| 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 | |
| 30 | typedef struct TAKParseContext { |
| 31 | ParseContext pc; |
| 32 | TAKStreamInfo ti; |
| 33 | int index; |
| 34 | } TAKParseContext; |
| 35 | |
| 36 | static 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 | } |
| 98 | found: |
| 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 | |
| 117 | AVCodecParser 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 | }; |