1/* 2 * FLV decoding. 3 * 4 * This file is part of FFmpeg. 5 * 6 * FFmpeg is free software; you can redistribute it and/or 7 * modify it under the terms of the GNU Lesser General Public 8 * License as published by the Free Software Foundation; either 9 * version 2.1 of the License, or (at your option) any later version. 10 * 11 * FFmpeg is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 14 * Lesser General Public License for more details. 15 * 16 * You should have received a copy of the GNU Lesser General Public 17 * License along with FFmpeg; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 19 */ 20 21#include "libavutil/imgutils.h" 22 23#include "codec_internal.h" 24#include "flvdec.h" 25#include "h263dec.h" 26#include "mpegvideo.h" 27#include "mpegvideodata.h" 28 29int ff_flv_decode_picture_header(MpegEncContext *s) 30{ 31 int format, width, height; 32 33 /* picture header */ 34 if (get_bits(&s->gb, 17) != 1) { 35 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); 36 return AVERROR_INVALIDDATA; 37 } 38 format = get_bits(&s->gb, 5); 39 if (format != 0 && format != 1) { 40 av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n"); 41 return AVERROR_INVALIDDATA; 42 } 43 s->h263_flv = format + 1; 44 s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */ 45 format = get_bits(&s->gb, 3); 46 switch (format) { 47 case 0: 48 width = get_bits(&s->gb, 8); 49 height = get_bits(&s->gb, 8); 50 break; 51 case 1: 52 width = get_bits(&s->gb, 16); 53 height = get_bits(&s->gb, 16); 54 break; 55 case 2: 56 width = 352; 57 height = 288; 58 break; 59 case 3: 60 width = 176; 61 height = 144; 62 break; 63 case 4: 64 width = 128; 65 height = 96; 66 break; 67 case 5: 68 width = 320; 69 height = 240; 70 break; 71 case 6: 72 width = 160; 73 height = 120; 74 break; 75 default: 76 width = height = 0; 77 break; 78 } 79 if (av_image_check_size(width, height, 0, s->avctx)) 80 return AVERROR(EINVAL); 81 s->width = width; 82 s->height = height; 83 84 s->pict_type = AV_PICTURE_TYPE_I + get_bits(&s->gb, 2); 85 s->droppable = s->pict_type > AV_PICTURE_TYPE_P; 86 if (s->droppable) 87 s->pict_type = AV_PICTURE_TYPE_P; 88 89 skip_bits1(&s->gb); /* deblocking flag */ 90 s->chroma_qscale = s->qscale = get_bits(&s->gb, 5); 91 92 s->h263_plus = 0; 93 94 s->h263_long_vectors = 0; 95 96 /* PEI */ 97 if (skip_1stop_8data_bits(&s->gb) < 0) 98 return AVERROR_INVALIDDATA; 99 100 s->f_code = 1; 101 102 if (s->ehc_mode) 103 s->avctx->sample_aspect_ratio= (AVRational){1,2}; 104 105 if (s->avctx->debug & FF_DEBUG_PICT_INFO) { 106 av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n", 107 s->droppable ? 'D' : av_get_picture_type_char(s->pict_type), 108 s->h263_flv - 1, s->qscale, s->picture_number); 109 } 110 111 s->y_dc_scale_table = s->c_dc_scale_table = ff_mpeg1_dc_scale_table; 112 113 return 0; 114} 115 116const FFCodec ff_flv_decoder = { 117 .p.name = "flv", 118 .p.long_name = NULL_IF_CONFIG_SMALL("FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"), 119 .p.type = AVMEDIA_TYPE_VIDEO, 120 .p.id = AV_CODEC_ID_FLV1, 121 .priv_data_size = sizeof(MpegEncContext), 122 .init = ff_h263_decode_init, 123 .close = ff_h263_decode_end, 124 FF_CODEC_DECODE_CB(ff_h263_decode_frame), 125 .p.capabilities = AV_CODEC_CAP_DRAW_HORIZ_BAND | AV_CODEC_CAP_DR1, 126 .caps_internal = FF_CODEC_CAP_INIT_THREADSAFE | 127 FF_CODEC_CAP_SKIP_FRAME_FILL_PARAM, 128 .p.max_lowres = 3, 129 .p.pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P, 130 AV_PIX_FMT_NONE }, 131}; 132