vda: Check the correct pointer for buffer allocation
[ffmpeg.git] / libavcodec / mpegaudio_parser.c
1 /*
2  * MPEG Audio parser
3  * Copyright (c) 2003 Fabrice Bellard
4  * Copyright (c) 2003 Michael Niedermayer
5  *
6  * This file is part of Libav.
7  *
8  * Libav 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  * Libav 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 Libav; 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 "mpegaudiodecheader.h"
25 #include "libavutil/common.h"
26
27
28 typedef struct MpegAudioParseContext {
29     ParseContext pc;
30     int frame_size;
31     uint32_t header;
32     int header_count;
33     int no_bitrate;
34 } MpegAudioParseContext;
35
36 #define MPA_HEADER_SIZE 4
37
38 /* header + layer + bitrate + freq + lsf/mpeg25 */
39 #define SAME_HEADER_MASK \
40    (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19))
41
42 static int mpegaudio_parse(AVCodecParserContext *s1,
43                            AVCodecContext *avctx,
44                            const uint8_t **poutbuf, int *poutbuf_size,
45                            const uint8_t *buf, int buf_size)
46 {
47     MpegAudioParseContext *s = s1->priv_data;
48     ParseContext *pc = &s->pc;
49     uint32_t state= pc->state;
50     int i;
51     int next= END_NOT_FOUND;
52
53     for(i=0; i<buf_size; ){
54         if(s->frame_size){
55             int inc= FFMIN(buf_size - i, s->frame_size);
56             i += inc;
57             s->frame_size -= inc;
58
59             if(!s->frame_size){
60                 next= i;
61                 break;
62             }
63         }else{
64             while(i<buf_size){
65                 int ret, sr, channels, bit_rate, frame_size;
66                 enum AVCodecID codec_id = avctx->codec_id;
67
68                 state= (state<<8) + buf[i++];
69
70                 ret = avpriv_mpa_decode_header(avctx, state, &sr, &channels, &frame_size, &bit_rate);
71                 if (ret < 4) {
72                     if (i > 4)
73                         s->header_count = -2;
74                 } else {
75                     if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header)
76                         s->header_count= -3;
77                     s->header= state;
78                     s->header_count++;
79                     s->frame_size = ret-4;
80
81                     if (s->header_count > 0) {
82                         avctx->sample_rate= sr;
83                         avctx->channels   = channels;
84                         s1->duration      = frame_size;
85                         if (s->no_bitrate || !avctx->bit_rate) {
86                             s->no_bitrate = 1;
87                             avctx->bit_rate += (bit_rate - avctx->bit_rate) / s->header_count;
88                         }
89                     }
90
91                     if (s1->flags & PARSER_FLAG_COMPLETE_FRAMES) {
92                         s->frame_size = 0;
93                         next = buf_size;
94                     } else if (codec_id == AV_CODEC_ID_MP3ADU) {
95                         avpriv_report_missing_feature(avctx,
96                             "MP3ADU full parser");
97                         return AVERROR_PATCHWELCOME;
98                     }
99
100                     break;
101                 }
102             }
103         }
104     }
105
106     pc->state= state;
107     if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) {
108         *poutbuf = NULL;
109         *poutbuf_size = 0;
110         return buf_size;
111     }
112
113     *poutbuf = buf;
114     *poutbuf_size = buf_size;
115     return next;
116 }
117
118
119 AVCodecParser ff_mpegaudio_parser = {
120     .codec_ids      = { AV_CODEC_ID_MP1, AV_CODEC_ID_MP2, AV_CODEC_ID_MP3, AV_CODEC_ID_MP3ADU },
121     .priv_data_size = sizeof(MpegAudioParseContext),
122     .parser_parse   = mpegaudio_parse,
123     .parser_close   = ff_parse_close,
124 };