3 * Copyright (C) 2004 Gildas Bazin
4 * Copyright (C) 2004 Benjamin Zores
5 * Copyright (C) 2006 Benjamin Larsson
6 * Copyright (C) 2007 Konstantin Shishkov
8 * This file is part of FFmpeg.
10 * FFmpeg is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU Lesser General Public
12 * License as published by the Free Software Foundation; either
13 * version 2.1 of the License, or (at your option) any later version.
15 * FFmpeg is distributed in the hope that it will be useful,
16 * but WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * Lesser General Public License for more details.
20 * You should have received a copy of the GNU Lesser General Public
21 * License along with FFmpeg; if not, write to the Free Software
22 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
26 * @file libavcodec/dca_parser.c
32 typedef struct DCAParseContext {
40 #define IS_MARKER(state, i, buf, buf_size) \
41 ((state == DCA_MARKER_14B_LE && (i < buf_size-2) && (buf[i+1] & 0xF0) == 0xF0 && buf[i+2] == 0x07) \
42 || (state == DCA_MARKER_14B_BE && (i < buf_size-2) && buf[i+1] == 0x07 && (buf[i+2] & 0xF0) == 0xF0) \
43 || state == DCA_MARKER_RAW_LE || state == DCA_MARKER_RAW_BE)
46 * finds the end of the current frame in the bitstream.
47 * @return the position of the first byte of the next frame, or -1
49 static int dca_find_frame_end(DCAParseContext * pc1, const uint8_t * buf,
54 ParseContext *pc = &pc1->pc;
56 start_found = pc->frame_start_found;
61 for (i = 0; i < buf_size; i++) {
62 state = (state << 8) | buf[i];
63 if (IS_MARKER(state, i, buf, buf_size)) {
64 if (pc1->lastmarker && state == pc1->lastmarker) {
67 } else if (!pc1->lastmarker) {
69 pc1->lastmarker = state;
76 for (; i < buf_size; i++) {
78 state = (state << 8) | buf[i];
79 if (state == DCA_HD_MARKER && !pc1->hd_pos)
80 pc1->hd_pos = pc1->size;
81 if (state == pc1->lastmarker && IS_MARKER(state, i, buf, buf_size)) {
82 if(pc1->framesize > pc1->size)
85 pc1->framesize = pc1->hd_pos ? pc1->hd_pos : pc1->size;
87 pc->frame_start_found = 0;
94 pc->frame_start_found = start_found;
99 static av_cold int dca_parse_init(AVCodecParserContext * s)
101 DCAParseContext *pc1 = s->priv_data;
107 static int dca_parse(AVCodecParserContext * s,
108 AVCodecContext * avctx,
109 const uint8_t ** poutbuf, int *poutbuf_size,
110 const uint8_t * buf, int buf_size)
112 DCAParseContext *pc1 = s->priv_data;
113 ParseContext *pc = &pc1->pc;
116 if (s->flags & PARSER_FLAG_COMPLETE_FRAMES) {
119 next = dca_find_frame_end(pc1, buf, buf_size);
121 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
128 *poutbuf_size = buf_size;
132 AVCodecParser dca_parser = {
134 sizeof(DCAParseContext),