From d632239c9cc5d97397b283bb7a36f2d9e818e1bd Mon Sep 17 00:00:00 2001 From: Panagiotis Issaris Date: Mon, 21 May 2007 12:51:29 +0000 Subject: Split the h261.c file into separate files for the encoder, decoder and common stuff. Originally committed as revision 9090 to svn://svn.ffmpeg.org/ffmpeg/trunk --- libavcodec/h261.c | 942 +----------------------------------------------------- 1 file changed, 3 insertions(+), 939 deletions(-) (limited to 'libavcodec/h261.c') diff --git a/libavcodec/h261.c b/libavcodec/h261.c index 042e683f90..1cf1e48992 100644 --- a/libavcodec/h261.c +++ b/libavcodec/h261.c @@ -1,5 +1,5 @@ /* - * H261 decoder + * H261 common code * Copyright (c) 2002-2004 Michael Niedermayer * Copyright (c) 2004 Maarten Daniels * @@ -27,37 +27,12 @@ #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 #define IS_FIL(a) ((a)&MB_TYPE_H261_FIL) -/** - * H261Context - */ -typedef struct H261Context{ - MpegEncContext s; - - int current_mba; - int previous_mba; - int mba_diff; - int mtype; - int current_mv_x; - int current_mv_y; - int gob_number; - int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read -}H261Context; - -static uint8_t static_rl_table_store[2][2*MAX_RUN + MAX_LEVEL + 3]; +uint8_t ff_h261_rl_table_store[2][2*MAX_RUN + MAX_LEVEL + 3]; void ff_h261_loop_filter(MpegEncContext *s){ H261Context * h= (H261Context*)s; @@ -78,914 +53,3 @@ void ff_h261_loop_filter(MpegEncContext *s){ s->dsp.h261_loop_filter(dest_cr, uvlinesize); } -int ff_h261_get_picture_format(int width, int height){ - // QCIF - if (width == 176 && height == 144) - return 0; - // CIF - else if (width == 352 && height == 288) - return 1; - // ERROR - else - return -1; -} - -static void h261_encode_block(H261Context * h, DCTELEM * block, - int n); -static int h261_decode_block(H261Context *h, DCTELEM *block, - int n, int coded); - -void ff_h261_encode_picture_header(MpegEncContext * s, int picture_number){ - H261Context * h = (H261Context *) s; - int format, temp_ref; - - align_put_bits(&s->pb); - - /* Update the pointer to last GOB */ - s->ptr_lastgob = pbBufPtr(&s->pb); - - put_bits(&s->pb, 20, 0x10); /* PSC */ - - temp_ref= s->picture_number * (int64_t)30000 * s->avctx->time_base.num / - (1001 * (int64_t)s->avctx->time_base.den); //FIXME maybe this should use a timestamp - put_bits(&s->pb, 5, temp_ref & 0x1f); /* TemporalReference */ - - 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 */ - - format = ff_h261_get_picture_format(s->width, s->height); - - put_bits(&s->pb, 1, format); /* 0 == QCIF, 1 == CIF */ - - put_bits(&s->pb, 1, 0); /* still image mode */ - put_bits(&s->pb, 1, 0); /* reserved */ - - put_bits(&s->pb, 1, 0); /* no PEI */ - if(format == 0) - h->gob_number = -1; - else - h->gob_number = 0; - h->current_mba = 0; -} - -/** - * Encodes a group of blocks header. - */ -static void h261_encode_gob_header(MpegEncContext * s, int mb_line){ - H261Context * h = (H261Context *)s; - if(ff_h261_get_picture_format(s->width, s->height) == 0){ - h->gob_number+=2; // QCIF - } - else{ - h->gob_number++; // CIF - } - put_bits(&s->pb, 16, 1); /* GBSC */ - put_bits(&s->pb, 4, h->gob_number); /* GN */ - put_bits(&s->pb, 5, s->qscale); /* GQUANT */ - put_bits(&s->pb, 1, 0); /* no GEI */ - h->current_mba = 0; - h->previous_mba = 0; - h->current_mv_x=0; - h->current_mv_y=0; -} - -void ff_h261_reorder_mb_index(MpegEncContext* s){ - int index= s->mb_x + s->mb_y*s->mb_width; - - if(index % 33 == 0) - h261_encode_gob_header(s,0); - - /* for CIF the GOB's are fragmented in the middle of a scanline - that's why we need to adjust the x and y index of the macroblocks */ - if(ff_h261_get_picture_format(s->width,s->height) == 1){ // CIF - s->mb_x = index % 11 ; index /= 11; - s->mb_y = index % 3 ; index /= 3; - s->mb_x+= 11*(index % 2); index /= 2; - s->mb_y+= 3*index; - - ff_init_block_index(s); - ff_update_block_index(s); - } -} - -static void h261_encode_motion(H261Context * h, int val){ - MpegEncContext * const s = &h->s; - int sign, code; - if(val==0){ - code = 0; - put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]); - } - else{ - if(val > 15) - val -=32; - if(val < -16) - val+=32; - sign = val < 0; - code = sign ? -val : val; - put_bits(&s->pb,h261_mv_tab[code][1],h261_mv_tab[code][0]); - put_bits(&s->pb,1,sign); - } -} - -static inline int get_cbp(MpegEncContext * s, - DCTELEM block[6][64]) -{ - int i, cbp; - cbp= 0; - for (i = 0; i < 6; i++) { - if (s->block_last_index[i] >= 0) - cbp |= 1 << (5 - i); - } - return cbp; -} -void ff_h261_encode_mb(MpegEncContext * s, - DCTELEM block[6][64], - int motion_x, int motion_y) -{ - H261Context * h = (H261Context *)s; - int mvd, mv_diff_x, mv_diff_y, i, cbp; - cbp = 63; // avoid warning - mvd = 0; - - h->current_mba++; - h->mtype = 0; - - if (!s->mb_intra){ - /* compute cbp */ - cbp= get_cbp(s, block); - - /* mvd indicates if this block is motion compensated */ - mvd = motion_x | motion_y; - - if((cbp | mvd | s->dquant ) == 0) { - /* skip macroblock */ - s->skip_count++; - h->current_mv_x=0; - h->current_mv_y=0; - return; - } - } - - /* MB is not skipped, encode MBA */ - put_bits(&s->pb, h261_mba_bits[(h->current_mba-h->previous_mba)-1], h261_mba_code[(h->current_mba-h->previous_mba)-1]); - - /* calculate MTYPE */ - if(!s->mb_intra){ - h->mtype++; - - if(mvd || s->loop_filter) - h->mtype+=3; - if(s->loop_filter) - h->mtype+=3; - if(cbp || s->dquant) - h->mtype++; - assert(h->mtype > 1); - } - - if(s->dquant) - h->mtype++; - - put_bits(&s->pb, h261_mtype_bits[h->mtype], h261_mtype_code[h->mtype]); - - h->mtype = h261_mtype_map[h->mtype]; - - if(IS_QUANT(h->mtype)){ - ff_set_qscale(s,s->qscale+s->dquant); - put_bits(&s->pb, 5, s->qscale); - } - - if(IS_16X16(h->mtype)){ - mv_diff_x = (motion_x >> 1) - h->current_mv_x; - mv_diff_y = (motion_y >> 1) - h->current_mv_y; - h->current_mv_x = (motion_x >> 1); - h->current_mv_y = (motion_y >> 1); - h261_encode_motion(h,mv_diff_x); - h261_encode_motion(h,mv_diff_y); - } - - h->previous_mba = h->current_mba; - - if(HAS_CBP(h->mtype)){ - assert(cbp>0); - put_bits(&s->pb,h261_cbp_tab[cbp-1][1],h261_cbp_tab[cbp-1][0]); - } - for(i=0; i<6; i++) { - /* encode each block */ - h261_encode_block(h, block[i], i); - } - - if ( ( h->current_mba == 11 ) || ( h->current_mba == 22 ) || ( h->current_mba == 33 ) || ( !IS_16X16 ( h->mtype ) )){ - h->current_mv_x=0; - h->current_mv_y=0; - } -} - -void ff_h261_encode_init(MpegEncContext *s){ - static int done = 0; - - if (!done) { - done = 1; - init_rl(&h261_rl_tcoeff, static_rl_table_store); - } - - s->min_qcoeff= -127; - s->max_qcoeff= 127; - s->y_dc_scale_table= - s->c_dc_scale_table= ff_mpeg1_dc_scale_table; -} - - -/** - * encodes a 8x8 block. - * @param block the 8x8 block - * @param n block index (0-3 are luma, 4-5 are chroma) - */ -static void h261_encode_block(H261Context * h, DCTELEM * block, int n){ - MpegEncContext * const s = &h->s; - int level, run, last, i, j, last_index, last_non_zero, sign, slevel, code; - RLTable *rl; - - rl = &h261_rl_tcoeff; - if (s->mb_intra) { - /* DC coef */ - level = block[0]; - /* 255 cannot be represented, so we clamp */ - if (level > 254) { - level = 254; - block[0] = 254; - } - /* 0 cannot be represented also */ - else if (level < 1) { - level = 1; - block[0] = 1; - } - if (level == 128) - put_bits(&s->pb, 8, 0xff); - else - put_bits(&s->pb, 8, level); - i = 1; - } else if((block[0]==1 || block[0] == -1) && (s->block_last_index[n] > -1)){ - //special case - put_bits(&s->pb,2,block[0]>0 ? 2 : 3 ); - 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 = s->intra_scantable.permutated[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, 0 /*no last in H.261, EOB is used*/, run, level); - if(run==0 && level < 16) - code+=1; - put_bits(&s->pb, rl->table_vlc[code][1], rl->table_vlc[code][0]); - if (code == rl->n) { - put_bits(&s->pb, 6, run); - assert(slevel != 0); - assert(level <= 127); - put_bits(&s->pb, 8, slevel & 0xff); - } else { - put_bits(&s->pb, 1, sign); - } - last_non_zero = i; - } - } - if(last_index > -1){ - put_bits(&s->pb, rl->table_vlc[0][1], rl->table_vlc[0][0]);// END OF BLOCK - } -} - -/***********************************************/ -/* decoding */ - -static VLC h261_mba_vlc; -static VLC h261_mtype_vlc; -static VLC h261_mv_vlc; -static VLC h261_cbp_vlc; - -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, static_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, its not where its 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; imb_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 thats 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, - 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 cant 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 these demuxng hack to avformat - 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; -} - -#ifdef CONFIG_ENCODERS -AVCodec h261_encoder = { - "h261", - CODEC_TYPE_VIDEO, - CODEC_ID_H261, - sizeof(H261Context), - MPV_encode_init, - MPV_encode_picture, - MPV_encode_end, - .pix_fmts= (enum PixelFormat[]){PIX_FMT_YUV420P, -1}, -}; -#endif - -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, -}; -- cgit v1.2.3