h261: Move function declarations to h261.h
[libav.git] / libavcodec / h261enc.c
CommitLineData
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1/*
2 * H261 encoder
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
5 *
2912e87a 6 * This file is part of Libav.
d632239c 7 *
2912e87a 8 * Libav is free software; you can redistribute it and/or
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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.
12 *
2912e87a 13 * Libav is distributed in the hope that it will be useful,
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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.
17 *
18 * You should have received a copy of the GNU Lesser General Public
2912e87a 19 * License along with Libav; if not, write to the Free Software
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20 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21 */
22
23/**
ba87f080 24 * @file
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25 * H.261 encoder.
26 */
27
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28#include "avcodec.h"
29#include "mpegvideo.h"
06e03fa0 30#include "h263.h"
d632239c 31#include "h261.h"
b3e83c96 32#include "h261data.h"
d632239c 33
88bd7fdc 34static void h261_encode_block(H261Context * h, int16_t * block,
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35 int n);
36
37int ff_h261_get_picture_format(int width, int height){
38 // QCIF
39 if (width == 176 && height == 144)
40 return 0;
41 // CIF
42 else if (width == 352 && height == 288)
43 return 1;
44 // ERROR
45 else
46 return -1;
47}
48
49void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){
50 H261Context * h = (H261Context *) s;
51 int format, temp_ref;
52
9f51c682 53 avpriv_align_put_bits(&s->pb);
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54
55 /* Update the pointer to last GOB */
fb53b4a0 56 s->ptr_lastgob = put_bits_ptr(&s->pb);
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57
58 put_bits(&s->pb, 20, 0x10); /* PSC */
59
60 temp_ref= s->picture_number * (int64_t)30000 * s->avctx->time_base.num /
61 (1001 * (int64_t)s->avctx->time_base.den); //FIXME maybe this should use a timestamp
6647ab80 62 put_sbits(&s->pb, 5, temp_ref); /* TemporalReference */
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63
64 put_bits(&s->pb, 1, 0); /* split screen off */
65 put_bits(&s->pb, 1, 0); /* camera off */
66 put_bits(&s->pb, 1, 0); /* freeze picture release off */
67
68 format = ff_h261_get_picture_format(s->width, s->height);
69
70 put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */
71
72 put_bits(&s->pb, 1, 0); /* still image mode */
73 put_bits(&s->pb, 1, 0); /* reserved */
74
75 put_bits(&s->pb, 1, 0); /* no PEI */
76 if(format == 0)
77 h->gob_number = -1;
78 else
79 h->gob_number = 0;
80 h->current_mba = 0;
81}
82
83/**
49bd8e4b 84 * Encode a group of blocks header.
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85 */
86static void h261_encode_gob_header(MpegEncContext * s, int mb_line){
87 H261Context * h = (H261Context *)s;
88 if(ff_h261_get_picture_format(s->width, s->height) == 0){
89 h->gob_number+=2; // QCIF
90 }
91 else{
92 h->gob_number++; // CIF
93 }
94 put_bits(&s->pb, 16, 1); /* GBSC */
95 put_bits(&s->pb, 4, h->gob_number); /* GN */
96 put_bits(&s->pb, 5, s->qscale); /* GQUANT */
97 put_bits(&s->pb, 1, 0); /* no GEI */
98 h->current_mba = 0;
99 h->previous_mba = 0;
100 h->current_mv_x=0;
101 h->current_mv_y=0;
102}
103
104void ff_h261_reorder_mb_index(MpegEncContext* s){
105 int index= s->mb_x + s->mb_y*s->mb_width;
106
107 if(index % 33 == 0)
108 h261_encode_gob_header(s,0);
109
110 /* for CIF the GOB's are fragmented in the middle of a scanline
111 that's why we need to adjust the x and y index of the macroblocks */
112 if(ff_h261_get_picture_format(s->width,s->height) == 1){ // CIF
113 s->mb_x = index % 11 ; index /= 11;
114 s->mb_y = index % 3 ; index /= 3;
115 s->mb_x+= 11*(index % 2); index /= 2;
116 s->mb_y+= 3*index;
117
118 ff_init_block_index(s);
119 ff_update_block_index(s);
120 }
121}
122
123static void h261_encode_motion(H261Context * h, int val){
124 MpegEncContext * const s = &h->s;
125 int sign, code;
126 if(val==0){
127 code = 0;
128 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
129 }
130 else{
131 if(val > 15)
132 val -=32;
133 if(val < -16)
134 val+=32;
135 sign = val < 0;
136 code = sign ? -val : val;
137 put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]);
138 put_bits(&s->pb,1,sign);
139 }
140}
141
142static inline int get_cbp(MpegEncContext * s,
88bd7fdc 143 int16_t block[6][64])
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144{
145 int i, cbp;
146 cbp= 0;
147 for (i = 0; i < 6; i++) {
148 if (s->block_last_index[i] >= 0)
149 cbp |= 1 << (5 - i);
150 }
151 return cbp;
152}
153void ff_h261_encode_mb(MpegEncContext * s,
88bd7fdc 154 int16_t block[6][64],
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155 int motion_x, int motion_y)
156{
157 H261Context * h = (H261Context *)s;
158 int mvd, mv_diff_x, mv_diff_y, i, cbp;
159 cbp = 63; // avoid warning
160 mvd = 0;
161
162 h->current_mba++;
163 h->mtype = 0;
164
165 if (!s->mb_intra){
166 /* compute cbp */
167 cbp= get_cbp(s, block);
168
169 /* mvd indicates if this block is motion compensated */
170 mvd = motion_x | motion_y;
171
172 if((cbp | mvd | s->dquant ) == 0) {
173 /* skip macroblock */
174 s->skip_count++;
175 h->current_mv_x=0;
176 h->current_mv_y=0;
177 return;
178 }
179 }
180
181 /* MB is not skipped, encode MBA */
182 put_bits(&s->pb, h261_mba_bits[(h->current_mba-h->previous_mba)-1], h261_mba_code[(h->current_mba-h->previous_mba)-1]);
183
184 /* calculate MTYPE */
185 if(!s->mb_intra){
186 h->mtype++;
187
188 if(mvd || s->loop_filter)
189 h->mtype+=3;
190 if(s->loop_filter)
191 h->mtype+=3;
192 if(cbp || s->dquant)
193 h->mtype++;
194 assert(h->mtype > 1);
195 }
196
197 if(s->dquant)
198 h->mtype++;
199
200 put_bits(&s->pb, h261_mtype_bits[h->mtype], h261_mtype_code[h->mtype]);
201
202 h->mtype = h261_mtype_map[h->mtype];
203
204 if(IS_QUANT(h->mtype)){
205 ff_set_qscale(s,s->qscale+s->dquant);
206 put_bits(&s->pb, 5, s->qscale);
207 }
208
209 if(IS_16X16(h->mtype)){
210 mv_diff_x = (motion_x >> 1) - h->current_mv_x;
211 mv_diff_y = (motion_y >> 1) - h->current_mv_y;
212 h->current_mv_x = (motion_x >> 1);
213 h->current_mv_y = (motion_y >> 1);
214 h261_encode_motion(h,mv_diff_x);
215 h261_encode_motion(h,mv_diff_y);
216 }
217
218 h->previous_mba = h->current_mba;
219
220 if(HAS_CBP(h->mtype)){
221 assert(cbp>0);
222 put_bits(&s->pb,h261_cbp_tab[cbp-1][1],h261_cbp_tab[cbp-1][0]);
223 }
224 for(i=0; i<6; i++) {
225 /* encode each block */
226 h261_encode_block(h, block[i], i);
227 }
228
229 if ( ( h->current_mba == 11 ) || ( h->current_mba == 22 ) || ( h->current_mba == 33 ) || ( !IS_16X16 ( h->mtype ) )){
230 h->current_mv_x=0;
231 h->current_mv_y=0;
232 }
233}
234
235void ff_h261_encode_init(MpegEncContext *s){
236 static int done = 0;
237
238 if (!done) {
239 done = 1;
e96b4a53 240 ff_init_rl(&h261_rl_tcoeff, ff_h261_rl_table_store);
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241 }
242
243 s->min_qcoeff= -127;
244 s->max_qcoeff= 127;
245 s->y_dc_scale_table=
246 s->c_dc_scale_table= ff_mpeg1_dc_scale_table;
247}
248
249
250/**
58c42af7 251 * Encode an 8x8 block.
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252 * @param block the 8x8 block
253 * @param n block index (0-3 are luma, 4-5 are chroma)
254 */
88bd7fdc 255static void h261_encode_block(H261Context * h, int16_t * block, int n){
d632239c 256 MpegEncContext * const s = &h->s;
38a7695f 257 int level, run, i, j, last_index, last_non_zero, sign, slevel, code;
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258 RLTable *rl;
259
260 rl = &h261_rl_tcoeff;
261 if (s->mb_intra) {
262 /* DC coef */
263 level = block[0];
264 /* 255 cannot be represented, so we clamp */
265 if (level > 254) {
266 level = 254;
267 block[0] = 254;
268 }
269 /* 0 cannot be represented also */
270 else if (level < 1) {
271 level = 1;
272 block[0] = 1;
273 }
274 if (level == 128)
275 put_bits(&s->pb, 8, 0xff);
276 else
277 put_bits(&s->pb, 8, level);
278 i = 1;
279 } else if((block[0]==1 || block[0] == -1) && (s->block_last_index[n] > -1)){
280 //special case
281 put_bits(&s->pb,2,block[0]>0 ? 2 : 3 );
282 i = 1;
283 } else {
284 i = 0;
285 }
286
287 /* AC coefs */
288 last_index = s->block_last_index[n];
289 last_non_zero = i - 1;
290 for (; i <= last_index; i++) {
291 j = s->intra_scantable.permutated[i];
292 level = block[j];
293 if (level) {
294 run = i - last_non_zero - 1;
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295 sign = 0;
296 slevel = level;
297 if (level < 0) {
298 sign = 1;
299 level = -level;
300 }
301 code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/, run, level);
302 if(run==0 && level < 16)
303 code+=1;
304 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
305 if (code == rl->n) {
306 put_bits(&s->pb, 6, run);
307 assert(slevel != 0);
308 assert(level <= 127);
6647ab80 309 put_sbits(&s->pb, 8, slevel);
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310 } else {
311 put_bits(&s->pb, 1, sign);
312 }
313 last_non_zero = i;
314 }
315 }
316 if(last_index > -1){
317 put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]);// END OF BLOCK
318 }
319}
320
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321FF_MPV_GENERIC_CLASS(h261)
322
d36beb3f 323AVCodec ff_h261_encoder = {
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324 .name = "h261",
325 .type = AVMEDIA_TYPE_VIDEO,
36ef5369 326 .id = AV_CODEC_ID_H261,
ec6402b7 327 .priv_data_size = sizeof(H261Context),
efd29844 328 .init = ff_MPV_encode_init,
445a7d48 329 .encode2 = ff_MPV_encode_picture,
efd29844 330 .close = ff_MPV_encode_end,
716d413c 331 .pix_fmts = (const enum AVPixelFormat[]){ AV_PIX_FMT_YUV420P, AV_PIX_FMT_NONE },
00c3b67b 332 .long_name = NULL_IF_CONFIG_SMALL("H.261"),
ed019b8e 333 .priv_class = &h261_class,
d632239c 334};