| 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 "flv.h" |
| 24 | #include "h263.h" |
| 25 | #include "mpegvideo.h" |
| 26 | |
| 27 | int ff_flv_decode_picture_header(MpegEncContext *s) |
| 28 | { |
| 29 | int format, width, height; |
| 30 | |
| 31 | /* picture header */ |
| 32 | if (get_bits_long(&s->gb, 17) != 1) { |
| 33 | av_log(s->avctx, AV_LOG_ERROR, "Bad picture start code\n"); |
| 34 | return AVERROR_INVALIDDATA; |
| 35 | } |
| 36 | format = get_bits(&s->gb, 5); |
| 37 | if (format != 0 && format != 1) { |
| 38 | av_log(s->avctx, AV_LOG_ERROR, "Bad picture format\n"); |
| 39 | return AVERROR_INVALIDDATA; |
| 40 | } |
| 41 | s->h263_flv = format + 1; |
| 42 | s->picture_number = get_bits(&s->gb, 8); /* picture timestamp */ |
| 43 | format = get_bits(&s->gb, 3); |
| 44 | switch (format) { |
| 45 | case 0: |
| 46 | width = get_bits(&s->gb, 8); |
| 47 | height = get_bits(&s->gb, 8); |
| 48 | break; |
| 49 | case 1: |
| 50 | width = get_bits(&s->gb, 16); |
| 51 | height = get_bits(&s->gb, 16); |
| 52 | break; |
| 53 | case 2: |
| 54 | width = 352; |
| 55 | height = 288; |
| 56 | break; |
| 57 | case 3: |
| 58 | width = 176; |
| 59 | height = 144; |
| 60 | break; |
| 61 | case 4: |
| 62 | width = 128; |
| 63 | height = 96; |
| 64 | break; |
| 65 | case 5: |
| 66 | width = 320; |
| 67 | height = 240; |
| 68 | break; |
| 69 | case 6: |
| 70 | width = 160; |
| 71 | height = 120; |
| 72 | break; |
| 73 | default: |
| 74 | width = height = 0; |
| 75 | break; |
| 76 | } |
| 77 | if (av_image_check_size(width, height, 0, s->avctx)) |
| 78 | return AVERROR(EINVAL); |
| 79 | s->width = width; |
| 80 | s->height = height; |
| 81 | |
| 82 | s->pict_type = AV_PICTURE_TYPE_I + get_bits(&s->gb, 2); |
| 83 | s->droppable = s->pict_type > AV_PICTURE_TYPE_P; |
| 84 | if (s->droppable) |
| 85 | s->pict_type = AV_PICTURE_TYPE_P; |
| 86 | |
| 87 | skip_bits1(&s->gb); /* deblocking flag */ |
| 88 | s->chroma_qscale = s->qscale = get_bits(&s->gb, 5); |
| 89 | |
| 90 | s->h263_plus = 0; |
| 91 | |
| 92 | s->unrestricted_mv = 1; |
| 93 | s->h263_long_vectors = 0; |
| 94 | |
| 95 | /* PEI */ |
| 96 | if (skip_1stop_8data_bits(&s->gb) < 0) |
| 97 | return AVERROR_INVALIDDATA; |
| 98 | |
| 99 | s->f_code = 1; |
| 100 | |
| 101 | if (s->ehc_mode) |
| 102 | s->avctx->sample_aspect_ratio= (AVRational){1,2}; |
| 103 | |
| 104 | if (s->avctx->debug & FF_DEBUG_PICT_INFO) { |
| 105 | av_log(s->avctx, AV_LOG_DEBUG, "%c esc_type:%d, qp:%d num:%d\n", |
| 106 | s->droppable ? 'D' : av_get_picture_type_char(s->pict_type), |
| 107 | s->h263_flv - 1, s->qscale, s->picture_number); |
| 108 | } |
| 109 | |
| 110 | s->y_dc_scale_table = s->c_dc_scale_table = ff_mpeg1_dc_scale_table; |
| 111 | |
| 112 | return 0; |
| 113 | } |
| 114 | |
| 115 | AVCodec ff_flv_decoder = { |
| 116 | .name = "flv", |
| 117 | .long_name = NULL_IF_CONFIG_SMALL("FLV / Sorenson Spark / Sorenson H.263 (Flash Video)"), |
| 118 | .type = AVMEDIA_TYPE_VIDEO, |
| 119 | .id = AV_CODEC_ID_FLV1, |
| 120 | .priv_data_size = sizeof(MpegEncContext), |
| 121 | .init = ff_h263_decode_init, |
| 122 | .close = ff_h263_decode_end, |
| 123 | .decode = ff_h263_decode_frame, |
| 124 | .capabilities = CODEC_CAP_DRAW_HORIZ_BAND | CODEC_CAP_DR1, |
| 125 | .max_lowres = 3, |
| 126 | .pix_fmts = (const enum AVPixelFormat[]) { AV_PIX_FMT_YUV420P, |
| 127 | AV_PIX_FMT_NONE }, |
| 128 | }; |