vp9_parser.c (2058B)
1 /* 2 * VP9 compatible video decoder 3 * 4 * Copyright (C) 2013 Ronald S. Bultje <rsbultje gmail com> 5 * Copyright (C) 2013 Clément Bœsch <u pkh me> 6 * 7 * This file is part of FFmpeg. 8 * 9 * FFmpeg is free software; you can redistribute it and/or 10 * modify it under the terms of the GNU Lesser General Public 11 * License as published by the Free Software Foundation; either 12 * version 2.1 of the License, or (at your option) any later version. 13 * 14 * FFmpeg is distributed in the hope that it will be useful, 15 * but WITHOUT ANY WARRANTY; without even the implied warranty of 16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 17 * Lesser General Public License for more details. 18 * 19 * You should have received a copy of the GNU Lesser General Public 20 * License along with FFmpeg; if not, write to the Free Software 21 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 22 */ 23 24 #include "libavutil/intreadwrite.h" 25 #include "libavcodec/get_bits.h" 26 #include "parser.h" 27 28 static int parse(AVCodecParserContext *ctx, 29 AVCodecContext *avctx, 30 const uint8_t **out_data, int *out_size, 31 const uint8_t *data, int size) 32 { 33 GetBitContext gb; 34 int res, profile, keyframe; 35 36 *out_data = data; 37 *out_size = size; 38 39 if (!size || (res = init_get_bits8(&gb, data, size)) < 0) 40 return size; // parsers can't return errors 41 get_bits(&gb, 2); // frame marker 42 profile = get_bits1(&gb); 43 profile |= get_bits1(&gb) << 1; 44 if (profile == 3) profile += get_bits1(&gb); 45 if (profile > 3) 46 return size; 47 48 avctx->profile = profile; 49 50 if (get_bits1(&gb)) { 51 keyframe = 0; 52 } else { 53 keyframe = !get_bits1(&gb); 54 } 55 56 if (!keyframe) { 57 ctx->pict_type = AV_PICTURE_TYPE_P; 58 ctx->key_frame = 0; 59 } else { 60 ctx->pict_type = AV_PICTURE_TYPE_I; 61 ctx->key_frame = 1; 62 } 63 64 return size; 65 } 66 67 const AVCodecParser ff_vp9_parser = { 68 .codec_ids = { AV_CODEC_ID_VP9 }, 69 .parser_parse = parse, 70 };