2 * lossless JPEG shared bits
4 * This file is part of Libav.
6 * Libav is free software; you can redistribute it and/or
7 * modify it under the terms of the GNU Lesser General Public
8 * License as published by the Free Software Foundation; either
9 * version 2.1 of the License, or (at your option) any later version.
11 * Libav is distributed in the hope that it will be useful,
12 * but WITHOUT ANY WARRANTY; without even the implied warranty of
13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
14 * Lesser General Public License for more details.
16 * You should have received a copy of the GNU Lesser General Public
17 * License along with Libav; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
24 #include "libavutil/common.h"
25 #include "libavutil/pixdesc.h"
26 #include "libavutil/pixfmt.h"
31 #include "mjpegenc_common.h"
34 /* table_class: 0 = DC coef, 1 = AC coefs */
35 static int put_huffman_table(PutBitContext *p, int table_class, int table_id,
36 const uint8_t *bits_table, const uint8_t *value_table)
40 put_bits(p, 4, table_class);
41 put_bits(p, 4, table_id);
46 put_bits(p, 8, bits_table[i]);
50 put_bits(p, 8, value_table[i]);
55 static void jpeg_table_header(PutBitContext *p, ScanTable *intra_scantable,
56 uint16_t intra_matrix[64])
63 put_bits(p, 16, 2 + 1 * (1 + 64));
64 put_bits(p, 4, 0); /* 8 bit precision */
65 put_bits(p, 4, 0); /* table 0 */
67 j = intra_scantable->permutated[i];
68 put_bits(p, 8, intra_matrix[j]);
74 ptr = put_bits_ptr(p);
75 put_bits(p, 16, 0); /* patched later */
77 size += put_huffman_table(p, 0, 0, avpriv_mjpeg_bits_dc_luminance,
79 size += put_huffman_table(p, 0, 1, avpriv_mjpeg_bits_dc_chrominance,
82 size += put_huffman_table(p, 1, 0, avpriv_mjpeg_bits_ac_luminance,
83 avpriv_mjpeg_val_ac_luminance);
84 size += put_huffman_table(p, 1, 1, avpriv_mjpeg_bits_ac_chrominance,
85 avpriv_mjpeg_val_ac_chrominance);
89 static void jpeg_put_comments(AVCodecContext *avctx, PutBitContext *p)
94 if (avctx->sample_aspect_ratio.num > 0 && avctx->sample_aspect_ratio.den > 0) {
98 avpriv_put_string(p, "JFIF", 1); /* this puts the trailing zero-byte too */
99 put_bits(p, 16, 0x0201); /* v 1.02 */
100 put_bits(p, 8, 0); /* units type: 0 - aspect ratio */
101 put_bits(p, 16, avctx->sample_aspect_ratio.num);
102 put_bits(p, 16, avctx->sample_aspect_ratio.den);
103 put_bits(p, 8, 0); /* thumbnail width */
104 put_bits(p, 8, 0); /* thumbnail height */
108 if (!(avctx->flags & CODEC_FLAG_BITEXACT)) {
111 ptr = put_bits_ptr(p);
112 put_bits(p, 16, 0); /* patched later */
113 avpriv_put_string(p, LIBAVCODEC_IDENT, 1);
114 size = strlen(LIBAVCODEC_IDENT)+3;
118 if (avctx->pix_fmt == AV_PIX_FMT_YUV420P ||
119 avctx->pix_fmt == AV_PIX_FMT_YUV422P ||
120 avctx->pix_fmt == AV_PIX_FMT_YUV444P) {
123 ptr = put_bits_ptr(p);
124 put_bits(p, 16, 0); /* patched later */
125 avpriv_put_string(p, "CS=ITU601", 1);
126 size = strlen("CS=ITU601")+3;
131 void ff_mjpeg_encode_picture_header(AVCodecContext *avctx, PutBitContext *pb,
132 ScanTable *intra_scantable,
133 uint16_t intra_matrix[64])
135 int chroma_h_shift, chroma_v_shift;
136 const int lossless = avctx->codec_id != AV_CODEC_ID_MJPEG;
137 int hsample[3], vsample[3];
139 av_pix_fmt_get_chroma_sub_sample(avctx->pix_fmt, &chroma_h_shift,
142 if (avctx->codec->id == AV_CODEC_ID_LJPEG &&
143 avctx->pix_fmt == AV_PIX_FMT_BGR24) {
144 vsample[0] = hsample[0] =
145 vsample[1] = hsample[1] =
146 vsample[2] = hsample[2] = 1;
149 vsample[1] = 2 >> chroma_v_shift;
150 vsample[2] = 2 >> chroma_v_shift;
152 hsample[1] = 2 >> chroma_h_shift;
153 hsample[2] = 2 >> chroma_h_shift;
158 jpeg_put_comments(avctx, pb);
160 jpeg_table_header(pb, intra_scantable, intra_matrix);
162 switch (avctx->codec_id) {
163 case AV_CODEC_ID_MJPEG: put_marker(pb, SOF0 ); break;
164 case AV_CODEC_ID_LJPEG: put_marker(pb, SOF3 ); break;
168 put_bits(pb, 16, 17);
169 if (lossless && avctx->pix_fmt == AV_PIX_FMT_BGR24)
170 put_bits(pb, 8, 9); /* 9 bits/component RCT */
172 put_bits(pb, 8, 8); /* 8 bits/component */
173 put_bits(pb, 16, avctx->height);
174 put_bits(pb, 16, avctx->width);
175 put_bits(pb, 8, 3); /* 3 components */
178 put_bits(pb, 8, 1); /* component number */
179 put_bits(pb, 4, hsample[0]); /* H factor */
180 put_bits(pb, 4, vsample[0]); /* V factor */
181 put_bits(pb, 8, 0); /* select matrix */
184 put_bits(pb, 8, 2); /* component number */
185 put_bits(pb, 4, hsample[1]); /* H factor */
186 put_bits(pb, 4, vsample[1]); /* V factor */
187 put_bits(pb, 8, 0); /* select matrix */
190 put_bits(pb, 8, 3); /* component number */
191 put_bits(pb, 4, hsample[2]); /* H factor */
192 put_bits(pb, 4, vsample[2]); /* V factor */
193 put_bits(pb, 8, 0); /* select matrix */
197 put_bits(pb, 16, 12); /* length */
198 put_bits(pb, 8, 3); /* 3 components */
201 put_bits(pb, 8, 1); /* index */
202 put_bits(pb, 4, 0); /* DC huffman table index */
203 put_bits(pb, 4, 0); /* AC huffman table index */
206 put_bits(pb, 8, 2); /* index */
207 put_bits(pb, 4, 1); /* DC huffman table index */
208 put_bits(pb, 4, lossless ? 0 : 1); /* AC huffman table index */
211 put_bits(pb, 8, 3); /* index */
212 put_bits(pb, 4, 1); /* DC huffman table index */
213 put_bits(pb, 4, lossless ? 0 : 1); /* AC huffman table index */
215 put_bits(pb, 8, lossless ? avctx->prediction_method + 1 : 0); /* Ss (not used) */
217 switch (avctx->codec_id) {
218 case AV_CODEC_ID_MJPEG: put_bits(pb, 8, 63); break; /* Se (not used) */
219 case AV_CODEC_ID_LJPEG: put_bits(pb, 8, 0); break; /* not used */
223 put_bits(pb, 8, 0); /* Ah/Al (not used) */
226 static void escape_FF(PutBitContext *pb, int start)
228 int size = put_bits_count(pb) - start * 8;
230 uint8_t *buf = pb->buf + start;
231 int align= (-(size_t)(buf))&3;
233 assert((size&7) == 0);
237 for(i=0; i<size && i<align; i++){
238 if(buf[i]==0xFF) ff_count++;
240 for(; i<size-15; i+=16){
243 v= *(uint32_t*)(&buf[i]);
244 acc= (((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
245 v= *(uint32_t*)(&buf[i+4]);
246 acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
247 v= *(uint32_t*)(&buf[i+8]);
248 acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
249 v= *(uint32_t*)(&buf[i+12]);
250 acc+=(((v & (v>>4))&0x0F0F0F0F)+0x01010101)&0x10101010;
258 if(buf[i]==0xFF) ff_count++;
261 if(ff_count==0) return;
264 skip_put_bytes(pb, ff_count);
266 for(i=size-1; ff_count; i--){
278 void ff_mjpeg_encode_stuffing(PutBitContext * pbc)
281 length= (-put_bits_count(pbc))&7;
282 if(length) put_bits(pbc, length, (1<<length)-1);
285 void ff_mjpeg_encode_picture_trailer(PutBitContext *pb, int header_bits)
287 ff_mjpeg_encode_stuffing(pb);
290 assert((header_bits & 7) == 0);
292 escape_FF(pb, header_bits >> 3);
297 void ff_mjpeg_encode_dc(PutBitContext *pb, int val,
298 uint8_t *huff_size, uint16_t *huff_code)
303 put_bits(pb, huff_size[0], huff_code[0]);
311 nbits= av_log2_16bit(val) + 1;
313 put_bits(pb, huff_size[nbits], huff_code[nbits]);
315 put_sbits(pb, nbits, mant);