2 * copyright (c) 2008 Paul Kendall <paul@kcbbs.gen.nz>
4 * This file is part of FFmpeg.
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.
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.
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
30 #include <sys/types.h>
34 #define LATM_HEADER 0x56e000 // 0x2b7 (11 bits)
35 #define LATM_MASK 0xFFE000 // top 11 bits
36 #define LATM_SIZE_MASK 0x001FFF // bottom 13 bits
38 typedef struct LATMParseContext{
44 * finds the end of the current frame in the bitstream.
45 * @return the position of the first byte of the next frame, or -1
47 static int latm_find_frame_end(AVCodecParserContext *s1, const uint8_t *buf,
50 LATMParseContext *s = s1->priv_data;
51 ParseContext *pc = &s->pc;
55 pic_found = pc->frame_start_found;
60 for (i = 0; i < buf_size; i++) {
61 state = (state<<8) | buf[i];
62 if ((state & LATM_MASK) == LATM_HEADER) {
72 /* EOF considered as end of frame */
75 if ((state & LATM_SIZE_MASK) - s->count <= buf_size) {
76 pc->frame_start_found = 0;
78 return (state & LATM_SIZE_MASK) - s->count;
83 pc->frame_start_found = pic_found;
89 static int latm_parse(AVCodecParserContext *s1, AVCodecContext *avctx,
90 const uint8_t **poutbuf, int *poutbuf_size,
91 const uint8_t *buf, int buf_size)
93 LATMParseContext *s = s1->priv_data;
94 ParseContext *pc = &s->pc;
97 if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
100 next = latm_find_frame_end(s1, buf, buf_size);
102 if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
109 *poutbuf_size = buf_size;
113 AVCodecParser aac_latm_parser = {
114 { CODEC_ID_AAC_LATM },
115 sizeof(LATMParseContext),