Libav 0.7.1
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00001 /* 00002 * Audio and Video frame extraction 00003 * Copyright (c) 2003 Fabrice Bellard 00004 * Copyright (c) 2003 Michael Niedermayer 00005 * 00006 * This file is part of Libav. 00007 * 00008 * Libav is free software; you can redistribute it and/or 00009 * modify it under the terms of the GNU Lesser General Public 00010 * License as published by the Free Software Foundation; either 00011 * version 2.1 of the License, or (at your option) any later version. 00012 * 00013 * Libav is distributed in the hope that it will be useful, 00014 * but WITHOUT ANY WARRANTY; without even the implied warranty of 00015 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00016 * Lesser General Public License for more details. 00017 * 00018 * You should have received a copy of the GNU Lesser General Public 00019 * License along with Libav; if not, write to the Free Software 00020 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA 00021 */ 00022 00023 #include "parser.h" 00024 #include "aac_ac3_parser.h" 00025 #include "aacadtsdec.h" 00026 #include "get_bits.h" 00027 #include "mpeg4audio.h" 00028 00029 static int aac_sync(uint64_t state, AACAC3ParseContext *hdr_info, 00030 int *need_next_header, int *new_frame_start) 00031 { 00032 GetBitContext bits; 00033 AACADTSHeaderInfo hdr; 00034 int size; 00035 union { 00036 uint64_t u64; 00037 uint8_t u8[8]; 00038 } tmp; 00039 00040 tmp.u64 = av_be2ne64(state); 00041 init_get_bits(&bits, tmp.u8+8-AAC_ADTS_HEADER_SIZE, AAC_ADTS_HEADER_SIZE * 8); 00042 00043 if ((size = ff_aac_parse_header(&bits, &hdr)) < 0) 00044 return 0; 00045 *need_next_header = 0; 00046 *new_frame_start = 1; 00047 hdr_info->sample_rate = hdr.sample_rate; 00048 hdr_info->channels = ff_mpeg4audio_channels[hdr.chan_config]; 00049 hdr_info->samples = hdr.samples; 00050 hdr_info->bit_rate = hdr.bit_rate; 00051 return size; 00052 } 00053 00054 static av_cold int aac_parse_init(AVCodecParserContext *s1) 00055 { 00056 AACAC3ParseContext *s = s1->priv_data; 00057 s->header_size = AAC_ADTS_HEADER_SIZE; 00058 s->sync = aac_sync; 00059 return 0; 00060 } 00061 00062 00063 AVCodecParser ff_aac_parser = { 00064 { CODEC_ID_AAC }, 00065 sizeof(AACAC3ParseContext), 00066 aac_parse_init, 00067 ff_aac_ac3_parse, 00068 ff_parse_close, 00069 };