yading@10: /* yading@10: * MPEG-1/2 decoder yading@10: * Copyright (c) 2000, 2001 Fabrice Bellard yading@10: * Copyright (c) 2002-2004 Michael Niedermayer yading@10: * yading@10: * This file is part of FFmpeg. yading@10: * yading@10: * FFmpeg is free software; you can redistribute it and/or yading@10: * modify it under the terms of the GNU Lesser General Public yading@10: * License as published by the Free Software Foundation; either yading@10: * version 2.1 of the License, or (at your option) any later version. yading@10: * yading@10: * FFmpeg is distributed in the hope that it will be useful, yading@10: * but WITHOUT ANY WARRANTY; without even the implied warranty of yading@10: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU yading@10: * Lesser General Public License for more details. yading@10: * yading@10: * You should have received a copy of the GNU Lesser General Public yading@10: * License along with FFmpeg; if not, write to the Free Software yading@10: * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA yading@10: */ yading@10: yading@10: /** yading@10: * @file yading@10: * MPEG-1/2 decoder yading@10: */ yading@10: yading@10: #define UNCHECKED_BITSTREAM_READER 1 yading@10: yading@10: //#define DEBUG yading@10: #include "libavutil/avassert.h" yading@10: #include "libavutil/timecode.h" yading@10: yading@10: #include "internal.h" yading@10: #include "avcodec.h" yading@10: #include "dsputil.h" yading@10: #include "mpegvideo.h" yading@10: #include "error_resilience.h" yading@10: #include "mpeg12.h" yading@10: #include "mpeg12data.h" yading@10: #include "mpeg12decdata.h" yading@10: #include "bytestream.h" yading@10: #include "vdpau_internal.h" yading@10: #include "xvmc_internal.h" yading@10: #include "thread.h" yading@10: yading@10: yading@10: uint8_t ff_mpeg12_static_rl_table_store[2][2][2*MAX_RUN + MAX_LEVEL + 3]; yading@10: yading@10: #define INIT_2D_VLC_RL(rl, static_size)\ yading@10: {\ yading@10: static RL_VLC_ELEM rl_vlc_table[static_size];\ yading@10: INIT_VLC_STATIC(&rl.vlc, TEX_VLC_BITS, rl.n + 2,\ yading@10: &rl.table_vlc[0][1], 4, 2,\ yading@10: &rl.table_vlc[0][0], 4, 2, static_size);\ yading@10: \ yading@10: rl.rl_vlc[0] = rl_vlc_table;\ yading@10: init_2d_vlc_rl(&rl);\ yading@10: } yading@10: yading@10: static void init_2d_vlc_rl(RLTable *rl) yading@10: { yading@10: int i; yading@10: yading@10: for (i = 0; i < rl->vlc.table_size; i++) { yading@10: int code = rl->vlc.table[i][0]; yading@10: int len = rl->vlc.table[i][1]; yading@10: int level, run; yading@10: yading@10: if (len == 0) { // illegal code yading@10: run = 65; yading@10: level = MAX_LEVEL; yading@10: } else if (len<0) { //more bits needed yading@10: run = 0; yading@10: level = code; yading@10: } else { yading@10: if (code == rl->n) { //esc yading@10: run = 65; yading@10: level = 0; yading@10: } else if (code == rl->n+1) { //eob yading@10: run = 0; yading@10: level = 127; yading@10: } else { yading@10: run = rl->table_run [code] + 1; yading@10: level = rl->table_level[code]; yading@10: } yading@10: } yading@10: rl->rl_vlc[0][i].len = len; yading@10: rl->rl_vlc[0][i].level = level; yading@10: rl->rl_vlc[0][i].run = run; yading@10: } yading@10: } yading@10: yading@10: void ff_mpeg12_common_init(MpegEncContext *s) yading@10: { yading@10: yading@10: s->y_dc_scale_table = yading@10: s->c_dc_scale_table = ff_mpeg2_dc_scale_table[s->intra_dc_precision]; yading@10: yading@10: } yading@10: yading@10: void ff_mpeg1_clean_buffers(MpegEncContext *s) yading@10: { yading@10: s->last_dc[0] = 1 << (7 + s->intra_dc_precision); yading@10: s->last_dc[1] = s->last_dc[0]; yading@10: s->last_dc[2] = s->last_dc[0]; yading@10: memset(s->last_mv, 0, sizeof(s->last_mv)); yading@10: } yading@10: yading@10: yading@10: /******************************************/ yading@10: /* decoding */ yading@10: yading@10: VLC ff_mv_vlc; yading@10: yading@10: VLC ff_dc_lum_vlc; yading@10: VLC ff_dc_chroma_vlc; yading@10: yading@10: VLC ff_mbincr_vlc; yading@10: VLC ff_mb_ptype_vlc; yading@10: VLC ff_mb_btype_vlc; yading@10: VLC ff_mb_pat_vlc; yading@10: yading@10: av_cold void ff_mpeg12_init_vlcs(void) yading@10: { yading@10: static int done = 0; yading@10: yading@10: if (!done) { yading@10: done = 1; yading@10: yading@10: INIT_VLC_STATIC(&ff_dc_lum_vlc, DC_VLC_BITS, 12, yading@10: ff_mpeg12_vlc_dc_lum_bits, 1, 1, yading@10: ff_mpeg12_vlc_dc_lum_code, 2, 2, 512); yading@10: INIT_VLC_STATIC(&ff_dc_chroma_vlc, DC_VLC_BITS, 12, yading@10: ff_mpeg12_vlc_dc_chroma_bits, 1, 1, yading@10: ff_mpeg12_vlc_dc_chroma_code, 2, 2, 514); yading@10: INIT_VLC_STATIC(&ff_mv_vlc, MV_VLC_BITS, 17, yading@10: &ff_mpeg12_mbMotionVectorTable[0][1], 2, 1, yading@10: &ff_mpeg12_mbMotionVectorTable[0][0], 2, 1, 518); yading@10: INIT_VLC_STATIC(&ff_mbincr_vlc, MBINCR_VLC_BITS, 36, yading@10: &ff_mpeg12_mbAddrIncrTable[0][1], 2, 1, yading@10: &ff_mpeg12_mbAddrIncrTable[0][0], 2, 1, 538); yading@10: INIT_VLC_STATIC(&ff_mb_pat_vlc, MB_PAT_VLC_BITS, 64, yading@10: &ff_mpeg12_mbPatTable[0][1], 2, 1, yading@10: &ff_mpeg12_mbPatTable[0][0], 2, 1, 512); yading@10: yading@10: INIT_VLC_STATIC(&ff_mb_ptype_vlc, MB_PTYPE_VLC_BITS, 7, yading@10: &table_mb_ptype[0][1], 2, 1, yading@10: &table_mb_ptype[0][0], 2, 1, 64); yading@10: INIT_VLC_STATIC(&ff_mb_btype_vlc, MB_BTYPE_VLC_BITS, 11, yading@10: &table_mb_btype[0][1], 2, 1, yading@10: &table_mb_btype[0][0], 2, 1, 64); yading@10: ff_init_rl(&ff_rl_mpeg1, ff_mpeg12_static_rl_table_store[0]); yading@10: ff_init_rl(&ff_rl_mpeg2, ff_mpeg12_static_rl_table_store[1]); yading@10: yading@10: INIT_2D_VLC_RL(ff_rl_mpeg1, 680); yading@10: INIT_2D_VLC_RL(ff_rl_mpeg2, 674); yading@10: } yading@10: } yading@10: yading@10: /** yading@10: * Find the end of the current frame in the bitstream. yading@10: * @return the position of the first byte of the next frame, or -1 yading@10: */ yading@10: int ff_mpeg1_find_frame_end(ParseContext *pc, const uint8_t *buf, int buf_size, AVCodecParserContext *s) yading@10: { yading@10: int i; yading@10: uint32_t state = pc->state; yading@10: yading@10: /* EOF considered as end of frame */ yading@10: if (buf_size == 0) yading@10: return 0; yading@10: yading@10: /* yading@10: 0 frame start -> 1/4 yading@10: 1 first_SEQEXT -> 0/2 yading@10: 2 first field start -> 3/0 yading@10: 3 second_SEQEXT -> 2/0 yading@10: 4 searching end yading@10: */ yading@10: yading@10: for (i = 0; i < buf_size; i++) { yading@10: av_assert1(pc->frame_start_found >= 0 && pc->frame_start_found <= 4); yading@10: if (pc->frame_start_found & 1) { yading@10: if (state == EXT_START_CODE && (buf[i] & 0xF0) != 0x80) yading@10: pc->frame_start_found--; yading@10: else if (state == EXT_START_CODE + 2) { yading@10: if ((buf[i] & 3) == 3) yading@10: pc->frame_start_found = 0; yading@10: else yading@10: pc->frame_start_found = (pc->frame_start_found + 1) & 3; yading@10: } yading@10: state++; yading@10: } else { yading@10: i = avpriv_find_start_code(buf + i, buf + buf_size, &state) - buf - 1; yading@10: if (pc->frame_start_found == 0 && state >= SLICE_MIN_START_CODE && state <= SLICE_MAX_START_CODE) { yading@10: i++; yading@10: pc->frame_start_found = 4; yading@10: } yading@10: if (state == SEQ_END_CODE) { yading@10: pc->frame_start_found = 0; yading@10: pc->state=-1; yading@10: return i+1; yading@10: } yading@10: if (pc->frame_start_found == 2 && state == SEQ_START_CODE) yading@10: pc->frame_start_found = 0; yading@10: if (pc->frame_start_found < 4 && state == EXT_START_CODE) yading@10: pc->frame_start_found++; yading@10: if (pc->frame_start_found == 4 && (state & 0xFFFFFF00) == 0x100) { yading@10: if (state < SLICE_MIN_START_CODE || state > SLICE_MAX_START_CODE) { yading@10: pc->frame_start_found = 0; yading@10: pc->state = -1; yading@10: return i - 3; yading@10: } yading@10: } yading@10: if (pc->frame_start_found == 0 && s && state == PICTURE_START_CODE) { yading@10: ff_fetch_timestamp(s, i - 3, 1); yading@10: } yading@10: } yading@10: } yading@10: pc->state = state; yading@10: return END_NOT_FOUND; yading@10: } yading@10: