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| Rev | Author | Line No. | Line |
|---|---|---|---|
| 4349 | Serge | 1 | /* |
| 2 | * MPEG Audio parser |
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| 3 | * Copyright (c) 2003 Fabrice Bellard |
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| 4 | * Copyright (c) 2003 Michael Niedermayer |
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| 5 | * |
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| 6 | * This file is part of FFmpeg. |
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| 7 | * |
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| 8 | * FFmpeg is free software; you can redistribute it and/or |
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| 9 | * modify it under the terms of the GNU Lesser General Public |
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| 10 | * License as published by the Free Software Foundation; either |
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| 11 | * version 2.1 of the License, or (at your option) any later version. |
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| 12 | * |
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| 13 | * FFmpeg is distributed in the hope that it will be useful, |
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| 14 | * but WITHOUT ANY WARRANTY; without even the implied warranty of |
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| 15 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
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| 16 | * Lesser General Public License for more details. |
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| 17 | * |
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| 18 | * You should have received a copy of the GNU Lesser General Public |
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| 19 | * License along with FFmpeg; if not, write to the Free Software |
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| 20 | * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
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| 21 | */ |
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| 22 | |||
| 23 | #include "parser.h" |
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| 24 | #include "mpegaudiodecheader.h" |
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| 25 | #include "libavutil/common.h" |
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| 26 | |||
| 27 | |||
| 28 | typedef struct MpegAudioParseContext { |
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| 29 | ParseContext pc; |
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| 30 | int frame_size; |
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| 31 | uint32_t header; |
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| 32 | int header_count; |
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| 33 | int no_bitrate; |
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| 34 | } MpegAudioParseContext; |
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| 35 | |||
| 36 | #define MPA_HEADER_SIZE 4 |
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| 37 | |||
| 38 | /* header + layer + bitrate + freq + lsf/mpeg25 */ |
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| 39 | #define SAME_HEADER_MASK \ |
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| 40 | (0xffe00000 | (3 << 17) | (3 << 10) | (3 << 19)) |
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| 41 | |||
| 42 | static int mpegaudio_parse(AVCodecParserContext *s1, |
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| 43 | AVCodecContext *avctx, |
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| 44 | const uint8_t **poutbuf, int *poutbuf_size, |
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| 45 | const uint8_t *buf, int buf_size) |
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| 46 | { |
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| 47 | MpegAudioParseContext *s = s1->priv_data; |
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| 48 | ParseContext *pc = &s->pc; |
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| 49 | uint32_t state= pc->state; |
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| 50 | int i; |
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| 51 | int next= END_NOT_FOUND; |
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| 52 | |||
| 53 | for(i=0; i |
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| 54 | if(s->frame_size){ |
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| 55 | int inc= FFMIN(buf_size - i, s->frame_size); |
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| 56 | i += inc; |
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| 57 | s->frame_size -= inc; |
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| 58 | state = 0; |
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| 59 | |||
| 60 | if(!s->frame_size){ |
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| 61 | next= i; |
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| 62 | break; |
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| 63 | } |
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| 64 | }else{ |
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| 65 | while(i |
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| 66 | int ret, sr, channels, bit_rate, frame_size; |
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| 67 | |||
| 68 | state= (state<<8) + buf[i++]; |
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| 69 | |||
| 70 | ret = avpriv_mpa_decode_header(avctx, state, &sr, &channels, &frame_size, &bit_rate); |
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| 71 | if (ret < 4) { |
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| 72 | if (i > 4) |
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| 73 | s->header_count = -2; |
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| 74 | } else { |
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| 75 | if((state&SAME_HEADER_MASK) != (s->header&SAME_HEADER_MASK) && s->header) |
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| 76 | s->header_count= -3; |
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| 77 | s->header= state; |
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| 78 | s->header_count++; |
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| 79 | s->frame_size = ret-4; |
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| 80 | |||
| 81 | if (s->header_count > 0) { |
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| 82 | avctx->sample_rate= sr; |
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| 83 | avctx->channels = channels; |
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| 84 | s1->duration = frame_size; |
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| 85 | if (s->no_bitrate || !avctx->bit_rate) { |
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| 86 | s->no_bitrate = 1; |
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| 87 | avctx->bit_rate += (bit_rate - avctx->bit_rate) / s->header_count; |
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| 88 | } |
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| 89 | } |
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| 90 | break; |
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| 91 | } |
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| 92 | } |
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| 93 | } |
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| 94 | } |
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| 95 | |||
| 96 | pc->state= state; |
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| 97 | if (ff_combine_frame(pc, next, &buf, &buf_size) < 0) { |
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| 98 | *poutbuf = NULL; |
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| 99 | *poutbuf_size = 0; |
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| 100 | return buf_size; |
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| 101 | } |
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| 102 | |||
| 103 | *poutbuf = buf; |
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| 104 | *poutbuf_size = buf_size; |
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| 105 | return next; |
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| 106 | } |
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| 107 | |||
| 108 | |||
| 109 | AVCodecParser ff_mpegaudio_parser = { |
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| 110 | .codec_ids = { AV_CODEC_ID_MP1, AV_CODEC_ID_MP2, AV_CODEC_ID_MP3 }, |
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| 111 | .priv_data_size = sizeof(MpegAudioParseContext), |
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| 112 | .parser_parse = mpegaudio_parse, |
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| 113 | .parser_close = ff_parse_close, |
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| 114 | }; |