1/* 2 * FLV decoding. 3 * This file is part of FFmpeg. 4 * 5 * FFmpeg is free software; you can redistribute it and/or 6 * modify it under the terms of the GNU Lesser General Public 7 * License as published by the Free Software Foundation; either 8 * version 2.1 of the License, or (at your option) any later version. 9 * 10 * FFmpeg is distributed in the hope that it will be useful, 11 * but WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * Lesser General Public License for more details. 14 * 15 * You should have received a copy of the GNU Lesser General Public 16 * License along with FFmpeg; if not, write to the Free Software 17 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 18 */ 19 20#include "mpegvideo.h" 21#include "h263.h" 22#include "flv.h" 23 24void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last){ 25 int is11 = get_bits1(gb); 26 *last = get_bits1(gb); 27 *run = get_bits(gb, 6); 28 if(is11){ 29 *level = get_sbits(gb, 11); 30 } else { 31 *level = get_sbits(gb, 7); 32 } 33} 34 35int ff_flv_decode_picture_header(MpegEncContext *s) 36{ 37 int format, width, height; 38 39 /* picture header */ 40 if (get_bits_long(&s->gb, 17) != 1) { 41 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); 42 return -1; 43 } 44 format = get_bits(&s->gb, 5); 45 if (format != 0 && format != 1) { 46 av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n"); 47 return -1; 48 } 49 s->h263_flv = format+1; 50 s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */ 51 format = get_bits(&s->gb, 3); 52 switch (format) { 53 case 0: 54 width = get_bits(&s->gb, 8); 55 height = get_bits(&s->gb, 8); 56 break; 57 case 1: 58 width = get_bits(&s->gb, 16); 59 height = get_bits(&s->gb, 16); 60 break; 61 case 2: 62 width = 352; 63 height = 288; 64 break; 65 case 3: 66 width = 176; 67 height = 144; 68 break; 69 case 4: 70 width = 128; 71 height = 96; 72 break; 73 case 5: 74 width = 320; 75 height = 240; 76 break; 77 case 6: 78 width = 160; 79 height = 120; 80 break; 81 default: 82 width = height = 0; 83 break; 84 } 85 if(avcodec_check_dimensions(s->avctx, width, height)) 86 return -1; 87 s->width = width; 88 s->height = height; 89 90 s->pict_type = FF_I_TYPE + get_bits(&s->gb, 2); 91 s->dropable= s->pict_type > FF_P_TYPE; 92 if (s->dropable) 93 s->pict_type = FF_P_TYPE; 94 95 skip_bits1(&s->gb); /* deblocking flag */ 96 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5); 97 98 s->h263_plus = 0; 99 100 s->unrestricted_mv = 1; 101 s->h263_long_vectors = 0; 102 103 /* PEI */ 104 while (get_bits1(&s->gb) != 0) { 105 skip_bits(&s->gb, 8); 106 } 107 s->f_code = 1; 108 109 if(s->avctx->debug & FF_DEBUG_PICT_INFO){ 110 av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n", 111 s->dropable ? 'D' : av_get_pict_type_char(s->pict_type), s->h263_flv-1, s->qscale, s->picture_number); 112 } 113 114 s->y_dc_scale_table= 115 s->c_dc_scale_table= ff_mpeg1_dc_scale_table; 116 117 return 0; 118} 119 120AVCodec flv_decoder = { 121 "flv", 122 AVMEDIA_TYPE_VIDEO, 123 CODEC_ID_FLV1, 124 sizeof(MpegEncContext), 125 ff_h263_decode_init, 126 NULL, 127 ff_h263_decode_end, 128 ff_h263_decode_frame, 129 CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1, 130 .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV) / Sorenson Spark / Sorenson H.263"), 131 .pix_fmts= ff_pixfmt_list_420, 132}; 133