blob: c9ba6bf062cdfab486ed593189039803905629a2
| 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 "libavutil/channel_layout.h" |
| 24 | #include "libavutil/common.h" |
| 25 | #include "parser.h" |
| 26 | #include "aac_ac3_parser.h" |
| 27 | |
| 28 | int ff_aac_ac3_parse(AVCodecParserContext *s1, |
| 29 | AVCodecContext *avctx, |
| 30 | const uint8_t **poutbuf, int *poutbuf_size, |
| 31 | const uint8_t *buf, int buf_size) |
| 32 | { |
| 33 | AACAC3ParseContext *s = s1->priv_data; |
| 34 | ParseContext *pc = &s->pc; |
| 35 | int len, i; |
| 36 | int new_frame_start; |
| 37 | int got_frame = 0; |
| 38 | |
| 39 | get_next: |
| 40 | i=END_NOT_FOUND; |
| 41 | if(s->remaining_size <= buf_size){ |
| 42 | if(s->remaining_size && !s->need_next_header){ |
| 43 | i= s->remaining_size; |
| 44 | s->remaining_size = 0; |
| 45 | }else{ //we need a header first |
| 46 | len=0; |
| 47 | for(i=s->remaining_size; i<buf_size; i++){ |
| 48 | s->state = (s->state<<8) + buf[i]; |
| 49 | if((len=s->sync(s->state, s, &s->need_next_header, &new_frame_start))) |
| 50 | break; |
| 51 | } |
| 52 | if(len<=0){ |
| 53 | i=END_NOT_FOUND; |
| 54 | }else{ |
| 55 | got_frame = 1; |
| 56 | s->state=0; |
| 57 | i-= s->header_size -1; |
| 58 | s->remaining_size = len; |
| 59 | if(!new_frame_start || pc->index+i<=0){ |
| 60 | s->remaining_size += i; |
| 61 | goto get_next; |
| 62 | } |
| 63 | } |
| 64 | } |
| 65 | } |
| 66 | |
| 67 | if(ff_combine_frame(pc, i, &buf, &buf_size)<0){ |
| 68 | s->remaining_size -= FFMIN(s->remaining_size, buf_size); |
| 69 | *poutbuf = NULL; |
| 70 | *poutbuf_size = 0; |
| 71 | return buf_size; |
| 72 | } |
| 73 | |
| 74 | *poutbuf = buf; |
| 75 | *poutbuf_size = buf_size; |
| 76 | |
| 77 | /* update codec info */ |
| 78 | if(s->codec_id) |
| 79 | avctx->codec_id = s->codec_id; |
| 80 | |
| 81 | if (got_frame) { |
| 82 | /* Due to backwards compatible HE-AAC the sample rate, channel count, |
| 83 | and total number of samples found in an AAC ADTS header are not |
| 84 | reliable. Bit rate is still accurate because the total frame |
| 85 | duration in seconds is still correct (as is the number of bits in |
| 86 | the frame). */ |
| 87 | if (avctx->codec_id != AV_CODEC_ID_AAC) { |
| 88 | avctx->sample_rate = s->sample_rate; |
| 89 | |
| 90 | /* (E-)AC-3: allow downmixing to stereo or mono */ |
| 91 | if (s->channels > 1 && |
| 92 | avctx->request_channel_layout == AV_CH_LAYOUT_MONO) { |
| 93 | avctx->channels = 1; |
| 94 | avctx->channel_layout = AV_CH_LAYOUT_MONO; |
| 95 | } else if (s->channels > 2 && |
| 96 | avctx->request_channel_layout == AV_CH_LAYOUT_STEREO) { |
| 97 | avctx->channels = 2; |
| 98 | avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| 99 | } else { |
| 100 | avctx->channels = s->channels; |
| 101 | avctx->channel_layout = s->channel_layout; |
| 102 | } |
| 103 | s1->duration = s->samples; |
| 104 | avctx->audio_service_type = s->service_type; |
| 105 | } |
| 106 | |
| 107 | avctx->bit_rate = s->bit_rate; |
| 108 | } |
| 109 | |
| 110 | return i; |
| 111 | } |
| 112 |