1/*
2 * Common AAC and AC-3 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 "config_components.h"
24
25#include "libavutil/channel_layout.h"
26#include "libavutil/common.h"
27#include "parser.h"
28#include "aac_ac3_parser.h"
29
30int ff_aac_ac3_parse(AVCodecParserContext *s1,
31                     AVCodecContext *avctx,
32                     const uint8_t **poutbuf, int *poutbuf_size,
33                     const uint8_t *buf, int buf_size)
34{
35    AACAC3ParseContext *s = s1->priv_data;
36    ParseContext *pc = &s->pc;
37    int len, i;
38    int new_frame_start;
39    int got_frame = 0;
40
41get_next:
42    i=END_NOT_FOUND;
43    if(s->remaining_size <= buf_size){
44        if(s->remaining_size && !s->need_next_header){
45            i= s->remaining_size;
46            s->remaining_size = 0;
47        }else{ //we need a header first
48            len=0;
49            for(i=s->remaining_size; i<buf_size; i++){
50                s->state = (s->state<<8) + buf[i];
51                if((len=s->sync(s->state, s, &s->need_next_header, &new_frame_start)))
52                    break;
53            }
54            if(len<=0){
55                i=END_NOT_FOUND;
56            }else{
57                got_frame = 1;
58                s->state=0;
59                i-= s->header_size -1;
60                s->remaining_size = len;
61                if(!new_frame_start || pc->index+i<=0){
62                    s->remaining_size += i;
63                    goto get_next;
64                }
65                else if (i < 0) {
66                    s->remaining_size += i;
67                }
68            }
69        }
70    }
71
72    if(ff_combine_frame(pc, i, &buf, &buf_size)<0){
73        s->remaining_size -= FFMIN(s->remaining_size, buf_size);
74        *poutbuf = NULL;
75        *poutbuf_size = 0;
76        return buf_size;
77    }
78
79    *poutbuf = buf;
80    *poutbuf_size = buf_size;
81
82    /* update codec info */
83    if(s->codec_id)
84        avctx->codec_id = s->codec_id;
85
86    if (got_frame) {
87        /* Due to backwards compatible HE-AAC the sample rate, channel count,
88           and total number of samples found in an AAC ADTS header are not
89           reliable. Bit rate is still accurate because the total frame
90           duration in seconds is still correct (as is the number of bits in
91           the frame). */
92        if (avctx->codec_id != AV_CODEC_ID_AAC) {
93            avctx->sample_rate = s->sample_rate;
94            if (!CONFIG_EAC3_DECODER || avctx->codec_id != AV_CODEC_ID_EAC3) {
95                av_channel_layout_uninit(&avctx->ch_layout);
96                if (s->channel_layout) {
97                    av_channel_layout_from_mask(&avctx->ch_layout, s->channel_layout);
98                } else {
99                    avctx->ch_layout.order       = AV_CHANNEL_ORDER_UNSPEC;
100                    avctx->ch_layout.nb_channels = s->channels;
101                }
102#if FF_API_OLD_CHANNEL_LAYOUT
103FF_DISABLE_DEPRECATION_WARNINGS
104                avctx->channels = avctx->ch_layout.nb_channels;
105                avctx->channel_layout = s->channel_layout;
106FF_ENABLE_DEPRECATION_WARNINGS
107#endif
108            }
109            s1->duration = s->samples;
110            avctx->audio_service_type = s->service_type;
111        }
112
113        /* Calculate the average bit rate */
114        s->frame_number++;
115        if (!CONFIG_EAC3_DECODER || avctx->codec_id != AV_CODEC_ID_EAC3) {
116            avctx->bit_rate +=
117                (s->bit_rate - avctx->bit_rate) / s->frame_number;
118        }
119    }
120
121    return i;
122}
123