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
28 #include "libavutil/avassert.h"
31 #include "mpegvideo.h"
36 extern uint8_t ff_h261_rl_table_store[2][2*MAX_RUN + MAX_LEVEL + 3];
38 static void h261_encode_block(H261Context * h, DCTELEM * block,
41 int ff_h261_get_picture_format(int width, int height){
43 if (width == 176 && height == 144)
46 else if (width == 352 && height == 288)
53 void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){
54 H261Context * h = (H261Context *) s;
57 avpriv_align_put_bits(&s->pb);
59 /* Update the pointer to last GOB */
60 s->ptr_lastgob = put_bits_ptr(&s->pb);
62 put_bits(&s->pb, 20, 0x10); /* PSC */
64 temp_ref= s->picture_number * (int64_t)30000 * s->avctx->time_base.num /
65 (1001 * (int64_t)s->avctx->time_base.den); //FIXME maybe this should use a timestamp
66 put_sbits(&s->pb, 5, temp_ref); /* TemporalReference */
68 put_bits(&s->pb, 1, 0); /* split screen off */
69 put_bits(&s->pb, 1, 0); /* camera off */
70 put_bits(&s->pb, 1, 0); /* freeze picture release off */
72 format = ff_h261_get_picture_format(s->width, s->height);
74 put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */
76 put_bits(&s->pb, 1, 0); /* still image mode */
77 put_bits(&s->pb, 1, 0); /* reserved */
79 put_bits(&s->pb, 1, 0); /* no PEI */
88 * Encode a group of blocks header.
90 static void h261_encode_gob_header(MpegEncContext * s, int mb_line){
91 H261Context * h = (H261Context *)s;
92 if(ff_h261_get_picture_format(s->width, s->height) == 0){
93 h->gob_number+=2; // QCIF
96 h->gob_number++; // CIF
98 put_bits(&s->pb, 16, 1); /* GBSC */
99 put_bits(&s->pb, 4, h->gob_number); /* GN */
100 put_bits(&s->pb, 5, s->qscale); /* GQUANT */
101 put_bits(&s->pb, 1, 0); /* no GEI */
108 void ff_h261_reorder_mb_index(MpegEncContext* s){
109 int index= s->mb_x + s->mb_y*s->mb_width;
112 h261_encode_gob_header(s,0);
114 /* for CIF the GOB's are fragmented in the middle of a scanline
115 that's why we need to adjust the x and y index of the macroblocks */
116 if(ff_h261_get_picture_format(s->width,s->height) == 1){ // CIF
117 s->mb_x = index % 11 ; index /= 11;
118 s->mb_y = index % 3 ; index /= 3;
119 s->mb_x+= 11*(index % 2); index /= 2;
122 ff_init_block_index(s);
123 ff_update_block_index(s);
127 static void h261_encode_motion(H261Context * h, int val){
128 MpegEncContext * const s = &h->s;
132 put_bits(&s->pb,ff_h261_mv_tab[code][1],ff_h261_mv_tab[code][0]);
140 code = sign ? -val : val;
141 put_bits(&s->pb,ff_h261_mv_tab[code][1],ff_h261_mv_tab[code][0]);
142 put_bits(&s->pb,1,sign);
146 static inline int get_cbp(MpegEncContext * s,
147 DCTELEM block[6][64])
151 for (i = 0; i < 6; i++) {
152 if (s->block_last_index[i] >= 0)
157 void ff_h261_encode_mb(MpegEncContext * s,
158 DCTELEM block[6][64],
159 int motion_x, int motion_y)
161 H261Context * h = (H261Context *)s;
162 int mvd, mv_diff_x, mv_diff_y, i, cbp;
163 cbp = 63; // avoid warning
171 cbp= get_cbp(s, block);
173 /* mvd indicates if this block is motion compensated */
174 mvd = motion_x | motion_y;
176 if((cbp | mvd | s->dquant ) == 0) {
177 /* skip macroblock */
185 /* MB is not skipped, encode MBA */
186 put_bits(&s->pb, ff_h261_mba_bits[(h->current_mba-h->previous_mba)-1], ff_h261_mba_code[(h->current_mba-h->previous_mba)-1]);
188 /* calculate MTYPE */
192 if(mvd || s->loop_filter)
198 av_assert1(h->mtype > 1);
204 put_bits(&s->pb, ff_h261_mtype_bits[h->mtype], ff_h261_mtype_code[h->mtype]);
206 h->mtype = ff_h261_mtype_map[h->mtype];
208 if(IS_QUANT(h->mtype)){
209 ff_set_qscale(s,s->qscale+s->dquant);
210 put_bits(&s->pb, 5, s->qscale);
213 if(IS_16X16(h->mtype)){
214 mv_diff_x = (motion_x >> 1) - h->current_mv_x;
215 mv_diff_y = (motion_y >> 1) - h->current_mv_y;
216 h->current_mv_x = (motion_x >> 1);
217 h->current_mv_y = (motion_y >> 1);
218 h261_encode_motion(h,mv_diff_x);
219 h261_encode_motion(h,mv_diff_y);
222 h->previous_mba = h->current_mba;
224 if(HAS_CBP(h->mtype)){
226 put_bits(&s->pb,ff_h261_cbp_tab[cbp-1][1],ff_h261_cbp_tab[cbp-1][0]);
229 /* encode each block */
230 h261_encode_block(h, block[i], i);
233 if ( ( h->current_mba == 11 ) || ( h->current_mba == 22 ) || ( h->current_mba == 33 ) || ( !IS_16X16 ( h->mtype ) )){
239 void ff_h261_encode_init(MpegEncContext *s){
244 ff_init_rl(&ff_h261_rl_tcoeff, ff_h261_rl_table_store);
250 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
255 * Encode an 8x8 block.
256 * @param block the 8x8 block
257 * @param n block index (0-3 are luma, 4-5 are chroma)
259 static void h261_encode_block(H261Context * h, DCTELEM * block, int n){
260 MpegEncContext * const s = &h->s;
261 int level, run, i, j, last_index, last_non_zero, sign, slevel, code;
264 rl = &ff_h261_rl_tcoeff;
268 /* 255 cannot be represented, so we clamp */
273 /* 0 cannot be represented also */
274 else if (level < 1) {
279 put_bits(&s->pb, 8, 0xff);
281 put_bits(&s->pb, 8, level);
283 } else if((block[0]==1 || block[0] == -1) && (s->block_last_index[n] > -1)){
285 put_bits(&s->pb,2,block[0]>0 ? 2 : 3 );
292 last_index = s->block_last_index[n];
293 last_non_zero = i - 1;
294 for (; i <= last_index; i++) {
295 j = s->intra_scantable.permutated[i];
298 run = i - last_non_zero - 1;
305 code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/, run, level);
306 if(run==0 && level < 16)
308 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
310 put_bits(&s->pb, 6, run);
311 av_assert1(slevel != 0);
312 av_assert1(level <= 127);
313 put_sbits(&s->pb, 8, slevel);
315 put_bits(&s->pb, 1, sign);
321 put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]);// END OF BLOCK
325 FF_MPV_GENERIC_CLASS(h261)
327 AVCodec ff_h261_encoder = {
329 .type = AVMEDIA_TYPE_VIDEO,
330 .id = AV_CODEC_ID_H261,
331 .priv_data_size = sizeof(H261Context),
332 .init = ff_MPV_encode_init,
333 .encode2 = ff_MPV_encode_picture,
334 .close = ff_MPV_encode_end,
335 .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
336 .long_name = NULL_IF_CONFIG_SMALL("H.261"),
337 .priv_class = &h261_class,