ljpegenc.c
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1 /*
2  * lossless JPEG encoder
3  * Copyright (c) 2000, 2001 Fabrice Bellard
4  * Copyright (c) 2003 Alex Beregszaszi
5  * Copyright (c) 2003-2004 Michael Niedermayer
6  *
7  * Support for external huffman table, various fixes (AVID workaround),
8  * aspecting, new decode_frame mechanism and apple mjpeg-b support
9  * by Alex Beregszaszi
10  *
11  * This file is part of Libav.
12  *
13  * Libav is free software; you can redistribute it and/or
14  * modify it under the terms of the GNU Lesser General Public
15  * License as published by the Free Software Foundation; either
16  * version 2.1 of the License, or (at your option) any later version.
17  *
18  * Libav is distributed in the hope that it will be useful,
19  * but WITHOUT ANY WARRANTY; without even the implied warranty of
20  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
21  * Lesser General Public License for more details.
22  *
23  * You should have received a copy of the GNU Lesser General Public
24  * License along with Libav; if not, write to the Free Software
25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26  */
27 
33 #include "avcodec.h"
34 #include "dsputil.h"
35 #include "mpegvideo.h"
36 #include "mjpeg.h"
37 #include "mjpegenc.h"
38 
39 
40 static int encode_picture_lossless(AVCodecContext *avctx, unsigned char *buf, int buf_size, void *data){
41  MpegEncContext * const s = avctx->priv_data;
42  MJpegContext * const m = s->mjpeg_ctx;
43  AVFrame *pict = data;
44  const int width= s->width;
45  const int height= s->height;
46  AVFrame * const p= (AVFrame*)&s->current_picture;
47  const int predictor= avctx->prediction_method+1;
48 
49  init_put_bits(&s->pb, buf, buf_size);
50 
51  *p = *pict;
53  p->key_frame= 1;
54 
56 
57  s->header_bits= put_bits_count(&s->pb);
58 
59  if(avctx->pix_fmt == PIX_FMT_BGRA){
60  int x, y, i;
61  const int linesize= p->linesize[0];
62  uint16_t (*buffer)[4]= (void *) s->rd_scratchpad;
63  int left[3], top[3], topleft[3];
64 
65  for(i=0; i<3; i++){
66  buffer[0][i]= 1 << (9 - 1);
67  }
68 
69  for(y = 0; y < height; y++) {
70  const int modified_predictor= y ? predictor : 1;
71  uint8_t *ptr = p->data[0] + (linesize * y);
72 
73  if(s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb)>>3) < width*3*4){
74  av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
75  return -1;
76  }
77 
78  for(i=0; i<3; i++){
79  top[i]= left[i]= topleft[i]= buffer[0][i];
80  }
81  for(x = 0; x < width; x++) {
82  buffer[x][1] = ptr[4*x+0] - ptr[4*x+1] + 0x100;
83  buffer[x][2] = ptr[4*x+2] - ptr[4*x+1] + 0x100;
84  buffer[x][0] = (ptr[4*x+0] + 2*ptr[4*x+1] + ptr[4*x+2])>>2;
85 
86  for(i=0;i<3;i++) {
87  int pred, diff;
88 
89  PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
90 
91  topleft[i]= top[i];
92  top[i]= buffer[x+1][i];
93 
94  left[i]= buffer[x][i];
95 
96  diff= ((left[i] - pred + 0x100)&0x1FF) - 0x100;
97 
98  if(i==0)
100  else
102  }
103  }
104  }
105  }else{
106  int mb_x, mb_y, i;
107  const int mb_width = (width + s->mjpeg_hsample[0] - 1) / s->mjpeg_hsample[0];
108  const int mb_height = (height + s->mjpeg_vsample[0] - 1) / s->mjpeg_vsample[0];
109 
110  for(mb_y = 0; mb_y < mb_height; mb_y++) {
111  if(s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb)>>3) < mb_width * 4 * 3 * s->mjpeg_hsample[0] * s->mjpeg_vsample[0]){
112  av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
113  return -1;
114  }
115  for(mb_x = 0; mb_x < mb_width; mb_x++) {
116  if(mb_x==0 || mb_y==0){
117  for(i=0;i<3;i++) {
118  uint8_t *ptr;
119  int x, y, h, v, linesize;
120  h = s->mjpeg_hsample[i];
121  v = s->mjpeg_vsample[i];
122  linesize= p->linesize[i];
123 
124  for(y=0; y<v; y++){
125  for(x=0; x<h; x++){
126  int pred;
127 
128  ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
129  if(y==0 && mb_y==0){
130  if(x==0 && mb_x==0){
131  pred= 128;
132  }else{
133  pred= ptr[-1];
134  }
135  }else{
136  if(x==0 && mb_x==0){
137  pred= ptr[-linesize];
138  }else{
139  PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
140  }
141  }
142 
143  if(i==0)
144  ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
145  else
147  }
148  }
149  }
150  }else{
151  for(i=0;i<3;i++) {
152  uint8_t *ptr;
153  int x, y, h, v, linesize;
154  h = s->mjpeg_hsample[i];
155  v = s->mjpeg_vsample[i];
156  linesize= p->linesize[i];
157 
158  for(y=0; y<v; y++){
159  for(x=0; x<h; x++){
160  int pred;
161 
162  ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
163 //printf("%d %d %d %d %8X\n", mb_x, mb_y, x, y, ptr);
164  PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
165 
166  if(i==0)
167  ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
168  else
170  }
171  }
172  }
173  }
174  }
175  }
176  }
177 
178  emms_c();
179 
181  s->picture_number++;
182 
183  flush_put_bits(&s->pb);
184  return put_bits_ptr(&s->pb) - s->pb.buf;
185 // return (put_bits_count(&f->pb)+7)/8;
186 }
187 
188 
189 AVCodec ff_ljpeg_encoder = { //FIXME avoid MPV_* lossless JPEG should not need them
190  .name = "ljpeg",
191  .type = AVMEDIA_TYPE_VIDEO,
192  .id = CODEC_ID_LJPEG,
193  .priv_data_size = sizeof(MpegEncContext),
195  .encode = encode_picture_lossless,
197  .long_name = NULL_IF_CONFIG_SMALL("Lossless JPEG"),
198 };