1/* 2 * Copyright (C) 2008 Michael Niedermayer 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/intreadwrite.h" 22#include "parser.h" 23 24typedef struct VP9ParseContext { 25 int n_frames; // 1-8 26 int size[8]; 27} VP9ParseContext; 28 29static void parse_frame(AVCodecParserContext *ctx, const uint8_t *buf, int size) 30{ 31 if (buf[0] & 0x4) { 32 ctx->pict_type = AV_PICTURE_TYPE_P; 33 ctx->key_frame = 0; 34 } else { 35 ctx->pict_type = AV_PICTURE_TYPE_I; 36 ctx->key_frame = 1; 37 } 38} 39 40static int parse(AVCodecParserContext *ctx, 41 AVCodecContext *avctx, 42 const uint8_t **out_data, int *out_size, 43 const uint8_t *data, int size) 44{ 45 VP9ParseContext *s = ctx->priv_data; 46 int marker; 47 48 if (size <= 0) { 49 *out_size = 0; 50 *out_data = data; 51 52 return 0; 53 } 54 55 if (s->n_frames > 0) { 56 *out_data = data; 57 *out_size = s->size[--s->n_frames]; 58 parse_frame(ctx, *out_data, *out_size); 59 60 return s->n_frames > 0 ? *out_size : size /* i.e. include idx tail */; 61 } 62 63 marker = data[size - 1]; 64 if ((marker & 0xe0) == 0xc0) { 65 int nbytes = 1 + ((marker >> 3) & 0x3); 66 int n_frames = 1 + (marker & 0x7), idx_sz = 2 + n_frames * nbytes; 67 68 if (size >= idx_sz && data[size - idx_sz] == marker) { 69 const uint8_t *idx = data + size + 1 - idx_sz; 70 int first = 1; 71 72 switch (nbytes) { 73#define case_n(a, rd) \ 74 case a: \ 75 while (n_frames--) { \ 76 unsigned sz = rd; \ 77 idx += a; \ 78 if (sz > size) { \ 79 s->n_frames = 0; \ 80 av_log(avctx, AV_LOG_ERROR, \ 81 "Superframe packet size too big: %u > %d\n", \ 82 sz, size); \ 83 return size; \ 84 } \ 85 if (first) { \ 86 first = 0; \ 87 *out_data = data; \ 88 *out_size = sz; \ 89 s->n_frames = n_frames; \ 90 } else { \ 91 s->size[n_frames] = sz; \ 92 } \ 93 data += sz; \ 94 size -= sz; \ 95 } \ 96 parse_frame(ctx, *out_data, *out_size); \ 97 return *out_size 98 99 case_n(1, *idx); 100 case_n(2, AV_RL16(idx)); 101 case_n(3, AV_RL24(idx)); 102 case_n(4, AV_RL32(idx)); 103 } 104 } 105 } 106 107 *out_data = data; 108 *out_size = size; 109 parse_frame(ctx, data, size); 110 111 return size; 112} 113 114AVCodecParser ff_vp9_parser = { 115 .codec_ids = { AV_CODEC_ID_VP9 }, 116 .priv_data_size = sizeof(VP9ParseContext), 117 .parser_parse = parse, 118}; 119