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, AVFrame *p, int *dest)
48 {
49  int blockx, blocky, x, y;
50  int luma = 0;
51  int height = FFMIN(avctx->height, C64YRES);
52  int width = FFMIN(avctx->width , C64XRES);
53  uint8_t *src = p->data[0];
54 
55  for (blocky = 0; blocky < C64YRES; blocky += 8) {
56  for (blockx = 0; blockx < C64XRES; blockx += 8) {
57  for (y = blocky; y < blocky + 8 && y < C64YRES; y++) {
58  for (x = blockx; x < blockx + 8 && x < C64XRES; x += 2) {
59  if(x < width && y < height) {
60  /* build average over 2 pixels */
61  luma = (src[(x + 0 + y * p->linesize[0])] +
62  src[(x + 1 + y * p->linesize[0])]) / 2;
63  /* write blocks as linear data now so they are suitable for elbg */
64  dest[0] = luma;
65  }
66  dest++;
67  }
68  }
69  }
70  }
71 }
72 
73 static void render_charset(AVCodecContext *avctx, uint8_t *charset,
74  uint8_t *colrammap)
75 {
76  A64Context *c = avctx->priv_data;
77  uint8_t row1, row2;
78  int charpos, x, y;
79  int a, b;
80  uint8_t pix;
81  int lowdiff, highdiff;
82  int *best_cb = c->mc_best_cb;
83  static uint8_t index1[256];
84  static uint8_t index2[256];
85  static uint8_t dither[256];
86  int i;
87  int distance;
88 
89  /* generate lookup-tables for dither and index before looping */
90  i = 0;
91  for (a=0; a < 256; a++) {
92  if(i < c->mc_pal_size -1 && a == c->mc_luma_vals[i + 1]) {
93  distance = c->mc_luma_vals[i + 1] - c->mc_luma_vals[i];
94  for(b = 0; b <= distance; b++) {
95  dither[c->mc_luma_vals[i] + b] = b * (DITHERSTEPS - 1) / distance;
96  }
97  i++;
98  }
99  if(i >= c->mc_pal_size - 1) dither[a] = 0;
100  index1[a] = i;
101  index2[a] = FFMIN(i + 1, c->mc_pal_size - 1);
102  }
103 
104  /* and render charset */
105  for (charpos = 0; charpos < CHARSET_CHARS; charpos++) {
106  lowdiff = 0;
107  highdiff = 0;
108  for (y = 0; y < 8; y++) {
109  row1 = 0; row2 = 0;
110  for (x = 0; x < 4; x++) {
111  pix = best_cb[y * 4 + x];
112 
113  /* accumulate error for brightest/darkest color */
114  if (index1[pix] >= 3)
115  highdiff += pix - c->mc_luma_vals[3];
116  if (index1[pix] < 1)
117  lowdiff += c->mc_luma_vals[1] - pix;
118 
119  row1 <<= 2;
120 
121  if (INTERLACED) {
122  row2 <<= 2;
123  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 0][x & 3])
124  row1 |= 3-(index2[pix] & 3);
125  else
126  row1 |= 3-(index1[pix] & 3);
127 
128  if (interlaced_dither_patterns[dither[pix]][(y & 3) * 2 + 1][x & 3])
129  row2 |= 3-(index2[pix] & 3);
130  else
131  row2 |= 3-(index1[pix] & 3);
132  }
133  else {
134  if (multi_dither_patterns[dither[pix]][(y & 3)][x & 3])
135  row1 |= 3-(index2[pix] & 3);
136  else
137  row1 |= 3-(index1[pix] & 3);
138  }
139  }
140  charset[y+0x000] = row1;
141  if (INTERLACED) charset[y+0x800] = row2;
142  }
143  /* do we need to adjust pixels? */
144  if (highdiff > 0 && lowdiff > 0 && c->mc_use_5col) {
145  if (lowdiff > highdiff) {
146  for (x = 0; x < 32; x++)
147  best_cb[x] = FFMIN(c->mc_luma_vals[3], best_cb[x]);
148  } else {
149  for (x = 0; x < 32; x++)
150  best_cb[x] = FFMAX(c->mc_luma_vals[1], best_cb[x]);
151  }
152  charpos--; /* redo now adjusted char */
153  /* no adjustment needed, all fine */
154  } else {
155  /* advance pointers */
156  best_cb += 32;
157  charset += 8;
158 
159  /* remember colorram value */
160  colrammap[charpos] = (highdiff > 0);
161  }
162  }
163 }
164 
166 {
167  A64Context *c = avctx->priv_data;
168  av_frame_free(&avctx->coded_frame);
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 + FF_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  avctx->coded_frame = av_frame_alloc();
221  if (!avctx->coded_frame) {
222  a64multi_close_encoder(avctx);
223  return AVERROR(ENOMEM);
224  }
225 
227  avctx->coded_frame->key_frame = 1;
228  if (!avctx->codec_tag)
229  avctx->codec_tag = AV_RL32("a64m");
230 
232 
233  return 0;
234 }
235 
236 static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
237 {
238  int a;
239  uint8_t temp;
240  /* only needs to be done in 5col mode */
241  /* XXX could be squeezed to 0x80 bytes */
242  for (a = 0; a < 256; a++) {
243  temp = colram[charmap[a + 0x000]] << 0;
244  temp |= colram[charmap[a + 0x100]] << 1;
245  temp |= colram[charmap[a + 0x200]] << 2;
246  if (a < 0xe8) temp |= colram[charmap[a + 0x300]] << 3;
247  buf[a] = temp << 2;
248  }
249 }
250 
252  const AVFrame *pict, int *got_packet)
253 {
254  A64Context *c = avctx->priv_data;
255  AVFrame *const p = avctx->coded_frame;
256 
257  int frame;
258  int x, y;
259  int b_height;
260  int b_width;
261 
262  int req_size, ret;
263  uint8_t *buf;
264 
265  int *charmap = c->mc_charmap;
266  uint8_t *colram = c->mc_colram;
267  uint8_t *charset = c->mc_charset;
268  int *meta = c->mc_meta_charset;
269  int *best_cb = c->mc_best_cb;
270 
271  int charset_size = 0x800 * (INTERLACED + 1);
272  int colram_size = 0x100 * c->mc_use_5col;
273  int screen_size;
274 
275  if(CROP_SCREENS) {
276  b_height = FFMIN(avctx->height,C64YRES) >> 3;
277  b_width = FFMIN(avctx->width ,C64XRES) >> 3;
278  screen_size = b_width * b_height;
279  } else {
280  b_height = C64YRES >> 3;
281  b_width = C64XRES >> 3;
282  screen_size = 0x400;
283  }
284 
285  /* no data, means end encoding asap */
286  if (!pict) {
287  /* all done, end encoding */
288  if (!c->mc_lifetime) return 0;
289  /* no more frames in queue, prepare to flush remaining frames */
290  if (!c->mc_frame_counter) {
291  c->mc_lifetime = 0;
292  }
293  /* still frames in queue so limit lifetime to remaining frames */
294  else c->mc_lifetime = c->mc_frame_counter;
295  /* still new data available */
296  } else {
297  /* fill up mc_meta_charset with data until lifetime exceeds */
298  if (c->mc_frame_counter < c->mc_lifetime) {
299  *p = *pict;
301  p->key_frame = 1;
302  to_meta_with_crop(avctx, p, 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  ff_init_elbg(meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
325  ff_do_elbg (meta, 32, 1000 * c->mc_lifetime, best_cb, CHARSET_CHARS, 50, charmap, &c->randctx);
326 
327  /* create colorram map and a c64 readable charset */
328  render_charset(avctx, charset, colram);
329 
330  /* copy charset to buf */
331  memcpy(buf, charset, charset_size);
332 
333  /* advance pointers */
334  buf += charset_size;
335  charset += charset_size;
336  }
337 
338  /* write x frames to buf */
339  for (frame = 0; frame < c->mc_lifetime; frame++) {
340  /* copy charmap to buf. buf is uchar*, charmap is int*, so no memcpy here, sorry */
341  for (y = 0; y < b_height; y++) {
342  for (x = 0; x < b_width; x++) {
343  buf[y * b_width + x] = charmap[y * b_width + x];
344  }
345  }
346  /* advance pointers */
347  buf += screen_size;
348  req_size += screen_size;
349 
350  /* compress and copy colram to buf */
351  if (c->mc_use_5col) {
352  a64_compress_colram(buf, charmap, colram);
353  /* advance pointers */
354  buf += colram_size;
355  req_size += colram_size;
356  }
357 
358  /* advance to next charmap */
359  charmap += 1000;
360  }
361 
362  AV_WB32(avctx->extradata + 4, c->mc_frame_counter);
363  AV_WB32(avctx->extradata + 8, charset_size);
364  AV_WB32(avctx->extradata + 12, screen_size + colram_size);
365 
366  /* reset counter */
367  c->mc_frame_counter = 0;
368 
369  pkt->pts = pkt->dts = c->next_pts;
371 
372  pkt->size = req_size;
373  pkt->flags |= AV_PKT_FLAG_KEY;
374  *got_packet = !!req_size;
375  }
376  return 0;
377 }
378 
380  .name = "a64multi",
381  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64"),
382  .type = AVMEDIA_TYPE_VIDEO,
383  .id = AV_CODEC_ID_A64_MULTI,
384  .priv_data_size = sizeof(A64Context),
386  .encode2 = a64multi_encode_frame,
388  .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
389  .capabilities = CODEC_CAP_DELAY,
390 };
391 
393  .name = "a64multi5",
394  .long_name = NULL_IF_CONFIG_SMALL("Multicolor charset for Commodore 64, extended with 5th color (colram)"),
395  .type = AVMEDIA_TYPE_VIDEO,
397  .priv_data_size = sizeof(A64Context),
399  .encode2 = a64multi_encode_frame,
401  .pix_fmts = (const enum AVPixelFormat[]) {AV_PIX_FMT_GRAY8, AV_PIX_FMT_NONE},
402  .capabilities = CODEC_CAP_DELAY,
403 };
const struct AVCodec * codec
Definition: avcodec.h:1059
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:135
#define INTERLACED
Definition: a64multienc.c:37
AVCodec ff_a64multi_encoder
Definition: a64multienc.c:379
AVFrame * coded_frame
the picture in the bitstream
Definition: avcodec.h:2532
int size
Definition: avcodec.h:974
AVCodec.
Definition: avcodec.h:2796
int mc_luma_vals[5]
Definition: a64enc.h:45
uint8_t
#define av_cold
Definition: attributes.h:66
AVFrame * av_frame_alloc(void)
Allocate an AVFrame and set its fields to default values.
Definition: frame.c:57
#define C64XRES
Definition: a64enc.h:33
#define AV_WB32(p, d)
Definition: intreadwrite.h:239
#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:1164
int mc_use_5col
Definition: a64enc.h:40
uint8_t * data
Definition: avcodec.h:973
int * mc_best_cb
Definition: a64enc.h:44
#define AV_PKT_FLAG_KEY
The packet contains a keyframe.
Definition: avcodec.h:1019
enum AVCodecID id
Definition: avcodec.h:2810
#define AV_LOG_ERROR
Something went wrong and cannot losslessly be recovered.
Definition: log.h:123
void av_free(void *ptr)
Free a memory block which has been allocated with av_malloc(z)() or av_realloc(). ...
Definition: mem.c:186
#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:713
#define AVERROR(e)
Definition: error.h:43
void av_frame_free(AVFrame **frame)
Free the frame and any dynamically allocated objects in it, e.g.
Definition: frame.c:69
#define NULL_IF_CONFIG_SMALL(x)
Return NULL if CONFIG_SMALL is true, otherwise the argument without modification. ...
Definition: internal.h:150
#define CROP_SCREENS
Definition: a64multienc.c:38
a64 video encoder - tables used by a64 encoders
void av_log(void *avcl, int level, const char *fmt,...)
Definition: log.c:169
const char * name
Name of the codec implementation.
Definition: avcodec.h:2803
#define DITHERSTEPS
Definition: a64multienc.c:35
static void to_meta_with_crop(AVCodecContext *avctx, AVFrame *p, int *dest)
Definition: a64multienc.c:47
#define FFMAX(a, b)
Definition: common.h:55
int flags
A combination of AV_PKT_FLAG values.
Definition: avcodec.h:979
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:531
void 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:353
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:196
#define FFMIN(a, b)
Definition: common.h:57
unsigned mc_frame_counter
Definition: a64enc.h:41
static void a64_compress_colram(unsigned char *buf, int *charmap, uint8_t *colram)
Definition: a64multienc.c:236
#define C64YRES
Definition: a64enc.h:34
int width
picture width / height.
Definition: avcodec.h:1224
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:1245
#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:134
static void render_charset(AVCodecContext *avctx, uint8_t *charset, uint8_t *colrammap)
Definition: a64multienc.c:73
int linesize[AV_NUM_DATA_POINTERS]
For video, size in bytes of each picture line.
Definition: frame.h:153
main external API structure.
Definition: avcodec.h:1050
static void close(AVCodecParserContext *s)
Definition: h264_parser.c:490
unsigned int codec_tag
fourcc (LSB first, so "ABCD" -> ('D'<<24) + ('C'<<16) + ('B'<<8) + 'A').
Definition: avcodec.h:1082
int extradata_size
Definition: avcodec.h:1165
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:251
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
void 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 global_quality
Global quality for codecs which cannot change it per frame.
Definition: avcodec.h:1130
uint8_t * data[AV_NUM_DATA_POINTERS]
pointer to the picture/channel planes.
Definition: frame.h:141
int64_t next_pts
Definition: a64enc.h:52
int height
Definition: gxfenc.c:72
AVCodec ff_a64multi5_encoder
Definition: a64multienc.c:392
Y , 8bpp.
Definition: pixfmt.h:73
static av_cold int a64multi_encode_init(AVCodecContext *avctx)
Definition: a64multienc.c:177
common internal api header.
common internal and external API header
int * mc_charmap
Definition: a64enc.h:43
static av_cold int init(AVCodecParserContext *s)
Definition: h264_parser.c:499
void * priv_data
Definition: avcodec.h:1092
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: a64enc.h:38
int key_frame
1 -> keyframe, 0-> not
Definition: frame.h:191
#define FF_QP2LAMBDA
factor to convert from H.263 QP to lambda
Definition: avutil.h:207
static av_cold int a64multi_close_encoder(AVCodecContext *avctx)
Definition: a64multienc.c:165
int64_t dts
Decompression timestamp in AVStream->time_base units; the time at which the packet is decompressed...
Definition: avcodec.h:972
uint8_t * mc_colram
Definition: a64enc.h:47
int mc_lifetime
Definition: a64enc.h:39
AVPixelFormat
Pixel format.
Definition: pixfmt.h:63
This structure stores compressed data.
Definition: avcodec.h:950
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:205
int64_t pts
Presentation timestamp in AVStream->time_base units; the time at which the decompressed packet will b...
Definition: avcodec.h:966
#define AV_NOPTS_VALUE
Undefined timestamp value.
Definition: avutil.h:228
static const uint8_t multi_dither_patterns[9][4][4]
dither patterns used vor rendering the multicolor charset
Definition: a64tables.h:36