diff options
Diffstat (limited to 'ffmpeg1/libavcodec/aac_ac3_parser.c')
| -rw-r--r-- | ffmpeg1/libavcodec/aac_ac3_parser.c | 104 |
1 files changed, 104 insertions, 0 deletions
diff --git a/ffmpeg1/libavcodec/aac_ac3_parser.c b/ffmpeg1/libavcodec/aac_ac3_parser.c new file mode 100644 index 0000000..6f1e188 --- /dev/null +++ b/ffmpeg1/libavcodec/aac_ac3_parser.c @@ -0,0 +1,104 @@ +/* + * 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/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; + + /* allow downmixing to stereo (or mono for AC-3) */ + if(avctx->request_channels > 0 && + avctx->request_channels < s->channels && + (avctx->request_channels <= 2 || + (avctx->request_channels == 1 && + (avctx->codec_id == AV_CODEC_ID_AC3 || + avctx->codec_id == AV_CODEC_ID_EAC3)))) { + avctx->channels = avctx->request_channels; + } 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; +} |
