3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
6 * This file is part of FFmpeg.
8 * FFmpeg is free software; you can redistribute it and/or
9 * modify it under the terms of the GNU Lesser General Public
10 * License as published by the Free Software Foundation; either
11 * version 2.1 of the License, or (at your option) any later version.
13 * FFmpeg is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
16 * Lesser General Public License for more details.
18 * You should have received a copy of the GNU Lesser General Public
19 * License along with FFmpeg; if not, write to the Free Software
20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
30 #include "mpegvideo.h"
34 extern uint8_t ff_h261_rl_table_store[2][2*MAX_RUN + MAX_LEVEL + 3];
36 static void h261_encode_block(H261Context * h, DCTELEM * block,
39 int ff_h261_get_picture_format(int width, int height){
41 if (width == 176 && height == 144)
44 else if (width == 352 && height == 288)
51 void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){
52 H261Context * h = (H261Context *) s;
55 align_put_bits(&s->pb);
57 /* Update the pointer to last GOB */
58 s->ptr_lastgob = pbBufPtr(&s->pb);
60 put_bits(&s->pb, 20, 0x10); /* PSC */
62 temp_ref= s->picture_number * (int64_t)30000 * s->avctx->time_base.num /
63 (1001 * (int64_t)s->avctx->time_base.den); //FIXME maybe this should use a timestamp
64 put_sbits(&s->pb, 5, temp_ref); /* TemporalReference */
66 put_bits(&s->pb, 1, 0); /* split screen off */
67 put_bits(&s->pb, 1, 0); /* camera off */
68 put_bits(&s->pb, 1, 0); /* freeze picture release off */
70 format = ff_h261_get_picture_format(s->width, s->height);
72 put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */
74 put_bits(&s->pb, 1, 0); /* still image mode */
75 put_bits(&s->pb, 1, 0); /* reserved */
77 put_bits(&s->pb, 1, 0); /* no PEI */
86 * Encodes a group of blocks header.
88 static void h261_encode_gob_header(MpegEncContext * s, int mb_line){
89 H261Context * h = (H261Context *)s;
90 if(ff_h261_get_picture_format(s->width, s->height) == 0){
91 h->gob_number+=2; // QCIF
94 h->gob_number++; // CIF
96 put_bits(&s->pb, 16, 1); /* GBSC */
97 put_bits(&s->pb, 4, h->gob_number); /* GN */
98 put_bits(&s->pb, 5, s->qscale); /* GQUANT */
99 put_bits(&s->pb, 1, 0); /* no GEI */
106 void ff_h261_reorder_mb_index(MpegEncContext* s){
107 int index= s->mb_x + s->mb_y*s->mb_width;
110 h261_encode_gob_header(s,0);
112 /* for CIF the GOB's are fragmented in the middle of a scanline
113 that's why we need to adjust the x and y index of the macroblocks */
114 if(ff_h261_get_picture_format(s->width,s->height) == 1){ // CIF
115 s->mb_x = index % 11 ; index /= 11;
116 s->mb_y = index % 3 ; index /= 3;
117 s->mb_x+= 11*(index % 2); index /= 2;
120 ff_init_block_index(s);
121 ff_update_block_index(s);
125 static void h261_encode_motion(H261Context * h, int val){
126 MpegEncContext * const s = &h->s;
130 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
138 code = sign ? -val : val;
139 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
140 put_bits(&s->pb,1,sign);
144 static inline int get_cbp(MpegEncContext * s,
145 DCTELEM block[6][64])
149 for (i = 0; i < 6; i++) {
150 if (s->block_last_index[i] >= 0)
155 void ff_h261_encode_mb(MpegEncContext * s,
156 DCTELEM block[6][64],
157 int motion_x, int motion_y)
159 H261Context * h = (H261Context *)s;
160 int mvd, mv_diff_x, mv_diff_y, i, cbp;
161 cbp = 63; // avoid warning
169 cbp= get_cbp(s, block);
171 /* mvd indicates if this block is motion compensated */
172 mvd = motion_x | motion_y;
174 if((cbp | mvd | s->dquant ) == 0) {
175 /* skip macroblock */
183 /* MB is not skipped, encode MBA */
184 put_bits(&s->pb, h261_mba_bits[(h->current_mba-h->previous_mba)-1], h261_mba_code[(h->current_mba-h->previous_mba)-1]);
186 /* calculate MTYPE */
190 if(mvd || s->loop_filter)
196 assert(h->mtype > 1);
202 put_bits(&s->pb, h261_mtype_bits[h->mtype], h261_mtype_code[h->mtype]);
204 h->mtype = h261_mtype_map[h->mtype];
206 if(IS_QUANT(h->mtype)){
207 ff_set_qscale(s,s->qscale+s->dquant);
208 put_bits(&s->pb, 5, s->qscale);
211 if(IS_16X16(h->mtype)){
212 mv_diff_x = (motion_x >> 1) - h->current_mv_x;
213 mv_diff_y = (motion_y >> 1) - h->current_mv_y;
214 h->current_mv_x = (motion_x >> 1);
215 h->current_mv_y = (motion_y >> 1);
216 h261_encode_motion(h,mv_diff_x);
217 h261_encode_motion(h,mv_diff_y);
220 h->previous_mba = h->current_mba;
222 if(HAS_CBP(h->mtype)){
224 put_bits(&s->pb,h261_cbp_tab[cbp-1][1],h261_cbp_tab[cbp-1][0]);
227 /* encode each block */
228 h261_encode_block(h, block[i], i);
231 if ( ( h->current_mba == 11 ) || ( h->current_mba == 22 ) || ( h->current_mba == 33 ) || ( !IS_16X16 ( h->mtype ) )){
237 void ff_h261_encode_init(MpegEncContext *s){
242 init_rl(&h261_rl_tcoeff, ff_h261_rl_table_store);
248 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
253 * encodes a 8x8 block.
254 * @param block the 8x8 block
255 * @param n block index (0-3 are luma, 4-5 are chroma)
257 static void h261_encode_block(H261Context * h, DCTELEM * block, int n){
258 MpegEncContext * const s = &h->s;
259 int level, run, last, i, j, last_index, last_non_zero, sign, slevel, code;
262 rl = &h261_rl_tcoeff;
266 /* 255 cannot be represented, so we clamp */
271 /* 0 cannot be represented also */
272 else if (level < 1) {
277 put_bits(&s->pb, 8, 0xff);
279 put_bits(&s->pb, 8, level);
281 } else if((block[0]==1 || block[0] == -1) && (s->block_last_index[n] > -1)){
283 put_bits(&s->pb,2,block[0]>0 ? 2 : 3 );
290 last_index = s->block_last_index[n];
291 last_non_zero = i - 1;
292 for (; i <= last_index; i++) {
293 j = s->intra_scantable.permutated[i];
296 run = i - last_non_zero - 1;
297 last = (i == last_index);
304 code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/, run, level);
305 if(run==0 && level < 16)
307 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
309 put_bits(&s->pb, 6, run);
311 assert(level <= 127);
312 put_sbits(&s->pb, 8, slevel);
314 put_bits(&s->pb, 1, sign);
320 put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]);// END OF BLOCK
324 AVCodec h261_encoder = {
332 .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUV420P, PIX_FMT_NONE},
333 .long_name= NULL_IF_CONFIG_SMALL("H.261"),