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mjpegenc.c
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1 /*
2  * MJPEG 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  * MJPEG encoder.
31  */
32 
33 #include "libavutil/pixdesc.h"
34 
35 #include "avcodec.h"
36 #include "mjpegenc_common.h"
37 #include "mpegvideo.h"
38 #include "mjpeg.h"
39 #include "mjpegenc.h"
40 
41 static uint8_t uni_ac_vlc_len[64 * 64 * 2];
42 static uint8_t uni_chroma_ac_vlc_len[64 * 64 * 2];
43 
44 static av_cold void init_uni_ac_vlc(const uint8_t huff_size_ac[256], uint8_t *uni_ac_vlc_len)
45 {
46  int i;
47 
48  for (i = 0; i < 128; i++) {
49  int level = i - 64;
50  int run;
51  if (!level)
52  continue;
53  for (run = 0; run < 64; run++) {
54  int len, code, nbits;
55  int alevel = FFABS(level);
56 
57  len = (run >> 4) * huff_size_ac[0xf0];
58 
59  nbits= av_log2_16bit(alevel) + 1;
60  code = ((15&run) << 4) | nbits;
61 
62  len += huff_size_ac[code] + nbits;
63 
64  uni_ac_vlc_len[UNI_AC_ENC_INDEX(run, i)] = len;
65  // We ignore EOB as its just a constant which does not change generally
66  }
67  }
68 }
69 
71 {
72  MJpegContext *m;
73 
74  if (s->width > 65500 || s->height > 65500) {
75  av_log(s, AV_LOG_ERROR, "JPEG does not support resolutions above 65500x65500\n");
76  return AVERROR(EINVAL);
77  }
78 
79  m = av_malloc(sizeof(MJpegContext));
80  if (!m)
81  return AVERROR(ENOMEM);
82 
83  s->min_qcoeff=-1023;
84  s->max_qcoeff= 1023;
85 
86  /* build all the huffman tables */
103 
110 
111  s->mjpeg_ctx = m;
112  return 0;
113 }
114 
116 {
117  av_freep(&s->mjpeg_ctx);
118 }
119 
120 static void encode_block(MpegEncContext *s, int16_t *block, int n)
121 {
122  int mant, nbits, code, i, j;
123  int component, dc, run, last_index, val;
124  MJpegContext *m = s->mjpeg_ctx;
125  uint8_t *huff_size_ac;
126  uint16_t *huff_code_ac;
127 
128  /* DC coef */
129  component = (n <= 3 ? 0 : (n&1) + 1);
130  dc = block[0]; /* overflow is impossible */
131  val = dc - s->last_dc[component];
132  if (n < 4) {
134  huff_size_ac = m->huff_size_ac_luminance;
135  huff_code_ac = m->huff_code_ac_luminance;
136  } else {
138  huff_size_ac = m->huff_size_ac_chrominance;
139  huff_code_ac = m->huff_code_ac_chrominance;
140  }
141  s->last_dc[component] = dc;
142 
143  /* AC coefs */
144 
145  run = 0;
146  last_index = s->block_last_index[n];
147  for(i=1;i<=last_index;i++) {
148  j = s->intra_scantable.permutated[i];
149  val = block[j];
150  if (val == 0) {
151  run++;
152  } else {
153  while (run >= 16) {
154  put_bits(&s->pb, huff_size_ac[0xf0], huff_code_ac[0xf0]);
155  run -= 16;
156  }
157  mant = val;
158  if (val < 0) {
159  val = -val;
160  mant--;
161  }
162 
163  nbits= av_log2_16bit(val) + 1;
164  code = (run << 4) | nbits;
165 
166  put_bits(&s->pb, huff_size_ac[code], huff_code_ac[code]);
167 
168  put_sbits(&s->pb, nbits, mant);
169  run = 0;
170  }
171  }
172 
173  /* output EOB only if not already 64 values */
174  if (last_index < 63 || run != 0)
175  put_bits(&s->pb, huff_size_ac[0], huff_code_ac[0]);
176 }
177 
178 void ff_mjpeg_encode_mb(MpegEncContext *s, int16_t block[12][64])
179 {
180  int i;
181  if (s->chroma_format == CHROMA_444) {
182  encode_block(s, block[0], 0);
183  encode_block(s, block[2], 2);
184  encode_block(s, block[4], 4);
185  encode_block(s, block[8], 8);
186  encode_block(s, block[5], 5);
187  encode_block(s, block[9], 9);
188 
189  if (16*s->mb_x+8 < s->width) {
190  encode_block(s, block[1], 1);
191  encode_block(s, block[3], 3);
192  encode_block(s, block[6], 6);
193  encode_block(s, block[10], 10);
194  encode_block(s, block[7], 7);
195  encode_block(s, block[11], 11);
196  }
197  } else {
198  for(i=0;i<5;i++) {
199  encode_block(s, block[i], i);
200  }
201  if (s->chroma_format == CHROMA_420) {
202  encode_block(s, block[5], 5);
203  } else {
204  encode_block(s, block[6], 6);
205  encode_block(s, block[5], 5);
206  encode_block(s, block[7], 7);
207  }
208  }
209 
210  s->i_tex_bits += get_bits_diff(s);
211 }
212 
213 // maximum over s->mjpeg_vsample[i]
214 #define V_MAX 2
216  const AVFrame *pic_arg, int *got_packet)
217 
218 {
219  MpegEncContext *s = avctx->priv_data;
220  AVFrame *pic;
221  int i, ret;
222  int chroma_h_shift, chroma_v_shift;
223 
224  av_pix_fmt_get_chroma_sub_sample(avctx->pix_fmt, &chroma_h_shift, &chroma_v_shift);
225 
226  //CODEC_FLAG_EMU_EDGE have to be cleared
228  return AVERROR(EINVAL);
229 
230  if ((avctx->height & 15) && avctx->strict_std_compliance > FF_COMPLIANCE_UNOFFICIAL) {
231  av_log(avctx, AV_LOG_ERROR,
232  "Heights which are not a multiple of 16 might fail with some decoders, "
233  "use vstrict=-1 / -strict -1 to use %d anyway.\n", avctx->height);
234  av_log(avctx, AV_LOG_WARNING, "If you have a device that plays AMV videos, please test if videos "
235  "with such heights work with it and report your findings to ffmpeg-devel@ffmpeg.org\n");
236  return AVERROR_EXPERIMENTAL;
237  }
238 
239  pic = av_frame_clone(pic_arg);
240  if (!pic)
241  return AVERROR(ENOMEM);
242  //picture should be flipped upside-down
243  for(i=0; i < 3; i++) {
244  int vsample = i ? 2 >> chroma_v_shift : 2;
245  pic->data[i] += pic->linesize[i] * (vsample * s->height / V_MAX - 1);
246  pic->linesize[i] *= -1;
247  }
248  ret = ff_mpv_encode_picture(avctx, pkt, pic, got_packet);
249  av_frame_free(&pic);
250  return ret;
251 }
252 
253 #if CONFIG_MJPEG_ENCODER
255 
256 AVCodec ff_mjpeg_encoder = {
257  .name = "mjpeg",
258  .long_name = NULL_IF_CONFIG_SMALL("MJPEG (Motion JPEG)"),
259  .type = AVMEDIA_TYPE_VIDEO,
260  .id = AV_CODEC_ID_MJPEG,
261  .priv_data_size = sizeof(MpegEncContext),
263  .encode2 = ff_mpv_encode_picture,
264  .close = ff_mpv_encode_end,
266  .pix_fmts = (const enum AVPixelFormat[]){
268  },
269  .priv_class = &mjpeg_class,
270 };
271 #endif
272 #if CONFIG_AMV_ENCODER
274 
275 AVCodec ff_amv_encoder = {
276  .name = "amv",
277  .long_name = NULL_IF_CONFIG_SMALL("AMV Video"),
278  .type = AVMEDIA_TYPE_VIDEO,
279  .id = AV_CODEC_ID_AMV,
280  .priv_data_size = sizeof(MpegEncContext),
282  .encode2 = amv_encode_picture,
283  .close = ff_mpv_encode_end,
284  .pix_fmts = (const enum AVPixelFormat[]){
286  },
287  .priv_class = &amv_class,
288 };
289 #endif