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-rw-r--r--libavcodec/h263.c1291
1 files changed, 1291 insertions, 0 deletions
diff --git a/libavcodec/h263.c b/libavcodec/h263.c
new file mode 100644
index 0000000000..35ecb15c2e
--- /dev/null
+++ b/libavcodec/h263.c
@@ -0,0 +1,1291 @@
+/*
+ * H263/MPEG4 backend for ffmpeg encoder and decoder
+ * Copyright (c) 2000,2001 Gerard Lantau.
+ * H263+ support for custom picture format.
+ * Copyright (c) 2001 Juan J. Sierralta P.
+ *
+ * This program is free software; you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation; either version 2 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, write to the Free Software
+ * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+#include <stdlib.h>
+#include <stdio.h>
+#include <string.h>
+#include "common.h"
+#include "dsputil.h"
+#include "avcodec.h"
+#include "mpegvideo.h"
+#include "h263data.h"
+#include "mpeg4data.h"
+
+#define NDEBUG
+#include <assert.h>
+
+static void h263_encode_block(MpegEncContext * s, DCTELEM * block,
+ int n);
+static void h263_encode_motion(MpegEncContext * s, int val);
+static void mpeg4_encode_block(MpegEncContext * s, DCTELEM * block,
+ int n);
+static int h263_decode_motion(MpegEncContext * s, int pred);
+static int h263_decode_block(MpegEncContext * s, DCTELEM * block,
+ int n, int coded);
+static int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
+ int n, int coded);
+
+int h263_get_picture_format(int width, int height)
+{
+ int format;
+
+ if (width == 128 && height == 96)
+ format = 1;
+ else if (width == 176 && height == 144)
+ format = 2;
+ else if (width == 352 && height == 288)
+ format = 3;
+ else if (width == 704 && height == 576)
+ format = 4;
+ else if (width == 1408 && height == 1152)
+ format = 5;
+ else
+ format = 7;
+ return format;
+}
+
+void h263_encode_picture_header(MpegEncContext * s, int picture_number)
+{
+ int format, umvplus;
+
+ align_put_bits(&s->pb);
+ put_bits(&s->pb, 22, 0x20);
+ put_bits(&s->pb, 8, ((s->picture_number * 30 * FRAME_RATE_BASE) /
+ s->frame_rate) & 0xff);
+
+ put_bits(&s->pb, 1, 1); /* marker */
+ put_bits(&s->pb, 1, 0); /* h263 id */
+ put_bits(&s->pb, 1, 0); /* split screen off */
+ put_bits(&s->pb, 1, 0); /* camera off */
+ put_bits(&s->pb, 1, 0); /* freeze picture release off */
+
+ if (!s->h263_plus) {
+ /* H.263v1 */
+ format = h263_get_picture_format(s->width, s->height);
+ put_bits(&s->pb, 3, format);
+ put_bits(&s->pb, 1, (s->pict_type == P_TYPE));
+ /* By now UMV IS DISABLED ON H.263v1, since the restrictions
+ of H.263v1 UMV implies to check the predicted MV after
+ calculation of the current MB to see if we're on the limits */
+ put_bits(&s->pb, 1, 0); /* unrestricted motion vector: off */
+ put_bits(&s->pb, 1, 0); /* SAC: off */
+ put_bits(&s->pb, 1, 0); /* advanced prediction mode: off */
+ put_bits(&s->pb, 1, 0); /* not PB frame */
+ put_bits(&s->pb, 5, s->qscale);
+ put_bits(&s->pb, 1, 0); /* Continuous Presence Multipoint mode: off */
+ } else {
+ /* H.263v2 */
+ /* H.263 Plus PTYPE */
+ put_bits(&s->pb, 3, 7);
+ put_bits(&s->pb,3,1); /* Update Full Extended PTYPE */
+ put_bits(&s->pb,3,6); /* Custom Source Format */
+ put_bits(&s->pb,1,0); /* Custom PCF: off */
+ umvplus = (s->pict_type == P_TYPE) && s->unrestricted_mv;
+ put_bits(&s->pb, 1, umvplus); /* Unrestricted Motion Vector */
+ put_bits(&s->pb,1,0); /* SAC: off */
+ put_bits(&s->pb,1,0); /* Advanced Prediction Mode: off */
+ put_bits(&s->pb,1,0); /* Advanced Intra Coding: off */
+ put_bits(&s->pb,1,0); /* Deblocking Filter: off */
+ put_bits(&s->pb,1,0); /* Slice Structured: off */
+ put_bits(&s->pb,1,0); /* Reference Picture Selection: off */
+ put_bits(&s->pb,1,0); /* Independent Segment Decoding: off */
+ put_bits(&s->pb,1,0); /* Alternative Inter VLC: off */
+ put_bits(&s->pb,1,0); /* Modified Quantization: off */
+ put_bits(&s->pb,1,1); /* "1" to prevent start code emulation */
+ put_bits(&s->pb,3,0); /* Reserved */
+
+ put_bits(&s->pb, 3, s->pict_type == P_TYPE);
+
+ put_bits(&s->pb,1,0); /* Reference Picture Resampling: off */
+ put_bits(&s->pb,1,0); /* Reduced-Resolution Update: off */
+ put_bits(&s->pb,1,0); /* Rounding Type */
+ put_bits(&s->pb,2,0); /* Reserved */
+ put_bits(&s->pb,1,1); /* "1" to prevent start code emulation */
+
+ /* This should be here if PLUSPTYPE */
+ put_bits(&s->pb, 1, 0); /* Continuous Presence Multipoint mode: off */
+
+ /* Custom Picture Format (CPFMT) */
+
+ put_bits(&s->pb,4,2); /* Aspect ratio: CIF 12:11 (4:3) picture */
+ put_bits(&s->pb,9,(s->width >> 2) - 1);
+ put_bits(&s->pb,1,1); /* "1" to prevent start code emulation */
+ put_bits(&s->pb,9,(s->height >> 2));
+ /* Unlimited Unrestricted Motion Vectors Indicator (UUI) */
+ if (umvplus)
+ put_bits(&s->pb,1,1); /* Limited according tables of Annex D */
+ put_bits(&s->pb, 5, s->qscale);
+ }
+
+ put_bits(&s->pb, 1, 0); /* no PEI */
+}
+
+void h263_encode_mb(MpegEncContext * s,
+ DCTELEM block[6][64],
+ int motion_x, int motion_y)
+{
+ int cbpc, cbpy, i, cbp, pred_x, pred_y;
+
+ // printf("**mb x=%d y=%d\n", s->mb_x, s->mb_y);
+ if (!s->mb_intra) {
+ /* compute cbp */
+ cbp = 0;
+ for (i = 0; i < 6; i++) {
+ if (s->block_last_index[i] >= 0)
+ cbp |= 1 << (5 - i);
+ }
+ if ((cbp | motion_x | motion_y) == 0) {
+ /* skip macroblock */
+ put_bits(&s->pb, 1, 1);
+ return;
+ }
+ put_bits(&s->pb, 1, 0); /* mb coded */
+ cbpc = cbp & 3;
+ put_bits(&s->pb,
+ inter_MCBPC_bits[cbpc],
+ inter_MCBPC_code[cbpc]);
+ cbpy = cbp >> 2;
+ cbpy ^= 0xf;
+ put_bits(&s->pb, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);
+
+ /* motion vectors: 16x16 mode only now */
+ h263_pred_motion(s, 0, &pred_x, &pred_y);
+
+ h263_encode_motion(s, motion_x - pred_x);
+ h263_encode_motion(s, motion_y - pred_y);
+ } else {
+ /* compute cbp */
+ cbp = 0;
+ for (i = 0; i < 6; i++) {
+ if (s->block_last_index[i] >= 1)
+ cbp |= 1 << (5 - i);
+ }
+
+ cbpc = cbp & 3;
+ if (s->pict_type == I_TYPE) {
+ put_bits(&s->pb,
+ intra_MCBPC_bits[cbpc],
+ intra_MCBPC_code[cbpc]);
+ } else {
+ put_bits(&s->pb, 1, 0); /* mb coded */
+ put_bits(&s->pb,
+ inter_MCBPC_bits[cbpc + 4],
+ inter_MCBPC_code[cbpc + 4]);
+ }
+ if (s->h263_pred) {
+ /* XXX: currently, we do not try to use ac prediction */
+ put_bits(&s->pb, 1, 0); /* no ac prediction */
+ }
+ cbpy = cbp >> 2;
+ put_bits(&s->pb, cbpy_tab[cbpy][1], cbpy_tab[cbpy][0]);
+ }
+
+ /* encode each block */
+ if (s->h263_pred) {
+ for (i = 0; i < 6; i++) {
+ mpeg4_encode_block(s, block[i], i);
+ }
+ } else {
+ for (i = 0; i < 6; i++) {
+ h263_encode_block(s, block[i], i);
+ }
+ }
+}
+
+static inline int mid_pred(int a, int b, int c)
+{
+ int vmin, vmax;
+ vmin = a;
+ if (b < vmin)
+ vmin = b;
+ if (c < vmin)
+ vmin = c;
+
+ vmax = a;
+ if (b > vmax)
+ vmax = b;
+ if (c > vmax)
+ vmax = c;
+
+ return a + b + c - vmin - vmax;
+}
+
+INT16 *h263_pred_motion(MpegEncContext * s, int block,
+ int *px, int *py)
+{
+ int x, y, wrap;
+ INT16 *A, *B, *C, *mot_val;
+
+ x = 2 * s->mb_x + 1 + (block & 1);
+ y = 2 * s->mb_y + 1 + ((block >> 1) & 1);
+ wrap = 2 * s->mb_width + 2;
+
+ mot_val = s->motion_val[(x) + (y) * wrap];
+
+ /* special case for first line */
+ if (y == 1 || s->first_slice_line) {
+ A = s->motion_val[(x-1) + (y) * wrap];
+ *px = A[0];
+ *py = A[1];
+ } else {
+ switch(block) {
+ default:
+ case 0:
+ A = s->motion_val[(x-1) + (y) * wrap];
+ B = s->motion_val[(x) + (y-1) * wrap];
+ C = s->motion_val[(x+2) + (y-1) * wrap];
+ break;
+ case 1:
+ case 2:
+ A = s->motion_val[(x-1) + (y) * wrap];
+ B = s->motion_val[(x) + (y-1) * wrap];
+ C = s->motion_val[(x+1) + (y-1) * wrap];
+ break;
+ case 3:
+ A = s->motion_val[(x-1) + (y) * wrap];
+ B = s->motion_val[(x-1) + (y-1) * wrap];
+ C = s->motion_val[(x) + (y-1) * wrap];
+ break;
+ }
+ *px = mid_pred(A[0], B[0], C[0]);
+ *py = mid_pred(A[1], B[1], C[1]);
+ }
+ return mot_val;
+}
+
+
+static void h263_encode_motion(MpegEncContext * s, int val)
+{
+ int range, l, m, bit_size, sign, code, bits;
+
+ if (val == 0) {
+ /* zero vector */
+ code = 0;
+ put_bits(&s->pb, mvtab[code][1], mvtab[code][0]);
+ } else {
+ bit_size = s->f_code - 1;
+ range = 1 << bit_size;
+ /* modulo encoding */
+ l = range * 32;
+ m = 2 * l;
+ if (val < -l) {
+ val += m;
+ } else if (val >= l) {
+ val -= m;
+ }
+
+ if (val >= 0) {
+ val--;
+ code = (val >> bit_size) + 1;
+ bits = val & (range - 1);
+ sign = 0;
+ } else {
+ val = -val;
+ val--;
+ code = (val >> bit_size) + 1;
+ bits = val & (range - 1);
+ sign = 1;
+ }
+
+ put_bits(&s->pb, mvtab[code][1] + 1, (mvtab[code][0] << 1) | sign);
+ if (bit_size > 0) {
+ put_bits(&s->pb, bit_size, bits);
+ }
+ }
+}
+
+void h263_encode_init_vlc(MpegEncContext *s)
+{
+ static int done = 0;
+
+ if (!done) {
+ done = 1;
+ init_rl(&rl_inter);
+ init_rl(&rl_intra);
+ }
+}
+
+static void h263_encode_block(MpegEncContext * s, DCTELEM * block, int n)
+{
+ int level, run, last, i, j, last_index, last_non_zero, sign, slevel;
+ int code;
+ RLTable *rl = &rl_inter;
+
+ if (s->mb_intra) {
+ /* DC coef */
+ level = block[0];
+ /* 255 cannot be represented, so we clamp */
+ if (level > 254) {
+ level = 254;
+ block[0] = 254;
+ }
+ if (level == 128)
+ put_bits(&s->pb, 8, 0xff);
+ else
+ put_bits(&s->pb, 8, level & 0xff);
+ i = 1;
+ } else {
+ i = 0;
+ }
+
+ /* AC coefs */
+ last_index = s->block_last_index[n];
+ last_non_zero = i - 1;
+ for (; i <= last_index; i++) {
+ j = zigzag_direct[i];
+ level = block[j];
+ if (level) {
+ run = i - last_non_zero - 1;
+ last = (i == last_index);
+ sign = 0;
+ slevel = level;
+ if (level < 0) {
+ sign = 1;
+ level = -level;
+ }
+ code = get_rl_index(rl, last, run, level);
+ put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
+ if (code == rl->n) {
+ put_bits(&s->pb, 1, last);
+ put_bits(&s->pb, 6, run);
+ put_bits(&s->pb, 8, slevel & 0xff);
+ } else {
+ put_bits(&s->pb, 1, sign);
+ }
+ last_non_zero = i;
+ }
+ }
+}
+
+/***************************************************/
+
+/* write mpeg4 VOP header */
+void mpeg4_encode_picture_header(MpegEncContext * s, int picture_number)
+{
+ align_put_bits(&s->pb);
+
+ put_bits(&s->pb, 32, 0x1B6); /* vop header */
+ put_bits(&s->pb, 2, s->pict_type - 1); /* pict type: I = 0 , P = 1 */
+ /* XXX: time base + 1 not always correct */
+ put_bits(&s->pb, 1, 1);
+ put_bits(&s->pb, 1, 0);
+
+ put_bits(&s->pb, 1, 1); /* marker */
+ put_bits(&s->pb, 4, 1); /* XXX: correct time increment */
+ put_bits(&s->pb, 1, 1); /* marker */
+ put_bits(&s->pb, 1, 1); /* vop coded */
+ if (s->pict_type == P_TYPE) {
+ s->no_rounding = 0;
+ put_bits(&s->pb, 1, s->no_rounding); /* rounding type */
+ }
+ put_bits(&s->pb, 3, 0); /* intra dc VLC threshold */
+
+ put_bits(&s->pb, 5, s->qscale);
+
+ if (s->pict_type != I_TYPE)
+ put_bits(&s->pb, 3, s->f_code); /* fcode_for */
+ // printf("****frame %d\n", picture_number);
+}
+
+void h263_dc_scale(MpegEncContext * s)
+{
+ int quant;
+
+ quant = s->qscale;
+ /* luminance */
+ if (quant < 5)
+ s->y_dc_scale = 8;
+ else if (quant > 4 && quant < 9)
+ s->y_dc_scale = (2 * quant);
+ else if (quant > 8 && quant < 25)
+ s->y_dc_scale = (quant + 8);
+ else
+ s->y_dc_scale = (2 * quant - 16);
+ /* chrominance */
+ if (quant < 5)
+ s->c_dc_scale = 8;
+ else if (quant > 4 && quant < 25)
+ s->c_dc_scale = ((quant + 13) / 2);
+ else
+ s->c_dc_scale = (quant - 6);
+}
+
+static int mpeg4_pred_dc(MpegEncContext * s, int n, UINT16 **dc_val_ptr, int *dir_ptr)
+{
+ int a, b, c, x, y, wrap, pred, scale;
+ UINT16 *dc_val;
+
+ /* find prediction */
+ if (n < 4) {
+ x = 2 * s->mb_x + 1 + (n & 1);
+ y = 2 * s->mb_y + 1 + ((n & 2) >> 1);
+ wrap = s->mb_width * 2 + 2;
+ dc_val = s->dc_val[0];
+ scale = s->y_dc_scale;
+ } else {
+ x = s->mb_x + 1;
+ y = s->mb_y + 1;
+ wrap = s->mb_width + 2;
+ dc_val = s->dc_val[n - 4 + 1];
+ scale = s->c_dc_scale;
+ }
+
+ /* B C
+ * A X
+ */
+ a = dc_val[(x - 1) + (y) * wrap];
+ b = dc_val[(x - 1) + (y - 1) * wrap];
+ c = dc_val[(x) + (y - 1) * wrap];
+
+ if (abs(a - b) < abs(b - c)) {
+ pred = c;
+ *dir_ptr = 1; /* top */
+ } else {
+ pred = a;
+ *dir_ptr = 0; /* left */
+ }
+ /* we assume pred is positive */
+ pred = (pred + (scale >> 1)) / scale;
+
+ /* prepare address for prediction update */
+ *dc_val_ptr = &dc_val[(x) + (y) * wrap];
+
+ return pred;
+}
+
+void mpeg4_pred_ac(MpegEncContext * s, INT16 *block, int n,
+ int dir)
+{
+ int x, y, wrap, i;
+ INT16 *ac_val, *ac_val1;
+
+ /* find prediction */
+ if (n < 4) {
+ x = 2 * s->mb_x + 1 + (n & 1);
+ y = 2 * s->mb_y + 1 + ((n & 2) >> 1);
+ wrap = s->mb_width * 2 + 2;
+ ac_val = s->ac_val[0][0];
+ } else {
+ x = s->mb_x + 1;
+ y = s->mb_y + 1;
+ wrap = s->mb_width + 2;
+ ac_val = s->ac_val[n - 4 + 1][0];
+ }
+ ac_val += ((y) * wrap + (x)) * 16;
+ ac_val1 = ac_val;
+ if (s->ac_pred) {
+ if (dir == 0) {
+ /* left prediction */
+ ac_val -= 16;
+ for(i=1;i<8;i++) {
+ block[i*8] += ac_val[i];
+ }
+ } else {
+ /* top prediction */
+ ac_val -= 16 * wrap;
+ for(i=1;i<8;i++) {
+ block[i] += ac_val[i + 8];
+ }
+ }
+ }
+ /* left copy */
+ for(i=1;i<8;i++)
+ ac_val1[i] = block[i * 8];
+ /* top copy */
+ for(i=1;i<8;i++)
+ ac_val1[8 + i] = block[i];
+}
+
+static inline void mpeg4_encode_dc(MpegEncContext * s, int level, int n, int *dir_ptr)
+{
+ int size, v, pred;
+ UINT16 *dc_val;
+
+ pred = mpeg4_pred_dc(s, n, &dc_val, dir_ptr);
+ if (n < 4) {
+ *dc_val = level * s->y_dc_scale;
+ } else {
+ *dc_val = level * s->c_dc_scale;
+ }
+
+ /* do the prediction */
+ level -= pred;
+ /* find number of bits */
+ size = 0;
+ v = abs(level);
+ while (v) {
+ v >>= 1;
+ size++;
+ }
+
+ if (n < 4) {
+ /* luminance */
+ put_bits(&s->pb, DCtab_lum[size][1], DCtab_lum[size][0]);
+ } else {
+ /* chrominance */
+ put_bits(&s->pb, DCtab_chrom[size][1], DCtab_chrom[size][0]);
+ }
+
+ /* encode remaining bits */
+ if (size > 0) {
+ if (level < 0)
+ level = (-level) ^ ((1 << size) - 1);
+ put_bits(&s->pb, size, level);
+ if (size > 8)
+ put_bits(&s->pb, 1, 1);
+ }
+}
+
+static void mpeg4_encode_block(MpegEncContext * s, DCTELEM * block, int n)
+{
+ int level, run, last, i, j, last_index, last_non_zero, sign, slevel;
+ int code, dc_pred_dir;
+ const RLTable *rl;
+
+ if (s->mb_intra) {
+ /* mpeg4 based DC predictor */
+ mpeg4_encode_dc(s, block[0], n, &dc_pred_dir);
+ i = 1;
+ rl = &rl_intra;
+ } else {
+ i = 0;
+ rl = &rl_inter;
+ }
+
+ /* AC coefs */
+ last_index = s->block_last_index[n];
+ last_non_zero = i - 1;
+ for (; i <= last_index; i++) {
+ j = zigzag_direct[i];
+ level = block[j];
+ if (level) {
+ run = i - last_non_zero - 1;
+ last = (i == last_index);
+ sign = 0;
+ slevel = level;
+ if (level < 0) {
+ sign = 1;
+ level = -level;
+ }
+ code = get_rl_index(rl, last, run, level);
+ put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
+ if (code == rl->n) {
+ int level1, run1;
+ level1 = level - rl->max_level[last][run];
+ if (level1 < 1)
+ goto esc2;
+ code = get_rl_index(rl, last, run, level1);
+ if (code == rl->n) {
+ esc2:
+ put_bits(&s->pb, 1, 1);
+ if (level > MAX_LEVEL)
+ goto esc3;
+ run1 = run - rl->max_run[last][level] - 1;
+ if (run1 < 0)
+ goto esc3;
+ code = get_rl_index(rl, last, run1, level);
+ if (code == rl->n) {
+ esc3:
+ /* third escape */
+ put_bits(&s->pb, 1, 1);
+ put_bits(&s->pb, 1, last);
+ put_bits(&s->pb, 6, run);
+ put_bits(&s->pb, 1, 1);
+ put_bits(&s->pb, 12, slevel & 0xfff);
+ put_bits(&s->pb, 1, 1);
+ } else {
+ /* second escape */
+ put_bits(&s->pb, 1, 0);
+ put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
+ put_bits(&s->pb, 1, sign);
+ }
+ } else {
+ /* first escape */
+ put_bits(&s->pb, 1, 0);
+ put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
+ put_bits(&s->pb, 1, sign);
+ }
+ } else {
+ put_bits(&s->pb, 1, sign);
+ }
+ last_non_zero = i;
+ }
+ }
+}
+
+
+
+/***********************************************/
+/* decoding */
+
+static VLC intra_MCBPC_vlc;
+static VLC inter_MCBPC_vlc;
+static VLC cbpy_vlc;
+static VLC mv_vlc;
+static VLC dc_lum, dc_chrom;
+
+void init_rl(RLTable *rl)
+{
+ INT8 max_level[MAX_RUN+1], max_run[MAX_LEVEL+1];
+ UINT8 index_run[MAX_RUN+1];
+ int last, run, level, start, end, i;
+
+ /* compute max_level[], max_run[] and index_run[] */
+ for(last=0;last<2;last++) {
+ if (last == 0) {
+ start = 0;
+ end = rl->last;
+ } else {
+ start = rl->last;
+ end = rl->n;
+ }
+
+ memset(max_level, 0, MAX_RUN + 1);
+ memset(max_run, 0, MAX_LEVEL + 1);
+ memset(index_run, rl->n, MAX_RUN + 1);
+ for(i=start;i<end;i++) {
+ run = rl->table_run[i];
+ level = rl->table_level[i];
+ if (index_run[run] == rl->n)
+ index_run[run] = i;
+ if (level > max_level[run])
+ max_level[run] = level;
+ if (run > max_run[level])
+ max_run[level] = run;
+ }
+ rl->max_level[last] = malloc(MAX_RUN + 1);
+ memcpy(rl->max_level[last], max_level, MAX_RUN + 1);
+ rl->max_run[last] = malloc(MAX_LEVEL + 1);
+ memcpy(rl->max_run[last], max_run, MAX_LEVEL + 1);
+ rl->index_run[last] = malloc(MAX_RUN + 1);
+ memcpy(rl->index_run[last], index_run, MAX_RUN + 1);
+ }
+}
+
+void init_vlc_rl(RLTable *rl)
+{
+ init_vlc(&rl->vlc, 9, rl->n + 1,
+ &rl->table_vlc[0][1], 4, 2,
+ &rl->table_vlc[0][0], 4, 2);
+}
+
+/* init vlcs */
+
+/* XXX: find a better solution to handle static init */
+void h263_decode_init_vlc(MpegEncContext *s)
+{
+ static int done = 0;
+
+ if (!done) {
+ done = 1;
+
+ init_vlc(&intra_MCBPC_vlc, 6, 8,
+ intra_MCBPC_bits, 1, 1,
+ intra_MCBPC_code, 1, 1);
+ init_vlc(&inter_MCBPC_vlc, 9, 20,
+ inter_MCBPC_bits, 1, 1,
+ inter_MCBPC_code, 1, 1);
+ init_vlc(&cbpy_vlc, 6, 16,
+ &cbpy_tab[0][1], 2, 1,
+ &cbpy_tab[0][0], 2, 1);
+ init_vlc(&mv_vlc, 9, 33,
+ &mvtab[0][1], 2, 1,
+ &mvtab[0][0], 2, 1);
+ init_rl(&rl_inter);
+ init_rl(&rl_intra);
+ init_vlc_rl(&rl_inter);
+ init_vlc_rl(&rl_intra);
+ init_vlc(&dc_lum, 9, 13,
+ &DCtab_lum[0][1], 2, 1,
+ &DCtab_lum[0][0], 2, 1);
+ init_vlc(&dc_chrom, 9, 13,
+ &DCtab_chrom[0][1], 2, 1,
+ &DCtab_chrom[0][0], 2, 1);
+ }
+}
+
+int h263_decode_mb(MpegEncContext *s,
+ DCTELEM block[6][64])
+{
+ int cbpc, cbpy, i, cbp, pred_x, pred_y, mx, my, dquant;
+ INT16 *mot_val;
+ static UINT8 quant_tab[4] = { -1, -2, 1, 2 };
+
+ if (s->pict_type == P_TYPE) {
+ if (get_bits(&s->gb, 1)) {
+ /* skip mb */
+ s->mb_intra = 0;
+ for(i=0;i<6;i++)
+ s->block_last_index[i] = -1;
+ s->mv_dir = MV_DIR_FORWARD;
+ s->mv_type = MV_TYPE_16X16;
+ s->mv[0][0][0] = 0;
+ s->mv[0][0][1] = 0;
+ return 0;
+ }
+ cbpc = get_vlc(&s->gb, &inter_MCBPC_vlc);
+ if (cbpc < 0)
+ return -1;
+ dquant = cbpc & 8;
+ s->mb_intra = ((cbpc & 4) != 0);
+ } else {
+ cbpc = get_vlc(&s->gb, &intra_MCBPC_vlc);
+ if (cbpc < 0)
+ return -1;
+ dquant = cbpc & 4;
+ s->mb_intra = 1;
+ }
+
+ if (!s->mb_intra) {
+ cbpy = get_vlc(&s->gb, &cbpy_vlc);
+ cbp = (cbpc & 3) | ((cbpy ^ 0xf) << 2);
+ if (dquant) {
+ s->qscale += quant_tab[get_bits(&s->gb, 2)];
+ if (s->qscale < 1)
+ s->qscale = 1;
+ else if (s->qscale > 31)
+ s->qscale = 31;
+ }
+ s->mv_dir = MV_DIR_FORWARD;
+ if ((cbpc & 16) == 0) {
+ /* 16x16 motion prediction */
+ s->mv_type = MV_TYPE_16X16;
+ h263_pred_motion(s, 0, &pred_x, &pred_y);
+ mx = h263_decode_motion(s, pred_x);
+ if (mx >= 0xffff)
+ return -1;
+ my = h263_decode_motion(s, pred_y);
+ if (my >= 0xffff)
+ return -1;
+ s->mv[0][0][0] = mx;
+ s->mv[0][0][1] = my;
+ } else {
+ s->mv_type = MV_TYPE_8X8;
+ for(i=0;i<4;i++) {
+ mot_val = h263_pred_motion(s, i, &pred_x, &pred_y);
+ mx = h263_decode_motion(s, pred_x);
+ if (mx >= 0xffff)
+ return -1;
+ my = h263_decode_motion(s, pred_y);
+ if (my >= 0xffff)
+ return -1;
+ s->mv[0][i][0] = mx;
+ s->mv[0][i][1] = my;
+ mot_val[0] = mx;
+ mot_val[1] = my;
+ }
+ }
+ } else {
+ s->ac_pred = 0;
+ if (s->h263_pred) {
+ s->ac_pred = get_bits(&s->gb, 1);
+ }
+ cbpy = get_vlc(&s->gb, &cbpy_vlc);
+ cbp = (cbpc & 3) | (cbpy << 2);
+ if (dquant) {
+ s->qscale += quant_tab[get_bits(&s->gb, 2)];
+ if (s->qscale < 1)
+ s->qscale = 1;
+ else if (s->qscale > 31)
+ s->qscale = 31;
+ }
+ }
+
+ /* decode each block */
+ if (s->h263_pred) {
+ for (i = 0; i < 6; i++) {
+ if (mpeg4_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1) < 0)
+ return -1;
+ }
+ } else {
+ for (i = 0; i < 6; i++) {
+ if (h263_decode_block(s, block[i], i, (cbp >> (5 - i)) & 1) < 0)
+ return -1;
+ }
+ }
+ return 0;
+}
+
+static int h263_decode_motion(MpegEncContext * s, int pred)
+{
+ int code, val, sign, shift, l, m;
+
+ code = get_vlc(&s->gb, &mv_vlc);
+ if (code < 0)
+ return 0xffff;
+
+ if (code == 0)
+ return pred;
+ sign = get_bits(&s->gb, 1);
+ shift = s->f_code - 1;
+ val = (code - 1) << shift;
+ if (shift > 0)
+ val |= get_bits(&s->gb, shift);
+ val++;
+ if (sign)
+ val = -val;
+ val += pred;
+
+ /* modulo decoding */
+ if (!s->h263_long_vectors) {
+ l = (1 << (s->f_code - 1)) * 32;
+ m = 2 * l;
+ if (val < -l) {
+ val += m;
+ } else if (val >= l) {
+ val -= m;
+ }
+ } else {
+ /* horrible h263 long vector mode */
+ if (pred < -31 && val < -63)
+ val += 64;
+ if (pred > 32 && val > 63)
+ val -= 64;
+ }
+ return val;
+}
+
+static int h263_decode_block(MpegEncContext * s, DCTELEM * block,
+ int n, int coded)
+{
+ int code, level, i, j, last, run;
+ RLTable *rl = &rl_inter;
+
+ if (s->mb_intra) {
+ /* DC coef */
+ if (s->h263_rv10 && s->rv10_version == 3 && s->pict_type == I_TYPE) {
+ int component, diff;
+ component = (n <= 3 ? 0 : n - 4 + 1);
+ level = s->last_dc[component];
+ if (s->rv10_first_dc_coded[component]) {
+ diff = rv_decode_dc(s, n);
+ if (diff == 0xffff)
+ return -1;
+ level += diff;
+ level = level & 0xff; /* handle wrap round */
+ s->last_dc[component] = level;
+ } else {
+ s->rv10_first_dc_coded[component] = 1;
+ }
+ } else {
+ level = get_bits(&s->gb, 8);
+ if (level == 255)
+ level = 128;
+ }
+ block[0] = level;
+ i = 1;
+ } else {
+ i = 0;
+ }
+ if (!coded) {
+ s->block_last_index[n] = i - 1;
+ return 0;
+ }
+
+ for(;;) {
+ code = get_vlc(&s->gb, &rl->vlc);
+ if (code < 0)
+ return -1;
+ if (code == rl->n) {
+ /* escape */
+ last = get_bits(&s->gb, 1);
+ run = get_bits(&s->gb, 6);
+ level = (INT8)get_bits(&s->gb, 8);
+ if (s->h263_rv10 && level == -128) {
+ /* XXX: should patch encoder too */
+ level = get_bits(&s->gb, 12);
+ level = (level << 20) >> 20;
+ }
+ } else {
+ run = rl->table_run[code];
+ level = rl->table_level[code];
+ last = code >= rl->last;
+ if (get_bits(&s->gb, 1))
+ level = -level;
+ }
+ i += run;
+ if (i >= 64)
+ return -1;
+ j = zigzag_direct[i];
+ block[j] = level;
+ if (last)
+ break;
+ i++;
+ }
+ s->block_last_index[n] = i;
+ return 0;
+}
+
+static int mpeg4_decode_dc(MpegEncContext * s, int n, int *dir_ptr)
+{
+ int level, pred, code;
+ UINT16 *dc_val;
+
+ if (n < 4)
+ code = get_vlc(&s->gb, &dc_lum);
+ else
+ code = get_vlc(&s->gb, &dc_chrom);
+ if (code < 0)
+ return -1;
+ if (code == 0) {
+ level = 0;
+ } else {
+ level = get_bits(&s->gb, code);
+ if ((level >> (code - 1)) == 0) /* if MSB not set it is negative*/
+ level = - (level ^ ((1 << code) - 1));
+ if (code > 8)
+ get_bits(&s->gb, 1); /* marker */
+ }
+
+ pred = mpeg4_pred_dc(s, n, &dc_val, dir_ptr);
+ level += pred;
+ if (level < 0)
+ level = 0;
+ if (n < 4) {
+ *dc_val = level * s->y_dc_scale;
+ } else {
+ *dc_val = level * s->c_dc_scale;
+ }
+ return level;
+}
+
+static int mpeg4_decode_block(MpegEncContext * s, DCTELEM * block,
+ int n, int coded)
+{
+ int code, level, i, j, last, run;
+ int dc_pred_dir;
+ RLTable *rl;
+ const UINT8 *scan_table;
+
+ if (s->mb_intra) {
+ /* DC coef */
+ level = mpeg4_decode_dc(s, n, &dc_pred_dir);
+ if (level < 0)
+ return -1;
+ block[0] = level;
+ i = 1;
+ if (!coded)
+ goto not_coded;
+ rl = &rl_intra;
+ if (s->ac_pred) {
+ if (dc_pred_dir == 0)
+ scan_table = ff_alternate_vertical_scan; /* left */
+ else
+ scan_table = ff_alternate_horizontal_scan; /* top */
+ } else {
+ scan_table = zigzag_direct;
+ }
+ } else {
+ i = 0;
+ if (!coded) {
+ s->block_last_index[n] = i - 1;
+ return 0;
+ }
+ rl = &rl_inter;
+ scan_table = zigzag_direct;
+ }
+
+ for(;;) {
+ code = get_vlc(&s->gb, &rl->vlc);
+ if (code < 0)
+ return -1;
+ if (code == rl->n) {
+ /* escape */
+ if (get_bits(&s->gb, 1) != 0) {
+ if (get_bits(&s->gb, 1) != 0) {
+ /* third escape */
+ last = get_bits(&s->gb, 1);
+ run = get_bits(&s->gb, 6);
+ get_bits(&s->gb, 1); /* marker */
+ level = get_bits(&s->gb, 12);
+ level = (level << 20) >> 20; /* sign extend */
+ get_bits(&s->gb, 1); /* marker */
+ } else {
+ /* second escape */
+ code = get_vlc(&s->gb, &rl->vlc);
+ if (code < 0 || code >= rl->n)
+ return -1;
+ run = rl->table_run[code];
+ level = rl->table_level[code];
+ last = code >= rl->last;
+ run += rl->max_run[last][level] + 1;
+ if (get_bits(&s->gb, 1))
+ level = -level;
+ }
+ } else {
+ /* first escape */
+ code = get_vlc(&s->gb, &rl->vlc);
+ if (code < 0 || code >= rl->n)
+ return -1;
+ run = rl->table_run[code];
+ level = rl->table_level[code];
+ last = code >= rl->last;
+ level += rl->max_level[last][run];
+ if (get_bits(&s->gb, 1))
+ level = -level;
+ }
+ } else {
+ run = rl->table_run[code];
+ level = rl->table_level[code];
+ last = code >= rl->last;
+ if (get_bits(&s->gb, 1))
+ level = -level;
+ }
+ i += run;
+ if (i >= 64)
+ return -1;
+ j = scan_table[i];
+ block[j] = level;
+ i++;
+ if (last)
+ break;
+ }
+ not_coded:
+ if (s->mb_intra) {
+ mpeg4_pred_ac(s, block, n, dc_pred_dir);
+ if (s->ac_pred) {
+ i = 64; /* XXX: not optimal */
+ }
+ }
+ s->block_last_index[n] = i - 1;
+ return 0;
+}
+
+/* most is hardcoded. should extend to handle all h263 streams */
+int h263_decode_picture_header(MpegEncContext *s)
+{
+ int format, width, height;
+
+ /* picture header */
+ if (get_bits(&s->gb, 22) != 0x20)
+ return -1;
+ get_bits(&s->gb, 8); /* picture timestamp */
+
+ if (get_bits(&s->gb, 1) != 1)
+ return -1; /* marker */
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* h263 id */
+ get_bits(&s->gb, 1); /* split screen off */
+ get_bits(&s->gb, 1); /* camera off */
+ get_bits(&s->gb, 1); /* freeze picture release off */
+
+ format = get_bits(&s->gb, 3);
+
+ if (format != 7) {
+ s->h263_plus = 0;
+ /* H.263v1 */
+ width = h263_format[format][0];
+ height = h263_format[format][1];
+ if (!width)
+ return -1;
+
+ s->pict_type = I_TYPE + get_bits(&s->gb, 1);
+
+ s->unrestricted_mv = get_bits(&s->gb, 1);
+ s->h263_long_vectors = s->unrestricted_mv;
+
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* SAC: off */
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* advanced prediction mode: off */
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* not PB frame */
+
+ s->qscale = get_bits(&s->gb, 5);
+ get_bits(&s->gb, 1); /* Continuous Presence Multipoint mode: off */
+ } else {
+ s->h263_plus = 1;
+ /* H.263v2 */
+ if (get_bits(&s->gb, 3) != 1)
+ return -1;
+ if (get_bits(&s->gb, 3) != 6) /* custom source format */
+ return -1;
+ get_bits(&s->gb, 12);
+ get_bits(&s->gb, 3);
+ s->pict_type = get_bits(&s->gb, 3) + 1;
+ if (s->pict_type != I_TYPE &&
+ s->pict_type != P_TYPE)
+ return -1;
+ get_bits(&s->gb, 7);
+ get_bits(&s->gb, 4); /* aspect ratio */
+ width = (get_bits(&s->gb, 9) + 1) * 4;
+ get_bits(&s->gb, 1);
+ height = get_bits(&s->gb, 9) * 4;
+ if (height == 0)
+ return -1;
+ s->qscale = get_bits(&s->gb, 5);
+ }
+ /* PEI */
+ while (get_bits(&s->gb, 1) != 0) {
+ get_bits(&s->gb, 8);
+ }
+ s->f_code = 1;
+ s->width = width;
+ s->height = height;
+ return 0;
+}
+
+/* decode mpeg4 VOP header */
+int mpeg4_decode_picture_header(MpegEncContext * s)
+{
+ int time_incr, startcode, state, v;
+
+ redo:
+ /* search next start code */
+ align_get_bits(&s->gb);
+ state = 0xff;
+ for(;;) {
+ v = get_bits(&s->gb, 8);
+ if (state == 0x000001) {
+ state = ((state << 8) | v) & 0xffffff;
+ startcode = state;
+ break;
+ }
+ state = ((state << 8) | v) & 0xffffff;
+ /* XXX: really detect end of frame */
+ if (state == 0)
+ return -1;
+ }
+
+ if (startcode == 0x120) {
+ int time_increment_resolution, width, height;
+
+ /* vol header */
+ get_bits(&s->gb, 1); /* random access */
+ get_bits(&s->gb, 8); /* vo_type */
+ get_bits(&s->gb, 1); /* is_ol_id */
+ get_bits(&s->gb, 4); /* vo_ver_id */
+ get_bits(&s->gb, 3); /* vo_priority */
+
+ get_bits(&s->gb, 4); /* aspect_ratio_info */
+ get_bits(&s->gb, 1); /* vol control parameter */
+ get_bits(&s->gb, 2); /* vol shape */
+ get_bits(&s->gb, 1); /* marker */
+
+ time_increment_resolution = get_bits(&s->gb, 16);
+ s->time_increment_bits = log2(time_increment_resolution - 1) + 1;
+ get_bits(&s->gb, 1); /* marker */
+
+ get_bits(&s->gb, 1); /* vop rate */
+ get_bits(&s->gb, s->time_increment_bits);
+ get_bits(&s->gb, 1); /* marker */
+
+ width = get_bits(&s->gb, 13);
+ get_bits(&s->gb, 1); /* marker */
+ height = get_bits(&s->gb, 13);
+ get_bits(&s->gb, 1); /* marker */
+
+ get_bits(&s->gb, 1); /* interfaced */
+ get_bits(&s->gb, 1); /* OBMC */
+ get_bits(&s->gb, 2); /* vol_sprite_usage */
+ get_bits(&s->gb, 1); /* not_8_bit */
+
+ get_bits(&s->gb, 1); /* vol_quant_type */
+ get_bits(&s->gb, 1); /* vol_quarter_pixel */
+ get_bits(&s->gb, 1); /* complexity_estimation_disabled */
+ get_bits(&s->gb, 1); /* resync_marker_disabled */
+ get_bits(&s->gb, 1); /* data_partioning_enabled */
+ goto redo;
+ } else if (startcode != 0x1b6) {
+ goto redo;
+ }
+
+ s->pict_type = get_bits(&s->gb, 2) + 1; /* pict type: I = 0 , P = 1 */
+ if (s->pict_type != I_TYPE &&
+ s->pict_type != P_TYPE)
+ return -1;
+
+ /* XXX: parse time base */
+ time_incr = 0;
+ while (get_bits(&s->gb, 1) != 0)
+ time_incr++;
+
+ get_bits(&s->gb, 1); /* marker */
+ get_bits(&s->gb, s->time_increment_bits);
+ get_bits(&s->gb, 1); /* marker */
+ /* vop coded */
+ if (get_bits(&s->gb, 1) != 1)
+ return -1;
+
+ if (s->pict_type == P_TYPE) {
+ /* rounding type for motion estimation */
+ s->no_rounding = get_bits(&s->gb, 1);
+ }
+
+ if (get_bits(&s->gb, 3) != 0)
+ return -1; /* intra dc VLC threshold */
+
+ s->qscale = get_bits(&s->gb, 5);
+
+ if (s->pict_type != I_TYPE) {
+ s->f_code = get_bits(&s->gb, 3); /* fcode_for */
+ }
+ return 0;
+}
+
+/* don't understand why they choose a different header ! */
+int intel_h263_decode_picture_header(MpegEncContext *s)
+{
+ int format;
+
+ /* picture header */
+ if (get_bits(&s->gb, 22) != 0x20)
+ return -1;
+ get_bits(&s->gb, 8); /* picture timestamp */
+
+ if (get_bits(&s->gb, 1) != 1)
+ return -1; /* marker */
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* h263 id */
+ get_bits(&s->gb, 1); /* split screen off */
+ get_bits(&s->gb, 1); /* camera off */
+ get_bits(&s->gb, 1); /* freeze picture release off */
+
+ format = get_bits(&s->gb, 3);
+ if (format != 7)
+ return -1;
+
+ s->h263_plus = 0;
+
+ s->pict_type = I_TYPE + get_bits(&s->gb, 1);
+
+ s->unrestricted_mv = get_bits(&s->gb, 1);
+ s->h263_long_vectors = s->unrestricted_mv;
+
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* SAC: off */
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* advanced prediction mode: off */
+ if (get_bits(&s->gb, 1) != 0)
+ return -1; /* not PB frame */
+
+ /* skip unknown header garbage */
+ get_bits(&s->gb, 41);
+
+ s->qscale = get_bits(&s->gb, 5);
+ get_bits(&s->gb, 1); /* Continuous Presence Multipoint mode: off */
+
+ /* PEI */
+ while (get_bits(&s->gb, 1) != 0) {
+ get_bits(&s->gb, 8);
+ }
+ s->f_code = 1;
+ return 0;
+}
generated by cgit v1.2.3 (git 2.39.1) at 2024-06-11 23:11:36 +0000