/*
- * H261 decoder
+ * H261 common code
* Copyright (c) 2002-2004 Michael Niedermayer <michaelni@gmx.at>
* Copyright (c) 2004 Maarten Daniels
*
- * This library is free software; you can redistribute it and/or
+ * 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 of the License, or (at your option) any later version.
+ * version 2.1 of the License, or (at your option) any later version.
*
- * This library is distributed in the hope that it will be useful,
+ * 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 this library; if not, write to the Free Software
- * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
+ * License along with FFmpeg; if not, write to the Free Software
+ * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
/**
- * @file h261.c
+ * @file
* h261codec.
*/
-#include "common.h"
#include "dsputil.h"
#include "avcodec.h"
-#include "mpegvideo.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
+#include "h261.h"
-#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 bits_left; //8 - nr of bits left of the following frame in the last byte in this frame
- int last_bits; //bits left of the following frame in the last byte in this frame
- int gob_start_code_skipped; // 1 if gob start code is already read before gob header is read
-}H261Context;
+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;
s->dsp.h261_loop_filter(dest_cr, uvlinesize);
}
-static 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->frame_rate_base /
- (1001 * (int64_t)s->avctx->frame_rate);
- 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){
- /* 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
- if((s->mb_x == 0 && (s->mb_y % 3 == 0) ) || (s->mb_x == 11 && ((s->mb_y -1 )% 3 == 0) ))
- h261_encode_gob_header(s,0);
- if(s->mb_x < 11 ){
- if((s->mb_y % 3) == 1 ){
- s->mb_x += 0;
- s->mb_y += 1;
- }
- else if( (s->mb_y % 3) == 2 ){
- s->mb_x += 11;
- s->mb_y -= 1;
- }
- }
- else{
- if((s->mb_y % 3) == 1 ){
- s->mb_x += 0;
- s->mb_y -= 1;
- }
- else if( (s->mb_y % 3) == 0 ){
- s->mb_x -= 11;
- s->mb_y += 1;
- }
- }
- ff_init_block_index(s);
- ff_update_block_index(s);
- /* for QCIF we don't need to reorder MB's
- there the GOB's aren't fragmented in the middle of a scanline */
- }else if(ff_h261_get_picture_format(s->width,s->height) == 0){ // QCIF
- if(s->mb_y % 3 == 0 && s->mb_x == 0)
- h261_encode_gob_header(s,0);
- }
-}
-
-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 > 16)
- 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)){
- 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);
- }
-
- 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,1,1);
- put_bits(&s->pb,1,block[0]>0 ? 0 : 1 );
- 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);
- if(slevel < -127){
- slevel = -127;
- }
- else if(slevel > 127){
- slevel = 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;
-
-void init_vlc_rl(RLTable *rl);
-
-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);
- init_vlc(&h261_mtype_vlc, H261_MTYPE_VLC_BITS, 10,
- h261_mtype_bits, 1, 1,
- h261_mtype_code, 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);
- init_vlc(&h261_cbp_vlc, H261_CBP_VLC_BITS, 63,
- &h261_cbp_tab[0][1], 2, 1,
- &h261_cbp_tab[0][0], 2, 1);
- init_rl(&h261_rl_tcoeff);
- init_vlc_rl(&h261_rl_tcoeff);
- }
-}
-
-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; 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);
- s->dsp.clear_blocks(s->block[0]);
-
- 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_skiped = 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, old_mtype;
-
- 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);
- s->dsp.clear_blocks(s->block[0]);
-
- // Read mtype
- old_mtype = h->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) || ( !IS_16X16 ( old_mtype ) ))
- {
- 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);
- }
-
- // 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;
- if(IS_16X16 ( h->mtype )){
- 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;
- }
- else{
- h->current_mv_x = s->mv[0][0][0] = 0;
- h->current_mv_x = s->mv[0][0][1] = 0;
- }
-
-intra:
- /* decode each block */
- if(s->mb_intra || HAS_CBP(h->mtype)){
- for (i = 0; i < 6; i++) {
- if (h261_decode_block(h, s->block[i], i, cbp&32) < 0){
- return SLICE_ERROR;
- }
- cbp+=cbp;
- }
- }
-
- 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 = (int8_t)get_bits(&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
- */
-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 */
- s->picture_number = get_bits(&s->gb, 5); /* picture timestamp */
-
- /* 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;
-}
-
-static int h261_find_frame_end(ParseContext *pc, AVCodecContext* avctx, const uint8_t *buf, int buf_size){
- int vop_found, i, j, bits_left, last_bits;
- uint32_t state;
-
- H261Context *h = avctx->priv_data;
-
- if(h){
- bits_left = h->bits_left;
- last_bits = h->last_bits;
- }
- else{
- bits_left = 0;
- last_bits = 0;
- }
-
- vop_found= pc->frame_start_found;
- state= pc->state;
- if(bits_left!=0 && !vop_found)
- state = state << (8-bits_left) | last_bits;
- i=0;
- if(!vop_found){
- for(i=0; i<buf_size; i++){
- state= (state<<8) | buf[i];
- for(j=0; j<8; j++){
- if(( ( (state<<j) | (buf[i]>>(8-j)) )>>(32-20) == 0x10 )&&(((state >> (17-j)) & 0x4000) == 0x0)){
- i++;
- vop_found=1;
- break;
- }
- }
- if(vop_found)
- break;
- }
- }
- if(vop_found){
- for(; i<buf_size; i++){
- if(avctx->flags & CODEC_FLAG_TRUNCATED)//XXX ffplay workaround, someone a better solution?
- state= (state<<8) | buf[i];
- for(j=0; j<8; j++){
- if(( ( (state<<j) | (buf[i]>>(8-j)) )>>(32-20) == 0x10 )&&(((state >> (17-j)) & 0x4000) == 0x0)){
- pc->frame_start_found=0;
- pc->state=-1;
- return i-3;
- }
- }
- }
- }
-
- pc->frame_start_found= vop_found;
- pc->state= state;
- return END_NOT_FOUND;
-}
-
-static int h261_parse(AVCodecParserContext *s,
- AVCodecContext *avctx,
- uint8_t **poutbuf, int *poutbuf_size,
- const uint8_t *buf, int buf_size)
-{
- ParseContext *pc = s->priv_data;
- int next;
-
- next= h261_find_frame_end(pc,avctx, buf, buf_size);
- if (ff_combine_frame(pc, next, (uint8_t **)&buf, &buf_size) < 0) {
- *poutbuf = NULL;
- *poutbuf_size = 0;
- return buf_size;
- }
- *poutbuf = (uint8_t *)buf;
- *poutbuf_size = buf_size;
- return next;
-}
-
-/**
- * returns the number of bytes consumed for building the current frame
- */
-static int get_consumed_bytes(MpegEncContext *s, int buf_size){
- if(s->flags&CODEC_FLAG_TRUNCATED){
- int pos= (get_bits_count(&s->gb)+7)>>3;
- pos -= s->parse_context.last_index;
- if(pos<0) pos=0;// padding is not really read so this might be -1
- return pos;
- }else{
- 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
- printf("*****frame %d size=%d\n", avctx->frame_number, buf_size);
- printf("bytes=%x %x %x %x\n", buf[0], buf[1], buf[2], buf[3]);
-#endif
- s->flags= avctx->flags;
- s->flags2= avctx->flags2;
-
- /* no supplementary picture */
- if (buf_size == 0) {
- return 0;
- }
-
- if(s->flags&CODEC_FLAG_TRUNCATED){
- int next;
-
- next= h261_find_frame_end(&s->parse_context,avctx, buf, buf_size);
-
- if( ff_combine_frame(&s->parse_context, next, &buf, &buf_size) < 0 )
- return buf_size;
- }
-
-
-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(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;
- ff_print_debug_info(s, pict);
-
- /* Return the Picture timestamp as the frame number */
- /* we substract 1 because it is added on utils.c */
- avctx->frame_number = s->picture_number - 1;
-
- *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_encoder = {
- "h261",
- CODEC_TYPE_VIDEO,
- CODEC_ID_H261,
- sizeof(H261Context),
- MPV_encode_init,
- MPV_encode_picture,
- MPV_encode_end,
-};
-
-AVCodec h261_decoder = {
- "h261",
- CODEC_TYPE_VIDEO,
- CODEC_ID_H261,
- sizeof(H261Context),
- h261_decode_init,
- NULL,
- h261_decode_end,
- h261_decode_frame,
- CODEC_CAP_TRUNCATED,
-};
-
-AVCodecParser h261_parser = {
- { CODEC_ID_H261 },
- sizeof(ParseContext),
- NULL,
- h261_parse,
- ff_parse_close,
-};