Imported Debian version 2.5.3~trusty1
[deb_ffmpeg.git] / ffmpeg / libavcodec / h261enc.c
CommitLineData
2ba45a60
DM
1/*
2 * H261 encoder
3 * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
4 * Copyright (c) 2004 Maarten Daniels
5 *
6 * This file is part of FFmpeg.
7 *
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.
12 *
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.
17 *
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
21 */
22
23/**
24 * @file
25 * H.261 encoder.
26 */
27
28#include "libavutil/attributes.h"
29#include "libavutil/avassert.h"
30#include "avcodec.h"
31#include "mpegutils.h"
32#include "mpegvideo.h"
33#include "h263.h"
34#include "h261.h"
35
36static uint8_t uni_h261_rl_len [64*64*2*2];
37#define UNI_ENC_INDEX(last,run,level) ((last)*128*64 + (run)*128 + (level))
38
39int ff_h261_get_picture_format(int width, int height)
40{
41 // QCIF
42 if (width == 176 && height == 144)
43 return 0;
44 // CIF
45 else if (width == 352 && height == 288)
46 return 1;
47 // ERROR
48 else
49 return -1;
50}
51
52void ff_h261_encode_picture_header(MpegEncContext *s, int picture_number)
53{
54 H261Context *h = (H261Context *)s;
55 int format, temp_ref;
56
57 avpriv_align_put_bits(&s->pb);
58
59 /* Update the pointer to last GOB */
60 s->ptr_lastgob = put_bits_ptr(&s->pb);
61
62 put_bits(&s->pb, 20, 0x10); /* PSC */
63
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 */
67
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 */
71
72 format = ff_h261_get_picture_format(s->width, s->height);
73
74 put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */
75
76 put_bits(&s->pb, 1, 0); /* still image mode */
77 put_bits(&s->pb, 1, 0); /* reserved */
78
79 put_bits(&s->pb, 1, 0); /* no PEI */
80 if (format == 0)
81 h->gob_number = -1;
82 else
83 h->gob_number = 0;
84 s->mb_skip_run = 0;
85}
86
87/**
88 * Encode a group of blocks header.
89 */
90static void h261_encode_gob_header(MpegEncContext *s, int mb_line)
91{
92 H261Context *h = (H261Context *)s;
93 if (ff_h261_get_picture_format(s->width, s->height) == 0) {
94 h->gob_number += 2; // QCIF
95 } else {
96 h->gob_number++; // CIF
97 }
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 */
102 s->mb_skip_run = 0;
103 s->last_mv[0][0][0] = 0;
104 s->last_mv[0][0][1] = 0;
105}
106
107void ff_h261_reorder_mb_index(MpegEncContext *s)
108{
109 int index = s->mb_x + s->mb_y * s->mb_width;
110
111 if (index % 11 == 0) {
112 if (index % 33 == 0)
113 h261_encode_gob_header(s, 0);
114 s->last_mv[0][0][0] = 0;
115 s->last_mv[0][0][1] = 0;
116 }
117
118 /* for CIF the GOB's are fragmented in the middle of a scanline
119 * that's why we need to adjust the x and y index of the macroblocks */
120 if (ff_h261_get_picture_format(s->width, s->height) == 1) { // CIF
121 s->mb_x = index % 11;
122 index /= 11;
123 s->mb_y = index % 3;
124 index /= 3;
125 s->mb_x += 11 * (index % 2);
126 index /= 2;
127 s->mb_y += 3 * index;
128
129 ff_init_block_index(s);
130 ff_update_block_index(s);
131 }
132}
133
134static void h261_encode_motion(H261Context *h, int val)
135{
136 MpegEncContext *const s = &h->s;
137 int sign, code;
138 if (val == 0) {
139 code = 0;
140 put_bits(&s->pb, ff_h261_mv_tab[code][1], ff_h261_mv_tab[code][0]);
141 } else {
142 if (val > 15)
143 val -= 32;
144 if (val < -16)
145 val += 32;
146 sign = val < 0;
147 code = sign ? -val : val;
148 put_bits(&s->pb, ff_h261_mv_tab[code][1], ff_h261_mv_tab[code][0]);
149 put_bits(&s->pb, 1, sign);
150 }
151}
152
153static inline int get_cbp(MpegEncContext *s, int16_t block[6][64])
154{
155 int i, cbp;
156 cbp = 0;
157 for (i = 0; i < 6; i++)
158 if (s->block_last_index[i] >= 0)
159 cbp |= 1 << (5 - i);
160 return cbp;
161}
162
163/**
164 * Encode an 8x8 block.
165 * @param block the 8x8 block
166 * @param n block index (0-3 are luma, 4-5 are chroma)
167 */
168static void h261_encode_block(H261Context *h, int16_t *block, int n)
169{
170 MpegEncContext *const s = &h->s;
171 int level, run, i, j, last_index, last_non_zero, sign, slevel, code;
172 RLTable *rl;
173
174 rl = &ff_h261_rl_tcoeff;
175 if (s->mb_intra) {
176 /* DC coef */
177 level = block[0];
178 /* 255 cannot be represented, so we clamp */
179 if (level > 254) {
180 level = 254;
181 block[0] = 254;
182 }
183 /* 0 cannot be represented also */
184 else if (level < 1) {
185 level = 1;
186 block[0] = 1;
187 }
188 if (level == 128)
189 put_bits(&s->pb, 8, 0xff);
190 else
191 put_bits(&s->pb, 8, level);
192 i = 1;
193 } else if ((block[0] == 1 || block[0] == -1) &&
194 (s->block_last_index[n] > -1)) {
195 // special case
196 put_bits(&s->pb, 2, block[0] > 0 ? 2 : 3);
197 i = 1;
198 } else {
199 i = 0;
200 }
201
202 /* AC coefs */
203 last_index = s->block_last_index[n];
204 last_non_zero = i - 1;
205 for (; i <= last_index; i++) {
206 j = s->intra_scantable.permutated[i];
207 level = block[j];
208 if (level) {
209 run = i - last_non_zero - 1;
210 sign = 0;
211 slevel = level;
212 if (level < 0) {
213 sign = 1;
214 level = -level;
215 }
216 code = get_rl_index(rl, 0 /*no last in H.261, EOB is used*/,
217 run, level);
218 if (run == 0 && level < 16)
219 code += 1;
220 put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
221 if (code == rl->n) {
222 put_bits(&s->pb, 6, run);
223 av_assert1(slevel != 0);
224 av_assert1(level <= 127);
225 put_sbits(&s->pb, 8, slevel);
226 } else {
227 put_bits(&s->pb, 1, sign);
228 }
229 last_non_zero = i;
230 }
231 }
232 if (last_index > -1)
233 put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]); // EOB
234}
235
236void ff_h261_encode_mb(MpegEncContext *s, int16_t block[6][64],
237 int motion_x, int motion_y)
238{
239 H261Context *h = (H261Context *)s;
240 int mvd, mv_diff_x, mv_diff_y, i, cbp;
241 cbp = 63; // avoid warning
242 mvd = 0;
243
244 h->mtype = 0;
245
246 if (!s->mb_intra) {
247 /* compute cbp */
248 cbp = get_cbp(s, block);
249
250 /* mvd indicates if this block is motion compensated */
251 mvd = motion_x | motion_y;
252
253 if ((cbp | mvd | s->dquant) == 0) {
254 /* skip macroblock */
255 s->skip_count++;
256 s->mb_skip_run++;
257 s->last_mv[0][0][0] = 0;
258 s->last_mv[0][0][1] = 0;
259 return;
260 }
261 }
262
263 /* MB is not skipped, encode MBA */
264 put_bits(&s->pb,
265 ff_h261_mba_bits[s->mb_skip_run],
266 ff_h261_mba_code[s->mb_skip_run]);
267 s->mb_skip_run = 0;
268
269 /* calculate MTYPE */
270 if (!s->mb_intra) {
271 h->mtype++;
272
273 if (mvd || s->loop_filter)
274 h->mtype += 3;
275 if (s->loop_filter)
276 h->mtype += 3;
277 if (cbp || s->dquant)
278 h->mtype++;
279 av_assert1(h->mtype > 1);
280 }
281
282 if (s->dquant)
283 h->mtype++;
284
285 put_bits(&s->pb,
286 ff_h261_mtype_bits[h->mtype],
287 ff_h261_mtype_code[h->mtype]);
288
289 h->mtype = ff_h261_mtype_map[h->mtype];
290
291 if (IS_QUANT(h->mtype)) {
292 ff_set_qscale(s, s->qscale + s->dquant);
293 put_bits(&s->pb, 5, s->qscale);
294 }
295
296 if (IS_16X16(h->mtype)) {
297 mv_diff_x = (motion_x >> 1) - s->last_mv[0][0][0];
298 mv_diff_y = (motion_y >> 1) - s->last_mv[0][0][1];
299 s->last_mv[0][0][0] = (motion_x >> 1);
300 s->last_mv[0][0][1] = (motion_y >> 1);
301 h261_encode_motion(h, mv_diff_x);
302 h261_encode_motion(h, mv_diff_y);
303 }
304
305 if (HAS_CBP(h->mtype)) {
306 av_assert1(cbp > 0);
307 put_bits(&s->pb,
308 ff_h261_cbp_tab[cbp - 1][1],
309 ff_h261_cbp_tab[cbp - 1][0]);
310 }
311 for (i = 0; i < 6; i++)
312 /* encode each block */
313 h261_encode_block(h, block[i], i);
314
315 if (!IS_16X16(h->mtype)) {
316 s->last_mv[0][0][0] = 0;
317 s->last_mv[0][0][1] = 0;
318 }
319}
320
321static av_cold void init_uni_h261_rl_tab(RLTable *rl, uint32_t *bits_tab,
322 uint8_t *len_tab)
323{
324 int slevel, run, last;
325
326 av_assert0(MAX_LEVEL >= 64);
327 av_assert0(MAX_RUN >= 63);
328
329 for(slevel=-64; slevel<64; slevel++){
330 if(slevel==0) continue;
331 for(run=0; run<64; run++){
332 for(last=0; last<=1; last++){
333 const int index= UNI_ENC_INDEX(last, run, slevel+64);
334 int level= slevel < 0 ? -slevel : slevel;
335 int len, code;
336
337 len_tab[index]= 100;
338
339 /* ESC0 */
340 code= get_rl_index(rl, 0, run, level);
341 len= rl->table_vlc[code][1] + 1;
342 if(last)
343 len += 2;
344
345 if(code!=rl->n && len < len_tab[index]){
346 len_tab [index]= len;
347 }
348 /* ESC */
349 len = rl->table_vlc[rl->n][1];
350 if(last)
351 len += 2;
352
353 if(len < len_tab[index]){
354 len_tab [index]= len;
355 }
356 }
357 }
358 }
359}
360
361av_cold void ff_h261_encode_init(MpegEncContext *s)
362{
363 ff_h261_common_init();
364
365 s->min_qcoeff = -127;
366 s->max_qcoeff = 127;
367 s->y_dc_scale_table =
368 s->c_dc_scale_table = ff_mpeg1_dc_scale_table;
369 s->ac_esc_length = 6+6+8;
370
371 init_uni_h261_rl_tab(&ff_h261_rl_tcoeff, NULL, uni_h261_rl_len);
372
373 s->intra_ac_vlc_length = s->inter_ac_vlc_length = uni_h261_rl_len;
374 s->intra_ac_vlc_last_length = s->inter_ac_vlc_last_length = uni_h261_rl_len + 128*64;
375}
376
377FF_MPV_GENERIC_CLASS(h261)
378
379AVCodec ff_h261_encoder = {
380 .name = "h261",
381 .long_name = NULL_IF_CONFIG_SMALL("H.261"),
382 .type = AVMEDIA_TYPE_VIDEO,
383 .id = AV_CODEC_ID_H261,
384 .priv_data_size = sizeof(H261Context),
385 .init = ff_mpv_encode_init,
386 .encode2 = ff_mpv_encode_picture,
387 .close = ff_mpv_encode_end,
388 .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P,
389 AV_PIX_FMT_NONE },
390 .priv_class = &h261_class,
391};