| /* |
| * Common AAC and AC-3 parser |
| * Copyright (c) 2003 Fabrice Bellard |
| * Copyright (c) 2003 Michael Niedermayer |
| * |
| * This file is part of FFmpeg. |
| * |
| * FFmpeg is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU Lesser General Public |
| * License as published by the Free Software Foundation; either |
| * version 2.1 of the License, or (at your option) any later version. |
| * |
| * FFmpeg is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * Lesser General Public License for more details. |
| * |
| * You should have received a copy of the GNU Lesser General Public |
| * License along with FFmpeg; if not, write to the Free Software |
| * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA |
| */ |
| |
| #include "libavutil/channel_layout.h" |
| #include "libavutil/common.h" |
| #include "parser.h" |
| #include "aac_ac3_parser.h" |
| |
| int ff_aac_ac3_parse(AVCodecParserContext *s1, |
| AVCodecContext *avctx, |
| const uint8_t **poutbuf, int *poutbuf_size, |
| const uint8_t *buf, int buf_size) |
| { |
| AACAC3ParseContext *s = s1->priv_data; |
| ParseContext *pc = &s->pc; |
| int len, i; |
| int new_frame_start; |
| |
| get_next: |
| i=END_NOT_FOUND; |
| if(s->remaining_size <= buf_size){ |
| if(s->remaining_size && !s->need_next_header){ |
| i= s->remaining_size; |
| s->remaining_size = 0; |
| }else{ //we need a header first |
| len=0; |
| for(i=s->remaining_size; i<buf_size; i++){ |
| s->state = (s->state<<8) + buf[i]; |
| if((len=s->sync(s->state, s, &s->need_next_header, &new_frame_start))) |
| break; |
| } |
| if(len<=0){ |
| i=END_NOT_FOUND; |
| }else{ |
| s->state=0; |
| i-= s->header_size -1; |
| s->remaining_size = len; |
| if(!new_frame_start || pc->index+i<=0){ |
| s->remaining_size += i; |
| goto get_next; |
| } |
| } |
| } |
| } |
| |
| if(ff_combine_frame(pc, i, &buf, &buf_size)<0){ |
| s->remaining_size -= FFMIN(s->remaining_size, buf_size); |
| *poutbuf = NULL; |
| *poutbuf_size = 0; |
| return buf_size; |
| } |
| |
| *poutbuf = buf; |
| *poutbuf_size = buf_size; |
| |
| /* update codec info */ |
| if(s->codec_id) |
| avctx->codec_id = s->codec_id; |
| |
| /* Due to backwards compatible HE-AAC the sample rate, channel count, |
| and total number of samples found in an AAC ADTS header are not |
| reliable. Bit rate is still accurate because the total frame duration in |
| seconds is still correct (as is the number of bits in the frame). */ |
| if (avctx->codec_id != AV_CODEC_ID_AAC) { |
| avctx->sample_rate = s->sample_rate; |
| |
| /* (E-)AC-3: allow downmixing to stereo or mono */ |
| if (s->channels > 1 && |
| avctx->request_channel_layout == AV_CH_LAYOUT_MONO) { |
| avctx->channels = 1; |
| avctx->channel_layout = AV_CH_LAYOUT_MONO; |
| } else if (s->channels > 2 && |
| avctx->request_channel_layout == AV_CH_LAYOUT_STEREO) { |
| avctx->channels = 2; |
| avctx->channel_layout = AV_CH_LAYOUT_STEREO; |
| } else { |
| avctx->channels = s->channels; |
| avctx->channel_layout = s->channel_layout; |
| } |
| s1->duration = s->samples; |
| avctx->audio_service_type = s->service_type; |
| } |
| |
| avctx->bit_rate = s->bit_rate; |
| |
| return i; |
| } |