Pass AACAC3ParseContext to sync() instead of individual arguments. Patch by
[ffmpeg.git] / libavcodec / aac_ac3_parser.c
1 /*
2  * Common AAC and AC3 parser
3  * Copyright (c) 2003 Fabrice Bellard.
4  * Copyright (c) 2003 Michael Niedermayer.
5  *
6  * This file is part of FFmpeg.
7  *
8  * FFmpeg is free software; you can redistribute it and/or
9  * modify it under the terms of the GNU Lesser General Public
10  * License as published by the Free Software Foundation; either
11  * version 2.1 of the License, or (at your option) any later version.
12  *
13  * FFmpeg is distributed in the hope that it will be useful,
14  * but WITHOUT ANY WARRANTY; without even the implied warranty of
15  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
16  * Lesser General Public License for more details.
17  *
18  * You should have received a copy of the GNU Lesser General Public
19  * License along with FFmpeg; if not, write to the Free Software
20  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
21  */
22
23 #include "parser.h"
24 #include "aac_ac3_parser.h"
25
26 int ff_aac_ac3_parse(AVCodecParserContext *s1,
27                      AVCodecContext *avctx,
28                      const uint8_t **poutbuf, int *poutbuf_size,
29                      const uint8_t *buf, int buf_size)
30 {
31     AACAC3ParseContext *s = s1->priv_data;
32     const uint8_t *buf_ptr;
33     int len;
34
35     *poutbuf = NULL;
36     *poutbuf_size = 0;
37
38     buf_ptr = buf;
39     while (buf_size > 0) {
40         int size_needed= s->frame_size ? s->frame_size : s->header_size;
41         len = s->inbuf_ptr - s->inbuf;
42
43         if(len<size_needed){
44             len = FFMIN(size_needed - len, buf_size);
45             memcpy(s->inbuf_ptr, buf_ptr, len);
46             buf_ptr      += len;
47             s->inbuf_ptr += len;
48             buf_size     -= len;
49         }
50
51         if (s->frame_size == 0) {
52             if ((s->inbuf_ptr - s->inbuf) == s->header_size) {
53                 len = s->sync(s);
54                 if (len == 0) {
55                     /* no sync found : move by one byte (inefficient, but simple!) */
56                     memmove(s->inbuf, s->inbuf + 1, s->header_size - 1);
57                     s->inbuf_ptr--;
58                 } else {
59                     s->frame_size = len;
60                     /* update codec info */
61                     avctx->sample_rate = s->sample_rate;
62                     /* allow downmixing to stereo (or mono for AC3) */
63                     if(avctx->request_channels > 0 &&
64                             avctx->request_channels < s->channels &&
65                             (avctx->request_channels <= 2 ||
66                             (avctx->request_channels == 1 &&
67                             avctx->codec_id == CODEC_ID_AC3))) {
68                         avctx->channels = avctx->request_channels;
69                     } else {
70                         avctx->channels = s->channels;
71                     }
72                     avctx->bit_rate = s->bit_rate;
73                     avctx->frame_size = s->samples;
74                 }
75             }
76         } else {
77             if(s->inbuf_ptr - s->inbuf == s->frame_size){
78                 *poutbuf = s->inbuf;
79                 *poutbuf_size = s->frame_size;
80                 s->inbuf_ptr = s->inbuf;
81                 s->frame_size = 0;
82                 break;
83             }
84         }
85     }
86     return buf_ptr - buf;
87 }