Libav 0.7.1
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00001 /* 00002 * FLV decoding. 00003 * This file is part of Libav. 00004 * 00005 * Libav is free software; you can redistribute it and/or 00006 * modify it under the terms of the GNU Lesser General Public 00007 * License as published by the Free Software Foundation; either 00008 * version 2.1 of the License, or (at your option) any later version. 00009 * 00010 * Libav is distributed in the hope that it will be useful, 00011 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00012 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00013 * Lesser General Public License for more details. 00014 * 00015 * You should have received a copy of the GNU Lesser General Public 00016 * License along with Libav; if not, write to the Free Software 00017 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00018 */ 00019 00020 #include "mpegvideo.h" 00021 #include "h263.h" 00022 #include "flv.h" 00023 #include "libavutil/imgutils.h" 00024 00025 void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last){ 00026 int is11 = get_bits1(gb); 00027 *last = get_bits1(gb); 00028 *run = get_bits(gb, 6); 00029 if(is11){ 00030 *level = get_sbits(gb, 11); 00031 } else { 00032 *level = get_sbits(gb, 7); 00033 } 00034 } 00035 00036 int ff_flv_decode_picture_header(MpegEncContext *s) 00037 { 00038 int format, width, height; 00039 00040 /* picture header */ 00041 if (get_bits_long(&s->gb, 17) != 1) { 00042 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); 00043 return -1; 00044 } 00045 format = get_bits(&s->gb, 5); 00046 if (format != 0 && format != 1) { 00047 av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n"); 00048 return -1; 00049 } 00050 s->h263_flv = format+1; 00051 s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */ 00052 format = get_bits(&s->gb, 3); 00053 switch (format) { 00054 case 0: 00055 width = get_bits(&s->gb, 8); 00056 height = get_bits(&s->gb, 8); 00057 break; 00058 case 1: 00059 width = get_bits(&s->gb, 16); 00060 height = get_bits(&s->gb, 16); 00061 break; 00062 case 2: 00063 width = 352; 00064 height = 288; 00065 break; 00066 case 3: 00067 width = 176; 00068 height = 144; 00069 break; 00070 case 4: 00071 width = 128; 00072 height = 96; 00073 break; 00074 case 5: 00075 width = 320; 00076 height = 240; 00077 break; 00078 case 6: 00079 width = 160; 00080 height = 120; 00081 break; 00082 default: 00083 width = height = 0; 00084 break; 00085 } 00086 if(av_image_check_size(width, height, 0, s->avctx)) 00087 return -1; 00088 s->width = width; 00089 s->height = height; 00090 00091 s->pict_type = AV_PICTURE_TYPE_I + get_bits(&s->gb, 2); 00092 s->dropable= s->pict_type > AV_PICTURE_TYPE_P; 00093 if (s->dropable) 00094 s->pict_type = AV_PICTURE_TYPE_P; 00095 00096 skip_bits1(&s->gb); /* deblocking flag */ 00097 s->chroma_qscale= s->qscale = get_bits(&s->gb, 5); 00098 00099 s->h263_plus = 0; 00100 00101 s->unrestricted_mv = 1; 00102 s->h263_long_vectors = 0; 00103 00104 /* PEI */ 00105 while (get_bits1(&s->gb) != 0) { 00106 skip_bits(&s->gb, 8); 00107 } 00108 s->f_code = 1; 00109 00110 if(s->avctx->debug & FF_DEBUG_PICT_INFO){ 00111 av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n", 00112 s->dropable ? 'D' : av_get_picture_type_char(s->pict_type), s->h263_flv-1, s->qscale, s->picture_number); 00113 } 00114 00115 s->y_dc_scale_table= 00116 s->c_dc_scale_table= ff_mpeg1_dc_scale_table; 00117 00118 return 0; 00119 } 00120 00121 AVCodec ff_flv_decoder = { 00122 "flv", 00123 AVMEDIA_TYPE_VIDEO, 00124 CODEC_ID_FLV1, 00125 sizeof(MpegEncContext), 00126 ff_h263_decode_init, 00127 NULL, 00128 ff_h263_decode_end, 00129 ff_h263_decode_frame, 00130 CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1, 00131 .max_lowres= 3, 00132 .long_name= NULL_IF_CONFIG_SMALL("Flash Video (FLV) / Sorenson Spark / Sorenson H.263"), 00133 .pix_fmts= ff_pixfmt_list_420, 00134 };