diff options
Diffstat (limited to 'contrib/ffmpeg/libavcodec/h261dec.c')
| -rw-r--r-- | contrib/ffmpeg/libavcodec/h261dec.c | 650 |
1 files changed, 0 insertions, 650 deletions
diff --git a/contrib/ffmpeg/libavcodec/h261dec.c b/contrib/ffmpeg/libavcodec/h261dec.c deleted file mode 100644 index 264a7d3f5..000000000 --- a/contrib/ffmpeg/libavcodec/h261dec.c +++ /dev/null @@ -1,650 +0,0 @@ -/* - * H261 decoder - * Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at> - * Copyright (c) 2004 Maarten Daniels - * - * This file is part of FFmpeg. - * - * FFmpeg is free software; you can redistribute it and/or - * modify it under the terms of the GNU Lesser General Public - * License as published by the Free Software Foundation; either - * version 2.1 of the License, or (at your option) any later version. - * - * FFmpeg 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 - * Lesser General Public License for more details. - * - * You should have received a copy of the GNU Lesser General Public - * License along with FFmpeg; if not, write to the Free Software - * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA - */ - -/** - * @file h261dec.c - * H.261 decoder. - */ - -#include "dsputil.h" -#include "avcodec.h" -#include "mpegvideo.h" -#include "h261.h" -#include "h261data.h" - -#define H261_MBA_VLC_BITS 9 -#define H261_MTYPE_VLC_BITS 6 -#define H261_MV_VLC_BITS 7 -#define H261_CBP_VLC_BITS 9 -#define TCOEFF_VLC_BITS 9 -#define MBA_STUFFING 33 -#define MBA_STARTCODE 34 - -extern uint8_t ff_h261_rl_table_store[2][2*MAX_RUN + MAX_LEVEL + 3]; - -static VLC h261_mba_vlc; -static VLC h261_mtype_vlc; -static VLC h261_mv_vlc; -static VLC h261_cbp_vlc; - -static int h261_decode_block(H261Context * h, DCTELEM * block, int n, int coded); - -static void h261_decode_init_vlc(H261Context *h){ - static int done = 0; - - if(!done){ - done = 1; - init_vlc(&h261_mba_vlc, H261_MBA_VLC_BITS, 35, - h261_mba_bits, 1, 1, - h261_mba_code, 1, 1, 1); - init_vlc(&h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10, - h261_mtype_bits, 1, 1, - h261_mtype_code, 1, 1, 1); - init_vlc(&h261_mv_vlc, H261_MV_VLC_BITS, 17, - &h261_mv_tab[0][1], 2, 1, - &h261_mv_tab[0][0], 2, 1, 1); - init_vlc(&h261_cbp_vlc, H261_CBP_VLC_BITS, 63, - &h261_cbp_tab[0][1], 2, 1, - &h261_cbp_tab[0][0], 2, 1, 1); - init_rl(&h261_rl_tcoeff, ff_h261_rl_table_store); - init_vlc_rl(&h261_rl_tcoeff, 1); - } -} - -static int h261_decode_init(AVCodecContext *avctx){ - H261Context *h= avctx->priv_data; - MpegEncContext * const s = &h->s; - - // set defaults - MPV_decode_defaults(s); - s->avctx = avctx; - - s->width = s->avctx->coded_width; - s->height = s->avctx->coded_height; - s->codec_id = s->avctx->codec->id; - - s->out_format = FMT_H261; - s->low_delay= 1; - avctx->pix_fmt= PIX_FMT_YUV420P; - - s->codec_id= avctx->codec->id; - - h261_decode_init_vlc(h); - - h->gob_start_code_skipped = 0; - - return 0; -} - -/** - * decodes the group of blocks header or slice header. - * @return <0 if an error occured - */ -static int h261_decode_gob_header(H261Context *h){ - unsigned int val; - MpegEncContext * const s = &h->s; - - if ( !h->gob_start_code_skipped ){ - /* Check for GOB Start Code */ - val = show_bits(&s->gb, 15); - if(val) - return -1; - - /* We have a GBSC */ - skip_bits(&s->gb, 16); - } - - h->gob_start_code_skipped = 0; - - h->gob_number = get_bits(&s->gb, 4); /* GN */ - s->qscale = get_bits(&s->gb, 5); /* GQUANT */ - - /* Check if gob_number is valid */ - if (s->mb_height==18){ //cif - if ((h->gob_number<=0) || (h->gob_number>12)) - return -1; - } - else{ //qcif - if ((h->gob_number!=1) && (h->gob_number!=3) && (h->gob_number!=5)) - return -1; - } - - /* GEI */ - while (get_bits1(&s->gb) != 0) { - skip_bits(&s->gb, 8); - } - - if(s->qscale==0) - return -1; - - // For the first transmitted macroblock in a GOB, MBA is the absolute address. For - // subsequent macroblocks, MBA is the difference between the absolute addresses of - // the macroblock and the last transmitted macroblock. - h->current_mba = 0; - h->mba_diff = 0; - - return 0; -} - -/** - * decodes the group of blocks / video packet header. - * @return <0 if no resync found - */ -static int ff_h261_resync(H261Context *h){ - MpegEncContext * const s = &h->s; - int left, ret; - - if ( h->gob_start_code_skipped ){ - ret= h261_decode_gob_header(h); - if(ret>=0) - return 0; - } - else{ - if(show_bits(&s->gb, 15)==0){ - ret= h261_decode_gob_header(h); - if(ret>=0) - return 0; - } - //OK, it is not where it is supposed to be ... - s->gb= s->last_resync_gb; - align_get_bits(&s->gb); - left= s->gb.size_in_bits - get_bits_count(&s->gb); - - for(;left>15+1+4+5; left-=8){ - if(show_bits(&s->gb, 15)==0){ - GetBitContext bak= s->gb; - - ret= h261_decode_gob_header(h); - if(ret>=0) - return 0; - - s->gb= bak; - } - skip_bits(&s->gb, 8); - } - } - - return -1; -} - -/** - * decodes skipped macroblocks - * @return 0 - */ -static int h261_decode_mb_skipped(H261Context *h, int mba1, int mba2 ) -{ - MpegEncContext * const s = &h->s; - int i; - - s->mb_intra = 0; - - for(i=mba1; i<mba2; i++){ - int j, xy; - - s->mb_x= ((h->gob_number-1) % 2) * 11 + i % 11; - s->mb_y= ((h->gob_number-1) / 2) * 3 + i / 11; - xy = s->mb_x + s->mb_y * s->mb_stride; - ff_init_block_index(s); - ff_update_block_index(s); - - for(j=0;j<6;j++) - s->block_last_index[j] = -1; - - s->mv_dir = MV_DIR_FORWARD; - s->mv_type = MV_TYPE_16X16; - s->current_picture.mb_type[xy]= MB_TYPE_SKIP | MB_TYPE_16x16 | MB_TYPE_L0; - s->mv[0][0][0] = 0; - s->mv[0][0][1] = 0; - s->mb_skipped = 1; - h->mtype &= ~MB_TYPE_H261_FIL; - - MPV_decode_mb(s, s->block); - } - - return 0; -} - -static int decode_mv_component(GetBitContext *gb, int v){ - int mv_diff = get_vlc2(gb, h261_mv_vlc.table, H261_MV_VLC_BITS, 2); - - /* check if mv_diff is valid */ - if ( mv_diff < 0 ) - return v; - - mv_diff = mvmap[mv_diff]; - - if(mv_diff && !get_bits1(gb)) - mv_diff= -mv_diff; - - v += mv_diff; - if (v <=-16) v+= 32; - else if(v >= 16) v-= 32; - - return v; -} - -static int h261_decode_mb(H261Context *h){ - MpegEncContext * const s = &h->s; - int i, cbp, xy; - - cbp = 63; - // Read mba - do{ - h->mba_diff = get_vlc2(&s->gb, h261_mba_vlc.table, H261_MBA_VLC_BITS, 2); - - /* Check for slice end */ - /* NOTE: GOB can be empty (no MB data) or exist only of MBA_stuffing */ - if (h->mba_diff == MBA_STARTCODE){ // start code - h->gob_start_code_skipped = 1; - return SLICE_END; - } - } - while( h->mba_diff == MBA_STUFFING ); // stuffing - - if ( h->mba_diff < 0 ){ - if ( get_bits_count(&s->gb) + 7 >= s->gb.size_in_bits ) - return SLICE_END; - - av_log(s->avctx, AV_LOG_ERROR, "illegal mba at %d %d\n", s->mb_x, s->mb_y); - return SLICE_ERROR; - } - - h->mba_diff += 1; - h->current_mba += h->mba_diff; - - if ( h->current_mba > MBA_STUFFING ) - return SLICE_ERROR; - - s->mb_x= ((h->gob_number-1) % 2) * 11 + ((h->current_mba-1) % 11); - s->mb_y= ((h->gob_number-1) / 2) * 3 + ((h->current_mba-1) / 11); - xy = s->mb_x + s->mb_y * s->mb_stride; - ff_init_block_index(s); - ff_update_block_index(s); - - // Read mtype - h->mtype = get_vlc2(&s->gb, h261_mtype_vlc.table, H261_MTYPE_VLC_BITS, 2); - h->mtype = h261_mtype_map[h->mtype]; - - // Read mquant - if ( IS_QUANT ( h->mtype ) ){ - ff_set_qscale(s, get_bits(&s->gb, 5)); - } - - s->mb_intra = IS_INTRA4x4(h->mtype); - - // Read mv - if ( IS_16X16 ( h->mtype ) ){ - // Motion vector data is included for all MC macroblocks. MVD is obtained from the macroblock vector by subtracting the - // vector of the preceding macroblock. For this calculation the vector of the preceding macroblock is regarded as zero in the - // following three situations: - // 1) evaluating MVD for macroblocks 1, 12 and 23; - // 2) evaluating MVD for macroblocks in which MBA does not represent a difference of 1; - // 3) MTYPE of the previous macroblock was not MC. - if ( ( h->current_mba == 1 ) || ( h->current_mba == 12 ) || ( h->current_mba == 23 ) || - ( h->mba_diff != 1)) - { - h->current_mv_x = 0; - h->current_mv_y = 0; - } - - h->current_mv_x= decode_mv_component(&s->gb, h->current_mv_x); - h->current_mv_y= decode_mv_component(&s->gb, h->current_mv_y); - }else{ - h->current_mv_x = 0; - h->current_mv_y = 0; - } - - // Read cbp - if ( HAS_CBP( h->mtype ) ){ - cbp = get_vlc2(&s->gb, h261_cbp_vlc.table, H261_CBP_VLC_BITS, 2) + 1; - } - - if(s->mb_intra){ - s->current_picture.mb_type[xy]= MB_TYPE_INTRA; - goto intra; - } - - //set motion vectors - s->mv_dir = MV_DIR_FORWARD; - s->mv_type = MV_TYPE_16X16; - s->current_picture.mb_type[xy]= MB_TYPE_16x16 | MB_TYPE_L0; - s->mv[0][0][0] = h->current_mv_x * 2;//gets divided by 2 in motion compensation - s->mv[0][0][1] = h->current_mv_y * 2; - -intra: - /* decode each block */ - if(s->mb_intra || HAS_CBP(h->mtype)){ - s->dsp.clear_blocks(s->block[0]); - for (i = 0; i < 6; i++) { - if (h261_decode_block(h, s->block[i], i, cbp&32) < 0){ - return SLICE_ERROR; - } - cbp+=cbp; - } - }else{ - for (i = 0; i < 6; i++) - s->block_last_index[i]= -1; - } - - MPV_decode_mb(s, s->block); - - return SLICE_OK; -} - -/** - * decodes a macroblock - * @return <0 if an error occured - */ -static int h261_decode_block(H261Context * h, DCTELEM * block, - int n, int coded) -{ - MpegEncContext * const s = &h->s; - int code, level, i, j, run; - RLTable *rl = &h261_rl_tcoeff; - const uint8_t *scan_table; - - // For the variable length encoding there are two code tables, one being used for - // the first transmitted LEVEL in INTER, INTER+MC and INTER+MC+FIL blocks, the second - // for all other LEVELs except the first one in INTRA blocks which is fixed length - // coded with 8 bits. - // NOTE: the two code tables only differ in one VLC so we handle that manually. - scan_table = s->intra_scantable.permutated; - if (s->mb_intra){ - /* DC coef */ - level = get_bits(&s->gb, 8); - // 0 (00000000b) and -128 (10000000b) are FORBIDDEN - if((level&0x7F) == 0){ - av_log(s->avctx, AV_LOG_ERROR, "illegal dc %d at %d %d\n", level, s->mb_x, s->mb_y); - return -1; - } - // The code 1000 0000 is not used, the reconstruction level of 1024 being coded as 1111 1111. - if (level == 255) - level = 128; - block[0] = level; - i = 1; - }else if(coded){ - // Run Level Code - // EOB Not possible for first level when cbp is available (that's why the table is different) - // 0 1 1s - // * * 0* - int check = show_bits(&s->gb, 2); - i = 0; - if ( check & 0x2 ){ - skip_bits(&s->gb, 2); - block[0] = ( check & 0x1 ) ? -1 : 1; - i = 1; - } - }else{ - i = 0; - } - if(!coded){ - s->block_last_index[n] = i - 1; - return 0; - } - for(;;){ - code = get_vlc2(&s->gb, rl->vlc.table, TCOEFF_VLC_BITS, 2); - if (code < 0){ - av_log(s->avctx, AV_LOG_ERROR, "illegal ac vlc code at %dx%d\n", s->mb_x, s->mb_y); - return -1; - } - if (code == rl->n) { - /* escape */ - // The remaining combinations of (run, level) are encoded with a 20-bit word consisting of 6 bits escape, 6 bits run and 8 bits level. - run = get_bits(&s->gb, 6); - level = get_sbits(&s->gb, 8); - }else if(code == 0){ - break; - }else{ - run = rl->table_run[code]; - level = rl->table_level[code]; - if (get_bits1(&s->gb)) - level = -level; - } - i += run; - if (i >= 64){ - av_log(s->avctx, AV_LOG_ERROR, "run overflow at %dx%d\n", s->mb_x, s->mb_y); - return -1; - } - j = scan_table[i]; - block[j] = level; - i++; - } - s->block_last_index[n] = i-1; - return 0; -} - -/** - * decodes the H261 picture header. - * @return <0 if no startcode found - */ -static int h261_decode_picture_header(H261Context *h){ - MpegEncContext * const s = &h->s; - int format, i; - uint32_t startcode= 0; - - for(i= s->gb.size_in_bits - get_bits_count(&s->gb); i>24; i-=1){ - startcode = ((startcode << 1) | get_bits(&s->gb, 1)) & 0x000FFFFF; - - if(startcode == 0x10) - break; - } - - if (startcode != 0x10){ - av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); - return -1; - } - - /* temporal reference */ - i= get_bits(&s->gb, 5); /* picture timestamp */ - if(i < (s->picture_number&31)) - i += 32; - s->picture_number = (s->picture_number&~31) + i; - - s->avctx->time_base= (AVRational){1001, 30000}; - s->current_picture.pts= s->picture_number; - - - /* PTYPE starts here */ - skip_bits1(&s->gb); /* split screen off */ - skip_bits1(&s->gb); /* camera off */ - skip_bits1(&s->gb); /* freeze picture release off */ - - format = get_bits1(&s->gb); - - //only 2 formats possible - if (format == 0){//QCIF - s->width = 176; - s->height = 144; - s->mb_width = 11; - s->mb_height = 9; - }else{//CIF - s->width = 352; - s->height = 288; - s->mb_width = 22; - s->mb_height = 18; - } - - s->mb_num = s->mb_width * s->mb_height; - - skip_bits1(&s->gb); /* still image mode off */ - skip_bits1(&s->gb); /* Reserved */ - - /* PEI */ - while (get_bits1(&s->gb) != 0){ - skip_bits(&s->gb, 8); - } - - // h261 has no I-FRAMES, but if we pass I_TYPE for the first frame, the codec crashes if it does - // not contain all I-blocks (e.g. when a packet is lost) - s->pict_type = P_TYPE; - - h->gob_number = 0; - return 0; -} - -static int h261_decode_gob(H261Context *h){ - MpegEncContext * const s = &h->s; - - ff_set_qscale(s, s->qscale); - - /* decode mb's */ - while(h->current_mba <= MBA_STUFFING) - { - int ret; - /* DCT & quantize */ - ret= h261_decode_mb(h); - if(ret<0){ - if(ret==SLICE_END){ - h261_decode_mb_skipped(h, h->current_mba, 33); - return 0; - } - av_log(s->avctx, AV_LOG_ERROR, "Error at MB: %d\n", s->mb_x + s->mb_y*s->mb_stride); - return -1; - } - - h261_decode_mb_skipped(h, h->current_mba-h->mba_diff, h->current_mba-1); - } - - return -1; -} - -/** - * returns the number of bytes consumed for building the current frame - */ -static int get_consumed_bytes(MpegEncContext *s, int buf_size){ - int pos= get_bits_count(&s->gb)>>3; - if(pos==0) pos=1; //avoid infinite loops (i doubt that is needed but ...) - if(pos+10>buf_size) pos=buf_size; // oops ;) - - return pos; -} - -static int h261_decode_frame(AVCodecContext *avctx, - void *data, int *data_size, - const uint8_t *buf, int buf_size) -{ - H261Context *h= avctx->priv_data; - MpegEncContext *s = &h->s; - int ret; - AVFrame *pict = data; - -#ifdef DEBUG - av_log(avctx, AV_LOG_DEBUG, "*****frame %d size=%d\n", avctx->frame_number, buf_size); - av_log(avctx, AV_LOG_DEBUG, "bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]); -#endif - s->flags= avctx->flags; - s->flags2= avctx->flags2; - - h->gob_start_code_skipped=0; - -retry: - - init_get_bits(&s->gb, buf, buf_size*8); - - if(!s->context_initialized){ - if (MPV_common_init(s) < 0) //we need the idct permutaton for reading a custom matrix - return -1; - } - - //we need to set current_picture_ptr before reading the header, otherwise we cannot store anyting im there - if(s->current_picture_ptr==NULL || s->current_picture_ptr->data[0]){ - int i= ff_find_unused_picture(s, 0); - s->current_picture_ptr= &s->picture[i]; - } - - ret = h261_decode_picture_header(h); - - /* skip if the header was thrashed */ - if (ret < 0){ - av_log(s->avctx, AV_LOG_ERROR, "header damaged\n"); - return -1; - } - - if (s->width != avctx->coded_width || s->height != avctx->coded_height){ - ParseContext pc= s->parse_context; //FIXME move this demuxing hack to libavformat - s->parse_context.buffer=0; - MPV_common_end(s); - s->parse_context= pc; - } - if (!s->context_initialized) { - avcodec_set_dimensions(avctx, s->width, s->height); - - goto retry; - } - - // for hurry_up==5 - s->current_picture.pict_type= s->pict_type; - s->current_picture.key_frame= s->pict_type == I_TYPE; - - /* skip everything if we are in a hurry>=5 */ - if(avctx->hurry_up>=5) return get_consumed_bytes(s, buf_size); - if( (avctx->skip_frame >= AVDISCARD_NONREF && s->pict_type==B_TYPE) - ||(avctx->skip_frame >= AVDISCARD_NONKEY && s->pict_type!=I_TYPE) - || avctx->skip_frame >= AVDISCARD_ALL) - return get_consumed_bytes(s, buf_size); - - if(MPV_frame_start(s, avctx) < 0) - return -1; - - ff_er_frame_start(s); - - /* decode each macroblock */ - s->mb_x=0; - s->mb_y=0; - - while(h->gob_number < (s->mb_height==18 ? 12 : 5)){ - if(ff_h261_resync(h)<0) - break; - h261_decode_gob(h); - } - MPV_frame_end(s); - -assert(s->current_picture.pict_type == s->current_picture_ptr->pict_type); -assert(s->current_picture.pict_type == s->pict_type); - *pict= *(AVFrame*)s->current_picture_ptr; - ff_print_debug_info(s, pict); - - *data_size = sizeof(AVFrame); - - return get_consumed_bytes(s, buf_size); -} - -static int h261_decode_end(AVCodecContext *avctx) -{ - H261Context *h= avctx->priv_data; - MpegEncContext *s = &h->s; - - MPV_common_end(s); - return 0; -} - -AVCodec h261_decoder = { - "h261", - CODEC_TYPE_VIDEO, - CODEC_ID_H261, - sizeof(H261Context), - h261_decode_init, - NULL, - h261_decode_end, - h261_decode_frame, - CODEC_CAP_DR1, -}; |