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msvideo1enc.c
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1 /*
2  * Microsoft Video-1 Encoder
3  * Copyright (c) 2009 Konstantin Shishkov
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  * Microsoft Video-1 encoder
25  */
26 
27 #include "avcodec.h"
28 #include "internal.h"
29 #include "bytestream.h"
30 #include "libavutil/lfg.h"
31 #include "elbg.h"
32 #include "libavutil/imgutils.h"
33 /**
34  * Encoder context
35  */
36 typedef struct Msvideo1EncContext {
41 
42  int block[16*3];
43  int block2[16*3];
44  int codebook[8*3];
45  int codebook2[8*3];
46  int output[16*3];
47  int output2[16*3];
48  int avg[3];
49  int bestpos;
50  int keyint;
52 
53 enum MSV1Mode{
54  MODE_SKIP = 0,
58 };
59 
60 #define SKIP_PREFIX 0x8400
61 #define SKIPS_MAX 0x0FFF
62 #define MKRGB555(in, off) ((in[off] << 10) | (in[off + 1] << 5) | (in[off + 2]))
63 
64 static const int remap[16] = { 0, 1, 4, 5, 2, 3, 6, 7, 8, 9, 12, 13, 10, 11, 14, 15 };
65 
67  const AVFrame *pict, int *got_packet)
68 {
69  Msvideo1EncContext * const c = avctx->priv_data;
70  AVFrame * const p = &c->pic;
71  uint16_t *src;
72  uint8_t *prevptr;
73  uint8_t *dst, *buf;
74  int keyframe = 0;
75  int no_skips = 1;
76  int i, j, k, x, y, ret;
77  int skips = 0;
78 
79  if ((ret = ff_alloc_packet2(avctx, pkt, avctx->width*avctx->height*9 + FF_MIN_BUFFER_SIZE)) < 0)
80  return ret;
81  dst= buf= pkt->data;
82 
83  *p = *pict;
84  if(!c->prev)
85  c->prev = av_malloc(avctx->width * 3 * (avctx->height + 3));
86  prevptr = c->prev + avctx->width * 3 * (FFALIGN(avctx->height, 4) - 1);
87  src = (uint16_t*)(p->data[0] + p->linesize[0]*(FFALIGN(avctx->height, 4) - 1));
88  if(c->keyint >= avctx->keyint_min)
89  keyframe = 1;
90 
91  p->quality = 24;
92 
93  for(y = 0; y < avctx->height; y += 4){
94  for(x = 0; x < avctx->width; x += 4){
95  int bestmode = MODE_SKIP;
96  int bestscore = INT_MAX;
97  int flags = 0;
98  int score;
99 
100  for(j = 0; j < 4; j++){
101  for(i = 0; i < 4; i++){
102  uint16_t val = src[x + i - j*p->linesize[0]/2];
103  for(k = 0; k < 3; k++){
104  c->block[(i + j*4)*3 + k] =
105  c->block2[remap[i + j*4]*3 + k] = (val >> (10-k*5)) & 0x1F;
106  }
107  }
108  }
109  if(!keyframe){
110  bestscore = 0;
111  for(j = 0; j < 4; j++){
112  for(i = 0; i < 4*3; i++){
113  int t = prevptr[x*3 + i - j*3*avctx->width] - c->block[i + j*4*3];
114  bestscore += t*t;
115  }
116  }
117  bestscore /= p->quality;
118  }
119  // try to find optimal value to fill whole 4x4 block
120  score = 0;
121  ff_init_elbg(c->block, 3, 16, c->avg, 1, 1, c->output, &c->rnd);
122  ff_do_elbg (c->block, 3, 16, c->avg, 1, 1, c->output, &c->rnd);
123  if(c->avg[0] == 1) // red component = 1 will be written as skip code
124  c->avg[0] = 0;
125  for(j = 0; j < 4; j++){
126  for(i = 0; i < 4; i++){
127  for(k = 0; k < 3; k++){
128  int t = c->avg[k] - c->block[(i+j*4)*3+k];
129  score += t*t;
130  }
131  }
132  }
133  score /= p->quality;
134  score += 2;
135  if(score < bestscore){
136  bestscore = score;
137  bestmode = MODE_FILL;
138  }
139  // search for optimal filling of 2-color block
140  score = 0;
141  ff_init_elbg(c->block, 3, 16, c->codebook, 2, 1, c->output, &c->rnd);
142  ff_do_elbg (c->block, 3, 16, c->codebook, 2, 1, c->output, &c->rnd);
143  // last output value should be always 1, swap codebooks if needed
144  if(!c->output[15]){
145  for(i = 0; i < 3; i++)
146  FFSWAP(uint8_t, c->codebook[i], c->codebook[i+3]);
147  for(i = 0; i < 16; i++)
148  c->output[i] ^= 1;
149  }
150  for(j = 0; j < 4; j++){
151  for(i = 0; i < 4; i++){
152  for(k = 0; k < 3; k++){
153  int t = c->codebook[c->output[i+j*4]*3 + k] - c->block[i*3+k+j*4*3];
154  score += t*t;
155  }
156  }
157  }
158  score /= p->quality;
159  score += 6;
160  if(score < bestscore){
161  bestscore = score;
162  bestmode = MODE_2COL;
163  }
164  // search for optimal filling of 2-color 2x2 subblocks
165  score = 0;
166  for(i = 0; i < 4; i++){
167  ff_init_elbg(c->block2 + i*4*3, 3, 4, c->codebook2 + i*2*3, 2, 1, c->output2 + i*4, &c->rnd);
168  ff_do_elbg (c->block2 + i*4*3, 3, 4, c->codebook2 + i*2*3, 2, 1, c->output2 + i*4, &c->rnd);
169  }
170  // last value should be always 1, swap codebooks if needed
171  if(!c->output2[15]){
172  for(i = 0; i < 3; i++)
173  FFSWAP(uint8_t, c->codebook2[i+18], c->codebook2[i+21]);
174  for(i = 12; i < 16; i++)
175  c->output2[i] ^= 1;
176  }
177  for(j = 0; j < 4; j++){
178  for(i = 0; i < 4; i++){
179  for(k = 0; k < 3; k++){
180  int t = c->codebook2[(c->output2[remap[i+j*4]] + (i&2) + (j&2)*2)*3+k] - c->block[i*3+k + j*4*3];
181  score += t*t;
182  }
183  }
184  }
185  score /= p->quality;
186  score += 18;
187  if(score < bestscore){
188  bestscore = score;
189  bestmode = MODE_8COL;
190  }
191 
192  if(bestmode == MODE_SKIP){
193  skips++;
194  no_skips = 0;
195  }
196  if((bestmode != MODE_SKIP && skips) || skips == SKIPS_MAX){
197  bytestream_put_le16(&dst, skips | SKIP_PREFIX);
198  skips = 0;
199  }
200 
201  switch(bestmode){
202  case MODE_FILL:
203  bytestream_put_le16(&dst, MKRGB555(c->avg,0) | 0x8000);
204  for(j = 0; j < 4; j++)
205  for(i = 0; i < 4; i++)
206  for(k = 0; k < 3; k++)
207  prevptr[x*3 + i*3 + k - j*3*avctx->width] = c->avg[k];
208  break;
209  case MODE_2COL:
210  for(j = 0; j < 4; j++){
211  for(i = 0; i < 4; i++){
212  flags |= (c->output[i + j*4]^1) << (i + j*4);
213  for(k = 0; k < 3; k++)
214  prevptr[x*3 + i*3 + k - j*3*avctx->width] = c->codebook[c->output[i + j*4]*3 + k];
215  }
216  }
217  bytestream_put_le16(&dst, flags);
218  bytestream_put_le16(&dst, MKRGB555(c->codebook, 0));
219  bytestream_put_le16(&dst, MKRGB555(c->codebook, 3));
220  break;
221  case MODE_8COL:
222  for(j = 0; j < 4; j++){
223  for(i = 0; i < 4; i++){
224  flags |= (c->output2[remap[i + j*4]]^1) << (i + j*4);
225  for(k = 0; k < 3; k++)
226  prevptr[x*3 + i*3 + k - j*3*avctx->width] = c->codebook2[(c->output2[remap[i+j*4]] + (i&2) + (j&2)*2)*3 + k];
227  }
228  }
229  bytestream_put_le16(&dst, flags);
230  bytestream_put_le16(&dst, MKRGB555(c->codebook2, 0) | 0x8000);
231  for(i = 3; i < 24; i += 3)
232  bytestream_put_le16(&dst, MKRGB555(c->codebook2, i));
233  break;
234  }
235  }
236  src -= p->linesize[0] << 1;
237  prevptr -= avctx->width * 3 * 4;
238  }
239  if(skips)
240  bytestream_put_le16(&dst, skips | SKIP_PREFIX);
241  //EOF
242  bytestream_put_byte(&dst, 0);
243  bytestream_put_byte(&dst, 0);
244 
245  if(no_skips)
246  keyframe = 1;
247  if(keyframe)
248  c->keyint = 0;
249  else
250  c->keyint++;
252  p->key_frame= keyframe;
253  if (keyframe) pkt->flags |= AV_PKT_FLAG_KEY;
254  pkt->size = dst - buf;
255  *got_packet = 1;
256 
257  return 0;
258 }
259 
260 
261 /**
262  * init encoder
263  */
265 {
266  Msvideo1EncContext * const c = avctx->priv_data;
267 
268  c->avctx = avctx;
269  if (av_image_check_size(avctx->width, avctx->height, 0, avctx) < 0) {
270  return -1;
271  }
272  if((avctx->width&3) || (avctx->height&3)){
273  av_log(avctx, AV_LOG_ERROR, "width and height must be multiplies of 4\n");
274  return -1;
275  }
276 
278  avctx->coded_frame = (AVFrame*)&c->pic;
279  avctx->bits_per_coded_sample = 16;
280 
281  c->keyint = avctx->keyint_min;
282  av_lfg_init(&c->rnd, 1);
283 
284  return 0;
285 }
286 
287 
288 
289 /**
290  * Uninit encoder
291  */
293 {
294  Msvideo1EncContext * const c = avctx->priv_data;
295 
296  av_freep(&c->prev);
297 
298  return 0;
299 }
300 
302  .name = "msvideo1",
303  .type = AVMEDIA_TYPE_VIDEO,
304  .id = AV_CODEC_ID_MSVIDEO1,
305  .priv_data_size = sizeof(Msvideo1EncContext),
306  .init = encode_init,
307  .encode2 = encode_frame,
308  .close = encode_end,
309  .pix_fmts = (const enum AVPixelFormat[]){AV_PIX_FMT_RGB555, AV_PIX_FMT_NONE},
310  .long_name = NULL_IF_CONFIG_SMALL("Microsoft Video-1"),
311 };