00001 /* 00002 * H.263i decoder 00003 * 00004 * This file is part of FFmpeg. 00005 * 00006 * FFmpeg is free software; you can redistribute it and/or 00007 * modify it under the terms of the GNU Lesser General Public 00008 * License as published by the Free Software Foundation; either 00009 * version 2.1 of the License, or (at your option) any later version. 00010 * 00011 * FFmpeg is distributed in the hope that it will be useful, 00012 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00013 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00014 * Lesser General Public License for more details. 00015 * 00016 * You should have received a copy of the GNU Lesser General Public 00017 * License along with FFmpeg; if not, write to the Free Software 00018 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00019 */ 00020 00021 #include "mpegvideo.h" 00022 #include "h263.h" 00023 00024 /* don't understand why they choose a different header ! */ 00025 int ff_intel_h263_decode_picture_header(MpegEncContext *s) 00026 { 00027 int format; 00028 00029 /* picture header */ 00030 if (get_bits_long(&s->gb, 22) != 0x20) { 00031 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); 00032 return -1; 00033 } 00034 s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */ 00035 00036 if (get_bits1(&s->gb) != 1) { 00037 av_log(s->avctx, AV_LOG_ERROR, "Bad marker\n"); 00038 return -1; /* marker */ 00039 } 00040 if (get_bits1(&s->gb) != 0) { 00041 av_log(s->avctx, AV_LOG_ERROR, "Bad H263 id\n"); 00042 return -1; /* h263 id */ 00043 } 00044 skip_bits1(&s->gb); /* split screen off */ 00045 skip_bits1(&s->gb); /* camera off */ 00046 skip_bits1(&s->gb); /* freeze picture release off */ 00047 00048 format = get_bits(&s->gb, 3); 00049 if (format == 0 || format == 6) { 00050 av_log(s->avctx, AV_LOG_ERROR, "Intel H263 free format not supported\n"); 00051 return -1; 00052 } 00053 s->h263_plus = 0; 00054 00055 s->pict_type = AV_PICTURE_TYPE_I + get_bits1(&s->gb); 00056 00057 s->unrestricted_mv = get_bits1(&s->gb); 00058 s->h263_long_vectors = s->unrestricted_mv; 00059 00060 if (get_bits1(&s->gb) != 0) { 00061 av_log(s->avctx, AV_LOG_ERROR, "SAC not supported\n"); 00062 return -1; /* SAC: off */ 00063 } 00064 s->obmc= get_bits1(&s->gb); 00065 s->pb_frame = get_bits1(&s->gb); 00066 00067 if (format < 6) { 00068 s->width = h263_format[format][0]; 00069 s->height = h263_format[format][1]; 00070 s->avctx->sample_aspect_ratio.num = 12; 00071 s->avctx->sample_aspect_ratio.den = 11; 00072 } else { 00073 format = get_bits(&s->gb, 3); 00074 if(format == 0 || format == 7){ 00075 av_log(s->avctx, AV_LOG_ERROR, "Wrong Intel H263 format\n"); 00076 return -1; 00077 } 00078 if(get_bits(&s->gb, 2)) 00079 av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n"); 00080 s->loop_filter = get_bits1(&s->gb); 00081 if(get_bits1(&s->gb)) 00082 av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n"); 00083 if(get_bits1(&s->gb)) 00084 s->pb_frame = 2; 00085 if(get_bits(&s->gb, 5)) 00086 av_log(s->avctx, AV_LOG_ERROR, "Bad value for reserved field\n"); 00087 if(get_bits(&s->gb, 5) != 1) 00088 av_log(s->avctx, AV_LOG_ERROR, "Invalid marker\n"); 00089 } 00090 if(format == 6){ 00091 int ar = get_bits(&s->gb, 4); 00092 skip_bits(&s->gb, 9); // display width 00093 skip_bits1(&s->gb); 00094 skip_bits(&s->gb, 9); // display height 00095 if(ar == 15){ 00096 s->avctx->sample_aspect_ratio.num = get_bits(&s->gb, 8); // aspect ratio - width 00097 s->avctx->sample_aspect_ratio.den = get_bits(&s->gb, 8); // aspect ratio - height 00098 } else { 00099 s->avctx->sample_aspect_ratio = ff_h263_pixel_aspect[ar]; 00100 } 00101 if (s->avctx->sample_aspect_ratio.num == 0) 00102 av_log(s->avctx, AV_LOG_ERROR, "Invalid aspect ratio.\n"); 00103 } 00104 00105 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5); 00106 skip_bits1(&s->gb); /* Continuous Presence Multipoint mode: off */ 00107 00108 if(s->pb_frame){ 00109 skip_bits(&s->gb, 3); //temporal reference for B-frame 00110 skip_bits(&s->gb, 2); //dbquant 00111 } 00112 00113 /* PEI */ 00114 while (get_bits1(&s->gb) != 0) { 00115 skip_bits(&s->gb, 8); 00116 } 00117 s->f_code = 1; 00118 00119 s->y_dc_scale_table= 00120 s->c_dc_scale_table= ff_mpeg1_dc_scale_table; 00121 00122 ff_h263_show_pict_info(s); 00123 00124 return 0; 00125 } 00126 00127 AVCodec ff_h263i_decoder = { 00128 .name = "h263i", 00129 .type = AVMEDIA_TYPE_VIDEO, 00130 .id = CODEC_ID_H263I, 00131 .priv_data_size = sizeof(MpegEncContext), 00132 .init = ff_h263_decode_init, 00133 .close = ff_h263_decode_end, 00134 .decode = ff_h263_decode_frame, 00135 .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1, 00136 .long_name = NULL_IF_CONFIG_SMALL("Intel H.263"), 00137 .pix_fmts= ff_pixfmt_list_420, 00138 }; 00139