FFmpeg  4.4.5
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 */
60 } A64Context;
61 
62 /* gray gradient */
63 static const uint8_t mc_colors[5]={0x0,0xb,0xc,0xf,0x1};
64 
65 /* other possible gradients - to be tested */
66 //static const uint8_t mc_colors[5]={0x0,0x8,0xa,0xf,0x7};
67 //static const uint8_t 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  uint8_t index1[256];
111  uint8_t index2[256];
112  uint8_t dither[256];
113  int i;
114  int distance;
115 
116  /* Generate lookup-tables for dither and index before looping.
117  * This code relies on c->mc_luma_vals[c->mc_pal_size - 1] being
118  * the maximum of all the mc_luma_vals values and on the minimum
119  * being zero; this ensures that dither is properly initialized. */
120  i = 0;
121  for (a=0; a < 256; a++) {
122  if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
123  distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
124  for(b = 0; b <= distance; b++) {
125  dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
126  }
127  i++;
128  }
129  if(i >= c->mc_pal_size - 1) dither[a] = 0;
130  index1[a] = i;
131  index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
132  }
133 
134  /* and render charset */
135  for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
136  lowdiff = 0;
137  highdiff = 0;
138  for (y = 0; y < 8; y++) {
139  row1 = 0; row2 = 0;
140  for (x = 0; x < 4; x++) {
141  pix = best_cb[y * 4 + x];
142 
143  /* accumulate error for brightest/darkest color */
144  if (index1[pix] >= 3)
145  highdiff += pix - c->mc_luma_vals[3];
146  if (index1[pix] < 1)
147  lowdiff += c->mc_luma_vals[1] - pix;
148 
149  row1 <<= 2;
150 
151  if (INTERLACED) {
152  row2 <<= 2;
153  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
154  row1 |= 3-(index2[pix] & 3);
155  else
156  row1 |= 3-(index1[pix] & 3);
157 
158  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
159  row2 |= 3-(index2[pix] & 3);
160  else
161  row2 |= 3-(index1[pix] & 3);
162  }
163  else {
164  if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
165  row1 |= 3-(index2[pix] & 3);
166  else
167  row1 |= 3-(index1[pix] & 3);
168  }
169  }
170  charset[y+0x000] = row1;
171  if (INTERLACED) charset[y+0x800] = row2;
172  }
173  /* do we need to adjust pixels? */
174  if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
175  if (lowdiff > highdiff) {
176  for (x = 0; x < 32; x++)
177  best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
178  } else {
179  for (x = 0; x < 32; x++)
180  best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
181  }
182  charpos--; /* redo now adjusted char */
183  /* no adjustment needed, all fine */
184  } else {
185  /* advance pointers */
186  best_cb += 32;
187  charset += 8;
188 
189  /* remember colorram value */
190  colrammap[charpos] = (highdiff > 0);
191  }
192  }
193 }
194 
196 {
197  A64Context *c = avctx->priv_data;
198  av_freep(&c->mc_meta_charset);
199  av_freep(&c->mc_best_cb);
200  av_freep(&c->mc_charset);
201  av_freep(&c->mc_charmap);
202  av_freep(&c->mc_colram);
203  return 0;
204 }
205 
207 {
208  A64Context *c = avctx->priv_data;
209  int a;
210  av_lfg_init(&c->randctx, 1);
211 
212  if (avctx->global_quality < 1) {
213  c->mc_lifetime = 4;
214  } else {
215  c->mc_lifetime = avctx->global_quality /= FF_QP2LAMBDA;
216  }
217 
218  av_log(avctx, AV_LOG_INFO, "charset lifetime set to %d frame(s)\n", c->mc_lifetime);
219 
220  c->mc_frame_counter = 0;
221  c->mc_use_5col = avctx->codec->id == AV_CODEC_ID_A64_MULTI5;
222  c->mc_pal_size = 4 + c->mc_use_5col;
223 
224  /* precalc luma values for later use */
225  for (a = 0; a < c->mc_pal_size; a++) {
226  c->mc_luma_vals[a]=a64_palette[mc_colors[a]][0] * 0.30 +
227  a64_palette[mc_colors[a]][1] * 0.59 +
228  a64_palette[mc_colors[a]][2] * 0.11;
229  }
230 
231  if (!(c->mc_meta_charset = av_mallocz_array(c->mc_lifetime, 32000 * sizeof(int))) ||
232  !(c->mc_best_cb = av_malloc(CHARSET_CHARS * 32 * sizeof(int))) ||
233  !(c->mc_charmap = av_mallocz_array(c->mc_lifetime, 1000 * sizeof(int))) ||
234  !(c->mc_colram = av_mallocz(CHARSET_CHARS * sizeof(uint8_t))) ||
235  !(c->mc_charset = av_malloc(0x800 * (INTERLACED+1) * sizeof(uint8_t)))) {
236  av_log(avctx, AV_LOG_ERROR, "Failed to allocate buffer memory.\n");
237  return AVERROR(ENOMEM);
238  }
239 
240  /* set up extradata */
241  if (!(avctx->extradata = av_mallocz(8 * 4 + AV_INPUT_BUFFER_PADDING_SIZE))) {
242  av_log(avctx, AV_LOG_ERROR, "Failed to allocate memory for extradata.\n");
243  return AVERROR(ENOMEM);
244  }
245  avctx->extradata_size = 8 * 4;
246  AV_WB32(avctx->extradata, c->mc_lifetime);
247  AV_WB32(avctx->extradata + 16, INTERLACED);
248 
249  if (!avctx->codec_tag)
250  avctx->codec_tag = AV_RL32("a64m");
251 
252  c->next_pts = AV_NOPTS_VALUE;
253 
254  return 0;
255 }
256 
257 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
258 {
259  int a;
260  uint8_t temp;
261  /* only needs to be done in 5col mode */
262  /* XXX could be squeezed to 0x80 bytes */
263  for (a = 0; a < 256; a++) {
264  temp = colram[charmap[a + 0x000]] << 0;
265  temp |= colram[charmap[a + 0x100]] << 1;
266  temp |= colram[charmap[a + 0x200]] << 2;
267  if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
268  buf[a] = temp << 2;
269  }
270 }
271 
273  const AVFrame *p, int *got_packet)
274 {
275  A64Context *c = avctx->priv_data;
276 
277  int frame;
278  int x, y;
279  int b_height;
280  int b_width;
281 
282  int req_size, ret;
283  uint8_t *buf = NULL;
284 
285  int *charmap = c->mc_charmap;
286  uint8_t *colram = c->mc_colram;
287  uint8_t *charset = c->mc_charset;
288  int *meta = c->mc_meta_charset;
289  int *best_cb = c->mc_best_cb;
290 
291  int charset_size = 0x800 * (INTERLACED + 1);
292  int colram_size = 0x100 * c->mc_use_5col;
293  int screen_size;
294 
295  if(CROP_SCREENS) {
296  b_height = FFMIN(avctx->height,C64YRES) >> 3;
297  b_width = FFMIN(avctx->width ,C64XRES) >> 3;
298  screen_size = b_width * b_height;
299  } else {
300  b_height = C64YRES >> 3;
301  b_width = C64XRES >> 3;
302  screen_size = 0x400;
303  }
304 
305  /* no data, means end encoding asap */
306  if (!p) {
307  /* all done, end encoding */
308  if (!c->mc_lifetime) return 0;
309  /* no more frames in queue, prepare to flush remaining frames */
310  if (!c->mc_frame_counter) {
311  c->mc_lifetime = 0;
312  }
313  /* still frames in queue so limit lifetime to remaining frames */
314  else c->mc_lifetime = c->mc_frame_counter;
315  /* still new data available */
316  } else {
317  /* fill up mc_meta_charset with data until lifetime exceeds */
318  if (c->mc_frame_counter < c->mc_lifetime) {
319  to_meta_with_crop(avctx, p, meta + 32000 * c->mc_frame_counter);
320  c->mc_frame_counter++;
321  if (c->next_pts == AV_NOPTS_VALUE)
322  c->next_pts = p->pts;
323  /* lifetime is not reached so wait for next frame first */
324  return 0;
325  }
326  }
327 
328  /* lifetime reached so now convert X frames at once */
329  if (c->mc_frame_counter == c->mc_lifetime) {
330  req_size = 0;
331  /* any frames to encode? */
332  if (c->mc_lifetime) {
333  int alloc_size = charset_size + c->mc_lifetime*(screen_size + colram_size);
334  if ((ret = ff_alloc_packet2(avctx, pkt, alloc_size, 0)) < 0)
335  return ret;
336  buf = pkt->data;
337 
338  /* calc optimal new charset + charmaps */
339  ret = avpriv_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
340  CHARSET_CHARS, 50, charmap, &c->randctx);
341  if (ret < 0)
342  return ret;
343  ret = avpriv_do_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb,
344  CHARSET_CHARS, 50, charmap, &c->randctx);
345  if (ret < 0)
346  return ret;
347 
348  /* create colorram map and a c64 readable charset */
349  render_charset(avctx, charset, colram);
350 
351  /* copy charset to buf */
352  memcpy(buf, charset, charset_size);
353 
354  /* advance pointers */
355  buf += charset_size;
356  req_size += charset_size;
357  }
358 
359  /* write x frames to buf */
360  for (frame = 0; frame < c->mc_lifetime; frame++) {
361  /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
362  for (y = 0; y < b_height; y++) {
363  for (x = 0; x < b_width; x++) {
364  buf[y * b_width + x] = charmap[y * b_width + x];
365  }
366  }
367  /* advance pointers */
368  buf += screen_size;
369  req_size += screen_size;
370 
371  /* compress and copy colram to buf */
372  if (c->mc_use_5col) {
373  a64_compress_colram(buf, charmap, colram);
374  /* advance pointers */
375  buf += colram_size;
376  req_size += colram_size;
377  }
378 
379  /* advance to next charmap */
380  charmap += 1000;
381  }
382 
383  AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
384  AV_WB32(avctx->extradata + 8, charset_size);
385  AV_WB32(avctx->extradata + 12, screen_size + colram_size);
386 
387  /* reset counter */
388  c->mc_frame_counter = 0;
389 
390  pkt->pts = pkt->dts = c->next_pts;
391  c->next_pts = AV_NOPTS_VALUE;
392 
393  av_assert0(pkt->size >= req_size);
394  pkt->size = req_size;
396  *got_packet = !!req_size;
397  }
398  return 0;
399 }
400 
401 #if CONFIG_A64MULTI_ENCODER
403  .name = "a64multi",
404  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
405  .type = AVMEDIA_TYPE_VIDEO,
406  .id = AV_CODEC_ID_A64_MULTI,
407  .priv_data_size = sizeof(A64Context),
409  .encode2 = a64multi_encode_frame,
410  .close = a64multi_close_encoder,
412  .capabilities = AV_CODEC_CAP_DELAY,
414 };
415 #endif
416 #if CONFIG_A64MULTI5_ENCODER
418  .name = "a64multi5",
419  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
420  .type = AVMEDIA_TYPE_VIDEO,
422  .priv_data_size = sizeof(A64Context),
424  .encode2 = a64multi_encode_frame,
425  .close = a64multi_close_encoder,
427  .capabilities = AV_CODEC_CAP_DELAY,
429 };
430 #endif
a64 video encoder - c64 colors in rgb
static const uint8_t a64_palette[16][3]
Definition: a64colors.h:33
static const uint8_t mc_colors[5]
Definition: a64multienc.c:63
#define INTERLACED
Definition: a64multienc.c:37
#define CROP_SCREENS
Definition: a64multienc.c:38
#define CHARSET_CHARS
Definition: a64multienc.c:36
#define C64YRES
Definition: a64multienc.c:41
static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
Definition: a64multienc.c:257
static void render_charset(AVCodecContext *avctx, uint8_t *charset, uint8_t *colrammap)
Definition: a64multienc.c:100
static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
Definition: a64multienc.c:195
static av_cold int a64multi_encode_init(AVCodecContext *avctx)
Definition: a64multienc.c:206
static int a64multi_encode_frame(AVCodecContext *avctx, AVPacket *pkt, const AVFrame *p, int *got_packet)
Definition: a64multienc.c:272
#define C64XRES
Definition: a64multienc.c:40
static void to_meta_with_crop(AVCodecContext *avctx, const AVFrame *p, int *dest)
Definition: a64multienc.c:69
#define DITHERSTEPS
Definition: a64multienc.c:35
a64 video encoder - tables used by a64 encoders
static const uint8_t multi_dither_patterns[9][4][4]
dither patterns used vor rendering the multicolor charset
Definition: a64tables.h:36
static const uint8_t interlaced_dither_patterns[9][8][4]
Definition: a64tables.h:93
AVCodec ff_a64multi5_encoder
AVCodec ff_a64multi_encoder
#define av_cold
Definition: attributes.h:88
uint8_t
simple assert() macros that are a bit more flexible than ISO C assert().
#define av_assert0(cond)
assert() equivalent, that is always enabled.
Definition: avassert.h:37
#define AV_RL32
Definition: intreadwrite.h:146
static av_cold int init(AVCodecContext *avctx)
Definition: avrndec.c:31
common internal and external API header
#define FFMIN(a, b)
Definition: common.h:105
#define FFMAX(a, b)
Definition: common.h:103
#define NULL
Definition: coverity.c:32
long long int64_t
Definition: coverity.c:34
static AVFrame * frame
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 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 ff_alloc_packet2(AVCodecContext *avctx, AVPacket *avpkt, int64_t size, int64_t min_size)
Check AVPacket size and/or allocate data.
Definition: encode.c:33
#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: codec.h:77
@ AV_CODEC_ID_A64_MULTI5
Definition: codec_id.h:193
@ AV_CODEC_ID_A64_MULTI
Definition: codec_id.h:192
#define AV_INPUT_BUFFER_PADDING_SIZE
Required number of additionally allocated bytes at the end of the input bitstream for decoding.
Definition: avcodec.h:215
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: packet.h:410
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:227
#define AVERROR(e)
Definition: error.h:43
#define AV_LOG_INFO
Standard information.
Definition: log.h:205
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:194
void * av_mallocz(size_t size)
Allocate a memory block with alignment suitable for all memory accesses (including vectors if availab...
Definition: mem.c:237
void * av_mallocz_array(size_t nmemb, size_t size)
Allocate a memory block for an array with av_mallocz().
Definition: mem.c:190
@ AVMEDIA_TYPE_VIDEO
Definition: avutil.h:201
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:248
int i
Definition: input.c:407
#define AV_WB32(p, v)
Definition: intreadwrite.h:419
av_cold void av_lfg_init(AVLFG *c, unsigned int seed)
Definition: lfg.c:32
#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:41
#define FF_CODEC_CAP_INIT_CLEANUP
The codec allows calling the close function for deallocation even if the init function returned a fai...
Definition: internal.h:49
common internal API header
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification.
Definition: internal.h:117
static enum AVPixelFormat pix_fmts[]
Definition: libkvazaar.c:309
static float distance(float x, float y, int band)
AVPixelFormat
Pixel format.
Definition: pixfmt.h:64
@ AV_PIX_FMT_NONE
Definition: pixfmt.h:65
@ AV_PIX_FMT_GRAY8
Y , 8bpp.
Definition: pixfmt.h:74
int mc_pal_size
Definition: a64multienc.c:56
unsigned mc_frame_counter
Definition: a64multienc.c:48
int mc_luma_vals[5]
Definition: a64multienc.c:52
uint8_t * mc_palette
Definition: a64multienc.c:55
int * mc_best_cb
Definition: a64multienc.c:51
AVLFG randctx
Definition: a64multienc.c:45
int mc_lifetime
Definition: a64multienc.c:46
uint8_t * mc_colram
Definition: a64multienc.c:54
int * mc_charmap
Definition: a64multienc.c:50
int mc_use_5col
Definition: a64multienc.c:47
uint8_t * mc_charset
Definition: a64multienc.c:53
int64_t next_pts
Definition: a64multienc.c:59
int * mc_meta_charset
Definition: a64multienc.c:49
main external API structure.
Definition: avcodec.h:536
int width
picture width / height.
Definition: avcodec.h:709
int global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:602
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:561
const struct AVCodec * codec
Definition: avcodec.h:545
uint8_t * extradata
some codecs need / can use extradata like Huffman tables.
Definition: avcodec.h:637
int extradata_size
Definition: avcodec.h:638
void * priv_data
Definition: avcodec.h:563
AVCodec.
Definition: codec.h:197
enum AVCodecID id
Definition: codec.h:211
const char * name
Name of the codec implementation.
Definition: codec.h:204
This structure describes decoded (raw) audio or video data.
Definition: frame.h:318
int64_t pts
Presentation timestamp in time_base units (time when frame should be shown to user).
Definition: frame.h:411
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:332
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:349
Context structure for the Lagged Fibonacci PRNG.
Definition: lfg.h:33
This structure stores compressed data.
Definition: packet.h:346
int flags
A combination of AV_PKT_FLAG values.
Definition: packet.h:375
int size
Definition: packet.h:370
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: packet.h:362
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed.
Definition: packet.h:368
uint8_t * data
Definition: packet.h:369
#define av_freep(p)
#define av_malloc(s)
#define av_log(a,...)
#define src
Definition: vp8dsp.c:255
AVPacket * pkt
Definition: movenc.c:59
#define height
#define width
const char * b
Definition: vf_curves.c:118
static const uint8_t dither[8][8]
Definition: vf_fspp.c:59
else temp
Definition: vf_mcdeint.c:259
static double c[64]