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#include "libavutil/imgutils.h" 24 25void ff_flv2_decode_ac_esc(GetBitContext *gb, int *level, int *run, int *last) 26{ 27 int is11 = get_bits1(gb); 28 *last = get_bits1(gb); 29 *run = get_bits(gb, 6); 30 if (is11) { 31 *level = get_sbits(gb, 11); 32 } else { 33 *level = get_sbits(gb, 7); 34 } 35} 36 37int ff_flv_decode_picture_header(MpegEncContext *s) 38{ 39 int format, width, height; 40 41 /* picture header */ 42 if (get_bits_long(&s->gb, 17) != 1) { 43 av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); 44 return AVERROR_INVALIDDATA; 45 } 46 format = get_bits(&s->gb, 5); 47 if (format != 0 && format != 1) { 48 av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n"); 49 return AVERROR_INVALIDDATA; 50 } 51 s->h263_flv = format + 1; 52 s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */ 53 format = get_bits(&s->gb, 3); 54 switch (format) { 55 case 0: 56 width = get_bits(&s->gb, 8); 57 height = get_bits(&s->gb, 8); 58 break; 59 case 1: 60 width = get_bits(&s->gb, 16); 61 height = get_bits(&s->gb, 16); 62 break; 63 case 2: 64 width = 352; 65 height = 288; 66 break; 67 case 3: 68 width = 176; 69 height = 144; 70 break; 71 case 4: 72 width = 128; 73 height = 96; 74 break; 75 case 5: 76 width = 320; 77 height = 240; 78 break; 79 case 6: 80 width = 160; 81 height = 120; 82 break; 83 default: 84 width = height = 0; 85 break; 86 } 87 if (av_image_check_size(width, height, 0, s->avctx)) 88 return AVERROR(EINVAL); 89 s->width = width; 90 s->height = height; 91 92 s->pict_type = AV_PICTURE_TYPE_I + get_bits(&s->gb, 2); 93 s->droppable = s->pict_type > AV_PICTURE_TYPE_P; 94 if (s->droppable) 95 s->pict_type = AV_PICTURE_TYPE_P; 96 97 skip_bits1(&s->gb); /* deblocking flag */ 98 s->chroma_qscale = s->qscale = get_bits(&s->gb, 5); 99 100 s->h263_plus = 0; 101 102 s->unrestricted_mv = 1; 103 s->h263_long_vectors = 0; 104 105 /* PEI */ 106 if (skip_1stop_8data_bits(&s->gb) < 0) 107 return AVERROR_INVALIDDATA; 108 109 s->f_code = 1; 110 111 if (s->ehc_mode) 112 s->avctx->sample_aspect_ratio= (AVRational){1,2}; 113 114 if (s->avctx->debug & FF_DEBUG_PICT_INFO) { 115 av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n", 116 s->droppable ? 'D' : av_get_picture_type_char(s->pict_type), 117 s->h263_flv - 1, s->qscale, s->picture_number); 118 } 119 120 s->y_dc_scale_table = s->c_dc_scale_table = ff_mpeg1_dc_scale_table; 121 122 return 0; 123} 124 125AVCodec ff_flv_decoder = { 126 .name = "flv", 127 .long_name = NULL_IF_CONFIG_SMALL("FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"), 128 .type = AVMEDIA_TYPE_VIDEO, 129 .id = AV_CODEC_ID_FLV1, 130 .priv_data_size = sizeof(MpegEncContext), 131 .init = ff_h263_decode_init, 132 .close = ff_h263_decode_end, 133 .decode = ff_h263_decode_frame, 134 .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1, 135 .max_lowres = 3, 136 .pix_fmts = (const enum AVPixelFormat[]) { 137 AV_PIX_FMT_YUV420P, 138 AV_PIX_FMT_NONE 139 }, 140}; 141