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-rw-r--r--libavcodec/mpeg12.c1530
1 files changed, 1530 insertions, 0 deletions
diff --git a/libavcodec/mpeg12.c b/libavcodec/mpeg12.c
new file mode 100644
index 0000000000..3e2e523560
--- /dev/null
+++ b/libavcodec/mpeg12.c
@@ -0,0 +1,1530 @@
+/*
+ * MPEG1 encoder / MPEG2 decoder
+ * Copyright (c) 2000,2001 Gerard Lantau.
+ *
+ * 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 "avcodec.h"
+#include "dsputil.h"
+#include "mpegvideo.h"
+
+#include "mpeg12data.h"
+
+//#define DEBUG
+
+#ifdef DEBUG
+#define dprintf(fmt,args...) printf(fmt, ## args)
+#else
+#define dprintf(fmt,args...)
+#endif
+
+/* Start codes. */
+#define SEQ_END_CODE 0x000001b7
+#define SEQ_START_CODE 0x000001b3
+#define GOP_START_CODE 0x000001b8
+#define PICTURE_START_CODE 0x00000100
+#define SLICE_MIN_START_CODE 0x00000101
+#define SLICE_MAX_START_CODE 0x000001af
+#define EXT_START_CODE 0x000001b5
+#define USER_START_CODE 0x000001b2
+
+static void mpeg1_encode_block(MpegEncContext *s,
+ DCTELEM *block,
+ int component);
+static void mpeg1_encode_motion(MpegEncContext *s, int val);
+static void mpeg1_skip_picture(MpegEncContext *s, int pict_num);
+static int mpeg1_decode_block(MpegEncContext *s,
+ DCTELEM *block,
+ int n);
+static int mpeg2_decode_block_non_intra(MpegEncContext *s,
+ DCTELEM *block,
+ int n);
+static int mpeg2_decode_block_intra(MpegEncContext *s,
+ DCTELEM *block,
+ int n);
+static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred);
+
+static void put_header(MpegEncContext *s, int header)
+{
+ align_put_bits(&s->pb);
+ put_bits(&s->pb, 32, header);
+}
+
+/* put sequence header if needed */
+static void mpeg1_encode_sequence_header(MpegEncContext *s)
+{
+ unsigned int vbv_buffer_size;
+ unsigned int fps, n, v;
+ UINT64 time_code;
+
+ if ((s->picture_number % s->gop_size) == 0) {
+ /* mpeg1 header repeated every gop */
+ put_header(s, SEQ_START_CODE);
+
+ /* search closest frame rate */
+ {
+ int i, dmin, d;
+ s->frame_rate_index = 0;
+ dmin = 0x7fffffff;
+ for(i=1;i<9;i++) {
+ d = abs(s->frame_rate - frame_rate_tab[i]);
+ if (d < dmin) {
+ dmin = d;
+ s->frame_rate_index = i;
+ }
+ }
+ }
+
+ put_bits(&s->pb, 12, s->width);
+ put_bits(&s->pb, 12, s->height);
+ put_bits(&s->pb, 4, 1); /* 1/1 aspect ratio */
+ put_bits(&s->pb, 4, s->frame_rate_index);
+ v = s->bit_rate / 400;
+ if (v > 0x3ffff)
+ v = 0x3ffff;
+ put_bits(&s->pb, 18, v);
+ put_bits(&s->pb, 1, 1); /* marker */
+ /* vbv buffer size: slightly greater than an I frame. We add
+ some margin just in case */
+ vbv_buffer_size = (3 * s->I_frame_bits) / (2 * 8);
+ put_bits(&s->pb, 10, (vbv_buffer_size + 16383) / 16384);
+ put_bits(&s->pb, 1, 1); /* constrained parameter flag */
+ put_bits(&s->pb, 1, 0); /* no custom intra matrix */
+ put_bits(&s->pb, 1, 0); /* no custom non intra matrix */
+
+ put_header(s, GOP_START_CODE);
+ put_bits(&s->pb, 1, 0); /* do drop frame */
+ /* time code : we must convert from the real frame rate to a
+ fake mpeg frame rate in case of low frame rate */
+ fps = frame_rate_tab[s->frame_rate_index];
+ time_code = s->fake_picture_number * FRAME_RATE_BASE;
+ s->gop_picture_number = s->fake_picture_number;
+ put_bits(&s->pb, 5, (time_code / (fps * 3600)) % 24);
+ put_bits(&s->pb, 6, (time_code / (fps * 60)) % 60);
+ put_bits(&s->pb, 1, 1);
+ put_bits(&s->pb, 6, (time_code / fps) % 60);
+ put_bits(&s->pb, 6, (time_code % fps) / FRAME_RATE_BASE);
+ put_bits(&s->pb, 1, 1); /* closed gop */
+ put_bits(&s->pb, 1, 0); /* broken link */
+ }
+
+ if (s->frame_rate < (24 * FRAME_RATE_BASE) && s->picture_number > 0) {
+ /* insert empty P pictures to slow down to the desired
+ frame rate. Each fake pictures takes about 20 bytes */
+ fps = frame_rate_tab[s->frame_rate_index];
+ n = ((s->picture_number * fps) / s->frame_rate) - 1;
+ while (s->fake_picture_number < n) {
+ mpeg1_skip_picture(s, s->fake_picture_number -
+ s->gop_picture_number);
+ s->fake_picture_number++;
+ }
+
+ }
+ s->fake_picture_number++;
+}
+
+
+/* insert a fake P picture */
+static void mpeg1_skip_picture(MpegEncContext *s, int pict_num)
+{
+ unsigned int mb_incr;
+
+ /* mpeg1 picture header */
+ put_header(s, PICTURE_START_CODE);
+ /* temporal reference */
+ put_bits(&s->pb, 10, pict_num & 0x3ff);
+
+ put_bits(&s->pb, 3, P_TYPE);
+ put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
+
+ put_bits(&s->pb, 1, 1); /* integer coordinates */
+ put_bits(&s->pb, 3, 1); /* forward_f_code */
+
+ put_bits(&s->pb, 1, 0); /* extra bit picture */
+
+ /* only one slice */
+ put_header(s, SLICE_MIN_START_CODE);
+ put_bits(&s->pb, 5, 1); /* quantizer scale */
+ put_bits(&s->pb, 1, 0); /* slice extra information */
+
+ mb_incr = 1;
+ put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
+ mbAddrIncrTable[mb_incr - 1][0]);
+
+ /* empty macroblock */
+ put_bits(&s->pb, 3, 1); /* motion only */
+
+ /* zero motion x & y */
+ put_bits(&s->pb, 1, 1);
+ put_bits(&s->pb, 1, 1);
+
+ /* output a number of empty slice */
+ mb_incr = s->mb_width * s->mb_height - 1;
+ while (mb_incr > 33) {
+ put_bits(&s->pb, 11, 0x008);
+ mb_incr -= 33;
+ }
+ put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
+ mbAddrIncrTable[mb_incr - 1][0]);
+
+ /* empty macroblock */
+ put_bits(&s->pb, 3, 1); /* motion only */
+
+ /* zero motion x & y */
+ put_bits(&s->pb, 1, 1);
+ put_bits(&s->pb, 1, 1);
+}
+
+void mpeg1_encode_picture_header(MpegEncContext *s, int picture_number)
+{
+ static int done;
+
+ if (!done) {
+ done = 1;
+ init_rl(&rl_mpeg1);
+ }
+ mpeg1_encode_sequence_header(s);
+
+ /* mpeg1 picture header */
+ put_header(s, PICTURE_START_CODE);
+ /* temporal reference */
+ put_bits(&s->pb, 10, (s->fake_picture_number -
+ s->gop_picture_number) & 0x3ff);
+
+ put_bits(&s->pb, 3, s->pict_type);
+ put_bits(&s->pb, 16, 0xffff); /* non constant bit rate */
+
+ if (s->pict_type == P_TYPE) {
+ put_bits(&s->pb, 1, 0); /* half pel coordinates */
+ put_bits(&s->pb, 3, s->f_code); /* forward_f_code */
+ }
+
+ put_bits(&s->pb, 1, 0); /* extra bit picture */
+
+ /* only one slice */
+ put_header(s, SLICE_MIN_START_CODE);
+ put_bits(&s->pb, 5, s->qscale); /* quantizer scale */
+ put_bits(&s->pb, 1, 0); /* slice extra information */
+}
+
+void mpeg1_encode_mb(MpegEncContext *s,
+ DCTELEM block[6][64],
+ int motion_x, int motion_y)
+{
+ int mb_incr, i, cbp, mb_x, mb_y;
+
+ mb_x = s->mb_x;
+ mb_y = s->mb_y;
+
+ /* compute cbp */
+ cbp = 0;
+ for(i=0;i<6;i++) {
+ if (s->block_last_index[i] >= 0)
+ cbp |= 1 << (5 - i);
+ }
+
+ /* skip macroblock, except if first or last macroblock of a slice */
+ if ((cbp | motion_x | motion_y) == 0 &&
+ (!((mb_x | mb_y) == 0 ||
+ (mb_x == s->mb_width - 1 && mb_y == s->mb_height - 1)))) {
+ s->mb_incr++;
+ } else {
+ /* output mb incr */
+ mb_incr = s->mb_incr;
+
+ while (mb_incr > 33) {
+ put_bits(&s->pb, 11, 0x008);
+ mb_incr -= 33;
+ }
+ put_bits(&s->pb, mbAddrIncrTable[mb_incr - 1][1],
+ mbAddrIncrTable[mb_incr - 1][0]);
+
+ if (s->pict_type == I_TYPE) {
+ put_bits(&s->pb, 1, 1); /* macroblock_type : macroblock_quant = 0 */
+ } else {
+ if (s->mb_intra) {
+ put_bits(&s->pb, 5, 0x03);
+ } else {
+ if (cbp != 0) {
+ if (motion_x == 0 && motion_y == 0) {
+ put_bits(&s->pb, 2, 1); /* macroblock_pattern only */
+ put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
+ } else {
+ put_bits(&s->pb, 1, 1); /* motion + cbp */
+ mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
+ mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
+ put_bits(&s->pb, mbPatTable[cbp - 1][1], mbPatTable[cbp - 1][0]);
+ }
+ } else {
+ put_bits(&s->pb, 3, 1); /* motion only */
+ mpeg1_encode_motion(s, motion_x - s->last_mv[0][0][0]);
+ mpeg1_encode_motion(s, motion_y - s->last_mv[0][0][1]);
+ }
+ }
+ }
+ for(i=0;i<6;i++) {
+ if (cbp & (1 << (5 - i))) {
+ mpeg1_encode_block(s, block[i], i);
+ }
+ }
+ s->mb_incr = 1;
+ }
+ s->last_mv[0][0][0] = motion_x;
+ s->last_mv[0][0][1] = motion_y;
+}
+
+static void mpeg1_encode_motion(MpegEncContext *s, int val)
+{
+ int code, bit_size, l, m, bits, range, sign;
+
+ if (val == 0) {
+ /* zero vector */
+ code = 0;
+ put_bits(&s->pb,
+ mbMotionVectorTable[0][1],
+ mbMotionVectorTable[0][0]);
+ } else {
+ bit_size = s->f_code - 1;
+ range = 1 << bit_size;
+ /* modulo encoding */
+ l = 16 * range;
+ 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,
+ mbMotionVectorTable[code][1],
+ mbMotionVectorTable[code][0]);
+ put_bits(&s->pb, 1, sign);
+ if (bit_size > 0) {
+ put_bits(&s->pb, bit_size, bits);
+ }
+ }
+}
+
+static inline void encode_dc(MpegEncContext *s, int diff, int component)
+{
+ int adiff, index;
+
+ adiff = abs(diff);
+ index = vlc_dc_table[adiff];
+ if (component == 0) {
+ put_bits(&s->pb, vlc_dc_lum_bits[index], vlc_dc_lum_code[index]);
+ } else {
+ put_bits(&s->pb, vlc_dc_chroma_bits[index], vlc_dc_chroma_code[index]);
+ }
+ if (diff > 0) {
+ put_bits(&s->pb, index, (diff & ((1 << index) - 1)));
+ } else if (diff < 0) {
+ put_bits(&s->pb, index, ((diff - 1) & ((1 << index) - 1)));
+ }
+}
+
+static void mpeg1_encode_block(MpegEncContext *s,
+ DCTELEM *block,
+ int n)
+{
+ int alevel, level, last_non_zero, dc, diff, i, j, run, last_index, sign;
+ int code, component;
+ RLTable *rl = &rl_mpeg1;
+
+ last_index = s->block_last_index[n];
+
+ /* DC coef */
+ if (s->mb_intra) {
+ component = (n <= 3 ? 0 : n - 4 + 1);
+ dc = block[0]; /* overflow is impossible */
+ diff = dc - s->last_dc[component];
+ encode_dc(s, diff, component);
+ s->last_dc[component] = dc;
+ i = 1;
+ } else {
+ /* encode the first coefficient : needs to be done here because
+ it is handled slightly differently */
+ level = block[0];
+ if (abs(level) == 1) {
+ code = ((UINT32)level >> 31); /* the sign bit */
+ put_bits(&s->pb, 2, code | 0x02);
+ i = 1;
+ } else {
+ i = 0;
+ last_non_zero = -1;
+ goto next_coef;
+ }
+ }
+
+ /* now quantify & encode AC coefs */
+ last_non_zero = i - 1;
+ for(;i<=last_index;i++) {
+ j = zigzag_direct[i];
+ level = block[j];
+ next_coef:
+#if 0
+ if (level != 0)
+ dprintf("level[%d]=%d\n", i, level);
+#endif
+ /* encode using VLC */
+ if (level != 0) {
+ run = i - last_non_zero - 1;
+ sign = 0;
+ alevel = level;
+ if (alevel < 0) {
+ sign = 1;
+ alevel = -alevel;
+ }
+ code = get_rl_index(rl, 0, run, alevel);
+ put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]);
+ if (code != rl->n) {
+ put_bits(&s->pb, 1, sign);
+ } else {
+ /* escape: only clip in this case */
+ put_bits(&s->pb, 6, run);
+ if (alevel < 128) {
+ put_bits(&s->pb, 8, level & 0xff);
+ } else {
+ if (level < 0) {
+ put_bits(&s->pb, 16, 0x8001 + level + 255);
+ } else {
+ put_bits(&s->pb, 16, level & 0xffff);
+ }
+ }
+ }
+ last_non_zero = i;
+ }
+ }
+ /* end of block */
+ put_bits(&s->pb, 2, 0x2);
+}
+
+/******************************************/
+/* decoding */
+
+static VLC dc_lum_vlc;
+static VLC dc_chroma_vlc;
+static VLC mv_vlc;
+static VLC mbincr_vlc;
+static VLC mb_ptype_vlc;
+static VLC mb_btype_vlc;
+static VLC mb_pat_vlc;
+
+void mpeg1_init_vlc(MpegEncContext *s)
+{
+ static int done = 0;
+
+ if (!done) {
+
+ init_vlc(&dc_lum_vlc, 9, 12,
+ vlc_dc_lum_bits, 1, 1,
+ vlc_dc_lum_code, 2, 2);
+ init_vlc(&dc_chroma_vlc, 9, 12,
+ vlc_dc_chroma_bits, 1, 1,
+ vlc_dc_chroma_code, 2, 2);
+ init_vlc(&mv_vlc, 9, 17,
+ &mbMotionVectorTable[0][1], 2, 1,
+ &mbMotionVectorTable[0][0], 2, 1);
+ init_vlc(&mbincr_vlc, 9, 34,
+ &mbAddrIncrTable[0][1], 2, 1,
+ &mbAddrIncrTable[0][0], 2, 1);
+ init_vlc(&mb_pat_vlc, 9, 63,
+ &mbPatTable[0][1], 2, 1,
+ &mbPatTable[0][0], 2, 1);
+
+ init_vlc(&mb_ptype_vlc, 6, 32,
+ &table_mb_ptype[0][1], 2, 1,
+ &table_mb_ptype[0][0], 2, 1);
+ init_vlc(&mb_btype_vlc, 6, 32,
+ &table_mb_btype[0][1], 2, 1,
+ &table_mb_btype[0][0], 2, 1);
+ init_rl(&rl_mpeg1);
+ init_rl(&rl_mpeg2);
+ /* cannot use generic init because we must add the EOB code */
+ init_vlc(&rl_mpeg1.vlc, 9, rl_mpeg1.n + 2,
+ &rl_mpeg1.table_vlc[0][1], 4, 2,
+ &rl_mpeg1.table_vlc[0][0], 4, 2);
+ init_vlc(&rl_mpeg2.vlc, 9, rl_mpeg2.n + 2,
+ &rl_mpeg2.table_vlc[0][1], 4, 2,
+ &rl_mpeg2.table_vlc[0][0], 4, 2);
+ }
+}
+
+static inline int get_dmv(MpegEncContext *s)
+{
+ if(get_bits(&s->gb, 1))
+ return 1 - (get_bits(&s->gb, 1) << 1);
+ else
+ return 0;
+}
+
+/* motion type (for mpeg2) */
+#define MT_FIELD 1
+#define MT_FRAME 2
+#define MT_16X8 2
+#define MT_DMV 3
+
+static int mpeg_decode_mb(MpegEncContext *s,
+ DCTELEM block[6][64])
+{
+ int i, j, k, cbp, val, code, mb_type, motion_type;
+
+ /* skip mb handling */
+ if (s->mb_incr == 0) {
+ /* read again increment */
+ s->mb_incr = 1;
+ for(;;) {
+ code = get_vlc(&s->gb, &mbincr_vlc);
+ if (code < 0)
+ return 1; /* error = end of slice */
+ if (code >= 33) {
+ if (code == 33) {
+ s->mb_incr += 33;
+ }
+ /* otherwise, stuffing, nothing to do */
+ } else {
+ s->mb_incr += code;
+ break;
+ }
+ }
+ }
+ if (++s->mb_x >= s->mb_width) {
+ s->mb_x = 0;
+ if (s->mb_y >= (s->mb_height - 1))
+ return -1;
+ s->mb_y++;
+ }
+ dprintf("decode_mb: x=%d y=%d\n", s->mb_x, s->mb_y);
+
+ if (--s->mb_incr != 0) {
+ /* skip mb */
+ s->mb_intra = 0;
+ for(i=0;i<6;i++)
+ s->block_last_index[i] = -1;
+ s->mv_type = MV_TYPE_16X16;
+ if (s->pict_type == P_TYPE) {
+ /* if P type, zero motion vector is implied */
+ s->mv_dir = MV_DIR_FORWARD;
+ s->mv[0][0][0] = s->mv[0][0][1] = 0;
+ s->last_mv[0][0][0] = s->last_mv[0][0][1] = 0;
+ } else {
+ /* if B type, reuse previous vectors and directions */
+ s->mv[0][0][0] = s->last_mv[0][0][0];
+ s->mv[0][0][1] = s->last_mv[0][0][1];
+ s->mv[1][0][0] = s->last_mv[1][0][0];
+ s->mv[1][0][1] = s->last_mv[1][0][1];
+ }
+ return 0;
+ }
+
+ switch(s->pict_type) {
+ default:
+ case I_TYPE:
+ if (get_bits(&s->gb, 1) == 0) {
+ if (get_bits(&s->gb, 1) == 0)
+ return -1;
+ mb_type = MB_QUANT | MB_INTRA;
+ } else {
+ mb_type = MB_INTRA;
+ }
+ break;
+ case P_TYPE:
+ mb_type = get_vlc(&s->gb, &mb_ptype_vlc);
+ if (mb_type < 0)
+ return -1;
+ break;
+ case B_TYPE:
+ mb_type = get_vlc(&s->gb, &mb_btype_vlc);
+ if (mb_type < 0)
+ return -1;
+ break;
+ }
+ dprintf("mb_type=%x\n", mb_type);
+ motion_type = 0; /* avoid warning */
+ if (mb_type & (MB_FOR|MB_BACK)) {
+ /* get additionnal motion vector type */
+ if (s->picture_structure == PICT_FRAME && s->frame_pred_frame_dct)
+ motion_type = MT_FRAME;
+ else
+ motion_type = get_bits(&s->gb, 2);
+ }
+ /* compute dct type */
+ if (s->picture_structure == PICT_FRAME &&
+ !s->frame_pred_frame_dct &&
+ (mb_type & (MB_PAT | MB_INTRA))) {
+ s->interlaced_dct = get_bits(&s->gb, 1);
+#ifdef DEBUG
+ if (s->interlaced_dct)
+ printf("interlaced_dct\n");
+#endif
+ } else {
+ s->interlaced_dct = 0; /* frame based */
+ }
+
+ if (mb_type & MB_QUANT) {
+ if (s->mpeg2) {
+ if (s->q_scale_type) {
+ s->qscale = non_linear_qscale[get_bits(&s->gb, 5)];
+ } else {
+ s->qscale = get_bits(&s->gb, 5) << 1;
+ }
+ } else {
+ /* for mpeg1, we use the generic unquant code */
+ s->qscale = get_bits(&s->gb, 5);
+ }
+ }
+ if (mb_type & MB_INTRA) {
+ if (s->concealment_motion_vectors) {
+ /* just parse them */
+ if (s->picture_structure != PICT_FRAME)
+ get_bits(&s->gb, 1); /* field select */
+ mpeg_decode_motion(s, s->mpeg_f_code[0][0], 0);
+ mpeg_decode_motion(s, s->mpeg_f_code[0][1], 0);
+ }
+ s->mb_intra = 1;
+ cbp = 0x3f;
+ memset(s->last_mv, 0, sizeof(s->last_mv)); /* reset mv prediction */
+ } else {
+ s->mb_intra = 0;
+ cbp = 0;
+ }
+ /* special case of implicit zero motion vector */
+ if (s->pict_type == P_TYPE && !(mb_type & MB_FOR)) {
+ s->mv_dir = MV_DIR_FORWARD;
+ s->mv_type = MV_TYPE_16X16;
+ s->last_mv[0][0][0] = 0;
+ s->last_mv[0][0][1] = 0;
+ s->mv[0][0][0] = 0;
+ s->mv[0][0][1] = 0;
+ } else if (mb_type & (MB_FOR | MB_BACK)) {
+ /* motion vectors */
+ s->mv_dir = 0;
+ for(i=0;i<2;i++) {
+ if (mb_type & (MB_FOR >> i)) {
+ s->mv_dir |= (MV_DIR_FORWARD >> i);
+ dprintf("mv_type=%d\n", motion_type);
+ switch(motion_type) {
+ case MT_FRAME: /* or MT_16X8 */
+ if (s->picture_structure == PICT_FRAME) {
+ /* MT_FRAME */
+ s->mv_type = MV_TYPE_16X16;
+ for(k=0;k<2;k++) {
+ val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
+ s->last_mv[i][0][k]);
+ s->last_mv[i][0][k] = val;
+ s->last_mv[i][1][k] = val;
+ /* full_pel: only for mpeg1 */
+ if (s->full_pel[i])
+ val = val << 1;
+ s->mv[i][0][k] = val;
+ dprintf("mv%d: %d\n", k, val);
+ }
+ } else {
+ /* MT_16X8 */
+ s->mv_type = MV_TYPE_16X8;
+ for(j=0;j<2;j++) {
+ s->field_select[i][j] = get_bits(&s->gb, 1);
+ for(k=0;k<2;k++) {
+ val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
+ s->last_mv[i][j][k]);
+ s->last_mv[i][j][k] = val;
+ s->mv[i][j][k] = val;
+ }
+ }
+ }
+ break;
+ case MT_FIELD:
+ if (s->picture_structure == PICT_FRAME) {
+ s->mv_type = MV_TYPE_FIELD;
+ for(j=0;j<2;j++) {
+ s->field_select[i][j] = get_bits(&s->gb, 1);
+ val = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
+ s->last_mv[i][j][0]);
+ s->last_mv[i][j][0] = val;
+ s->mv[i][j][0] = val;
+ dprintf("fmx=%d\n", val);
+ val = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
+ s->last_mv[i][j][1] >> 1);
+ s->last_mv[i][j][1] = val << 1;
+ s->mv[i][j][1] = val;
+ dprintf("fmy=%d\n", val);
+ }
+ } else {
+ s->mv_type = MV_TYPE_16X16;
+ s->field_select[i][0] = get_bits(&s->gb, 1);
+ for(k=0;k<2;k++) {
+ val = mpeg_decode_motion(s, s->mpeg_f_code[i][k],
+ s->last_mv[i][0][k]);
+ s->last_mv[i][0][k] = val;
+ s->last_mv[i][1][k] = val;
+ s->mv[i][0][k] = val;
+ }
+ }
+ break;
+ case MT_DMV:
+ {
+ int dmx, dmy, mx, my, m;
+
+ mx = mpeg_decode_motion(s, s->mpeg_f_code[i][0],
+ s->last_mv[i][0][0]);
+ s->last_mv[i][0][0] = mx;
+ s->last_mv[i][1][0] = mx;
+ dmx = get_dmv(s);
+ my = mpeg_decode_motion(s, s->mpeg_f_code[i][1],
+ s->last_mv[i][0][1] >> 1);
+ dmy = get_dmv(s);
+ s->mv_type = MV_TYPE_DMV;
+ /* XXX: totally broken */
+ if (s->picture_structure == PICT_FRAME) {
+ s->last_mv[i][0][1] = my << 1;
+ s->last_mv[i][1][1] = my << 1;
+
+ m = s->top_field_first ? 1 : 3;
+ /* top -> top pred */
+ s->mv[i][0][0] = mx;
+ s->mv[i][0][1] = my << 1;
+ s->mv[i][1][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
+ s->mv[i][1][1] = ((my * m + (my > 0)) >> 1) + dmy - 1;
+ m = 4 - m;
+ s->mv[i][2][0] = mx;
+ s->mv[i][2][1] = my << 1;
+ s->mv[i][3][0] = ((mx * m + (mx > 0)) >> 1) + dmx;
+ s->mv[i][3][1] = ((my * m + (my > 0)) >> 1) + dmy + 1;
+ } else {
+ s->last_mv[i][0][1] = my;
+ s->last_mv[i][1][1] = my;
+ s->mv[i][0][0] = mx;
+ s->mv[i][0][1] = my;
+ s->mv[i][1][0] = ((mx + (mx > 0)) >> 1) + dmx;
+ s->mv[i][1][1] = ((my + (my > 0)) >> 1) + dmy - 1
+ /* + 2 * cur_field */;
+ }
+ }
+ break;
+ }
+ }
+ }
+ }
+
+ if ((mb_type & MB_INTRA) && s->concealment_motion_vectors) {
+ get_bits(&s->gb, 1); /* marker */
+ }
+
+ if (mb_type & MB_PAT) {
+ cbp = get_vlc(&s->gb, &mb_pat_vlc);
+ if (cbp < 0)
+ return -1;
+ cbp++;
+ }
+ dprintf("cbp=%x\n", cbp);
+
+ if (s->mpeg2) {
+ if (s->mb_intra) {
+ for(i=0;i<6;i++) {
+ if (cbp & (1 << (5 - i))) {
+ if (mpeg2_decode_block_intra(s, block[i], i) < 0)
+ return -1;
+ }
+ }
+ } else {
+ for(i=0;i<6;i++) {
+ if (cbp & (1 << (5 - i))) {
+ if (mpeg2_decode_block_non_intra(s, block[i], i) < 0)
+ return -1;
+ }
+ }
+ }
+ } else {
+ for(i=0;i<6;i++) {
+ if (cbp & (1 << (5 - i))) {
+ if (mpeg1_decode_block(s, block[i], i) < 0)
+ return -1;
+ }
+ }
+ }
+ return 0;
+}
+
+/* as h263, but only 17 codes */
+static int mpeg_decode_motion(MpegEncContext *s, int fcode, int pred)
+{
+ int code, sign, val, m, l, shift;
+
+ code = get_vlc(&s->gb, &mv_vlc);
+ if (code < 0) {
+ return 0xffff;
+ }
+ if (code == 0) {
+ return pred;
+ }
+ sign = get_bits(&s->gb, 1);
+ shift = fcode - 1;
+ val = (code - 1) << shift;
+ if (shift > 0)
+ val |= get_bits(&s->gb, shift);
+ val++;
+ if (sign)
+ val = -val;
+ val += pred;
+
+ /* modulo decoding */
+ l = (1 << shift) * 16;
+ m = 2 * l;
+ if (val < -l) {
+ val += m;
+ } else if (val >= l) {
+ val -= m;
+ }
+ return val;
+}
+
+static inline int decode_dc(MpegEncContext *s, int component)
+{
+ int code, diff;
+
+ if (component == 0) {
+ code = get_vlc(&s->gb, &dc_lum_vlc);
+ } else {
+ code = get_vlc(&s->gb, &dc_chroma_vlc);
+ }
+ if (code < 0)
+ return 0xffff;
+ if (code == 0) {
+ diff = 0;
+ } else {
+ diff = get_bits(&s->gb, code);
+ if ((diff & (1 << (code - 1))) == 0)
+ diff = (-1 << code) | (diff + 1);
+ }
+ return diff;
+}
+
+static int mpeg1_decode_block(MpegEncContext *s,
+ DCTELEM *block,
+ int n)
+{
+ int level, dc, diff, i, j, run;
+ int code, component;
+ RLTable *rl = &rl_mpeg1;
+
+ if (s->mb_intra) {
+ /* DC coef */
+ component = (n <= 3 ? 0 : n - 4 + 1);
+ diff = decode_dc(s, component);
+ if (diff >= 0xffff)
+ return -1;
+ dc = s->last_dc[component];
+ dc += diff;
+ s->last_dc[component] = dc;
+ block[0] = dc;
+ dprintf("dc=%d diff=%d\n", dc, diff);
+ i = 1;
+ } else {
+ int bit_cnt, v;
+ UINT32 bit_buf;
+ UINT8 *buf_ptr;
+ i = 0;
+ /* special case for the first coef. no need to add a second vlc table */
+ SAVE_BITS(&s->gb);
+ SHOW_BITS(&s->gb, v, 2);
+ if (v & 2) {
+ run = 0;
+ level = 1 - ((v & 1) << 1);
+ FLUSH_BITS(2);
+ RESTORE_BITS(&s->gb);
+ goto add_coef;
+ }
+ RESTORE_BITS(&s->gb);
+ }
+
+ /* now quantify & encode AC coefs */
+ for(;;) {
+ code = get_vlc(&s->gb, &rl->vlc);
+ if (code < 0) {
+ return -1;
+ }
+ if (code == 112) {
+ break;
+ } else if (code == 111) {
+ /* escape */
+ run = get_bits(&s->gb, 6);
+ level = get_bits(&s->gb, 8);
+ level = (level << 24) >> 24;
+ if (level == -128) {
+ level = get_bits(&s->gb, 8) - 256;
+ } else if (level == 0) {
+ level = get_bits(&s->gb, 8);
+ }
+ } else {
+ run = rl->table_run[code];
+ level = rl->table_level[code];
+ if (get_bits(&s->gb, 1))
+ level = -level;
+ }
+ i += run;
+ if (i >= 64)
+ return -1;
+ add_coef:
+ dprintf("%d: run=%d level=%d\n", n, run, level);
+ j = zigzag_direct[i];
+ block[j] = level;
+ i++;
+ }
+ s->block_last_index[n] = i;
+ return 0;
+}
+
+/* Also does unquantization here, since I will never support mpeg2
+ encoding */
+static int mpeg2_decode_block_non_intra(MpegEncContext *s,
+ DCTELEM *block,
+ int n)
+{
+ int level, i, j, run;
+ int code;
+ RLTable *rl = &rl_mpeg1;
+ const UINT8 *scan_table;
+ const UINT16 *matrix;
+ int mismatch;
+
+ if (s->alternate_scan)
+ scan_table = ff_alternate_vertical_scan;
+ else
+ scan_table = zigzag_direct;
+ mismatch = 1;
+
+ {
+ int bit_cnt, v;
+ UINT32 bit_buf;
+ UINT8 *buf_ptr;
+ i = 0;
+ if (n < 4)
+ matrix = s->non_intra_matrix;
+ else
+ matrix = s->chroma_non_intra_matrix;
+
+ /* special case for the first coef. no need to add a second vlc table */
+ SAVE_BITS(&s->gb);
+ SHOW_BITS(&s->gb, v, 2);
+ if (v & 2) {
+ run = 0;
+ level = 1 - ((v & 1) << 1);
+ FLUSH_BITS(2);
+ RESTORE_BITS(&s->gb);
+ goto add_coef;
+ }
+ RESTORE_BITS(&s->gb);
+ }
+
+ /* now quantify & encode AC coefs */
+ for(;;) {
+ code = get_vlc(&s->gb, &rl->vlc);
+ if (code < 0)
+ return -1;
+ if (code == 112) {
+ break;
+ } else if (code == 111) {
+ /* escape */
+ run = get_bits(&s->gb, 6);
+ level = get_bits(&s->gb, 12);
+ level = (level << 20) >> 20;
+ } else {
+ run = rl->table_run[code];
+ level = rl->table_level[code];
+ if (get_bits(&s->gb, 1))
+ level = -level;
+ }
+ i += run;
+ if (i >= 64)
+ return -1;
+ add_coef:
+ j = scan_table[i];
+ dprintf("%d: run=%d level=%d\n", n, run, level);
+ level = ((level * 2 + 1) * s->qscale * matrix[j]) / 32;
+ /* XXX: is it really necessary to saturate since the encoder
+ knows whats going on ? */
+ mismatch ^= level;
+ block[j] = level;
+ i++;
+ }
+ block[63] ^= (mismatch & 1);
+ s->block_last_index[n] = i;
+ return 0;
+}
+
+static int mpeg2_decode_block_intra(MpegEncContext *s,
+ DCTELEM *block,
+ int n)
+{
+ int level, dc, diff, i, j, run;
+ int code, component;
+ RLTable *rl;
+ const UINT8 *scan_table;
+ const UINT16 *matrix;
+ int mismatch;
+
+ if (s->alternate_scan)
+ scan_table = ff_alternate_vertical_scan;
+ else
+ scan_table = zigzag_direct;
+ mismatch = 1;
+
+ /* DC coef */
+ component = (n <= 3 ? 0 : n - 4 + 1);
+ diff = decode_dc(s, component);
+ if (diff >= 0xffff)
+ return -1;
+ dc = s->last_dc[component];
+ dc += diff;
+ s->last_dc[component] = dc;
+ block[0] = dc << (3 - s->intra_dc_precision);
+ dprintf("dc=%d\n", block[0]);
+ i = 1;
+ if (s->intra_vlc_format)
+ rl = &rl_mpeg2;
+ else
+ rl = &rl_mpeg1;
+ if (n < 4)
+ matrix = s->intra_matrix;
+ else
+ matrix = s->chroma_intra_matrix;
+
+ /* now quantify & encode AC coefs */
+ for(;;) {
+ code = get_vlc(&s->gb, &rl->vlc);
+ if (code < 0)
+ return -1;
+ if (code == 112) {
+ break;
+ } else if (code == 111) {
+ /* escape */
+ run = get_bits(&s->gb, 6);
+ level = get_bits(&s->gb, 12);
+ level = (level << 20) >> 20;
+ } else {
+ run = rl->table_run[code];
+ level = rl->table_level[code];
+ if (get_bits(&s->gb, 1))
+ level = -level;
+ }
+ i += run;
+ if (i >= 64)
+ return -1;
+ j = scan_table[i];
+ dprintf("%d: run=%d level=%d\n", n, run, level);
+ level = (level * s->qscale * matrix[j]) / 16;
+ /* XXX: is it really necessary to saturate since the encoder
+ knows whats going on ? */
+ mismatch ^= level;
+ block[j] = level;
+ i++;
+ }
+ block[63] ^= (mismatch & 1);
+ s->block_last_index[n] = i;
+ return 0;
+}
+
+/* compressed picture size */
+#define PICTURE_BUFFER_SIZE 100000
+
+typedef struct Mpeg1Context {
+ MpegEncContext mpeg_enc_ctx;
+ UINT32 header_state;
+ int start_code; /* current start code */
+ UINT8 buffer[PICTURE_BUFFER_SIZE];
+ UINT8 *buf_ptr;
+ int buffer_size;
+ int mpeg_enc_ctx_allocated; /* true if decoding context allocated */
+} Mpeg1Context;
+
+static int mpeg_decode_init(AVCodecContext *avctx)
+{
+ Mpeg1Context *s = avctx->priv_data;
+
+ s->header_state = 0xff;
+ s->mpeg_enc_ctx_allocated = 0;
+ s->buffer_size = PICTURE_BUFFER_SIZE;
+ s->start_code = -1;
+ s->buf_ptr = s->buffer;
+ s->mpeg_enc_ctx.picture_number = 0;
+ return 0;
+}
+
+/* return the 8 bit start code value and update the search
+ state. Return -1 if no start code found */
+static int find_start_code(UINT8 **pbuf_ptr, UINT8 *buf_end,
+ UINT32 *header_state)
+{
+ UINT8 *buf_ptr;
+ unsigned int state, v;
+ int val;
+
+ state = *header_state;
+ buf_ptr = *pbuf_ptr;
+ while (buf_ptr < buf_end) {
+ v = *buf_ptr++;
+ if (state == 0x000001) {
+ state = ((state << 8) | v) & 0xffffff;
+ val = state;
+ goto found;
+ }
+ state = ((state << 8) | v) & 0xffffff;
+ }
+ val = -1;
+ found:
+ *pbuf_ptr = buf_ptr;
+ *header_state = state;
+ return val;
+}
+
+static int mpeg1_decode_picture(AVCodecContext *avctx,
+ UINT8 *buf, int buf_size)
+{
+ Mpeg1Context *s1 = avctx->priv_data;
+ MpegEncContext *s = &s1->mpeg_enc_ctx;
+ int ref, f_code;
+
+ init_get_bits(&s->gb, buf, buf_size);
+
+ ref = get_bits(&s->gb, 10); /* temporal ref */
+ s->pict_type = get_bits(&s->gb, 3);
+ dprintf("pict_type=%d\n", s->pict_type);
+ get_bits(&s->gb, 16);
+ if (s->pict_type == P_TYPE || s->pict_type == B_TYPE) {
+ s->full_pel[0] = get_bits(&s->gb, 1);
+ f_code = get_bits(&s->gb, 3);
+ if (f_code == 0)
+ return -1;
+ s->mpeg_f_code[0][0] = f_code;
+ s->mpeg_f_code[0][1] = f_code;
+ }
+ if (s->pict_type == B_TYPE) {
+ s->full_pel[1] = get_bits(&s->gb, 1);
+ f_code = get_bits(&s->gb, 3);
+ if (f_code == 0)
+ return -1;
+ s->mpeg_f_code[1][0] = f_code;
+ s->mpeg_f_code[1][1] = f_code;
+ }
+ s->y_dc_scale = 8;
+ s->c_dc_scale = 8;
+ s->first_slice = 1;
+ return 0;
+}
+
+static void mpeg_decode_sequence_extension(MpegEncContext *s)
+{
+ int horiz_size_ext, vert_size_ext;
+ int bit_rate_ext, vbv_buf_ext, low_delay;
+ int frame_rate_ext_n, frame_rate_ext_d;
+
+ get_bits(&s->gb, 8); /* profil and level */
+ get_bits(&s->gb, 1); /* progressive_sequence */
+ get_bits(&s->gb, 2); /* chroma_format */
+ horiz_size_ext = get_bits(&s->gb, 2);
+ vert_size_ext = get_bits(&s->gb, 2);
+ s->width |= (horiz_size_ext << 12);
+ s->height |= (vert_size_ext << 12);
+ bit_rate_ext = get_bits(&s->gb, 12); /* XXX: handle it */
+ s->bit_rate = ((s->bit_rate / 400) | (bit_rate_ext << 12)) * 400;
+ get_bits(&s->gb, 1); /* marker */
+ vbv_buf_ext = get_bits(&s->gb, 8);
+ low_delay = get_bits(&s->gb, 1);
+ frame_rate_ext_n = get_bits(&s->gb, 2);
+ frame_rate_ext_d = get_bits(&s->gb, 5);
+ if (frame_rate_ext_d >= 1)
+ s->frame_rate = (s->frame_rate * frame_rate_ext_n) / frame_rate_ext_d;
+ dprintf("sequence extension\n");
+ s->mpeg2 = 1;
+}
+
+static void mpeg_decode_quant_matrix_extension(MpegEncContext *s)
+{
+ int i, v;
+
+ if (get_bits(&s->gb, 1)) {
+ for(i=0;i<64;i++) {
+ v = get_bits(&s->gb, 8);
+ s->intra_matrix[i] = v;
+ s->chroma_intra_matrix[i] = v;
+ }
+ }
+ if (get_bits(&s->gb, 1)) {
+ for(i=0;i<64;i++) {
+ v = get_bits(&s->gb, 8);
+ s->non_intra_matrix[i] = v;
+ s->chroma_non_intra_matrix[i] = v;
+ }
+ }
+ if (get_bits(&s->gb, 1)) {
+ for(i=0;i<64;i++) {
+ v = get_bits(&s->gb, 8);
+ s->chroma_intra_matrix[i] = v;
+ }
+ }
+ if (get_bits(&s->gb, 1)) {
+ for(i=0;i<64;i++) {
+ v = get_bits(&s->gb, 8);
+ s->chroma_non_intra_matrix[i] = v;
+ }
+ }
+}
+
+static void mpeg_decode_picture_coding_extension(MpegEncContext *s)
+{
+ s->full_pel[0] = s->full_pel[1] = 0;
+ s->mpeg_f_code[0][0] = get_bits(&s->gb, 4);
+ s->mpeg_f_code[0][1] = get_bits(&s->gb, 4);
+ s->mpeg_f_code[1][0] = get_bits(&s->gb, 4);
+ s->mpeg_f_code[1][1] = get_bits(&s->gb, 4);
+ s->intra_dc_precision = get_bits(&s->gb, 2);
+ s->picture_structure = get_bits(&s->gb, 2);
+ s->top_field_first = get_bits(&s->gb, 1);
+ s->frame_pred_frame_dct = get_bits(&s->gb, 1);
+ s->concealment_motion_vectors = get_bits(&s->gb, 1);
+ s->q_scale_type = get_bits(&s->gb, 1);
+ s->intra_vlc_format = get_bits(&s->gb, 1);
+ s->alternate_scan = get_bits(&s->gb, 1);
+ s->repeat_first_field = get_bits(&s->gb, 1);
+ s->chroma_420_type = get_bits(&s->gb, 1);
+ s->progressive_frame = get_bits(&s->gb, 1);
+ /* composite display not parsed */
+ dprintf("dc_preci=%d\n", s->intra_dc_precision);
+ dprintf("pict_structure=%d\n", s->picture_structure);
+ dprintf("conceal=%d\n", s->concealment_motion_vectors);
+ dprintf("intrafmt=%d\n", s->intra_vlc_format);
+ dprintf("frame_pred_frame_dct=%d\n", s->frame_pred_frame_dct);
+}
+
+static void mpeg_decode_extension(AVCodecContext *avctx,
+ UINT8 *buf, int buf_size)
+{
+ Mpeg1Context *s1 = avctx->priv_data;
+ MpegEncContext *s = &s1->mpeg_enc_ctx;
+ int ext_type;
+
+ init_get_bits(&s->gb, buf, buf_size);
+
+ ext_type = get_bits(&s->gb, 4);
+ switch(ext_type) {
+ case 0x1:
+ /* sequence ext */
+ mpeg_decode_sequence_extension(s);
+ break;
+ case 0x3:
+ /* quant matrix extension */
+ mpeg_decode_quant_matrix_extension(s);
+ break;
+ case 0x8:
+ /* picture extension */
+ mpeg_decode_picture_coding_extension(s);
+ break;
+ }
+}
+
+/* return 1 if end of frame */
+static int mpeg_decode_slice(AVCodecContext *avctx,
+ AVPicture *pict,
+ int start_code,
+ UINT8 *buf, int buf_size)
+{
+ Mpeg1Context *s1 = avctx->priv_data;
+ MpegEncContext *s = &s1->mpeg_enc_ctx;
+ int ret;
+ DCTELEM block[6][64];
+
+ start_code = (start_code - 1) & 0xff;
+ if (start_code >= s->mb_height)
+ return -1;
+ s->last_dc[0] = 1 << (7 + s->intra_dc_precision);
+ s->last_dc[1] = s->last_dc[0];
+ s->last_dc[2] = s->last_dc[0];
+ memset(s->last_mv, 0, sizeof(s->last_mv));
+ s->mb_x = -1;
+ s->mb_y = start_code;
+ s->mb_incr = 0;
+
+ /* start frame decoding */
+ if (s->first_slice) {
+ s->first_slice = 0;
+ MPV_frame_start(s);
+ }
+
+ init_get_bits(&s->gb, buf, buf_size);
+
+ s->qscale = get_bits(&s->gb, 5);
+ /* extra slice info */
+ while (get_bits(&s->gb, 1) != 0) {
+ get_bits(&s->gb, 8);
+ }
+
+ for(;;) {
+ memset(block, 0, sizeof(block));
+ ret = mpeg_decode_mb(s, block);
+ dprintf("ret=%d\n", ret);
+ if (ret < 0)
+ return -1;
+ if (ret == 1)
+ break;
+ MPV_decode_mb(s, block);
+ }
+
+ /* end of slice reached */
+ if (s->mb_x == (s->mb_width - 1) &&
+ s->mb_y == (s->mb_height - 1)) {
+ /* end of image */
+ UINT8 **picture;
+
+ MPV_frame_end(s);
+
+ /* XXX: incorrect reported qscale for mpeg2 */
+ if (s->pict_type == B_TYPE) {
+ picture = s->current_picture;
+ avctx->quality = s->qscale;
+ } else {
+ /* latency of 1 frame for I and P frames */
+ /* XXX: use another variable than picture_number */
+ if (s->picture_number == 0) {
+ picture = NULL;
+ } else {
+ picture = s->last_picture;
+ avctx->quality = s->last_qscale;
+ }
+ s->last_qscale = s->qscale;
+ s->picture_number++;
+ }
+ if (picture) {
+ pict->data[0] = picture[0];
+ pict->data[1] = picture[1];
+ pict->data[2] = picture[2];
+ pict->linesize[0] = s->linesize;
+ pict->linesize[1] = s->linesize / 2;
+ pict->linesize[2] = s->linesize / 2;
+ return 1;
+ } else {
+ return 0;
+ }
+ } else {
+ return 0;
+ }
+}
+
+static int mpeg1_decode_sequence(AVCodecContext *avctx,
+ UINT8 *buf, int buf_size)
+{
+ Mpeg1Context *s1 = avctx->priv_data;
+ MpegEncContext *s = &s1->mpeg_enc_ctx;
+ int width, height, i, v;
+
+ init_get_bits(&s->gb, buf, buf_size);
+
+ width = get_bits(&s->gb, 12);
+ height = get_bits(&s->gb, 12);
+ get_bits(&s->gb, 4);
+ s->frame_rate_index = get_bits(&s->gb, 4);
+ if (s->frame_rate_index == 0)
+ return -1;
+ s->bit_rate = get_bits(&s->gb, 18) * 400;
+ if (get_bits(&s->gb, 1) == 0) /* marker */
+ return -1;
+ if (width <= 0 || height <= 0 ||
+ (width % 2) != 0 || (height % 2) != 0)
+ return -1;
+ if (width != s->width ||
+ height != s->height) {
+ /* start new mpeg1 context decoding */
+ s->out_format = FMT_MPEG1;
+ if (s1->mpeg_enc_ctx_allocated) {
+ MPV_common_end(s);
+ }
+ s->width = width;
+ s->height = height;
+ s->has_b_frames = 1;
+ avctx->width = width;
+ avctx->height = height;
+ avctx->frame_rate = frame_rate_tab[s->frame_rate_index];
+ avctx->bit_rate = s->bit_rate;
+
+ if (MPV_common_init(s) < 0)
+ return -1;
+ mpeg1_init_vlc(s);
+ s1->mpeg_enc_ctx_allocated = 1;
+ }
+
+ get_bits(&s->gb, 10); /* vbv_buffer_size */
+ get_bits(&s->gb, 1);
+
+ /* get matrix */
+ if (get_bits(&s->gb, 1)) {
+ for(i=0;i<64;i++) {
+ v = get_bits(&s->gb, 8);
+ s->intra_matrix[i] = v;
+ s->chroma_intra_matrix[i] = v;
+ }
+ } else {
+ for(i=0;i<64;i++) {
+ v = default_intra_matrix[i];
+ s->intra_matrix[i] = v;
+ s->chroma_intra_matrix[i] = v;
+ }
+ }
+ if (get_bits(&s->gb, 1)) {
+ for(i=0;i<64;i++) {
+ v = get_bits(&s->gb, 8);
+ s->non_intra_matrix[i] = v;
+ s->chroma_non_intra_matrix[i] = v;
+ }
+ } else {
+ for(i=0;i<64;i++) {
+ v = default_non_intra_matrix[i];
+ s->non_intra_matrix[i] = v;
+ s->chroma_non_intra_matrix[i] = v;
+ }
+ }
+
+ /* we set mpeg2 parameters so that it emulates mpeg1 */
+ s->progressive_sequence = 1;
+ s->progressive_frame = 1;
+ s->picture_structure = PICT_FRAME;
+ s->frame_pred_frame_dct = 1;
+ s->mpeg2 = 0;
+ return 0;
+}
+
+/* handle buffering and image synchronisation */
+static int mpeg_decode_frame(AVCodecContext *avctx,
+ void *data, int *data_size,
+ UINT8 *buf, int buf_size)
+{
+ Mpeg1Context *s = avctx->priv_data;
+ UINT8 *buf_end, *buf_ptr, *buf_start;
+ int len, start_code_found, ret, code, start_code, input_size;
+ AVPicture *picture = data;
+
+ dprintf("fill_buffer\n");
+
+ *data_size = 0;
+ /* special case for last picture */
+ if (buf_size == 0) {
+ MpegEncContext *s2 = &s->mpeg_enc_ctx;
+ if (s2->picture_number > 0) {
+ picture->data[0] = s2->next_picture[0];
+ picture->data[1] = s2->next_picture[1];
+ picture->data[2] = s2->next_picture[2];
+ picture->linesize[0] = s2->linesize;
+ picture->linesize[1] = s2->linesize / 2;
+ picture->linesize[2] = s2->linesize / 2;
+ *data_size = sizeof(AVPicture);
+ }
+ return 0;
+ }
+
+ buf_ptr = buf;
+ buf_end = buf + buf_size;
+ while (buf_ptr < buf_end) {
+ buf_start = buf_ptr;
+ /* find start next code */
+ code = find_start_code(&buf_ptr, buf_end, &s->header_state);
+ if (code >= 0) {
+ start_code_found = 1;
+ } else {
+ start_code_found = 0;
+ }
+ /* copy to buffer */
+ len = buf_ptr - buf_start;
+ if (len + (s->buf_ptr - s->buffer) > s->buffer_size) {
+ /* data too big : flush */
+ s->buf_ptr = s->buffer;
+ if (start_code_found)
+ s->start_code = code;
+ } else {
+ memcpy(s->buf_ptr, buf_start, len);
+ s->buf_ptr += len;
+
+ if (start_code_found) {
+ /* prepare data for next start code */
+ input_size = s->buf_ptr - s->buffer;
+ start_code = s->start_code;
+ s->buf_ptr = s->buffer;
+ s->start_code = code;
+ switch(start_code) {
+ case SEQ_START_CODE:
+ mpeg1_decode_sequence(avctx, s->buffer,
+ input_size);
+ break;
+
+ case PICTURE_START_CODE:
+ /* we have a complete image : we try to decompress it */
+ mpeg1_decode_picture(avctx,
+ s->buffer, input_size);
+ break;
+ case EXT_START_CODE:
+ mpeg_decode_extension(avctx,
+ s->buffer, input_size);
+ break;
+ default:
+ if (start_code >= SLICE_MIN_START_CODE &&
+ start_code <= SLICE_MAX_START_CODE) {
+ ret = mpeg_decode_slice(avctx, picture,
+ start_code, s->buffer, input_size);
+ if (ret == 1) {
+ /* got a picture: exit */
+ *data_size = sizeof(AVPicture);
+ goto the_end;
+ }
+ }
+ break;
+ }
+ }
+ }
+ }
+ the_end:
+ return buf_ptr - buf;
+}
+
+static int mpeg_decode_end(AVCodecContext *avctx)
+{
+ Mpeg1Context *s = avctx->priv_data;
+
+ if (s->mpeg_enc_ctx_allocated)
+ MPV_common_end(&s->mpeg_enc_ctx);
+ return 0;
+}
+
+AVCodec mpeg_decoder = {
+ "mpegvideo",
+ CODEC_TYPE_VIDEO,
+ CODEC_ID_MPEG1VIDEO,
+ sizeof(Mpeg1Context),
+ mpeg_decode_init,
+ NULL,
+ mpeg_decode_end,
+ mpeg_decode_frame,
+};
generated by cgit v1.2.3 (git 2.39.1) at 2024-07-01 20:54:58 +0000