FFmpeg
 All Data Structures Files Functions Variables Typedefs Enumerations Enumerator Macros Groups Pages
ljpegenc.c
Go to the documentation of this file.
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 FFmpeg.
12  *
13  * FFmpeg 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  * FFmpeg 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 FFmpeg; if not, write to the Free Software
25  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26  */
27 
28 /**
29  * @file
30  * lossless JPEG encoder.
31  */
32 
33 #include "avcodec.h"
34 #include "internal.h"
35 #include "mpegvideo.h"
36 #include "mjpeg.h"
37 #include "mjpegenc.h"
38 
39 
40 static int encode_picture_lossless(AVCodecContext *avctx, AVPacket *pkt,
41  const AVFrame *pict, int *got_packet)
42 {
43  MpegEncContext * const s = avctx->priv_data;
44  MJpegContext * const m = s->mjpeg_ctx;
45  const int width= s->width;
46  const int height= s->height;
47  AVFrame * const p = &s->current_picture.f;
48  const int predictor= avctx->prediction_method+1;
49  const int mb_width = (width + s->mjpeg_hsample[0] - 1) / s->mjpeg_hsample[0];
50  const int mb_height = (height + s->mjpeg_vsample[0] - 1) / s->mjpeg_vsample[0];
51  int ret, max_pkt_size = FF_MIN_BUFFER_SIZE;
52 
53  if (avctx->pix_fmt == AV_PIX_FMT_BGRA)
54  max_pkt_size += width * height * 3 * 4;
55  else {
56  max_pkt_size += mb_width * mb_height * 3 * 4
57  * s->mjpeg_hsample[0] * s->mjpeg_vsample[0];
58  }
59 
60  if (!s->edge_emu_buffer &&
61  (ret = ff_mpv_frame_size_alloc(s, pict->linesize[0])) < 0) {
62  av_log(avctx, AV_LOG_ERROR, "failed to allocate context scratch buffers.\n");
63  return ret;
64  }
65 
66  if ((ret = ff_alloc_packet2(avctx, pkt, max_pkt_size)) < 0)
67  return ret;
68 
69  init_put_bits(&s->pb, pkt->data, pkt->size);
70 
71  *p = *pict;
72  p->pict_type= AV_PICTURE_TYPE_I;
73  p->key_frame= 1;
74 
75  ff_mjpeg_encode_picture_header(s);
76 
77  s->header_bits= put_bits_count(&s->pb);
78 
79  if(avctx->pix_fmt == AV_PIX_FMT_BGR0
80  || avctx->pix_fmt == AV_PIX_FMT_BGRA
81  || avctx->pix_fmt == AV_PIX_FMT_BGR24){
82  int x, y, i;
83  const int linesize= p->linesize[0];
84  uint16_t (*buffer)[4]= (void *) s->rd_scratchpad;
85  int left[3], top[3], topleft[3];
86 
87  for(i=0; i<3; i++){
88  buffer[0][i]= 1 << (9 - 1);
89  }
90 
91  for(y = 0; y < height; y++) {
92  const int modified_predictor= y ? predictor : 1;
93  uint8_t *ptr = p->data[0] + (linesize * y);
94 
95  if(s->pb.buf_end - s->pb.buf - (put_bits_count(&s->pb)>>3) < width*3*4){
96  av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
97  return -1;
98  }
99 
100  for(i=0; i<3; i++){
101  top[i]= left[i]= topleft[i]= buffer[0][i];
102  }
103  for(x = 0; x < width; x++) {
104  if(avctx->pix_fmt == AV_PIX_FMT_BGR24){
105  buffer[x][1] = ptr[3*x+0] - ptr[3*x+1] + 0x100;
106  buffer[x][2] = ptr[3*x+2] - ptr[3*x+1] + 0x100;
107  buffer[x][0] = (ptr[3*x+0] + 2*ptr[3*x+1] + ptr[3*x+2])>>2;
108  }else{
109  buffer[x][1] = ptr[4*x+0] - ptr[4*x+1] + 0x100;
110  buffer[x][2] = ptr[4*x+2] - ptr[4*x+1] + 0x100;
111  buffer[x][0] = (ptr[4*x+0] + 2*ptr[4*x+1] + ptr[4*x+2])>>2;
112  }
113 
114  for(i=0;i<3;i++) {
115  int pred, diff;
116 
117  PREDICT(pred, topleft[i], top[i], left[i], modified_predictor);
118 
119  topleft[i]= top[i];
120  top[i]= buffer[x+1][i];
121 
122  left[i]= buffer[x][i];
123 
124  diff= ((left[i] - pred + 0x100)&0x1FF) - 0x100;
125 
126  if(i==0)
127  ff_mjpeg_encode_dc(s, diff, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
128  else
129  ff_mjpeg_encode_dc(s, diff, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
130  }
131  }
132  }
133  }else{
134  int mb_x, mb_y, i;
135 
136  for(mb_y = 0; mb_y < mb_height; mb_y++) {
137  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]){
138  av_log(s->avctx, AV_LOG_ERROR, "encoded frame too large\n");
139  return -1;
140  }
141  for(mb_x = 0; mb_x < mb_width; mb_x++) {
142  if(mb_x==0 || mb_y==0){
143  for(i=0;i<3;i++) {
144  uint8_t *ptr;
145  int x, y, h, v, linesize;
146  h = s->mjpeg_hsample[i];
147  v = s->mjpeg_vsample[i];
148  linesize= p->linesize[i];
149 
150  for(y=0; y<v; y++){
151  for(x=0; x<h; x++){
152  int pred;
153 
154  ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
155  if(y==0 && mb_y==0){
156  if(x==0 && mb_x==0){
157  pred= 128;
158  }else{
159  pred= ptr[-1];
160  }
161  }else{
162  if(x==0 && mb_x==0){
163  pred= ptr[-linesize];
164  }else{
165  PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
166  }
167  }
168 
169  if(i==0)
170  ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
171  else
172  ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
173  }
174  }
175  }
176  }else{
177  for(i=0;i<3;i++) {
178  uint8_t *ptr;
179  int x, y, h, v, linesize;
180  h = s->mjpeg_hsample[i];
181  v = s->mjpeg_vsample[i];
182  linesize= p->linesize[i];
183 
184  for(y=0; y<v; y++){
185  for(x=0; x<h; x++){
186  int pred;
187 
188  ptr = p->data[i] + (linesize * (v * mb_y + y)) + (h * mb_x + x); //FIXME optimize this crap
189  PREDICT(pred, ptr[-linesize-1], ptr[-linesize], ptr[-1], predictor);
190 
191  if(i==0)
192  ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_luminance, m->huff_code_dc_luminance); //FIXME ugly
193  else
194  ff_mjpeg_encode_dc(s, *ptr - pred, m->huff_size_dc_chrominance, m->huff_code_dc_chrominance);
195  }
196  }
197  }
198  }
199  }
200  }
201  }
202 
203  emms_c();
204  av_assert0(s->esc_pos == s->header_bits >> 3);
205  ff_mjpeg_encode_stuffing(s);
206  ff_mjpeg_encode_picture_trailer(s);
207  s->picture_number++;
208 
209  flush_put_bits(&s->pb);
210  pkt->size = put_bits_ptr(&s->pb) - s->pb.buf;
211  pkt->flags |= AV_PKT_FLAG_KEY;
212  *got_packet = 1;
213 
214  return 0;
215 // return (put_bits_count(&f->pb)+7)/8;
216 }
217 
218 
219 AVCodec ff_ljpeg_encoder = { //FIXME avoid MPV_* lossless JPEG should not need them
220  .name = "ljpeg",
221  .type = AVMEDIA_TYPE_VIDEO,
222  .id = AV_CODEC_ID_LJPEG,
223  .priv_data_size = sizeof(MpegEncContext),
224  .init = ff_MPV_encode_init,
225  .encode2 = encode_picture_lossless,
226  .close = ff_MPV_encode_end,
227  .pix_fmts = (const enum AVPixelFormat[]){
228  AV_PIX_FMT_BGR24, AV_PIX_FMT_BGRA, AV_PIX_FMT_BGR0,
229  AV_PIX_FMT_YUVJ420P, AV_PIX_FMT_YUVJ444P, AV_PIX_FMT_YUVJ422P,
230  AV_PIX_FMT_YUV420P, AV_PIX_FMT_YUV444P, AV_PIX_FMT_YUV422P,
231  AV_PIX_FMT_NONE},
232  .long_name = NULL_IF_CONFIG_SMALL("Lossless JPEG"),
233 };
Generated on Sat May 25 2013 04:01:06 for FFmpeg by   doxygen 1.8.2