1 /* 2 * AAC ADTS header decoding prototypes and structures 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 #ifndef AVCODEC_ADTS_HEADER_H 24 #define AVCODEC_ADTS_HEADER_H 25 26 #include "get_bits.h" 27 28 typedef struct AACADTSHeaderInfo { 29 uint32_t sample_rate; 30 uint32_t samples; 31 uint32_t bit_rate; 32 uint8_t crc_absent; 33 uint8_t object_type; 34 uint8_t sampling_index; 35 uint8_t chan_config; 36 uint8_t num_aac_frames; 37 uint32_t frame_length; 38 } AACADTSHeaderInfo; 39 40 /** 41 * Parse the ADTS frame header to the end of the variable header, which is 42 * the first 54 bits. 43 * @param[in] gbc BitContext containing the first 54 bits of the frame. 44 * @param[out] hdr Pointer to struct where header info is written. 45 * @return Returns 0 on success, -1 if there is a sync word mismatch, 46 * -2 if the version element is invalid, -3 if the sample rate 47 * element is invalid, or -4 if the bit rate element is invalid. 48 */ 49 int ff_adts_header_parse(GetBitContext *gbc, AACADTSHeaderInfo *hdr); 50 51 /** 52 * Parse the ADTS frame header contained in the buffer, which is 53 * the first 54 bits. 54 * @param[in] buf Pointer to buffer containing the first 54 bits of the frame. 55 * @param[in] size Size of buffer containing the first 54 bits of the frame. 56 * @param[out] phdr Pointer to pointer to struct AACADTSHeaderInfo for which 57 * memory is allocated and header info is written into it. After using the header 58 * information, the allocated memory must be freed by using av_free. 59 * @return Returns 0 on success, -1 if there is a sync word mismatch, 60 * -2 if the version element is invalid, -3 if the sample rate 61 * element is invalid, or -4 if the bit rate element is invalid. 62 */ 63 int avpriv_adts_header_parse(AACADTSHeaderInfo **phdr, const uint8_t *buf, size_t size); 64 65 #endif /* AVCODEC_ADTS_HEADER_H */ 66