0; a < 256; a++) {
119  if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
120  distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
121  for(b = 0; b <= distance; b++) {
122  dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
123  }
124  i++;
125  }
126  if(i >= c->mc_pal_size - 1) dither[a] = 0;
127  index1[a] = i;
128  index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
129  }
130 
131  /* and render charset */
132  for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
133  lowdiff = 0;
134  highdiff = 0;
135  for (y = 0; y < 8; y++) {
136  row1 = 0; row2 = 0;
137  for (x = 0; x < 4; x++) {
138  pix = best_cb[y * 4 + x];
139 
140  /* accumulate error for brightest/darkest color */
141  if (index1[pix] >= 3)
142  highdiff += pix - c->mc_luma_vals[3];
143  if (index1[pix] < 1)
144  lowdiff += c->mc_luma_vals[1] - pix;
145 
146  row1 <<= 2;
147 
148  if (INTERLACED) {
149  row2 <<= 2;
150  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
151  row1 |= 3-(index2[pix] & 3);
152  else
153  row1 |= 3-(index1[pix] & 3);
154 
155  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
156  row2 |= 3-(index2[pix] & 3);
157  else
158  row2 |= 3-(index1[pix] & 3);
159  }
160  else {
161  if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
162  row1 |= 3-(index2[pix] & 3);
163  else
164  row1 |= 3-(index1[pix] & 3);
165  }
166  }
167  charset[y+0x000] = row1;
168  if (INTERLACED) charset[y+0x800] = row2;
169  }
170  /* do we need to adjust pixels? */
171  if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
172  if (lowdiff > highdiff) {
173  for (x = 0; x < 32; x++)
174  best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
175  } else {
176  for (x = 0; x < 32; x++)
177  best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
178  }
179  charpos--; /* redo now adjusted char */
180  /* no adjustment needed, all fine */
181  } else {
182  /* advance pointers */
183  best_cb += 32;
184  charset += 8;
185 
186  /* remember colorram value */
187  colrammap[charpos] = (highdiff > 0);
188  }
189  }
190 }
191 
193 {
194  A64Context *c = avctx->priv_data;
196  av_freep(&c->mc_best_cb);
197  av_freep(&c->mc_charset);
198  av_freep(&c->mc_charmap);
199  av_freep(&c->mc_colram);
200  return 0;
201 }
202 
204 {
205  A64Context *c = avctx->priv_data;
206  int a;
207  av_lfg_init(&c->randctx, 1);
208 
209  if (avctx->global_quality < 1) {
210  c->mc_lifetime = 4;
211  } else {
212  c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
213  }
214 
215  av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
216 
217  c->mc_frame_counter = 0;
218  c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
219  c->mc_pal_size = 4 + c->mc_use_5col;
220 
221  /* precalc luma values for later use */
222  for (a = 0; a < c->mc_pal_size; a++) {
223  c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
224  a64_palette[mc_colors[a]][1] * 0.59 +
225  a64_palette[mc_colors[a]][2] * 0.11;
226  }
227 
228  if (!(c->mc_meta_charset = av_mallocz_array(c->mc_lifetime, 32000 * sizeof(int))) ||
229  !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
230  !(c->mc_charmap = av_mallocz_array(c->mc_lifetime, 1000 * sizeof(int))) ||
231  !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
232  !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
233  av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
234  return AVERROR(ENOMEM);
235  }
236 
237  /* set up extradata */
238  if (!(avctx->extradata = av_mallocz(8 * 4 + AV_INPUT_BUFFER_PADDING_SIZE))) {
239  av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
240  return AVERROR(ENOMEM);
241  }
242  avctx->extradata_size = 8 * 4;
243  AV_WB32(avctx->extradata, c->mc_lifetime);
244  AV_WB32(avctx->extradata + 16, INTERLACED);
245 
246  if (!avctx->codec_tag)
247  avctx->codec_tag = AV_RL32("a64m");
248 
250 
251  return 0;
252 }
253 
254 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
255 {
256  int a;
257  uint8_t temp;
258  /* only needs to be done in 5col mode */
259  /* XXX could be squeezed to 0x80 bytes */
260  for (a = 0; a < 256; a++) {
261  temp = colram[charmap[a + 0x000]] << 0;
262  temp |= colram[charmap[a + 0x100]] << 1;
263  temp |= colram[charmap[a + 0x200]] << 2;
264  if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
265  buf[a] = temp << 2;
266  }
267 }
268 
270  const AVFrame *p, int *got_packet)
271 {
272  A64Context *c = avctx->priv_data;
273 
274  int frame;
275  int x, y;
276  int b_height;
277  int b_width;
278 
279  int req_size, ret;
280  uint8_t *buf = NULL;
281 
282  int *charmap = c->mc_charmap;
283  uint8_t *colram = c->mc_colram;
284  uint8_t *charset = c->mc_charset;
285  int *meta = c->mc_meta_charset;
286  int *best_cb = c->mc_best_cb;
287 
288  int charset_size = 0x800 * (INTERLACED + 1);
289  int colram_size = 0x100 * c->mc_use_5col;
290  int screen_size;
291 
292  if(CROP_SCREENS) {
293  b_height = FFMIN(avctx->height,C64YRES) >> 3;
294  b_width = FFMIN(avctx->width ,C64XRES) >> 3;
295  screen_size = b_width * b_height;
296  } else {
297  b_height = C64YRES >> 3;
298  b_width = C64XRES >> 3;
299  screen_size = 0x400;
300  }
301 
302  /* no data, means end encoding asap */
303  if (!p) {
304  /* all done, end encoding */
305  if (!c->mc_lifetime) return 0;
306  /* no more frames in queue, prepare to flush remaining frames */
307  if (!c->mc_frame_counter) {
308  c->mc_lifetime = 0;
309  }
310  /* still frames in queue so limit lifetime to remaining frames */
311  else c->mc_lifetime = c->mc_frame_counter;
312  /* still new data available */
313  } else {
314  /* fill up mc_meta_charset with data until lifetime exceeds */
315  if (c->mc_frame_counter < c->mc_lifetime) {
316  to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
317  c->mc_frame_counter++;
318  if (c->next_pts == AV_NOPTS_VALUE)
319  c->next_pts = p->pts;
320  /* lifetime is not reached so wait for next frame first */
321  return 0;
322  }
323  }
324 
325  /* lifetime reached so now convert X frames at once */
326  if (c->mc_frame_counter == c->mc_lifetime) {
327  req_size = 0;
328  /* any frames to encode? */
329  if (c->mc_lifetime) {
330  int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
331  if ((ret = ff_alloc_packet2(avctx, pkt, alloc_size, 0)) < 0)
332  return ret;
333  buf = pkt->data;
334 
335  /* calc optimal new charset + charmaps */
336  ret = avpriv_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
337  CHARSET_CHARS, 50, charmap, &c->randctx);
338  if (ret < 0)
339  return ret;
340  ret = avpriv_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
341  CHARSET_CHARS, 50, charmap, &c->randctx);
342  if (ret < 0)
343  return ret;
344 
345  /* create colorram map and a c64 readable charset */
346  render_charset(avctx, charset, colram);
347 
348  /* copy charset to buf */
349  memcpy(buf, charset, charset_size);
350 
351  /* advance pointers */
352  buf += charset_size;
353  req_size += charset_size;
354  }
355 
356  /* write x frames to buf */
357  for (frame = 0; frame < c->mc_lifetime; frame++) {
358  /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
359  for (y = 0; y < b_height; y++) {
360  for (x = 0; x < b_width; x++) {
361  buf[y * b_width + x] = charmap[y * b_width + x];
362  }
363  }
364  /* advance pointers */
365  buf += screen_size;
366  req_size += screen_size;
367 
368  /* compress and copy colram to buf */
369  if (c->mc_use_5col) {
370  a64_compress_colram(buf, charmap, colram);
371  /* advance pointers */
372  buf += colram_size;
373  req_size += colram_size;
374  }
375 
376  /* advance to next charmap */
377  charmap += 1000;
378  }
379 
380  AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
381  AV_WB32(avctx->extradata + 8, charset_size);
382  AV_WB32(avctx->extradata + 12, screen_size + colram_size);
383 
384  /* reset counter */
385  c->mc_frame_counter = 0;
386 
387  pkt->pts = pkt->dts = c->next_pts;
389 
390  av_assert0(pkt->size >= req_size);
391  pkt->size = req_size;
392  pkt->flags |= AV_PKT_FLAG_KEY;
393  *got_packet = !!req_size;
394  }
395  return 0;
396 }
397 
398 #if CONFIG_A64MULTI_ENCODER
399 AVCodec ff_a64multi_encoder = {
400  .name = "a64multi",
401  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
402  .type = AVMEDIA_TYPE_VIDEO,
403  .id = AV_CODEC_ID_A64_MULTI,
404  .priv_data_size = sizeof(A64Context),
406  .encode2 = a64multi_encode_frame,
407  .close = a64multi_close_encoder,
409  .capabilities = AV_CODEC_CAP_DELAY,
410 };
411 #endif
412 #if CONFIG_A64MULTI5_ENCODER
413 AVCodec ff_a64multi5_encoder = {
414  .name = "a64multi5",
415  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
416  .type = AVMEDIA_TYPE_VIDEO,
418  .priv_data_size = sizeof(A64Context),
420  .encode2 = a64multi_encode_frame,
421  .close = a64multi_close_encoder,
423  .capabilities = AV_CODEC_CAP_DELAY,
424 };
425 #endif
Definition: lfg.h:25
#define NULL
Definition: coverity.c:32
const struct AVCodec * codec
Definition: avcodec.h:1691
#define C64XRES
Definition: a64multienc.c:40
This structure describes decoded (raw) audio or video data.
Definition: frame.h:190
#define INTERLACED
Definition: a64multienc.c:37
else temp
Definition: vf_mcdeint.c:259
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:35
uint8_t * mc_palette
Definition: a64multienc.c:55
int size
Definition: avcodec.h:1608
const char * b
Definition: vf_curves.c:113
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:252
static AVPacket pkt
#define src
Definition: vp8dsp.c:254
AVCodec.
Definition: avcodec.h:3607
int mc_luma_vals[5]
Definition: a64multienc.c:52
#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:984
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
uint8_t
#define av_cold
Definition: attributes.h:82
#define av_malloc(s)
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:274
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:1797
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
#define height
uint8_t * data
Definition: avcodec.h:1607
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:1639
enum AVCodecID id
Definition: avcodec.h:3621
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:176
#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:176
#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:3614
#define DITHERSTEPS
Definition: a64multienc.c:35
#define FFMAX(a, b)
Definition: common.h:94
static void * av_mallocz_array(size_t nmemb, size_t size)
Definition: mem.h:226
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:1613
#define C64YRES
Definition: a64multienc.c:41
static float distance(float x, float y, int band)
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:269
#define CHARSET_CHARS
Definition: a64multienc.c:36
#define FFMIN(a, b)
Definition: common.h:96
unsigned mc_frame_counter
Definition: a64multienc.c:48
#define width
static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
Definition: a64multienc.c:254
int width
picture width / height.
Definition: avcodec.h:1869
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:100
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
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:221
main external API structure.
Definition: avcodec.h:1682
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:1714
void * buf
Definition: avisynth_c.h:690
int extradata_size
Definition: avcodec.h:1798
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 ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
Definition: utils.c:1723
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:262
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1763
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:204
int64_t next_pts
Definition: a64multienc.c:59
Y , 8bpp.
Definition: pixfmt.h:70
static av_cold int a64multi_encode_init(AVCodecContext *avctx)
Definition: a64multienc.c:203
common internal api header.
common internal and external API header
int * mc_charmap
Definition: a64multienc.c:50
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding...
Definition: avcodec.h:734
void * priv_data
Definition: avcodec.h:1724
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
static AVCodec * c
#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:192
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:1606
#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:87
AVPixelFormat
Pixel format.
Definition: pixfmt.h:60
This structure stores compressed data.
Definition: avcodec.h:1584
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:1600
#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