1/* 2 * TAK parser 3 * Copyright (c) 2012 Michael Niedermayer 4 * 5 * This file is part of FFmpeg. 6 * 7 * FFmpeg is free software; you can redistribute it and/or 8 * modify it under the terms of the GNU Lesser General Public 9 * License as published by the Free Software Foundation; either 10 * version 2.1 of the License, or (at your option) any later version. 11 * 12 * FFmpeg is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15 * Lesser General Public License for more details. 16 * 17 * You should have received a copy of the GNU Lesser General Public 18 * License along with FFmpeg; if not, write to the Free Software 19 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 20 */ 21 22/** 23 * @file 24 * TAK parser 25 **/ 26 27#include "tak.h" 28#include "parser.h" 29 30typedef struct TAKParseContext { 31 ParseContext pc; 32 TAKStreamInfo ti; 33 int index; 34} TAKParseContext; 35 36static int tak_parse(AVCodecParserContext *s, AVCodecContext *avctx, 37 const uint8_t **poutbuf, int *poutbuf_size, 38 const uint8_t *buf, int buf_size) 39{ 40 TAKParseContext *t = s->priv_data; 41 ParseContext *pc = &t->pc; 42 int next = END_NOT_FOUND; 43 GetBitContext gb; 44 int consumed = 0; 45 int needed = buf_size ? TAK_MAX_FRAME_HEADER_BYTES : 8; 46 47 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) { 48 TAKStreamInfo ti; 49 init_get_bits(&gb, buf, buf_size); 50 if (!ff_tak_decode_frame_header(avctx, &gb, &ti, 127)) 51 s->duration = t->ti.last_frame_samples ? t->ti.last_frame_samples 52 : t->ti.frame_samples; 53 *poutbuf = buf; 54 *poutbuf_size = buf_size; 55 return buf_size; 56 } 57 58 while (buf_size || t->index + needed <= pc->index) { 59 if (buf_size && t->index + TAK_MAX_FRAME_HEADER_BYTES > pc->index) { 60 int tmp_buf_size = FFMIN(2 * TAK_MAX_FRAME_HEADER_BYTES, 61 buf_size); 62 const uint8_t *tmp_buf = buf; 63 64 if (ff_combine_frame(pc, END_NOT_FOUND, &tmp_buf, &tmp_buf_size) != -1) 65 return AVERROR(ENOMEM); 66 consumed += tmp_buf_size; 67 buf += tmp_buf_size; 68 buf_size -= tmp_buf_size; 69 } 70 71 for (; t->index + needed <= pc->index; t->index++) { 72 if (pc->buffer[ t->index ] == 0xFF && 73 pc->buffer[ t->index + 1 ] == 0xA0) { 74 TAKStreamInfo ti; 75 76 init_get_bits(&gb, pc->buffer + t->index, 77 8 * (pc->index - t->index)); 78 if (!ff_tak_decode_frame_header(avctx, &gb, 79 pc->frame_start_found ? &ti : &t->ti, 127) && 80 !ff_tak_check_crc(pc->buffer + t->index, 81 get_bits_count(&gb) / 8)) { 82 if (!pc->frame_start_found) { 83 pc->frame_start_found = 1; 84 s->duration = t->ti.last_frame_samples ? 85 t->ti.last_frame_samples : 86 t->ti.frame_samples; 87 s->key_frame = !!(t->ti.flags & TAK_FRAME_FLAG_HAS_INFO); 88 } else { 89 pc->frame_start_found = 0; 90 next = t->index - pc->index; 91 t->index = 0; 92 goto found; 93 } 94 } 95 } 96 } 97 } 98found: 99 100 if (consumed && !buf_size && next == END_NOT_FOUND || 101 ff_combine_frame(pc, next, &buf, &buf_size) < 0) { 102 *poutbuf = NULL; 103 *poutbuf_size = 0; 104 return buf_size + consumed; 105 } 106 107 if (next != END_NOT_FOUND) { 108 next += consumed; 109 pc->overread = FFMAX(0, -next); 110 } 111 112 *poutbuf = buf; 113 *poutbuf_size = buf_size; 114 return next; 115} 116 117AVCodecParser ff_tak_parser = { 118 .codec_ids = { AV_CODEC_ID_TAK }, 119 .priv_data_size = sizeof(TAKParseContext), 120 .parser_parse = tak_parse, 121 .parser_close = ff_parse_close, 122}; 123